Ingles 20/3/09 09:45 Página I · 2020. 6. 30. · 2: Trancutaneous oxygen saturation Sec: Second(s) SMA: Spinal muscular atrophy S/T: Spontaneous/timed mode T: Timed mode Ti: Inspiratory

Finantial support by

Endorsed by Spanish Pediatric Intensive Care Society

Ingles 20/3/09 09:45 Página I

All rights reserved. No part of this publication may be reproduced or distributed in any form or bymeans, or stored in a data base or retrieval system, without the prior written permission of thepublished.

© 2009 by ErgonC/ Arboleda, 1. 28221 Majadahonda (Madrid)Pza. Josep Pallach 12. 08035 Barcelona

ISBN: 978-84-8473-757-5Depósito Legal: M-13380-2009

Ingles 17/3/09 10:55 Página II

Writing the second edition of “Non-Invasive Ven-tilation in Pediatrics” was truly a team effort, dra-wing on the input and assistance of numerousindividuals.

The first edition was well received and provedhighly useful for the courses organized by the Res-piratory Group of the SECIP. Therefore, we wouldfirst like to thank all of the students and participantsin these courses. These individuals, in continuing toamass experience at their centers, have shown usthat our text has addressed a real need in the medi-cal field.

We also express our gratitude to the doctors andhospital staff from our wards: thanks to these pro-fessionals, some wards have been able to quintuplethe number of patients treated with NIV in less thanthree years, and others have been able to incorpo-rate NIV as a routine procedure.

We are also indebted to all of the pediatric inten-

sivists whose wards provided data for the EPIVE-NIP study, as well as those who contributed to eva-luating the quality control indices in the new chapteron healthcare assistance, quality control and clini-cal training for NIV.

We would also like to thank A. Alarcón Allen(Attending Physician, Neonatal Ward, HospitalSant Joan de Deu, Barcelona) and Rubén D. Res-trepo (MD RRT FAARC, Associate Professor, Depart-ment of Respiratory Care, The University of TexasHealth Science Center at San Antonio, San Anto-nio, Texas) for having revised the English transla-tion and for their invaluable suggestions on thebook.

Lastly, those of us at Hospital Sant Joan de Déuwould like to thank the Invest4Children Foundation,which has enabled us to provide NIV to far morechildren than we could have ever dreamed of fouryears ago.

Acknowledgements

Alberto Medina VillanuevaMartí Pons Òdena

Federico Martinón-Torres

We dedicate this book

to our wives and children

for keeping us up all night

after we get off of duty

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Ingles 16/3/09 17:50 Página IV

Carmen Antelo LandeiraSección de Neumología Pediátrica.Hospital Infantil La Paz (Madrid)

Marta Los Arcos SolasUnidad de Cuidados Intensivos Pediátricos.Hospital Universitario Central de Asturias (Oviedo)

Isabel Barrio Gómez de AgüeroSección de Neumología Pediátrica. Hospital Infantil «La Paz» (Madrid)

Mónica Balaguer GargalloUnidad de Cuidados Intensivos Pediátricos.Hospital Universitario Sant Joan de Déu (Barcelona)

José Manuel Blanco GonzálezUnidad de Cuidados Intensivos Pediátricos. Hospital Universitario Sant Joan de Déu (Barcelona)

Francisco José Cambra LasaosaUnidad de Cuidados Intensivos Pediátricos.Hospital Universitario Sant Joan de Déu (Barcelona)

Félix Castillo SalinasServicio de Neonatología. Hospital Vall d'Hebrón (Barcelona)

Andrés Concha TorreUnidad de Cuidados Intensivos Pediátricos.Hospital Universitario Central de Asturias (Oviedo)

Lola Elorza FernándezServicio de Neonatología. Hospital Universitario La Paz (Madrid)

Antonio Esquinas RodríguezServicio de Cuidados Intensivos.Hospital Morales Meseguer (Murcia)

Miguel José dos Santos FélixLaboratorio de sueño y ventilación.Hospital Pediátrico de Coimbra (Portugal)

José Ramón Fernández LorenzoServicio Neonatologia-UCI neonatal. Hospital Clinico Universitario. Santiago de Compostela (La Coruña)

Paula Fernández DeschampsUnidad de Cuidados Intensivos Pediátricos.Hospital Niño Jesús (Madrid)

Maria Luisa Franco FernéndezHospital General Universitario Gregorio Marañón (Madrid)

Mirella GaboliUnidad de Cuidados Intensivos Pediátricos.Hospital Universitario de Salamanca

M ª Ángeles García TeresaUnidad de Cuidados Intensivos Pediátricos.Hospital Niño Jesús (Madrid)

Julio García-Maribona Rodríguez-MaribonaUnidad de Cuidados Intensivos Pediátricos.Hospital Universitario Central de Asturias (Oviedo)

Teresa Gavela PérezUnidad de Cuidados Intensivos Pediátricos.Hospital Niño Jesús (Madrid)

Teresa Gili BigatàUnidad de Cuidados Intensivos Pediátricos.Corporació Sanitaria Parc Taulí (Sabadell. Barcelona)

Pedro Gómez de Quero MasiaUnidad de Cuidados Intensivos Pediátricos.Hospital Universitario de Salamanca

Authors

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Miguel GonçalvesUnidad de Fisiopatología y Rehabilitación.Departamento de Medicina Pulmonar.Hospital Sao Joao. Porto (Portugal)

Margarita González PérezUnidad de Cuidados Intensivos PediátricosHospital Universitario Central de Asturias (Oviedo)

Manuel Gresa MuñozComplejo Hospitalario UniversitarioMaterno-Insular de Las Palmas

Antonio Gutiérrez LasoHospital Universitario La Fe (Valencia)

Emili Ibiza PalaciosUnidad de Cuidados Intensivos Pediátricos.Hospital Universitario La Fe (Valencia)

Maria Helena Lopes EstêvãoLaboratorio de sueño y ventilación.Hospital Pediátrico de Coimbra (Portugal)

Jesús López-Herce CidSección de Cuidados Intensivos Pediátricos.Hospital General Universitario Gregorio Marañón (Madrid)

Jon López de Heredia GoyaUCI NeonatalHospital de Cruces (Bilbao)

Antonio Losada MartínezHH.UU. Virgen del Rocío. Hospital de la Mujer. Hospital Infantil (Sevilla)

Carmen Martínez CarrascoSección de Neumología Pediátrica.Hospital Infantil La Paz (Madrid)

Federico Martinón-TorresServicio de Críticos y Urgencias.Hospital Clínico Universitario (Santiago de Compostela)

Juan Mayordomo ColungaUnidad de Urgencias Pediátricas.Hospital Universitario Central de Asturias (Oviedo)

Alberto Medina VillanuevaUnidad de Cuidados Intensivos Pediátricos.Hospital Universitario Central de Asturias (Oviedo)

Sergio Menéndez CuervoUnidad de Cuidados Intensivos Pediátricos.Hospital Universitario Central de Asturias (Oviedo)

Xavier Miracle EchegoyenServicio de Neonatología. Hospital Clínic-Casa Maternitat (Barcelona)

Vicent Modesto i AlapontUnidad de Cuidados Intensivos Pediátricos.Hospital Universitario La Fe (Valencia)

Juan Carlos Monroy Mogollón†Unidad de Cuidados Intensivos Pediátricos.Hospital Universitario Sant Joan de Déu (Barcelona)

Julio Moreno HernandoServicio de Neonatología. Unidad de Cuidados IntensivosNeonatales. Hospital Universitario Sant Joan de Déu (Barcelona)

Mª José Pérez GarcíaUnidad de Cuidados Intensivos Pediátricos.Hospital Niño Jesús (Madrid)

Martí Pons ÒdenaUnidad de Cuidados Intensivos Pediátricos.Hospital Universitario Sant Joan de Déu (Barcelona)

Javier Pilar OriveUnidad de Cuidados Intensivos Pediátricos.Hospital de Cruces. Baracaldo

Raquel Porto AbalUnidad de Cuidados Intensivos Pediátricos.Hospital Niño Jesús (Madrid)

Corsino Rey GalánUnidad de Cuidados Intensivos Pediátricos.Hospital Universitario Central de Asturias (Oviedo)

Antonio Rodríguez NuñezServicio de Críticos y Urgencias. Hospital Clínico Universitario (Santiago de Compostela). Departamento de Pediatría.Universidad de Santiago de Compostela

Adolfo Valls SolerServicio de Neonatología. Catedrático de Pediatría de la Universidad del País VascoHospital de Cruces (Bilbao)

Silvia Vidal i MicóUnidad de Cuidados Intensivos Pediátricos.Hospital Universitario La Fe (Valencia)

Ingles 16/3/09 17:50 Página VI

Reading medical texts that are more than tenyears old usually provokes one of two reactions: weeither laugh at the inaccuracy of the author’s hypo-theses, or we are taken aback by the author’s pres-cience.

The aim of this second edition of “Non-invasiveVentilation in Pediatrics” was to incorporate all ofthe knowledge accumulated in the past four years.Nonetheless, due to the limited body of literatureon NIV, there are many aspects of this treatment

that are dictated primarily by experience and byeach author’s opinion.

We hope that the colleague that reads this textnow, does so with a critical eye, remembering thathistory repeats itself and that, consequently, manyof the opinions published in this text will be scien-tifically refuted in the future. Nonetheless, with allhumility, we hope that some of the hypotheses pre-sented here will ultimately be confirmed.

Prologue

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AF: Assisted flowARDS: Acute respiratory difficulty syndromeARF: Acute respiratory failureAV: assisted volumeAVAPS: Average volume assured pressure supportBiPAP: Bi-level positive airway pressureCCHS: Congenital central hypoventilation syndromeCm: centimetersCNS: Central nervous systemCOPD: Chronic obstructive pulmonary diseaseCPAP: Continuous positive airway pressureCRF: Chronic respiratory failureE: ElasticityEPAP: Expiratory positive airway pressureF: FlowFig: FigureFiO2: Fraction of inspired oxygenHMV: Home mechanical ventilationHz: HertzIFD: Infant Flow DrivIFDA: Infant Flow Drive AdvanceIPAP: Inspiratory positive airway pressureIPPV: intermittent positive pressure ventilationIV: IntravenousFRC: Functional residual capacityFVC: Functional vital capacityL: LitersLPM: Liters per minuteMI-E: Mechanical insufflation-exsufflationMin: minutes (s)n-CPAP: Nasal continuous positive airway pressuren-IPPV: Nasal intermittent positive pressure

ventilation

NIV: Non-invasive ventilationn-SIPPV: Nasal synchronized intermittent positive

pressure ventilationNMD: Neuromuscular diseaseNNPV: Non-invasive negative pressure ventilationNRDS: Neonatal respiratory difficulty syndromeOSAS: Obstructive sleep apnea syndromePaO2: Arterial oxygen pressurePaCO2: Arterial carbond dioxide pressurePACV: Pressure-assisted/controlled ventilationPAV: Proportional assisted ventilationPCV: Pressure-controlled ventilationPEEP: Positive-end expiratory pressurePEP: positive expiratory pressurePICU: Pediatric intensive care unitPIP: Peak inspiratory pressurePmusc: Respiratory muscle pressurePP: Positive pressurePS: Pressure supportR: ResistanceRF: Respiratory frequencyRPM: Respirations per minuteS: Spontaneous modeSaO2: Trancutaneous oxygen saturationSec: Second(s)SMA: Spinal muscular atrophyS/T: Spontaneous/timed modeT: Timed modeTi: Inspiratory timeV: Volume of air that enters the lungsVCV: Volume-controlled ventilationV/Q: Ratio of ventilation to perfusionVt: Tidal volume

Abbreviations

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1. History and clinical use of non-invasive ventilation 1C. Rey, M. Pons, J. Mayordomo and M. Los Arcos

2. Physiology of respiratory dynamics. Application to non-invasive ventilation 7V. Modesto, S. Vidal and E. Ibiza

3. Indications and contra-indications of non-invasive ventilation in patients with acute respiratory failure 11M. Gáboli and M. Pons

4. Conditions and settings for delivering non-invasive ventilation 17M. Gáboli, J. Mayordomo, P. Gómez de Quero and M. Pons

5. Non-invasive ventilation interfaces 25A. Concha, A. Medina, M. Pons and F. Martinón-Torres

6. Non-invasive ventilation devices 37S. Menéndez, A. Medina, F. Martinón-Torres and C. Rey

7. Non-invasive ventilation modes and methods for pediatric patients 47J. López-Herce and J. Pilar

8. Non-invasive ventilation methodology for acute pediatric pathologies 59M. Pons, T. Gili and A. Medina

9. Caring for non-invasive ventilation patients 65J. García-Maribona, M. González, J.M. Blanco and J.C. Monroy†

10. Monitoring of non-invasive ventilation for pediatric patients 75M.A. García Teresa, R. Porto and P. Fernández

11. Complications and technical difficulties in non-invasive ventilation 81M. Pons and M. Balaguer

12. Sedation in non-invasive ventilation 87M. Los Arcos, J. Mayordomo and M. Gáboli

13. Failure analysis and predictive factors in non-invasive ventilation 91M. Pons, A. Medina, F. Martinón-Torres and J. Mayordomo

Contents

Ingles 16/3/09 17:50 Página XI

14. Non-invasive ventilation with heliox 99F. Martinón-Torres

15. Humidification and bronchodilator therapy in non-invasive ventilation 107A. Esquinas and M. Pons

16. Fiberoptic bronchoscopy in non-invasive ventilation 115M.I. Barrio, M.C. Antelo and M.C. Martínez

17. Neonatal non-invasive ventilation 119F. Castillo, D. Elorza, M.L. Franco, J. Fernández, M. Gresa, A. Gutiérrez, I. López de Heredia, J. Miracle, J. Moreno, A. Losada and A. Valls Soler Grupo Respiratorio Sociedad Española de Neonatología

18. Indications of non-invasive ventilation in chronic pediatric pathologies 125M.H. Estêvão and M.J. dos Santos

19. Methodology for pediatric non-invasive ventilation in the home 137M.Á. García Teresa, T. Gavela and M.J. Pérez

20. Respiratory physiotherapy in non-invasive ventilation 147M.R. Gonçalves

21. Healthcare assistance, quality control and clinical training for non-invasive ventilation of acute pediatric patients 157T. Gili, A. Medina and M. Pons

22. Ethical aspects of non-invasive ventilation 163F.J. Cambra, M.H. Estêvão and A. Rodríguez Núñez

23. Summary and algorithms 169A. Medina, M. Pons and F. Martinón-Torres

Index 179

Translated from the Spanish by Gregory Qushair for SciLingua, except for Chapter 20, ”Respiratoryphysiotherapy in Non-Invasive Ventilation”, which was originally written in English by M.R. Gonçalves.

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INTRODUCTIONNon-invasive ventilation (NIV) can be defined

as ventilation which does not require artificial entry—via tracheotomy or endotracheal intubation—beyondthe vocal chords of the patient’s respiratory track.Various mechanisms have been used to deliver NIV,and different eras have witnessed the predominanceof certain devices and techniques over others. Galenowas the first to describe experimental ventilation,observing how inflation of a dead animal with airvia the larynx caused its bronchi to fill and its lungsto expand. Vesalio is believed to have later performedthe first ever artificial ventilation during the autopsyof a Spanish nobleman whose lungs he inflated withair.

This chapter provides a historical summary ofnegative pressure ventilation, ventilation usingrocking beds and pneumatic belts, and ventilationvia nasal masks and face masks. Current clinical useof NIV in Spain is then reviewed.

NEGATIVE PRESSURE VENTILATIONThe first techniques used for mechanical

ventilation were based on non-invasive systems thatgenerated negative pressure over the chest wall. Thefirst “tank” negative pressure respirator wasdeveloped by Dalziel in Scotland in 1832. Jonespatented an apparatus similar to Dalziel’s, inKentucky in 1864, recommending its use for thetreatment of asthma, bronchitis, paralysis, neuralgias,

rheumatism, seminal weakness and dyspepsia. Figure1 shows a negative pressure respirator presented byWoillez at the French Academy of Medicine in 1876.The patient was placed into a cylindrical containerwith their head sticking out. An adjustable elasticrubber collar was used around the patient's neck toobtain a perfect seal. Manual expansion of the pumpcreated a sub-atmospheric pressure in the tank,whereas pressure on the pump caused the pressureof the tank to return to atmospheric level. Negativeextrathoracic pressure was transmitted via the chestwall, and analogously to the action of negativepleural pressure during spontaneous respiration, thesystem generated a flow of air from the mouth tothe lung.

Substitution of an electric source for manualpressure, and a leather diaphragm for the pump,provided so-called “tank” respirators, or “iron lungs”,whose use peaked during the polio epidemic of the1930's to the 1950's. The first negative pressurerespirator to be widely used in the clinic was theDrinker-Shaw iron lung, developed in 1928. A majorpolio epidemic in 1931 led Emerson to manufacturea smaller and simpler respirator. This apparatus wascheaper and easier to operate than its predecessorsand boasted several technological improvements;hence, it was widely used and enabled several livesto be saved during epidemics of respiratory paralysiscaused by polio.

From the 1960’s to the 1970’s, a negativepressure ventilator similar to iron lungs was used to

History and clinical use of non-invasive ventilation

C. Rey, M. Pons, J. Mayordomo and M. Los Arcos

Chapter 1

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treat hyaline membrane disease in neonates. In thisrespirator, the neonate’s head was placed inside ofa chamber into which humidified oxygen could beadded, while the rest of its body was maintained ina hermetically sealed chamber to which negativepressure was applied.

The aforementioned systems had numerouslimitations: they easily led to obstructions of theupper airway through closure of the glottis, interferedwith physical examination of the patient, causedskeletomuscular disorders, and were burdened bytheir large size, among other factors. Due to theseproblems, use of these respirators was eventuallyabandoned, as new forms of mechanical ventilationwere sought.

ROCKING BEDS AND PNEUMATIC BELTSRocking beds and pneumatic belts, or

pneumobelts, are NIV tools that were developedand that reached their peak use during the finalperiod of the polio epidemic. Both are based onexploiting gravity to help the movements of thediaphragm and were especially utile for patients witha paralytic or very weak diaphragm.

In the early 1930’s Eve described the use ofmanual rocking to favor ventilation in two patientswith acute respiratory paralysis. The techniqueconsisted of positioning the patient in a bed thatrocked 45° up and down. The change in weight ofthe abdominal viscera moved the diaphragm up anddown alternately, creating a new method of artificialrespiration. The technique was later accepted by the

British Navy as a recommended way of revivingvictims of near-drowning. Subsequent studiesdemonstrated the utility of this type of artificialrespiration as compared to other methods. Indeed,it remained in the revival protocols until the 1960’s,when mouth to mouth resuscitation took over asthe initial form of artificial respiration. Automaticrocking beds were introduced in the 1940's as a typeof ventilatory aid. In 1950, the American Council onPhysical Medicine and Rehabilitation accepted arocking bed designed by McKesson as a tool forweaning polio patients off of iron lungs. This bedfacilitated nursing care and provided the patientwith more freedom; however, it was very noisy andheavy. The Emerson rocking bed, used extensivelyduring the 1950’s and 1960’s, was quieter andlighter. Nonetheless, control of the polio epidemicthrough vaccination led to a drastic fall in demandfor these beds. It is estimated that in the UnitedStates only 80 rocking beds are still in use; they areemployed for polio survivors. The majority of patientshave sought other forms of ventilation assistance.

Pneumobelts deliver intermittent abdominalpressure by assisting diaphragmatic movements.They also arose in the final period of the polioepidemic, and were designed to overcome thelimitations of the ventilators available at that time.Pneumobelts enabled total freedom of the upperextremities and the mouth, making it easier for thepatient to remain seated. A diurnal ventilator wasfor patients in wheelchairs. As in the case of rockingbeds, once the polio epidemic had come undercontrol, pneumobelts lost their primary indication.Albeit several modifications were eventually madeto the original mechanism, including a combinationof pneumatic belt and intermittent positive pressureventilation, pneumobelts are now very rarely used.

NASAL MASKS AND FACE MASKSThe first non-invasive positive pressure ventilation

(NPPV) systems were used at the beginning of the20th century by surgeons to perform operationsthat implied opening of the thorax. Brauer isconsidered the first surgeon to have used a positivepressure system, which consisted of a small cabininto which the patient’s head was introduced. Asalternatives to these small cabins, other surgeonsdesigned face masks and hermetically sealed helmets

2 C. Rey, M. Pons, J. Mayordomo, M. Los Arcos

Figure 1. Manually operated negative pressure ventilator.


to generate positive pressure in the airway. However,with the advent of translaryngeal intubationtechniques, these NPPV systems were abandoned.

Outside of surgery, the limitations of negativepressure NIV systems, coupled with the technologicaladvances made during WWII, led to standard use ofpositive pressure mechanical ventilation viaendotracheal or tracheotomy tubes. In 1907 thecompany Dräger developed one of the first NIVventilators, the Pulmotor (Fig 2.), which was usedfor resuscitation. In 1935 Barach reported the useof a respirator that provided continuous positiveairway pressure (CPAP) via a mask for patientssuffering from various forms of acute respiratoryfailure (ARF). Nonetheless, it was not until the 1970’sthat NVPP began to emerge as a slightly lessaggressive alternative, simultaneously circumventingthe complications associated with endotracheal tubeswhile improving the quality of life of the patient—namely, by preserving the defense mechanisms ofthe airway and enabling patients to speak andswallow. This type of ventilation assistance employedintermittent positive pressure via a mouthpiece. Initialexperiences with this method appeared favorable:it had been reported that NIV could controlhypercapnia in patients with acute respiratory failure.However, in subsequent studies, including a multi-center study by the US National Institutes of Health(NIH), it was found that NIV combined withnebulizer therapy for patients with chronicobstructive pulmonary disease did not provide anyadded advantage compared to the nebulizer therapyalone.

In the 1980’s continuous positive airway pressurevia the nasal passage (nasal CPAP, or n-CPAP) wasfirst used for patients with sleep apnea and affordedgood results. Intermittent positive pressure ventilationvia the nasal passage (nasal IPPV, or n-IPPV) was soonemployed, improving ventilation in patients withchronic respiratory failure (CRF), especially duringsleep. Multiple studies on NVPP were subsequentlyperformed in patients with ARF or CRF, sleep apnea,or respiratory difficulty after extubation, withincreasingly positive results obtained.

CLINICAL USE OF NIV (Spain)Use of NVPP has undergone surged in the past

5 years. In 2002 a survey in Spain that was

performed using an electronic hospital mailing list(UCIP-net) revealed that only four pediatric intensivecare units (PICUs) were equipped with NIV-specificventilators and had written NIV protocols, andtherefore, performed NIV for their patients. However,in the past 5 years, there has been an exponentialincrease in the use of NIV in pediatrics; hence, alarge percentage of Spanish PICUs now perform thistype of ventilation assistance.

From October 2004 to February 2004, anepidemiological study on pediatric NIV wasperformed by eight PICUs in Spain. The studyencompassed 109 cases of NIV use in 104 patients(mean age: 12 months) in which the overall efficacywas 78%. In the PICU of Hospital UniversitarioCentral de Asturias (HUCA), which has seven bedsand averages approximately 300 annual admissions,during the past 3 years there have been 119 casesof NIV use in 93 patients (mean age: 3 years; agerange: 1 month to 16 years). NIV was indicatedfor type I respiratory failure (RF) in 25% of the cases,for type II RF in 50%, and for post-extubation RF inthe remaining 25%. NIV-specific ventilators wereused in 95% of the cases. The primary interface usedwas oral-nasal (74%); in one case, a full face maskwas employed. The average duration of the NIV was35 hours. Favorable progress was obtained:mechanical ventilation was not required in 80% ofthe cases. Failure of NIV was greater in post-extubation RF (36%) and type I RF (27%) than intype II RF (8%). There were no complications in 80%of the cases; the complications in the remaining 20%were principally minor: self-limited skin lesions (16%),

3History and clinical use of non-invasive ventilation

Figure 2. The Pulmotor.


pneumothorax (3%) and upper airway bleeding(1%).

Figure 3 shows an important trend: the changein the use of NIV compared to conventionalmechanical ventilation (CMV) in the PICU at HUCA.As observed in the Figure, use of NIV has risen whileuse of CMV has steadily decreased, leading theformer to surpass the latter for the first time ever in2007.

Figure 4 reveals a similar trend at the PICU ofHospital Universitario Sant Joan de Déu de Barcelona,based on data collected from 287 cases between2002 and 2006. Note that there is a major differencein the mean age of the two treatment groups (NIVgroup: 7.6 years; CMV group: 2.5 years). Moreover,the NIV group exhibited a lower rate of nosocomialinfection as well as a shorter mean hospital stay.

In the past decade NIV has been the subject ofover 1,500 scientific articles, including 14 meta-analyses. There is growing interest in pediatric NIV,as demonstrated at the 5th World Congress onPediatric Critical Care, held in June 2007, whichfeatured a roundtable discussion and fifteencommunications on NIV.

In summary, NIV has represented a majoradvance in the treatment of ARF, and its utility hasbeen well established in several clinical researchpublications. When properly applied, NIV is a non-aggressive respiratory support method with few sideeffects. Nonetheless, it has yet to be systematically

employed for all children with ARF. Several moreyears will be needed until all patients for whom NIVwould be useful will be able to receive it.

REFERENCES

1. Drinker P, Shaw LA. An apparatus for the prolonged adminis-tration of artificial respiration: I. Design for adults and children.J Clin Invest 1929;7:229-47.

2. Crone NL. The treatment of acute poliomyelitis with the respi-rator. N Engl J Med 1934;210:621-3.

3. Colice GL. Historical perspective on the development of mecha-nical ventilation. En: Tobin MJ Ed. Principles and practice ofmechanical ventilation. McGraw-Hill, INC. New York 1994;1-36.

4. Levine S, Levy S, Henson D. Negative pressure ventilation. CritCare Clin 1990;3:505-31.

5. Eve FC. Actuation of the inert diaphragm. Lancet 1932;2:995-7.

6. Plum F, Whendon GD. The rapid-rocking bed: its effect on theventilation of poliomyelitis patients with respiratory paralysis. NEngl J Med 1951;245:235-40.

7. Hill NS. Use of the rocking bed, pneumobelt, and other non-invasive aids to ventilation. En: Tobin MJ Ed. Principles and prac-tice of mechanical ventilation. McGraw-Hill, INC. New York1994;413-25.

8. Carter HA. McKesson respiraid rocking bed accepted. JAMA1950;144:1181.

9. The Intermittent Positive Pressure Breathing Trial Group. Inter-mittent positive pressure breathing therapy of chronic obstruc-tive pulmonary disease. Ann Intern Med 1983;99:610-20.

10. DiMarco AF, Connors AF, Altose MD. Management of chronicalveolar hipoventilation with nasal positive pressure breathing.Chest 1987;92:952-4.

4 C. Rey, M. Pons, J. Mayordomo, M. Los Arcos

Figure 3. Change in use of conventional mechanical ventila-tion and non-invasive ventilation in the Pediatric Intensive CareUnit of Hospital Universitario Central de Asturias, 2000 to 2007.Data are presented as percentages relative to the total num-ber of admitted patients. CMV: conventional mechanical ven-tilation; NIV: non-invasive ventilation

2000 2002 2004 2006

35

30

25

20

15

10

5

0

CMVNIV

Year

2001 2003 2005 2007Perc

enta

ge o

f tre

ated

pat

ient

s re

lativ

eto

tot

al n

umbe

r of

pat

ient

s

Figure 4. Change in use of non-invasive ventilation in thePediatric Intensive Care Unit of Hospital Universitario SantJoan de Déu de Barcelona, 2000 to 2008.NIV: non-invasiveventilation; post-extub: post-extubation.

NIVPost-extub. NIVTotal NIV

Year

Num

ber

of p

atie

nts

2002

1009080706050403020100

2003 2004 2005 2006 2007 2008


11. Belman MJ, Soo Hoo GW, Kuei JH, Shadmehr R. Efficacy of posi-tive vs negative pressure ventilation in unloading the respiratorymuscles. Chest 1990;98:850-6.

12. Medina A, Prieto S, Los Arcos M, Rey C, Concha A, MenéndezS, et al. Aplicación de ventilación no invasiva en una unidad decuidados intensivos pediátricos. An Esp Pediatr 2005;62:13-9.

13. Corrales E, Pons M, López-Herce J, Martinón-Torres F, García MA,Medina A, González Y. Estudio epidemiológico de la ventilaciónno invasiva en las Ucip de España. XXII Congreso Nacional de laSECIP, 2005. An Pediatr (Barc) 2007;67:91-100.

14. Pons M, Mayordomo J, Barón Ruiz I, Palomeque Rico A. Com-

parative analysis between conventional mechanical ventilationand non invasive ventilation in 4 years in our picu. World pedia-tric intensive care medicine congress. Geneve 2007. Pediatr CritCare Med 2007;8(3, Suppl):A268.

15. Hess DR, Fessler HE. Respiratory controversies in the critical care set-ting. Should noninvasive positive-pressure ventilation be used in allforms of acute respiratory failure? Respir Care 2007;52:568-78.

16. Burns KE, Adhikari NK, Meade MO. Noninvasive positive pres-sure ventilation as a weaning strategy for intubated adults withrespiratory failure. Cochrane Database Syst Rev 2003;(4):CD004127.

5History and clinical use of non-invasive ventilation


INTRODUCTION Unfortunately, physicians do not have the

opportunity to administer non-invasive ventilation(NIV) until nearly a decade after having studiedphysiology. Hence, the authors of this chapterthought it would be apropos to review the basics ofhow humans breathe, how the body adjusts tosituations of respiratory failure (RF), and how NIVcan reverse RF.

RESPIRATORY PHYSIOLOGYIn order to deliver air to the lungs during

inspiration, the respiratory musculature must createsufficient pressure to overcome two forces: theincrease in the recoil pressure of the lung once itis filled, which is a static force, and the frictionassociated with airway flow, which is a dynamicforce. During expiration, air exits the lungspassively.

To enable better understanding of how NIV withpressure support (PS) functions, this chapter firstreviews the static properties of respiratory mechanics,and then reviews the dynamic properties: how theflow of air is produced from the atmosphere towardsthe alveoli during inspiration and in the oppositedirection during expiration.

Static properties of respiratory mechanicsThe static properties of respiratory mechanics

are studied in conditions of airflow equal to 0 L/s

(liters per second). The pressure inside of the mouthcorresponds to the atmospheric pressure (Patm),which at sea level is equal to 760 mm Hg; however,for pulmonary physiology calculations, its value istaken as 0 cm H2O (the reference pressure). Theinterior pressure in the alveoli (Palv) and the interiorpressure in the pleural space (Ppl) are static pressuresand must be measured in the absence of airflow.The static difference between these two pressuresis defined here as the transpulmonary pressure (PTP),or pressure of pulmonary retraction, such that PTP =Palv - Ppl. The static difference between the interiorpressure in the pleural space and the atmosphericpressure is defined here as the elastic recoil pressureof the chest wall (PW), such that PW = Ppl - Patm. Thesum of PTP and PW is called the total recoil pressureof the respiratory system.

Within the scope of this chapter, there is onlyone main concept of interest from static respiratorymechanics: the volume of the lung only changeswhen the magnitude of PTP changes. Though itseems counterintuitive, it is not the value of Palv thatcauses the volume of lung to change, but rather thevalue of PTP. As the lung fills with air each value ofpulmonary volume corresponds to a specific valueof PTP. Regardless of the values of Palv and Ppl, at a PTPvalue of +5 cm H20, the lung will fill with air to avolume equal to its functional residual capacity (FRC);at a PTP value of + 30 cm H20, the lung will be attotal lung capacity (TLC); and at a PTP value of +3cm H20, the lung will be at its residual volume (RV).

Physiology of respiratory dynamics.Application to non-invasive ventilation

V. Modesto, S. Vidal and E. Ibiza

Chapter 2


For greater detail on this concept, the reader isreferred to other sources(1).

Respiratory dynamicsTo enable a more detailed study of the dynamic

behavior of the respiratory system, two types ofdiagrams are used in this chapter (shown in Figures1 to 7 below). The first type shows a graduatedvertical bar which reflects the pressure values of thesystem (in cm H2O), whereby positive valuescorrespond to super-atmospheric pressure, andnegative values, to sub-atmospheric pressure. Thesecond type shows volume plotted against time; inthis plot, a point on the curve shows the position ofthe respiratory cycle with respect to time for eachof the phases.

Analogously to fluid dynamics, respiratorydynamics is governed by the general principle thatair always moves along the pressure gradient. If thereis no gradient between the mouth and the alveoli,then there is no flow of air. If the Palv is lower thanthe Patm, then air enters the alveoli, whereas if Palvis higher than Patm, then air exits the alveoli. OncePalv and Patm balance out, the flow of air stops.

Before an inspiration, the respiratory musculature(i.e. the diaphragm and supporting muscles) is atrest (Fig. 1). The natural tendency of the chest wallto retract leads to a sub-atmospheric pressure in thepleural space (Ppl) of ca. -5 cm H2O; however, at thispoint Palv = Patm = 0 cm H2O, so there is no flow ofair. Hence, the transpulmonary pressure (PTP) = 0 cmH2O - (- 5 cm H2O) = + 5 cm H2O, which drives thelung volume to FRC, the volume of the respiratorysystem at rest.

Inspiration begins with contraction of theinspiratory muscles immediately before air entersthe body (Fig. 2). This leads to a decrease in pressurein the pleural space (Ppl). At this initial instant, no airhas yet entered the body: the volume of the lunghas not changed, meaning that, as explained above,the PTP initially remains constant. This can onlyhappen if, immediately before air begins to enter,the drop in Ppl causes a drop in Palv of equalmagnitude. It is this decrease in Palv at levels lowerthan Patm that establishes the gradient which causesair to enter.

The decrease in Palv generates a flow of air intothe system, causing the lungs to fill with air and

8 V. Modesto, S. Vidal, E. Ibiza

Figure 1. Phase of apnea before inspiration. PTP: transpul-monary pressure; PW: elastic recoil pressure of the chest wall.

Figure 2. Initial phase of inspiration: contraction of the diaph-ragm. PTP: transpulmonary pressure; PW: elastic recoil pressu-re of the chest wall.

Figure 3 A and B. Final phase of inspiration. A) The drop inalveolar pressure begins the flow of air inwards. The lunggains volume, which causes the transpulmonary pressure (PTP)to increase until B), the moment of maximum muscular con-traction. The maximum PTP coincides with the maximum lungvolume, but Palv balances out with the atmospheric pressu-re, so no more air enters.

Super-atmospheric pressure

Atmospheric pressure(cm H2O)

Sub-atmospheric pressure

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consequently, increase in volume (Fig. 3A). Thechange in lung volume leads the PTP to graduallyincrease: contraction of the muscles causes a furtherdrop in Ppl, but, as air enters the alveoli, the decreasein Palv is not substantial. This situation remains steadyduring the entire inspiration until, in the final phase,muscular contraction peaks, pulmonary volume andPTP reach their maximum values, and Palv and Patmbalance out, causing the flow of air to stop andproducing the inspiratory pause.

After the inspiratory pause there is a brief totalstop in respiratory muscle contraction (Fig. 4). Thelung remains at maximum volume, meaning thatthe value of PTP is equal to that during the inspiratorypause (i.e. no volume has yet been lost); however,the stop in contraction causes the value of Ppl toreach zero. At this point, PTP is entirely the result ofPalv, which reaches its maximum value due to thetendency of lung tissue to passively retract. Theincrease in Palv to levels above Patm establishes thegradient which causes air to exit (Fig. 5).

Once all of the air has left (Fig. 6), the flow stops:Palv and Patm balance out to 0 cm H2O, Ppl returns toits rest level of -5 cm H2O, PTP reaches 5 cm H2O,and lung volume is equal to FRC. The process thenbegins again.

The physiological basis of pressure support If upon inspiration the patient is unable to

generate sufficient force to contract the muscles inorder for Ppl to reach a given value (e.g. < -7 cm

H2O), then the situation shown in Figure 7A arises.As Palv is equal to Patm, the maximum PTP will be +7cm H2O, and the lung will barely be able to fill withair. This is the clinical scenario of a patient enteringinto respiratory failure. If at this point, and only forthe duration of the inspiration, the airway can bequickly pressurized to enable Palv to rise up to a pre-established value (known as pressure support, orSP), then with the same level of muscle effort (Ppl= –7 cm H2O) a much higher value of PTP can bereached, and the lung can reach a much greaterinspiratory volume (Fig. 7B). When the inspirationstops, the airway depressurizes just as in spontaneousventilation: the stop in muscular contraction drives

9Physiology of respiratory dynamics. Application to non-invasive ventilation

Figure 4. Abrupt stop in muscular contraction. The volumeand the transpulmonary pressure remain constant, but thealveolar pressure reaches its maximum value. PTP: transpul-monary pressure.

Figure 5. Exiting of air during passive expiration. PTP: trans-pulmonary pressure.

Figure 6. Pre-inspiratory apnea.

Atmospheric pressure (cm H2O)







Inspiration

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PTPAlveolar

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lum

e

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the value of Ppl to zero. Again, at this point PTP isgoverned by Palv, which reaches its maximum valuedue to the tendency of lung tissue to passivelyretract. As explained above, the increase in Palv tovalues above Patm generates the gradient whichenables air to exit the body.

Ventilation with pressure support requires a wayof knowing when the inspiration begins (i.e. theinspiratory trigger), establishment of a pressure valueat which to pressurize the airway during inspirationonly, and a way of knowing when the inspiration ends(i.e. the expiratory trigger). Hence, use of pressuresupport, in what is known as spontaneous/timed (S/T)mode in NIV-specific ventilators, is dictated by thefollowing key factors: • Inspiratory synchrony• Expiratory synchrony• Rapid compensation for leaks in the system, in

order to reach pre-established pressure valuesduring inspiration. Obtaining good resultsdepends on the specific characteristics of eachventilator, especially for patients with highphysiological requirements (e.g. high respiratoryfrequency, short inspiratory time, and weak peakinspiratory flow), including infants, prematureneonates, and patients suffering fromneuromuscular diseases.

REFERENCES

1. Ball WC (1996) Interactive Respiratory Physiology. Johns Hop-kins School of Medicine. http://oac.med.jhmi. edu/res_phys/

10 V. Modesto, S. Vidal, E. Ibiza

Figure 7 A and B. A) Respiratory failure: the patient is notcapable of generating transpulmonary pressure (PTP) greaterthan + 7 cm H2O. B) Use of pressure support (PS): with thesame effort, the patient reaches a higher PTP, and the lungfills to a greater volume.

Inspiration

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INDICATIONS

Non-invasive ventilation in acute respiratoryfailure

The indications of non-invasive ventilation (NIV)in acute respiratory failure (ARF) are beingincreasingly better defined; consequently, it isbecoming safer and more successful. As with othermedical procedures, NIV was first used in adultpatients, and then based on these experiences, itwas gradually extended to specific areas inpediatrics. The rise in NIV use stems from a desireto avoid the complications inherent to invasiveventilation as well as an aim to better use resources.NIV can reduce hospital stays and the costs ofhospital admissions and improve patient comfort.However, careful selection of candidate patients,availability of adequate material, and physician andnursing care continue to be the determinant factorsfor successful treatment of ARF with NIV—muchmore so than in the case of chronic respiratoryfailure (CRF).

The objectives for NIV in ARF comprise:ameliorating patient symptoms, reducing theworkload of respiratory muscles, and improving gasexchange in patients who do not require intubationand conventional mechanical ventilation (CMV);however, NIV is never intended for substituting thesetechniques if they are clearly required. NIV ismaintained while the patient is treated for the cause(e.g. infection or surgery) of respiratory failure (RF).

When selecting an ARF patient for NIV treatment,the following factors should be considered:a. Clinical criteria: symptoms and signs of respiratory

difficulty (e.g. moderate or severe dyspnea, highrespiratory frequency, use of accessory respiratorymuscles, and paradoxical breathing).

b. Blood gas criteria: PaCO2 > 45 mm Hg and pH <7.35; or (PaO2/FiO2) < 250; or, if arterial bloodgas test is not available, the ratio of peripheralsaturation (SatO2) to FiO2 < 320, when SatO2< 98%, which is the criterion used in the PALIVE(Pediatric Acute Lung Injury MechanicalVentilation) multi-center study on acuterespiratory distress syndrome (ARDS), which usedcriteria from an article on adult patients.

c. The cause of ARF.d. Lack of contra-indications (see separate section

below). In the case of any doubts, a one-hourtest treatment of NIV could be administered, inwhich the patient is closely monitored in ordernot to delay intubation (if required).The following factors are predictors of success

for use of NIV in ARF:a. The process or condition triggering the ARF is

relatively mild.b. A high level of cooperation from the patient and

a high level of patient-ventilator coordination.c. Optimal adaptation of the interface to the patient

(i.e. in size and shape).d. Improved gas exchange, heart rate and respiratory

frequency in the first two hours of NIV.

Indications and contra-indications ofnon-invasive ventilation in patients

with acute respiratory failure

M. Gáboli and M. Pons

Chapter 3


e. A moderate level of initial hypercapnia (PaCO2between 45 and 90 mm Hg).

f. A moderate level of respiratory acidosis (pHbetween 7.20 and 7.35).

g. Acute respiratory distress syndrome (ARDS) inwhich (PaO2/FiO2) > 150. The clearest sign ofsuccess of NIV is a drop in respiratory frequency.Contrariwise, agitation, worsening of respiratorydifficulties, and worsening of gas exchange areall indicative of failure of NIV. Hence, monitoringof vital signs and blood gases (when indicated)should be prioritized in the first few hours oftreatment (see Chapter 10).

Indications of NIV in the acute patient• During the course of neuromuscular diseases

(NMDs), affectation of respiratory muscles leadsto progressive chronic respiratory failure,although this still allows the patient to maintaina certain minimum quality of life. However, inthe presence of a precipitating factor—typicallya respiratory infection, convulsions, or medicalintervention, or an intercurrent illness whichlimits daily physical activity or demands greatermuscle effort—ARF arises, primarily via alveolarhypoventilation. In a recent study, NIV wasshown to be a safe and effective first line oftreatment for infants and children suffering fromNMD. The authors of the study emphasize theimportance of recognizing patients who canmaintain sufficient respiration without use of aventilator, whom they consider as idealcandidates for NIV, given that conventionalmechanical ventilation (CMV) via endotrachealintubation with sedation and analgesia wouldfurther weaken respiratory muscles, complicateweaning and often imply definitive tracheotomy.They even propose that use of conscious sedationto facilitate coupling of the NIV interface to thepatient should be considered before ruling outNIV.

• Analogously to the case of NMDs, diseases ofthe chest wall and of the spinal cord imply arestrictive form of respiratory failure and a highpropensity to atelectasis. In these cases, NIV isnot only utile during flare-ups, but also duringthe perioperative period of surgery to correctthoracic defects, in which it facilitates weaningfrom mechanical ventilation.

• Indication of NIV to facilitate extubation andprevent reintubation in adult patients is currentlyaccepted by the majority of authors. Patientswho could most benefit from use of NIV afterextubation or even after decannulation are thosewith chronic lung disease. Hence, the typicalpediatric patient who could benefit from NIVwould be a preterm infant who has undergonetracheal intubation for administration ofsurfactant, for whom extubation may be advisedto diminish any side effects of mechanicalventilation on their immature lungs.

• In patients with acute airway obstruction, suchas that which occurs in laryngitis and in certainpharyngeal-tonsillar infections, NIV can markedlyreduce the muscle effort required for breathingand improve gas exchange. It must be notedthat use of NIV here is not free of risks and shouldbe performed in the presence of experts inmanaging complicated airways, with adequatematerial available for establishing a definitiveairway and only if the patient maintains theirphysiological reflexes for airway protection.

• For ARF related to bronchiolitis, NIV can beindicated at different moments and for differentreasons. For the youngest patients, who presentwith apneas, CPAP tends to be indicated as inthe case of apneas in preterm infants. Patientstend to respond favorably, except in the case ofsevere apneas and/or if the infection developsinto pneumonia. NIV then takes on the sameindications and limitations described for severecases of hypoxemia. For patients with obstructiverespiratory failure, with an increase in respiratorymuscle effort as well as secondary retention ofCO2, NIV with two levels of pressure (bi-levelpositive pressure airway ventilation, or BiPAP)tends to be indicated, namely for improving gasexchange and reducing respiratory effort.Nonetheless, a recent random study whichdemonstrated that use of CPAP alone wassufficient to improve hypercapnia warrantsmention. The benefits of NIV employing mixturesof helium and oxygen (which are less dense thanair) are also noteworthy; these are detailed inChapter 14. The greatest challenge in this typeof pathology resides in the fact that adequatematerial is often difficult to find for these patients(typically, infants younger than 3 months).

12 M. Gáboli, M. Pons


• Indication of NIV in pediatric patients with severehypoxemia due to asthma remains highlycontroversial. The complications implied in CMVfor this pathology have led to the search foralternate ventilatory strategies. NIV has beenshown to improve oxygenation in patients duringsevere asthmatic attacks. NIV treatment ofchildren with this pathology has scarcely beenstudied, and the few existing reports deal withsmall patient populations: 33 (Mayordomo-Colunga), five (Carroll) and three (Akingbola).Nonetheless, in the study by Mayordomo-Colunga, NIV only failed in one case. This isaccomplished through a minor adjustment ofthe V/Q mismatch, whereby using a PEEP whichdoes not exceed 80 to 90% of the auto-PEEP incombination with an inspiratory positive airwaypressure (IPAP) or a pressure support (PS) lowersthe level of respiratory effort required to maintainan adequate flow volume for gas exchange. Thegreatest challenge in clinical practice is to ensurethat the patient couples well to the ventilator,without any agitation; this often requires lightsedation (see Chapter 12). However, in respiratoryfailure with hypercapnia due to an asthmaticattack, NIV has not proven superior to CMV, nordoes it lead to a lower number of requiredintubations. Early administration of NIV (i.e.before total respiratory failure), and use ofventilators that are very sensitive to the respiratoryefforts of the patient, and that consequentlyenable good synchronization, may be importantfactors in the success of the treatment.

• Indication of NIV in severe hypoxemic respiratoryfailure (i.e. [PaO2/FiO2] < 300), such as that whichoccurs in ARDS or in acute pulmonary lesions(ALI), is also the subject of intense debate. Themajority of studies on adult patients do notdifferentiate among the different causes of ARDS(i.e. whether it is primarily pulmonary orsystemic), nor do they distinguish between ALIof infectious or traumatic origins. Currently, themost widely accepted conclusion is that NIV cannot be recommended universally for ARDSpatients ([PaO2/FiO2] < 150); rather, it shouldbe reserved for hemodynamically stable patientswithout metabolic acidosis, and should only beadministered in an ICU by staff with NIVexpertise. In a recent study of adults, the authors

observed that up to 54% of patients with ARDSthat had initially been treated with NIV did notrequire intubation. They also reported that a(PaO2/FiO2) value > 175 after one hour of NIVis indicative that the treatment will be successfuland stated that for patients with (PaO2/FiO2) <175, NIV must be considered even if all theintubation criteria are not strictly met. Patientswho benefitted from NIV had significantly lesscomplications, especially those of an infectiousnature, and required fewer days in the ICUcompared to patients treated from the beginningwith endotracheal intubation and mechanicalventilation. Few promising studies on severelyhypoxemic pediatric patients exist, and nouniversal guidelines have yet been establishedfor this pathology. It seems reasonable toextrapolate the findings from adult patients andthen proceed cautiously in the most severepediatric patients (according to the level ofseverity upon admission), without delayingintubation in those patients who, after one hourof treatment, do not exhibit any clinical or bloodgas improvement (see Chapters 13 and 23).

• Among situations of ARF in adult patients, use ofNIV is probably most well-documented for acutepulmonary edema (APE). NIV, in either CPAP orBiPAP modes, has been shown to rapidly improvegas exchange and lead to lower intubation andmortality rates and is relatively cost-effective. NIVin APE currently tends to begin in the ER and iseven used during extra-hospital transport. APEis much less frequent in pediatric patients thanin adult patients, owing to the rarity of cardiacischemia in the pediatric age. Cardiogenic APE(CAPE) may be the first sign of severe cardiacinsufficiency (e.g. myocarditis, myocardiopathyor a congenital deformation). In this case, if thereis any clear cause of hemodynamic instability,then NIV must be used cautiously, in the PICUand with strict monitoring. Contrariwise, if theAPE is due to hypervolemia and a periodicdecompensation of a known and controlledcardiac condition that arises in the post-operativeperiod of corrective cardiac surgery, then NIV,owing to its mildness, should be attempted asthe first treatment option in tandem with thespecific medical treatment. Among non-cardiogenic edema, a noteworthy type is that of

13Indications and contra-indications of non-invasive ventilation in patients with acute respiratory failure


APE due to negative intrathoracic pressure, whichis caused by a spontaneous forced respirationagainst an obstruction in the upper airway. Thisscenario has been reported in patients after ear,nose and throat (ENT) surgery. In these cases, inwhich the mechanism appears to be an increasein permeability due to a change in pressure inthe pulmonary arterioles and capillaries, if theairway is permeable and safe, then the responseto NIV tends to be very good and the patienttends to improve within a few hours. Lastly, if theedema is found within the context of an ALI (e.g.due to inhalation of toxic material, infection ortrauma), then the level to which the pulmonaryparenchyma has been affected and the grade ofthe hypoxemia should be evaluated as describedabove for ARDS.

• NIV has also proven effective for ARF in patientswho have undergone autologous bone marrowtransplant. The efficacy of NIV for this patientgroup is limited to certain etiologies such asAPE following hyperhydration before achemotherapy session. More severe etiologies(e.g. pulmonary hemorrhage) call for intubationand CMV. NIV seems to involve fewercomplications than CMV. NIV has likewiseproven utile in pediatric ARF patients affectedby oncological pathology.

• Albeit anecdotal, NIV has been used in one casein which intubation was impossible. Althoughthis application can not be considered a trueindication of NIV, it should nonetheless beconsidered in extreme situations.

• Finally, the palliative indication of NIV inoncology and neurology patients should not beforgotten. In these patients NIV can improve anintercurrent process or ease symptoms ofrespiratory difficulty.

CONTRA-INDICATIONSAll techniques, regardless of their novelty or

sophistication, have their respective limitations andcontra-indications. The main contra-indications ofNIV are described below (Table IV, chapter 23).

When protection of the airway is requiredFor situations in which ventilation is indicated

for protection of the airway (e.g. coma or active

digestive hemorrhage) NIV is absolutely contra-indicated, since, as with use of a laryngeal mask, itcan not guarantee this protection. The onlyexception to this rule is for patients with hypercapnicencephalopathy, who can derive neurologicalbenefits from a short (2 to 3 hours) test treatmentof NIV.

Severe respiratory failureContra-indication of NIV in severe RF is

supported by data on adult patients: a highermortality rate has been observed in patients thatreceived intubation after preliminary NIV treatment.However, patients for whom intubation is not a validoption due to the causative disease are an exception.As previously mentioned, in ARDS with (PaO2/FiO2)< 150 indicates a high risk of technical failure of NIV;hence, NIV should generally be considered contra-indicated for severe RF.

Fixed obstruction of the airwayNIV is contra-indicated in these situations, which

take too long to resolve for it to be effective.

Abundant and thick secretionsRestricted access to cleaning the airway

–especially in the case of an oral-nasal interface inpatients with limited coughing ability– is a high riskfactor for NIV failure.

VomitingAs with abundant secretions, the presence of

vomit makes maintaining a well-positioned interfacefor continuous administration of NIV nearlyimpossible.

Hemodynamic instability: shock For patients in this severe state, the concept of

energy conservation should be applied: respiratoryeffort is eliminated, and therefore, NIV should notbe used. In post-operative cardiac patients, thepresence of arrhythmias can often be considered acontra-indication for NIV.

Craniofacial malformations, trauma and burnsNIV is impossible to administer in patients with

lesions in the area where the NIV interface wouldbe positioned. Moreover, positive pressure in thepresence of ethmoidal fractures has been associated



with orbital herniation. Some authors havepostulated that application of NIV in patients withcerebrospinal fluid (CSF) fistulae implies an increasedrisk of post-traumatic meningitis.

PneumothoraxRegardless of how it is delivered, positive pressure

always has negative consequences for lungs withpneumothorax. However, experience with adultpatients does not contra-indicate use of NIV indrained pneumothorax.

Recent gastrointestinal surgeryDehiscence of esophageal sutures has been

described in patients who received NIV during thepost-operative period. The entry of a large volumeof air into the digestive tract with esophageal and/orgastric distension implies a risk during the immediatepost-operative period. However, currently there arepublications that demonstrate the efficacy of NIV atlow pressure without complications.

Despite the existence of certain contra-indications, in the Guidelines of the British ThoracicSociety, use of NIV is accepted as long as intubationis planned or the indication is palliative.

REFERENCES1. Antonelli M, Conti G, Esquinas A, Montini L, Maggiore SM,

Bello G, et al. A multiple-center survey on the use in clinicalpractice of noninvasive ventilation as a first-line interventionfor acute respiratory distress syndrome. Crit Care Med 2007;35:18-25.

2. Hamel DS, Klonin H. The role of noninvasive ventilation for acuterespiratory failure. Respir Care Clin N Am 2006;12:421-35.

3. Venkataraman ST. Mechanical ventilation and respiratory care.En: Fuhrman BP, Zimmerman JJ. Pediatric Critical Care. 3ª ed.Mosby Elsevier.

4. Nava S, Navalesi P, Conti G. Time of non-invasive ventilation.Intensive Care Med 2006;32:361-70.

5. Teague WG. Non-invasive positive pressure ventilation: currentstatus in paediatric patients. Paediatric Respiratory Review2005;6:52-60.

6. Bach JR, Niranjian V. Noninvasive ventilation in children. In BachJR editor, Noninvasive mechanical ventilation. Philadelphia: Han-ley & Belfus, 2002;203222.

7. Nørregaard O. Noninvasive ventilation in children. Eur Respir J2002;20:1332-42.

8. Todd W Rice, Artur P Wheeler, Gordon R Bernard, Douglas L Hay-den, David Schoenfeld, Lorraine B Ware. Comparison of theSpO2/FiO2 ratio and the PaO2/FiO2 in patients with acute lunginjury or ARDS. Chest 2007;132:410-7.

15Indications and contra-indications of non-invasive ventilation in patients with acute respiratory failure

Table I. Causative processes of acute respiratory failure(ARF) for which use of non-invasive ventilation (NIV) shouldbe considered

Decompensated diseases of the central nervoussystem• Congenital (e.g. respiratory sequelae in infantile cere-

bral paralysis)• Acquired (nearly always palliative indication: e.g. cere-

bral tumors)• Central hypoventilation with hypercapnia• Apneas in preterm infants• Apneas in infants

Decompensated abnormalities of the chest wall andof the spinal column• Malformations of the chest wall• Ankylosing spondylitis• Kyphoscoliosis• Achondroplasia• Obesity hypoventilation syndrome

Decompensated neuromuscular diseases in whichrespiratory muscles are affected• Diseases of the second motor neuron (e.g. spinal mus-

cle atrophy)• Guillain-Barré syndrome without signs of bulbar affec-

tation• Diseases of, or damage to, the phrenic nerve• Myasthenia gravis and other congenital myasthenic

syndromes• Myopathies (e.g. congenital, mitochondrial, metabo-

lic or inflammatory, or deposition diseases)• Muscular dystrophies• Myotonic dystrophy• Polio and its after-effects • Botulism (Use NIV with caution)

Diseases of the upper respiratory tract• Obstruction of the upper airway (e.g. laryngitis or

laryngotracheitis)

Decompensated pulmonary diseases• Acute pulmonary edema• Pneumonia• Atelectasis • Bronchiolitis • Cystic fibrosis • Asthma• Neonatal acute respiratory distress syndrome

Other scenarios• Apnea after adenotonsillectomy• Post-operative period after surgical correction of sco-

liosis• Pulmonary complications caused by sickle cell anemia• Early extubation• As support in procedures involving sedation• Severe respiratory failure in terminal illness (palliati-

ve indication)


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15. Girault C, Daudenthun I, CHevron V, Tamion F, Leroy J, Bon-marchand G. Noninvasive ventilation as a systematic extubationand weaning technique in acute-on-chronic respiratory failure;a prospective, randomized study. Am J Respir Crit Care Med1999;160:86-92.

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23. Rabitsch W, Staudionger T, Locker GJ, Köstler WJ, Laczika K, FrassM, et al. Respiratory failure after stem cell transplantation: impro-ved outcome with non-invasive ventilation 2005;46:1151-7.

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25. Piastra M, Antonelli M, Chiaretti A, Polidori G, Polidori L, ContiG. Treatment of acute respiratory failure by helmet-deliverednon-invasive pressure support ventilation in children withacute leukemia: a pilot study. Intensive Care Med2004;30:472-6.

26. Campion A, Huvenna H, Letemtres S, Noizet O, Biroche A, Die-pendaele JF et al. Non invasive ventilation in infant with severeinfection presumable due to respiratory syncitial virus: feasibi-lity and failure criteria. Arch Pediatr 2006;13:1404-9.

27. Soma T, Hino M , Kida K, Kudoh S. A Prospective and Rando-mized Study for Improvement of Acute Asthma by Non-invasi-ve Positive Pressure Ventilation (NPPV). Intern Med.2008;47:493-501.

28. Soroksky A, Stav D, Shpirer I. A Pilot Prospective, Randomized,Placebo-Controlled Trial of Bilevel Positive Airway Pressure inAcute Asthmatic Attack. Chest 2003;123:1018-25.

29. Beers SL, Abramo TJ, Bracken A, Wiebe RA. Bilevel positive air-way pressure in the treatment of status asthmaticus in pedia-trics. American Journal of Emergency Medicine 2007; 25:6–9.

30. Akingbola OA, Simakajornboon N, Hadley Jr EF, Hopkins RL.Noninvasive positive-pressure ventilation in pediatric statusasthmaticus. Pediatr Crit Care Med 2002;3:181-4.

31. Carroll CL, Schramm CM. Noninvasive positive pressure venti-lation for the treatment of status asthmaticus in children. AnnAllergy Asthma Immunol 2006; 96:454-9.

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INTRODUCTION When considering the conditions and settings

required for administering non-invasive ventilation(NIV), the first aspect to evaluate is the limitationsof the equipment to be used.

Firstly, as with other apparatuses, fixed NIVventilators require AC power and gas tanks (oxygenand medicinal air) and can only be used in hospitals(and only in designated areas). Portable NIVventilators enable greater flexibility, although themajority of them do not have an oxygen blender,and therefore, have limited use for treatment ofseverely hypoxemic patients. Moreover, appropriateventilators and interfaces must be available for eachtype of patient, which in pediatrics impliesmaintaining a broad array of materials andaccessories.

Secondly, personnel caring for the pediatricpatient must have a certain level of expertise inNIV. Although NIV-specific ventilators tend to berelatively easy to operate, no personnel shouldinitiate NIV or change any NIV parameter if theylack fundamental knowledge of the method, donot have experience in treating acute patients, orare not qualified to detect and treat any possiblecomplications.

Lastly, hospital staff must consider theavailability of materials for cardio-respiratorymonitoring (in principle, non-invasive) of patientsand for performing CPR.

If all of the aforementioned conditions have beenmet, then NIV can basically be performed anywhereby using a portable ventilator. However, it ispreferable to maintain acute patients, and to performany changes in the ventilatory parameters for chronicpatients, in a hospital. Application of NIV outside ofthe hospital should be reserved for pre-establishedtreatment of chronic patients.

The following sections provide an overview ofNIV in the pediatric intensive care unit (PICU),general ward, intermediate care areas, ER, deliveryroom and other hospital areas (e.g. sleeplaboratories, diagnostic radiology and the operatingroom), during transport, and lastly, at home.

It should be underscored that factors such asventilator type, and the availability of trained,experienced personnel on hand 24 hours a day, canhave greater influence on the outcome of NIV thanthe location where it is performed.

NIV IN THE PEDIATRIC INTENSIVE CARE UNITThe location which best ensures successful NIV

of acute patients is the PICU, where patients canmost quickly be rescued via intubation andconventional mechanical ventilation (CMV). Someauthors recommend initiating NIV in the PICU forpatients with acute respiratory failure (ARF), whilerecognizing its potential efficacy for patients withstable chronic respiratory failure (CRF).

Conditions and settings for deliveringnon-invasive ventilation

M. Gáboli, J. Mayordomo, P. Gómez de Quero and M. Pons

Chapter 4


Whenever NIV is performed outside of thePICU, it should be treated as an early form ofintervention, but never with the same criteria asthose with which CMV is indicated, since the riskof failure—and consequently, any risks for thepatient—can be extremely high. In contrast to thecase of adults who are not in the ICU, NIV is notused as respiratory support for children who arenot in the PICU.

Only one prospective randomized controlledtrial study on the efficacy of NIV in pediatric acuterespiratory failure have been performed.

Criteria for initiating NIV in the pediatric intensive care unit

Initiation of NIV in the PICU is recommended forpatients presenting with respiratory acidosis,respiratory failure pathology (e.g. pneumonia, acutelung injury [ALI], acute respiratory distress syndrome[ARDS] and asthma). Patients who do not show signsof improvement within the first 2 hours of NIVtreatment in the general ward should be transferredto the PICU to continue NIV under closer observation.The criteria for starting NIV in the PICU comprise: • Respiratory insufficiency which requires FiO2 >

0.4.• Apneas.• pH < 7.30, either initially or after 2 hours of

ineffective NIV treatment in the general ward.• Respiratory therapist, medical or nursing staff in

the general ward has limited experience withNIV.

• Patient or family are not cooperating.

Material • NIV-specific ventilator equipped with an oxygen

blender.• Conventional ventilator with an NIV option.• Interface (preferably oral-nasal).• Assisted cough for neuromuscular disease

patients.

PersonnelAdministration of NIV requires trained medical

and nursing staff, plus respiratory physicaltherapists for neuromuscular disease (NMD)patients. If the latter are not available, they canbe replaced with nurses to perform physicaltherapy.

NIV IN THE GENERAL WARD AND IN INTERMEDIATE CARE AREAS

Recent studies on adult patients show that NIVperformed in the general ward reduces the need forintubation and shortens hospital stay. One multi-center study reported a lower hospital mortality rate.Nonetheless, this technique requires closemonitoring of the patient and a clearly establishedprotocol for transferring the patient to the ICU. Thecriteria may vary among hospitals in function of theavailability of nursing staff and the level of trainingof the personnel. Another factor to consider forpediatric patients is the amount of stress thatadmission into the PICU could imply.

Intermediate respiratory care units (IRCUs), whichexist in countries such as the United States and Italy,have been shown to be cost-effective and can evenimprove patient life expectancy.

NIV in acute pediatric patients can rarely bestarted in the general ward, although some centershave reported periodic experiences in cancer andNMD patients with heightened ARF or CRF. This typeof administration requires qualified personnel whoare available 24 hours a day.

The ideal option for patients in these areas is toprovide an intermediate care unit staffed with trainedpersonnel. The criteria for initiating NIV in the generalward or in intermediate care areas comprise:• Respiratory insufficiency which requires FiO2

< 0.4.• Initial pH > 7.3• Expert staff available 24 hours a day• Patient and family are cooperating

Material• NIV-specific ventilator (no blender required).• Assisted cough for neuromuscular disease

patients.

Personnel Medical and nursing staff, respiratory therapists

must be trained in NIV use.

NIV IN PEDIATRIC EMERGENCIESTo date, in most hospitals NIV in pediatric

patients has generally been administered in thePICU. The ever growing body of evidence on theefficacy of NIV for ARF (primarily Type II), and the

18 M. Gáboli, J. Mayordomo, P. Gómez de Quero, M. Pons


increasing amount of experience with it at manyhospitals, has led to administration of this techniquein less ideal scenarios, such as pediatric emergencies.Moreover, better results have been reported forearly initiation of NIV; hence, the child who is toreceive NIV should be transported to the PICU asquickly as possible.

Several articles on adult patients have beenpublished that demonstrate that NIV can be safelyadministered in the ER to select ARF or CRF patients,such as those suffering from heightened chronicobstructive pulmonary disease (COPD) or acutepulmonary edema (APE), terminal patients, or thosewho have rejected more advanced support methods.Indication of NIV in the ER is less established forasthma and for pneumonia and other types ofhypoxemic or Type I ARF.

All of the aforementioned articles underscorethat the expertise of hospital staff is key to the successof NIV. Given that ER staff may not be ideally suitedto the task, or that the ER may provide less thanoptimal conditions for patient monitoring, NIV inthe ER should only be administered to patients withthe least severe diagnoses.

The NIV mode (CPAP or BiPAP) to be employedin the ER should be the same one used in the ICU.Albeit the recent literature does not clearly favor onemode over the other, certain publications havedescribed CPAP as being simpler.

Indications and ModesAs there is no published list of indications of NIV

for pediatric emergencies, the authors of this chapterhave compiled one here. It must be emphasize thatdespite the fact that NIV in the ER is not performedfor severe ARF patients, hospital staff must alwayshave the material required for emergency intubationprepared and at hand.1. Asthmatic patients with marked respiratory effort

who do not respond sufficiently to conventionalinhalation therapy and oral or parenteralcorticosteroids: These patients can benefit fromNIV in BiPAP mode. The ideal patient for NIVin the ER would be an older child capable ofcooperating who is suffering a moderate tosevere asthmatic attack.

2. NMD patients with ARF, above all, those withupper airway respiratory infections: Thesepatients can respond very well to NIV, given that

their lack of muscle force enables good patient-ventilator synchrony. Some of these patients mayreceive NIV at home, which can facilitatecooperation on their part or the part of theirfamilies.

3. Infants suffering from bronchiolitis (Type I or II):These patients should initially be treated withCPAP via nasal prongs or nasal tube, which canafford better adaption and less air leakage thando nasal or oral-nasal masks.

4. Immunodepressed ARF patients for whomeventual intubation could imply seriouscomplications and for whom rapid administrationof NIV can prevent worsening of respiratoryfailure.

5. Older children with pneumonia and associatedmarked respiratory effort: These patients requireeven closer monitoring than those cited above,as Type I ARF implies much greater risk of NIVfailure than does Type II ARF. CPAP providesbetter gas exchange, although BiPAP decreasesthe load on inspiratory muscles. These patientsshould only be treated by ER personnel withbroad experience in NIV and should beimmediately transferred to the PICU. Patientswith ALI—and of course, those with ARDS—aswell as infants with pneumonia or some othercause of Type I ARF should be immediatelytransferred to the PICU for initiation of NIV orCMV.

Potential problemsThe main problems that can arise with use of

NIV in pediatric emergencies comprise:• Lack of experience or training among hospital

personnel• Rejection of NIV by hospital personnel, above

all, if it fails• Insufficient monitoring • Excessive workload for medical and nursing staff,

namely due to the close monitoring required forthese patients, especially at the onset of NIVadministration

NIV DURING TRANSPORT OF PEDIATRICPATIENTS

Mechanical ventilation during transport ofcritically ill children has improved substantially,

19Conditions and settings for delivering non-invasive ventilation


especially due to advances in portable ventilatorsand monitoring systems, which now provide similarperformance to that typically obtained in the ICU.Although the outlook for NIV during transport maybe promising, there is no specific literature withstrong evidence from which any recommendationson its use could be made.

One of the first things to ensure before transportbegins is that the patient has a permeable airway;if there is any doubt, then the patient should beintubated. This would be the principal limitation onthe application of NIV during transport. One of themajor risks implied in using NIV is a delay inintubation, which must be avoided at all costs beforeand during transport.

Types of transportTransport can be classified into two main groups:

intra-hospital and extra-hospital. NIV is much easierto administer inside the hospital, since it enablesmuch greater safety in terms of controlling thepatient’s airway.

Portable ventilators and ventilation systemsA broad range of commercially available portable

ventilators is now available. However, few of theseare specifically adapted for NIV. Although the Osiris2® and 3®, and the Oxylog 3000®, can perform leakcompensation for adaptation to NIV, use of thesedevices during transport of pediatric patients isproblematic. The Osiris 2® and 3® are only equippedfor positive pressure ventilation with mixtures of air:they can not be used with 100% O2. The Oxylog3000® features a flow sensor with a minimumthreshold of 3 liters per minute (lpm), which isinadequate for young pediatric patients with reducedinspiratory strength. Other ventilators which can bemade portable are not specific for NIV and are notamenable to the difficult working conditions impliedin transporting patients. Conventional ventilators(e.g. Servo-i® and Savina®) can be used, althoughthey are excessively large and are very susceptibleto damage from continuous use in inadequateconditions.

Home ventilators (e.g. VS Ultra® and LegendAir®) meet several of the requisites for use of NIVduring transport of pediatric patients: they are small,flexible, and easy to program. However, they areseverely limited by their lack of an oxygen blender;

hence, their use implies incorporation an oxygen T-piece in line with the tubing and the flow meter.The maximum flow of O2 supplied is 15 lpm andthe FiO2 does not exceed 50%. As such, theseventilators can not be used in hypoxemic patientswhose O2 requirements exceed said value or whosecondition is highly likely to worsen during transport.Some of these ventilators are equipped with oxygenenriching systems that enable FiO2 levels near 80%.

There are now NIV ventilators that can be usedas both conventional and portable ventilators (e.g.Elisée® and Carina®). They feature oxygen blenders,graphic monitoring, and highly sensitive triggeringsystems and are small and light. Although theseventilators are very expensive—which limits theirpracticality for use exclusively during transport—they remain an attractive option due to their multi-functionality (i.e. CMV, NIV and portable ventilation).

Ventilators that feature continuous flow (e.g.Babylog 2000®, CF120® and BabyPac 100®) can beused to administer CPAP in neonates and infants.These are practical for initial treatment of patientsin early phases of Type I ARF (i.e. hyaline membranedisease [HMD], Type I-pattern bronchiolitis, etc.) orType II ARF (i.e. apneas in neonatals or secondaryto bronchiolitis) who can benefit from early CPAPtreatment instead of administration of pure O2. Useof BiPAP with these ventilators is difficult, given thatnone of them are equipped with a trigger, andtherefore, can only perform intermittent mandatoryventilation (IMV). Consequently, these ventilators maysuffer from a high level of desynchronization; hence,they are not the best devices for use during transport.

Another option is the Boussignac CPAP system,which is now used in the pre-hospital stabilizationand transport of adult patients with acute Type IARF. Albeit no studies on its efficacy in childrenhave been published, the authors of this chapterbelieve that it could prove highly utile, as it ischeap, simple (it does not require a respirator) andcomfortable and enables pulmonary recruitmentwhile simultaneously providing effective oxygentherapy.

Indications and ventilation modesPatients should be diligently selected, as the

priority during transport is to maintain permeabilityof the airway. In terms of choosing the ventilationmode, the easiest option seems to be CPAP used

20 M. Gáboli, J. Mayordomo, P. Gómez de Quero, M. Pons


either with ventilators featuring continuous flow orwith systems that are directly adaptable to flowmeters (e.g. Boussignac CPAP or Vygon® CPAP), asthis enables faster adaptation to the patient than useof BiPAP, which demands more careful monitoringand longer adaptation time. Furthermore, systemsfor administering BiPAP generally do not feature anoxygen blender; therefore, they have limited use insituations in which patient control is difficult, suchas in transport.

Based on the premises outlined above, NIV intransport may be easier for patients with Type I ARF(e.g. HMD, near drowning, and meconiumaspiration) than those with Type II. Nonetheless, inType I patients, NIV should only be administered tothose who do not have major respiratory difficultiesor heightened oxygen requirements and who arenot hemodynamically compromised; it is contra-indicated for patients with ALI or ARDS. In Type IIpatients, NIV should be limited to patients whoseoxygen needs are less than 50%. In any case, whenevaluating NIV for use during transport of a pediatricpatient, the contra-indications of NIV, and the specificrisks implied in transporting the patient, shouldalways be very carefully considered.

NIV AT HOME

Indications NIV at home is primarily indicated for CRF that

demands intermittent mechanical ventilation andfor respiratory sleep disorders.

Objectives• Improve the patient’s quality of life: avoiding

flare-ups, preserving cardiopulmonary function,maintaining adequate growth and developmentat each age, and improving the chances ofacademic and social integration.

• Increasing survival rate.

ModesNIV can be performed at home with either

positive pressure (NPPV) or negative pressure(NNPV). The former is typically preferred as it is moreeffective, easier to use during transport and doesnot imply obstruction of the upper airway (anoccasional consequence of NNPV).

ConditionsNIV can be performed at home for patients who

have maintained respiratory autonomy and theability to expectorate and who do not have anydifficulty swallowing. The upper airway must bepermeable, without any fixed obstruction ordeformation that substantially alters it morphology.

In order for parents to care for their children athome, it is crucial that they receive a detailedexplanation of the objectives sought with NIV andthat they give their full approval and cooperation.Patients must also be taught about the specific NIVtreatment that they are to receive and its benefitsin a manner appropriate to their age, cognitive leveland emotional state, and must understand that thesuccess of the treatment will be greatly facilitatedby their cooperation.

Family members and others who are to care forthe child must also be trained in home use of theapparatuses, rapid detection of major problems thatcould arise during NIV administration (e.g.disconnection of the apparatus, mask leaks, sores,and hypoventilation with hypoxia), and maneuversto solve said problems, and must know how toquickly alert emergency services in the event thatthese maneuvers prove insufficient.

It is absolutely critical that there be a team ofhospital personnel to periodically monitor the patient'sprogress, evaluate any required changes in the NIVparameters, quickly solve any complications that mayarise, and maintain close contact with equipmentproviders. This team would preferably have at leastone doctor with expertise in respiratory pathologyand critical pediatric illnesses, as well as nursing staff,a rehabilitation physician and a physical therapist thatis trained in respiratory pathology. The team and thepatient (or family or care provider) must be able tocontact each other by telephone at any time.

If the patient can not be easily transferred to theteam, or if the level of home care can not beguaranteed to meet that provided in the hospital,then home administration of NIV should be seriouslyreconsidered.

Control guidelines: Initially, it would be advisablefor the team to visit the patient at 2 to 4 weeks afterthe start of home NIV, and then at 2 to 6 months(according to the stability of the patient), as well asanytime that the patient suffers from some type ofintercurrent condition that affects the NIV.

21Conditions and settings for delivering non-invasive ventilation


NIV IN OTHER LOCATIONS

NIV in sleep laboratoriesRespiratory sleep disorders in pediatrics

encompass a broad array of clinical situations suchas obstructive sleep apnea (OSA) and sleep apneahypopnea syndrome (SAHS), increased resistance inthe upper airway, nocturnal asthma symptoms, andother conditions involving chronic alteration ofrespiratory function.

Sleep laboratories outfitted for children providethe ideal environment to diagnose the respiratorychanges that arise during this period, and can alsoserve as the ideal location to begin NIV (ifindicated).

NIV in diagnostic radiologyOne of the latest areas to which NIV has been

adapted is the radiology ward. Radiologicalexamination can be affected as the patient breathes.As infants and small children can not cooperateduring radiological exams by pausing at the end ofeach deep breath, they must often be sedated toensure that they do not move during chest CTs(whether standard or high-resolution). Some authorshave suggested using NIV (administered via facialmask) to induce a controlled respiratory pause of8 to 12 seconds, du

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Ingles 20/3/09 09:45 Página I · 2020. 6. 30. · 2: Trancutaneous oxygen saturation Sec: Second(s) SMA: Spinal muscular atrophy S/T: Spontaneous/timed mode T: Timed mode Ti: Inspiratory