Respiratory Failure in the Pediatric Patient

•Ndidi Musa M.D. •Associate Professor of Pediatrics •Medical College of Wisconsin •Pediatric Cardiac Intensivist • Children’s Hospital of Wisconsin

Objectives

• Recognize different types of respiratory failure

• Pathophysiology

• Management

• Adjuncts to respiratory support

Scope of The Problem

Respiratory Failure

Anatomy

• Upper Airway

– Humidifies inhaled gases

– Site of most resistances to airflow

• Lower Airway

– Conducting airways (anatomic dead space)

– Site of gas exchange (Resp bronchioles, alveoli)

Respiratory Failure

• Inability of the pulmonary system to meet the metabolic needs of the body not always associated with distress

• Two crucial metabolic roles – Ventilation –elimination of CO2 byproduct of cellular

respiration

– Oxygenation-delivery to tissues for utilization

• 3 forms of respiratory failure – Hypoxemic

– Hypercarbic

– Mixed

Approach to Respiratory Failure

• Drive issue- patient won’t breath – CNS (Head injury, Status epilepticus, sedation)

– Toxin( Drugs)

• Work issue- patient can’t breath because of strength or load – Airways (Resistance-UAO, asthma, bronchiolitis)

– Lungs (Compliance- Pnuemonia)

– Pump ( Muscle problem- prolonged illness, GBS)

Approach to Respiratory Failure

• Basic mechanism of hypoxemia

– Ventilation perfusion mismatch most common

– Diffusion

– Alveolar hypoventilation

– Shunt

• Intra cardiac

• Extra cardiac (intra- pulmonary)

– Hypoxia- arterial O2 sat reduced

Hypoxemic Respiratory Failure

• Hypoxemic hypoxia – Arterial oxygen saturation is reduced

• Anemic hypoxia – SaO2 normal but O2 content reduced by low Hgb

inadequate O2 carrying capacity

• Ischemic hypoxia – Blood flow to tissue is low Hgb and O2 concentration

normal but cardiac output is low(hypovelemia, myocardial insufficiency)

• Histotoxic hypoxia – Tissue unable to utilize O2,(cyanide or CO poison)

Defined as a PaO2 < 60mmHg

Hypercapnic Respiratory Failure

• Decreased Tidal volume – Minute ventilation (volume of air in and out of

lung/minute) MV= RR x Tidal volume • Shallow breathing,

– compliance (stiff lungs)

– airway resistance

• Decreased Respiratory Rate – Drive

• Increased physiologic dead space

• Increased carbon dioxide production

Defined as a PaCO2 > 50mmHg

Categorization of Respiratory Failure by Severity

• Respiratory distress

– Increased RR

– Increased effort (flaring, retractions, use of accessory muscles)

• Respiratory Failure

– Clinical state of inadequate oxygenation ventilation or both

– End stage of respiratory distress

Respiratory Distress

Intrinsic Pulmonary problem

• Upper airway obstruction – Laryngotracheobronchitis

• Lower airway obstruction – Asthma

– Bronciolitis

• Lung parenchyma – Pneumonia

– Pulmonary edema

Systemic problem

• Malaria

• Shock

• Dehydration

• Anemia

• Heart disease

• Renal disease

Causes of Respiratory Distress

Pneumonia

Malaria

Anaemia

Asthma

Dehydration

Crackles

Wheeze

Sunken eyes Skin Turgor Acidosis

Pallor Acidosis

Acidosis Blood film

Difficulty breathing Retractions Tachypnea

Courtesy Dr B Bevins

Treat underlying causes Pnuemonia -O2,Abx,Fluids

Asthma-Bronchodilators,Fluids Dehydration- Fluids

Anemia-Blood Malaria- Antimalarials, fluids,

Management

• Depends on cause

• Airway

• Breathing

• Circulation

Stabilization

• Airway

– Clear (unobstructed for normal breathing)

– Maintainable (simple measures- head tilt, suction)

– Not maintainable (Advanced interventions)

Stabilization

• Breathing – Respiratory rate

– Effort • Nasal flaring

• Retractions

• Minute ventilation (volume of air in and out of lung/minute) MV= RR x Tidal volume – Shallow breathing, stiff lungs or airway resistance

– Lung sounds

– Pulse oximetry

Pulse Oximetry

“The systematic use of pulse oximetry to monitor and treat children in resource-poor developing countries, when coupled with a reliable oxygen supply, improves quality of care and reduces mortality” Trevor Duke

Annals of Tropical Paediatrics (2009) 29, 165–175

Pulse Oximetry

• Systematic review of 21 published and unpublished articles

• 16,000 children with acute lower respiratory infection

• the median hypoxemia prevalence among 13 studies which included children with WHO-defined severe and very severe pneumonia was 13.3% (9.3–37.5%)

• 11–20 million children are admitted to hospital each year with Pneumonia,

• 1.5–2.7 million episodes of hospitalized pneumonia associated with hypoxemia occur in young children globally each year.

Annals of Tropical Paediatrics (2009) 29, 165–175

Scatter diagram showing the correlation between the respiratory rate and oxygen saturation.

Rajesh V T et al. Arch Dis Child 2000;82:46-49

©2000 by BMJ Publishing Group Ltd and Royal College of Paediatrics and Child Health

RR> 60 correlated with low SaO2

Who do you screen?

Annals of Tropical Paediatrics (2009) 29, 165–175

Oxygen Availability

Oxygen is an essential medicine: a call for international action Hypoxaemia is commonly associated with mortality in developing countries, yet feasible and costeffective ways to address hypoxaemia receive little or no attention in current global health strategies.Oxygen treatment has been used in medicine for almost 100 years, but in developing countries most seriously ill newborns, children and adults do not have access to oxygen or the simple test that can detect hypoxaemia. Improving access to oxygen and pulse oximetry has demonstrated a reduction in mortality from childhood pneumonia by up to 35% in high-burden child pneumonia settings. The cost-effectiveness of an oxygen systems strategy compares favourably with other higher profile child survival interventions, such as new vaccines. In addition to its use in treating acute respiratory illness, oxygen treatment is required for the optimal management of many other conditions in adults and children, and is essential for safe surgery, anaesthesia and obstetric care. Oxygen concentrators provide the most consistent and least expensive source of oxygen in health facilities where power supplies are reliable. Oxygen concentrators are sustainable in developing country settings if a systematic approach involving nurses, doctors, technicians and administrators is adopted. Improving oxygen systems is an entry point for improving the quality of care. For these broad reasons, and for its vital importance in reducing deaths due to lung disease in 2010: Year of the Lung, oxygen deserves a higher priority on the global health agenda. Keywords oxygen; hypoxaemia; pneumonia; lung disease; health systems HYPOXAEMIA is a major cause of morbidity and mortality associated with acute and chronic lung disease in children and adults. Hypoxaemia is a low level of oxygen in the arterial© 2010

Improving access to oxygen and pulse oximetry has demonstrated a reduction in mortality from childhood pneumonia by up to 35% in high-burden child pneumonia settings. The cost-effectiveness of an oxygen systems strategy compares favorably with other higher profile child survival interventions, such as new vaccines.

Oxygen Therapy

Oxygen concentrators work best with nasal cannulas.

Nasal(neonate)C

annula

Conversion

(Gomella-Lange)

Flow

rate

≅ FI02

¼L 34%

½L 44%

¾L 60%

1L 66%

In an adult 1L flow ≅ 24% FIO2

↑FIO2 by 4% for every 1L flow ↑up to 6 L flow

(2L ≅28%)

Advantage in developed world

Reality we have to deal with

Using The Tools We Have

• Monitoring allows the recognition of a patient early in distress or early warning signs of respiratory failure.

• Tools

– Physical exam

– Monitor

• Cardio-respiratory monitor

• Pulse oximeter

Golden Hour

Respiratory Distress

Respiratory Failure

Cardiopulmonary Arrest

Possibly Hours

Potentially minutes

Constant Re-assessment

Early Resuscitation

Improved Outcome

Respiratory rate Retractions Oxygen saturation

Oxygen Antibiotics Airway support Ventilation

Respiratory Rate Retractions O2 Saturation

Early recognition

Triage Emergency Care

Adjuncts To Respiratory Support

• Continuous positive airway pressure(CPAP)

• Non Invasive positive pressure ventilation (NPPV or BIPAP)

• Indications

– Patient who has increased work of breathing despite oxygen support • Pneumonia

• Asthma

• Gullian barré Syndrome(GBS)

• Congestive heart failure

CPAP or BiPAP

Non Invasive Mechanical Ventilation(NPV)

Contraindication of NPV

• Respiratory arrest

• Cardiovascular instability

• Somnolence

• High risk of aspiration

• Craniofacial trauma

Non Invasive Mechanical ventilation

• Advantages

– Avoids upper airway trauma

– Leaves airway defenses intact

– Comfortable

– Sedation needs less

• Disadvantages

– Gastric distention

– Facial skin necrosis

– Airleak

Bubble CPAP

Bubble CPAP

• Low resistance delivery system

• Large bore tubing

• Nasal prongs

• Fit appropriately and prevent leaks

• Warm humidified gas

• Suction 3-4 hrs

Bubble CPAP

• Maintains positive pressure in airway during spontaneous ventilation

• improves oxygenation

• Splint the airway, diaphragm

• Prevents alveolar collapse

Bubble CPAP

• Monitoring

– Respiratory

– CVS

– GI

– Thermoregulation

Summary

Systematic approach to a patient in respiratory distress

Complete assessment and reassessment of the patient

Communication - Interdisciplinary team approach

Residents Nursing

PATIENT

Specialist

Team Training…building competence to Excellence!

Acknowledgement

• Slides from

– Dr Vinay Nardkarni

– Dr Trevor Duke

– Dr David Hehir

– Dr Bill Bevins

– Dr From Mali