Respiratory System of the Respiratory System of the NewbornNewborn

• Revised by Gillian McRavin-Johnson, Revised by Gillian McRavin-Johnson, RNCRNC

• MHS-Good Samaritan HospitalMHS-Good Samaritan Hospital

• Carmelita Rivero, RNC, MSNCarmelita Rivero, RNC, MSN

• Madigan Army Medical CenterMadigan Army Medical Center

ObjectivesObjectives

• Review anatomy and physiology of the Review anatomy and physiology of the respiratory system.respiratory system.

• List symptoms and identify treatments of List symptoms and identify treatments of Transient Tachypnea of the Newborn.Transient Tachypnea of the Newborn.

• List symptoms and identify treatments of List symptoms and identify treatments of Respiratory Distress Syndrome.Respiratory Distress Syndrome.

• List symptoms and identity treatments of List symptoms and identity treatments of Meconium Aspiration Syndrome.Meconium Aspiration Syndrome.

• Define and discuss causes of apnea. Define and discuss causes of apnea. • Review current NRP guidelines for immediate Review current NRP guidelines for immediate

resuscitation of Newborn.resuscitation of Newborn.

EmbryologyEmbryology

• Embryonic stage:Embryonic stage: week 1- week 1-5 - A single lung bud begins 5 - A single lung bud begins to divide into 3 sections. to divide into 3 sections. Pulmonary vein joins lung Pulmonary vein joins lung bud.bud.

• Pseudoglandular stage:Pseudoglandular stage: week 5-17 - Conducting week 5-17 - Conducting airways are formed. airways are formed. Capillary bed is formed, no Capillary bed is formed, no connection to lung buds. connection to lung buds. Diaphragm develops.Diaphragm develops.

• Canalicular stage:Canalicular stage: week week 17-24 - Gas-exchanging 17-24 - Gas-exchanging acini units appear and type acini units appear and type II cells appear. Capillaries II cells appear. Capillaries invade terminal airway invade terminal airway walls.walls.

Respiratory CellsRespiratory Cells

• Type I PneumocytesType I Pneumocytes - 90% of surface area - 90% of surface area• Serve the function of gas exchangeServe the function of gas exchange• Type II Pneumocytes - Type II Pneumocytes - 66% of cells but only 3% of 66% of cells but only 3% of

surface areasurface area• Most important function is the synthesis and secretion of Most important function is the synthesis and secretion of

surfactantsurfactant• Glucocorticoids and thyroid hormones hasten maturationGlucocorticoids and thyroid hormones hasten maturation• Weeks 24-26 - alveolar sacs appear in limited quantity, type Weeks 24-26 - alveolar sacs appear in limited quantity, type

II cells are unable to release enough surfactant to maintain II cells are unable to release enough surfactant to maintain air breathingair breathing

• Terminal sac stage:Terminal sac stage: week 24-37 - Type II cells increase week 24-37 - Type II cells increase and mature, lung size and surface area increase rapidly. and mature, lung size and surface area increase rapidly. Capillary loops increaseCapillary loops increase

• Alveolar stage:Alveolar stage: week 30-8/10 years - Continued alveolar week 30-8/10 years - Continued alveolar proliferation and development proliferation and development

Respiratory AssessmentRespiratory Assessment

• NormalNormal respiratory raterespiratory rate: 40-60 RPM: 40-60 RPM

• TachypneaTachypnea : : >60 RPM>60 RPM

• Temperature, stressTemperature, stress

• C-Section C-Section

• PainPain

• Persistent tachypnea - Lung pathologyPersistent tachypnea - Lung pathology

Respiratory AssessmentRespiratory Assessment• Maternal HistoryMaternal History• Type and quality of chest movementType and quality of chest movement• Abnormal Breath soundsAbnormal Breath sounds• NasalNasal Flaring, Gasping, Expiratory gruntingFlaring, Gasping, Expiratory grunting- Sighing and RetractionsSighing and Retractions

Cont. Respiratory Cont. Respiratory AssessmentAssessment

Asymmetrical breathing -Asymmetrical breathing -PneumothoraxPneumothoraxDiaphragmatic HerniaDiaphragmatic HerniaHeart defects with failureHeart defects with failurePhrenic nerve damagePhrenic nerve damage

Abnormal breath soundsAbnormal breath soundsObstructionObstructionInflammationInflammation

Fetal TransitionFetal Transition

• Lung sacs are filled with fluidLung sacs are filled with fluid

• Labor and initial breaths force fluid from Labor and initial breaths force fluid from lungslungs

• Oxygen causes capillaries in lungs to dilateOxygen causes capillaries in lungs to dilate

• Pulmonary pressure lowers and blood from Pulmonary pressure lowers and blood from right side of heart bypasses PDA to enter right side of heart bypasses PDA to enter lungslungs

• The change in pressure causes the PDA and The change in pressure causes the PDA and the foramen ovale to closethe foramen ovale to close

General TreatmentGeneral Treatment

• OxygenOxygen– OxyhoodOxyhood– CPAPCPAP– VentilatorVentilator

• GlucoseGlucose• Blood pressure supportBlood pressure support• Normal temperature rangeNormal temperature range• Minimal stimulation, Cluster CareMinimal stimulation, Cluster Care

Blood GasesBlood Gases

• Why are blood gasses important?Why are blood gasses important?

• H+ ions and CO2H+ ions and CO2

• Correction vs. CompensationCorrection vs. Compensation

• Respiratory vs. MetabolicRespiratory vs. Metabolic

Blood GasesBlood Gases

• ValuesValues– pH 7.35-7.45 pH 7.35-7.45 – paCO2 35-45 paCO2 35-45 – paO2 50-70paO2 50-70– HCO3 18-24HCO3 18-24– Base -2-+2Base -2-+2– Oxygen Saturation 90-94%Oxygen Saturation 90-94%

Respiratory – Respiratory – PCO2PCO2

Metabolic –Metabolic –

HCO3HCO3

AcidosisAcidosis

pH pH

AlkalosisAlkalosis

pHpH

Transient Tachypnea of the Transient Tachypnea of the NewbornNewborn

A.K.A. Wet Lung SyndromeA.K.A. Wet Lung Syndrome

Retained Lung FluidRetained Lung Fluid

Or RDS Type IIOr RDS Type II

TTNB: PathophysiologyTTNB: Pathophysiology

• Excess fluid in the lungs usu. due to lack of Excess fluid in the lungs usu. due to lack of thoracic squeeze, failure to clear normal fetal thoracic squeeze, failure to clear normal fetal lung fluid, or bothlung fluid, or both

• Fluid accumulates in the peribronchial Fluid accumulates in the peribronchial lymphatics and bronchovascular spaceslymphatics and bronchovascular spaces

• Fetal lung fluid is normally cleared via two Fetal lung fluid is normally cleared via two ways:ways:– Expulsion during deliveryExpulsion during delivery– Absorption after delivery in pulmonary circulation Absorption after delivery in pulmonary circulation

and lymphatic drainageand lymphatic drainage

TTNB: RisksTTNB: Risks

• Tend to be term or near term with mature Tend to be term or near term with mature lungslungs

• Increased RiskIncreased Risk– Cesarean SectionCesarean Section– Breech BirthsBreech Births– Second Born TwinSecond Born Twin– Rapid DeliveryRapid Delivery– Maternal Heavy SedationMaternal Heavy Sedation– PolycythemiaPolycythemia– Hypothermia after deliveryLGA babiesHypothermia after deliveryLGA babies

TTNB: SymptomsTTNB: Symptoms

• Tachypnea (60-140 BPM) rarely lasting Tachypnea (60-140 BPM) rarely lasting longer than 48-96 hourslonger than 48-96 hours

• Possible mild cyanosisPossible mild cyanosis

• Retractions, nasal flaring, and gruntingRetractions, nasal flaring, and grunting

• Decreased breath sounds, but no ralesDecreased breath sounds, but no rales

• Possible barrel-shaped chest Possible barrel-shaped chest

TTNB: DiagnosisTTNB: Diagnosis

• TTNB is a diagnosis of exclusionTTNB is a diagnosis of exclusion• A diagnosis of TTNB can only be made A diagnosis of TTNB can only be made

after resolution of symptoms in the first 4 after resolution of symptoms in the first 4 daysdays

• CXR shows increased lung fluid and CXR shows increased lung fluid and prominent vascular markings prominent vascular markings

• CXR can be identical to RDS in the first 3 CXR can be identical to RDS in the first 3 hours of lifehours of life

• ABG - mild hypoxemia, mild hypercapnia, ABG - mild hypoxemia, mild hypercapnia, normal pHnormal pH

TTNB: InterventionsTTNB: Interventions

• Assisted ventilation is rarely requiredAssisted ventilation is rarely required• Provide appropriate oxygen therapy to Provide appropriate oxygen therapy to

maintain ABG’s within normal limitsmaintain ABG’s within normal limits• CPAP may be useful for the first few hours CPAP may be useful for the first few hours

when severe pulmonary involvement is when severe pulmonary involvement is presentpresent

• Use Neopuff/T-piece resuscitator to provide Use Neopuff/T-piece resuscitator to provide CpapCpap

• Provide calories to support increased Provide calories to support increased respiratory workrespiratory work

• May require gavage feeds when tachypneic May require gavage feeds when tachypneic

Respiratory Distress Respiratory Distress SyndromeSyndrome

Respiratory Distress Respiratory Distress Syndrome: The CauseSyndrome: The Cause

• Pathophysiology: Surfactant Pathophysiology: Surfactant DeficiencyDeficiency

• The Problem: Surface TensionThe Problem: Surface Tension

• The sides of the alveoli are attracted The sides of the alveoli are attracted to each other and, when in proximity, to each other and, when in proximity, stick togetherstick together

• Surfactant lowers surface tension 50-Surfactant lowers surface tension 50-100 times, especially at expiration100 times, especially at expiration

RDS: StatisticsRDS: Statistics

• 60% of 24-28 weekers and 30% of 60% of 24-28 weekers and 30% of 28-34 weekers develop RDS28-34 weekers develop RDS

• Mortality from RDS decreased from Mortality from RDS decreased from ~100% to < 10%~100% to < 10%

• RDS is the major cause of respiratory RDS is the major cause of respiratory distress in newborns and prematurity distress in newborns and prematurity is the most important risk factoris the most important risk factor

RDS: RisksRDS: Risks

• Increased RiskIncreased Risk– PrematurityPrematurity– Males vs femalesMales vs females– Whites vs non-whitesWhites vs non-whites– Infants of diabetic mothersInfants of diabetic mothers– Presence of asphyxiaPresence of asphyxia– Cesarean section esp. without laborCesarean section esp. without labor– Second twinSecond twin– Prenatal maternal hypotensionPrenatal maternal hypotension– Rh-factor incompatibilityRh-factor incompatibility

RDS: RisksRDS: Risks

• Decreased RiskDecreased Risk– Prolonged rupture of membranesProlonged rupture of membranes– Intrauterine growth restrictionIntrauterine growth restriction– Pregnancy-induced hypertensionPregnancy-induced hypertension– Maternal heroin addictionMaternal heroin addiction– Prenatal corticosteroidsPrenatal corticosteroids

RDS: SymptomsRDS: Symptoms

• Occur within 4-24 hours of delivery, worsen during Occur within 4-24 hours of delivery, worsen during the first 48 hours, and begin to improve by 72 the first 48 hours, and begin to improve by 72 hourshours

• Symptoms:Symptoms:– retractionsretractions– see-saw respirationssee-saw respirations– expiratory gruntingexpiratory grunting– nasal flaringnasal flaring– tachypneatachypnea– decreased/unequal breath soundsdecreased/unequal breath sounds– poor air entry/fine rales on auscultationpoor air entry/fine rales on auscultation

RDS: SymptomsRDS: Symptoms

• Other symptomsOther symptoms– tachycardiatachycardia– hypothermiahypothermia– hypoglycemiahypoglycemia– Generalized cyanosisGeneralized cyanosis– hypotensionhypotension– hypotoniahypotonia– apneaapnea

RDS: DiagnosisRDS: Diagnosis

• L/S ratio or PG presenceL/S ratio or PG presence

• Initial CXRInitial CXR

• Decreased lung complianceDecreased lung compliance

• Increased work of breathingIncreased work of breathing

• ABG - hypoxemia and hypercapniaABG - hypoxemia and hypercapnia

RDS:Interventions - RDS:Interventions - RespiratoryRespiratory

• Respiratory support - O2, CPAP, VentRespiratory support - O2, CPAP, Vent

• Continuous monitoring - saturations, Continuous monitoring - saturations, ABGsABGs

• Serial evaluations and CXRsSerial evaluations and CXRs

• Administration of exogenous Administration of exogenous surfactantsurfactant

RDS:Prevention - RDS:Prevention - RespiratoryRespiratory

• Improved prenatal care to decrease Improved prenatal care to decrease preterm deliveries, antenatal steroids preterm deliveries, antenatal steroids (28-32 weeks)(28-32 weeks)

• Early and effective resuscitationEarly and effective resuscitation

Surfactant Benefits: A Surfactant Benefits: A ReviewReview

• Increases alveolar stability - Increases alveolar stability - decreases atalectasisdecreases atalectasis

• Increases complianceIncreases compliance

• Decreases work of breathingDecreases work of breathing

• More uniform alveolar recruitment on More uniform alveolar recruitment on inspirationinspiration

• Decreases pulmonary edemaDecreases pulmonary edema

Benefits of SurfactantBenefits of Surfactant

• Exogenous surfactant has decreased Exogenous surfactant has decreased mortality in infants (500-1500 g) by mortality in infants (500-1500 g) by 28%28%

• Decreases air leaks by as much as 50-Decreases air leaks by as much as 50-60%60%

• No change in incidence of PDA, BPD, or No change in incidence of PDA, BPD, or IVHIVH

Drawbacks of SurfactantDrawbacks of Surfactant

• Non-uniform distributionNon-uniform distribution

• Inactivation by proteinaceous edemaInactivation by proteinaceous edema

• Oxygenation and tidal volume Oxygenation and tidal volume breaths continue to cause damagebreaths continue to cause damage

• Permanent lung damagePermanent lung damage

• Inhibitory effect on future lung Inhibitory effect on future lung growthgrowth

Meconium Aspiration Meconium Aspiration SyndromeSyndrome

Meconium Aspiration Meconium Aspiration SyndromeSyndrome• Meconium stained amniotic fluid is Meconium stained amniotic fluid is

noted in 10-15% of all babies noted in 10-15% of all babies delivered.delivered.

• Meconium may be aspirated from the Meconium may be aspirated from the trachea in about 56% of infants born trachea in about 56% of infants born with thick meconium.with thick meconium.

• About 1/3 of infants with meconium About 1/3 of infants with meconium below the cords become ill and below the cords become ill and require intensive care. require intensive care.

MAS: PathophysiologyMAS: Pathophysiology

• Damage is caused by two Damage is caused by two problemsproblems::– The bile salts and enzymes cause a The bile salts and enzymes cause a

chemical pneumonitis.chemical pneumonitis.– Meconium occludes distal airways Meconium occludes distal airways

causing several types of physical causing several types of physical lung damage.lung damage.

Cont. MAS Cont. MAS PathophysiologyPathophysiology•Physical lung Physical lung damagedamage::

-The meconium completely -The meconium completely occludes the airway and the occludes the airway and the distal alveoli remain distal alveoli remain atalectaticatalectatic

-The ball-valve effect - air -The ball-valve effect - air gets in the alveoli but gets in the alveoli but can’t get out.can’t get out.-Meconium moves lower -Meconium moves lower in airway and traps in airway and traps alveoli with air inside.alveoli with air inside.

MAS: RisksMAS: Risks

• Tend to be term, post-term, or SGA.Tend to be term, post-term, or SGA.– Prolonged laborProlonged labor– Fetal bradycardia and distressFetal bradycardia and distress– Breech presentationBreech presentation– Presence of meconium-stained fluidPresence of meconium-stained fluid– Delivery by cesarean sectionDelivery by cesarean section

MAS: SymptomsMAS: Symptoms

• Meconium staining of umbilical cord, nails, Meconium staining of umbilical cord, nails, and skinand skin

• Hyperexpansion of chest - “barrel chest”Hyperexpansion of chest - “barrel chest”

• Respiratory distress - 50% of casesRespiratory distress - 50% of cases– grunting, irregular/gasping respirationsgrunting, irregular/gasping respirations– retractions, nasal flaringretractions, nasal flaring– tachypneatachypnea– coarse bronchial breath sounds with ralescoarse bronchial breath sounds with rales

MAS: DiagnosisMAS: Diagnosis

• ABG - hypoxemia, acidosisABG - hypoxemia, acidosis

• CXR - hyperinflated lungs - 20-30%CXR - hyperinflated lungs - 20-30%

Severity is determined by:Severity is determined by:– Consistency of meconiumConsistency of meconium– Amount of meconiumAmount of meconium– Degree of consolidation on the CXRDegree of consolidation on the CXR

Worst Case ScenarioWorst Case Scenario

• PPHN: Persistent Pulmonary PPHN: Persistent Pulmonary HypertensionHypertension– Lung capillaries remain constrictedLung capillaries remain constricted– Pulmonary artery pressures remain higher Pulmonary artery pressures remain higher

than systemic blood pressurethan systemic blood pressure– High lung pressure pushes blood through High lung pressure pushes blood through

Foramen ovale and ductus arteriosusForamen ovale and ductus arteriosus– Blood is not oxygenated Blood is not oxygenated – Hypoxemia and acidosis lead to further Hypoxemia and acidosis lead to further

pulmonary vasoconstrictionpulmonary vasoconstriction

MAS: Interventions - Secondary MAS: Interventions - Secondary Conditions/InfectionConditions/Infection

• Continuous monitoring of vital signs, Continuous monitoring of vital signs, ABGs, CXRs ABGs, CXRs

• Treat hypotension, acidosis, anemia, Treat hypotension, acidosis, anemia, infectioninfection– Hypotension and acidosis worsen Hypotension and acidosis worsen

respiratory distressrespiratory distress– Meconium is an excellent growth Meconium is an excellent growth

medium for bacteriamedium for bacteria

Apnea in the Newborn Apnea in the Newborn

Definition of ApneaDefinition of Apnea

• The cessation of respiratory air flow The cessation of respiratory air flow and/or respiratory movement for 20 and/or respiratory movement for 20 seconds or longer.seconds or longer.

• The cessation of respiratory air flow The cessation of respiratory air flow is associated with pallor, is associated with pallor, bradycardia, cyanosis, oxygen bradycardia, cyanosis, oxygen desaturation, or a change in level of desaturation, or a change in level of consciousness.consciousness.

Types of ApneaTypes of Apnea

Apnea occurring at delivery:Apnea occurring at delivery:

Primary ApneaPrimary Apnea – Cessation of respiratory – Cessation of respiratory movements from asphyxia during the delivery movements from asphyxia during the delivery process; exposure to O2 will induce process; exposure to O2 will induce respirationsrespirations

Secondary ApneaSecondary Apnea – Caused by prolonged – Caused by prolonged asphyxia; infant will require resuscitationasphyxia; infant will require resuscitation

Primary and secondary apnea can be Primary and secondary apnea can be indistinguishable at birthindistinguishable at birth

Causes of ApneaCauses of Apnea

• PrematurityPrematurity• Respiratory disordersRespiratory disorders• Immature respiratory centerImmature respiratory center

– Obstructive airwayObstructive airway• Infection Infection • Sleep stateSleep state• Temperature instability – try to keep temp at low Temperature instability – try to keep temp at low

end of normalend of normal• Cardiovascular disordersCardiovascular disorders• Drugs - Drugs – Drugs - Drugs – narcotics, anticonvulsants, anesthesia's, narcotics, anticonvulsants, anesthesia's,

magnesium sulfatemagnesium sulfate

Causes of ApneaCauses of Apnea

• Reflex stimulation – Gastroesophageal reflux, Reflex stimulation – Gastroesophageal reflux, pharyngeal stimulationpharyngeal stimulation

• Environmental Environmental – Rapid warming, vasodilates your NBRapid warming, vasodilates your NB– Hypothermia, hyperthermiaHypothermia, hyperthermia– Elevated environmental temperatureElevated environmental temperature– FeedingFeeding– StoolingStooling– Painful stimuliPainful stimuli

Apnea: DiagnosisApnea: Diagnosis

• Physical examPhysical exam

• Documentation of apneic spellsDocumentation of apneic spells– LengthLength– Time in relation to occurrence – feeding, Time in relation to occurrence – feeding,

procedure, stooling, sleepprocedure, stooling, sleep– PositionPosition– Associated bradycardia or color changeAssociated bradycardia or color change– Type of stimulation needed to resolve apneic Type of stimulation needed to resolve apneic

episode.episode.

Apnea: DiagnosisApnea: Diagnosis

•Laboratory workup – infection, Laboratory workup – infection, respiratory alteration, metabolic respiratory alteration, metabolic alterationalteration– CBC with differential, plateletsCBC with differential, platelets– Blood gasBlood gas– Blood cultures, spinal tap, Blood cultures, spinal tap,

urine, CRPurine, CRP

Apnea: InterventionsApnea: Interventions

• Treat the specific disease or Treat the specific disease or underlying cause.underlying cause.

• Keep temperature normothermicKeep temperature normothermic

• Avoid triggers:Avoid triggers:– vigorous suctioningvigorous suctioning– hot/cold to facehot/cold to face– sudden gastric distensionsudden gastric distension

Apnea: InterventionsApnea: Interventions

• Prone positioningProne positioning

• Shoulder rollShoulder roll

• Prevent hyperoxiaPrevent hyperoxia

• Prevent painful stimuli - loud noises, Prevent painful stimuli - loud noises, extremely vigorous tactile extremely vigorous tactile stimulation or strong odorsstimulation or strong odors

• Chart spells completelyChart spells completely

NRP Clinical Changes - Highlights

• Supplemental oxygen use will emphasize starting low, and increasing as needed. For instance, apneic term infants in the DR will be bagged initially on room air, preterm infants on 30-40% oxygen

• Oxygen saturation monitors should be placed on a distressed infant as early as possible, optimally in the first 60-90 seconds

• Oxygen blenders should be available in all delivery settings

• Evaluation of clinical skills will include an integrated skills station and a simulation with debriefing

NRP Clinical Changes - Highlights

• Equipment check is a new performance skill on its own.

• Bulb suctioning will not be routine, but reserved for infants with obvious obstruction or who need positive pressure ventilation

• When an umbilical line must be placed while chest compressions are being performed the two thumb method will be used from the head of the bed

• Intubation is to be completed in 30 seconds, not 20 • The endotracheal epinephrine dose range is increased

to 0.5-1 ml/kg/dose

Kattwinkel J et al. Pediatrics 2010;126:e1400-e1413

• NRPNRP

AlgorithmAlgorithm

Targeted Preductal SPO2

After Birth

1 min 60%-65%2 min 65%-70%3 min 70%-75%4 min 75%-80%5 min 80%-85%10 min 85%-95%

NEOPUFF/ T-piece NEOPUFF/ T-piece ResuscitatorResuscitator

Settings: Settings: Neopuff and Neopuff and • >37 weeks>37 weeks• O2 at 8 LPM O2 at 8 LPM • Max pop-off 40Max pop-off 40• Pip 20cwp / PEEP 4 Pip 20cwp / PEEP 4 • FIO2 @ 21%FIO2 @ 21%

• <37 weeks<37 weeks• O2 at 8LPMO2 at 8LPM• Max pop-off 40Max pop-off 40• PIP 16cwp / PEEP 6PIP 16cwp / PEEP 6• FIO@ @ 30%FIO@ @ 30%

Silverman-Anderson Retraction Silverman-Anderson Retraction ScoreScore

FETAL CIRCULATIONFETAL CIRCULATION

Summary:Summary:

• Youtube repeat - Fetal Circulation RaYoutube repeat - Fetal Circulation Rapp

ReferencesReferences

• Kattwinkel J et al. Pediatrics 2010;126:e1400-e1413

• Neonatal Resuscitation Text Book 6th Edition

• Utube uploaded by: iraislabonga n March 3, 2011

• Multicare Health Systems Policy on T-piece Resuscitator use in delivery room revised 2009

• S.T.A.B.L.E. Program Learner Manual

• http://intl-radiographics.rsna.org