CONGENITAL AND ACQUIRED RESPIRATORY DISORDERS IN INFANTS

CONGENITAL AND ACQUIRED RESPIRATORY DISORDERS IN INFANTS

OBJECTIVESOBJECTIVES

Review of Cardio-Pulmonary Development. Review of Cardio-Pulmonary Development. Define changes that occur during transition Define changes that occur during transition

to extra-uterine life with emphasis on to extra-uterine life with emphasis on breathing mechanics.breathing mechanics.

Identify infants at risk for and who have Identify infants at risk for and who have respiratory distressrespiratory distress

Review of common neonatal disease states.Review of common neonatal disease states.

STAGES OF

NORMAL LUNG GROWTH

STAGES OF

NORMAL LUNG GROWTHEmbryonic - first 5 weeks; formation of proximal Embryonic - first 5 weeks; formation of proximal

airwaysairways

Pseudoglandular - 5-16 weeks; formation of Pseudoglandular - 5-16 weeks; formation of conducting airwaysconducting airways

Canalicular - 16-24 weeks; formation of aciniCanalicular - 16-24 weeks; formation of acini

Saccular - 24 - 36 weeks; development of gas-Saccular - 24 - 36 weeks; development of gas-exchange unitsexchange units

Alveolar - 36 weeks and up; expansion of surface Alveolar - 36 weeks and up; expansion of surface areaarea

Pseudoglandular6-16 weeks

Pseudoglandular6-16 weeks

Canalicular Phase16-24 weeks

Canalicular Phase16-24 weeks

Saccular Phase24-34 weeks

Saccular Phase24-34 weeks

PHYSIOLOGIC MATURATION(Surfactant Production)PHYSIOLOGIC MATURATION(Surfactant Production) Type 2 pneumocytes appear at 24-26 weeksType 2 pneumocytes appear at 24-26 weeks

Responsible for reduction of alveolar surface tension.Responsible for reduction of alveolar surface tension. LaPlace’s LawLaPlace’s Law

Lipid profile as indicator of lung maturityLipid profile as indicator of lung maturity L/S RatioL/S Ratio Flourescence Polarization - FLMFlourescence Polarization - FLM

Many other factors influence lung maturationMany other factors influence lung maturation

Maturational FactorsMaturational Factors

StimulationStimulation Glucorticoids, ACTHGlucorticoids, ACTH Thyroid Hormones, Thyroid Hormones,

TRFTRF EGFEGF HeroinHeroin Aminophyline,cAMPAminophyline,cAMP InterferonInterferon EstrogensEstrogens

InhibitionInhibition Diabetes (insulin, Diabetes (insulin,

hyperglycemia, butyric hyperglycemia, butyric acid)acid)

TestosteroneTestosterone TGF-BTGF-B BarbituratesBarbiturates ProlactinProlactin

FETAL CIRCULATIONFETAL CIRCULATION

TRANSITIONTO

EXTRA-UTERINE LIFE

TRANSITIONTO

EXTRA-UTERINE LIFE Fetal BreathingFetal Breathing Instantaneous; liquid filled to air filled lungsInstantaneous; liquid filled to air filled lungs Maintenance of FRCMaintenance of FRC Placental blood flow terminationPlacental blood flow termination Decreased PVRDecreased PVR Closure of fetal shuntsClosure of fetal shunts

MECHANICS OF BREATHINGMECHANICS OF BREATHING

Respiratory Control Center...CNSRespiratory Control Center...CNS Metabolic NeedsMetabolic Needs

Negative pressure breathingNegative pressure breathing Compliance and ResistanceCompliance and Resistance

Inspiratory MusclesInspiratory Muscles Rib Cage Rib Cage

““Compliability becomes a liability”Compliability becomes a liability”

Signs of Respiratory DistressSigns of Respiratory Distress

TachypneaTachypnea Intercostal retractionsIntercostal retractions Nasal FlaringNasal Flaring Grunting Grunting CyanosisCyanosis

When is it abnormal to show signs of respiratory distress?When is it abnormal to show signs of respiratory distress? When tachypnea, retractions, flaring, or When tachypnea, retractions, flaring, or

grunting persist beyond one hour after grunting persist beyond one hour after birth.birth.

When there is worsening tachypnea, When there is worsening tachypnea, retractions, flaring or grunting at any retractions, flaring or grunting at any time.time.

Any time there is cyanosisAny time there is cyanosis

Causes of Neonatal Respiratory DistressCauses of Neonatal Respiratory Distress Obstructive/restrictive - mucous, choanal atresia, Obstructive/restrictive - mucous, choanal atresia,

pneumothorax, diaphragmatic hernia.pneumothorax, diaphragmatic hernia. Primary lung problem - Respiratory Distress Primary lung problem - Respiratory Distress

Syndrome (RDS), meconium aspiration, bacterial Syndrome (RDS), meconium aspiration, bacterial pneumonia, transient (TTN).pneumonia, transient (TTN).

NonNon-pulmonary -hypovolemia/hypotension, -pulmonary -hypovolemia/hypotension, congenital heart disease, hypoxia, acidosis, congenital heart disease, hypoxia, acidosis, cold stress, anemia, polycythemiacold stress, anemia, polycythemia

Infants at Risk for Developing Respiratory DistressInfants at Risk for Developing Respiratory Distress Preterm InfantsPreterm Infants Infants with birth asphyxiaInfants with birth asphyxia Infants of Diabetic MothersInfants of Diabetic Mothers Infants born by Cesarean SectionInfants born by Cesarean Section Infants born to mothers with fever, ProlongedInfants born to mothers with fever, Prolonged

ROM, foul-smelling amniotic fluid.ROM, foul-smelling amniotic fluid. Meconium in amniotic fluid.Meconium in amniotic fluid. Other problemsOther problems

Evaluation of Respiratory DistressEvaluation of Respiratory Distress Administer Oxygen and other necessary Administer Oxygen and other necessary

emergency treatmentemergency treatment Vital sign assessmentVital sign assessment Determine cause-- physical exam, Chest Determine cause-- physical exam, Chest

x-ray, ABG, Screening tests: Hematocrit, x-ray, ABG, Screening tests: Hematocrit, blood glucose, CBCblood glucose, CBC

Sepsis work-upSepsis work-up

Principles of TherapyPrinciples of Therapy

Improve oxygen delivery to lungsImprove oxygen delivery to lungs-- supplemental -- supplemental oxygen, CPAP, assisted ventilation, surfactantoxygen, CPAP, assisted ventilation, surfactant

Improve blood flow to lungsImprove blood flow to lungs-- volume expanders, blood -- volume expanders, blood transfusion, partial exchange transfusion for high transfusion, partial exchange transfusion for high hematocrit, correct acidosis (metabolic/respiratory)hematocrit, correct acidosis (metabolic/respiratory)

Minimize oxygen consumptionMinimize oxygen consumption-- neutral thermal -- neutral thermal environment, warming/humidifying oxygen, withhold environment, warming/humidifying oxygen, withhold oral feedings, minimal handlingoral feedings, minimal handling

DISEASE STATESDISEASE STATES

Respiratory Distress SyndromeRespiratory Distress Syndrome Transient Tachypnea of the NewbornTransient Tachypnea of the Newborn Meconium Aspiration SyndromeMeconium Aspiration Syndrome Persistent Hypertension of the NewbornPersistent Hypertension of the Newborn Congenital PneumoniaCongenital Pneumonia Congenital MalformationsCongenital Malformations Acquired ProcessesAcquired Processes

RESPIRATORY DISTRESS SYNDROME

RESPIRATORY DISTRESS SYNDROME

Surfactant DeficiencySurfactant Deficiency

Tidal Volume VentilationTidal Volume Ventilation

Pulmonary Injury SequencePulmonary Injury Sequence

CLINICAL FEATURES OF RDS

CLINICAL FEATURES OF RDS

Tachypnea/ApneaTachypnea/Apnea DyspneaDyspnea Grunting/FlaringGrunting/Flaring HypoxemiaHypoxemia Radiographic FeaturesRadiographic Features Pulmonary Function AbnormalitiesPulmonary Function Abnormalities

Early RDSEarly RDS

Progressive RDSProgressive RDS

Late RDSLate RDS

Hyaline Membrane DiseaseHyaline Membrane Disease

THERAPY FOR RDSTHERAPY FOR RDS

Oxygen - maintain PaO2 > 50 torrOxygen - maintain PaO2 > 50 torr Nasal CPAPNasal CPAP Intermittent Mandatory VentilationIntermittent Mandatory Ventilation Surfactant ReplacementSurfactant Replacement High Frequency VentilationHigh Frequency Ventilation Intercurrent TherapiesIntercurrent Therapies

PIEPIE

PIE PathologyPIE Pathology

PIE HistologyPIE Histology

Pneumothorax/PIEPneumothorax/PIE

PneumothoraxPneumothorax

PneumopericardiumPneumopericardium

TRANSIENT TACHYPNEA OF THE NEWBORN

TRANSIENT TACHYPNEA OF THE NEWBORN

Delayed Fluid ResorptionDelayed Fluid Resorption Hard to differentiate early on from RDS Hard to differentiate early on from RDS

both clinicaly and radiographicaly both clinicaly and radiographicaly especially in the premature infantespecially in the premature infant

Initial therapy similar to RDS, but hospital Initial therapy similar to RDS, but hospital course is quite differentcourse is quite different

Wet LungWet Lung

MECONIUM ASPIRATION SYNDROME

MECONIUM ASPIRATION SYNDROME

Chemical PneumonitisChemical Pneumonitis Surfactant InactivationSurfactant Inactivation Potential for InfectionPotential for Infection Potential for Pulmonary HypertensionPotential for Pulmonary Hypertension Management varies on severityManagement varies on severity

Meconium AspirationMeconium Aspiration

PERSISTENT PULMONARY HYPERTENSION

PERSISTENT PULMONARY HYPERTENSION

Usually secondary to primary pulmonary Usually secondary to primary pulmonary disease statedisease state

Pulmonary Vascular LabilityPulmonary Vascular Lability Treat the underlying problemTreat the underlying problem Maintain normo-oxygenationMaintain normo-oxygenation Selective Pulmonary VasodilatorsSelective Pulmonary Vasodilators Pray for good luckPray for good luck

PPHNPPHN

CONGENITAL PNEUMONIACONGENITAL PNEUMONIA

Infectious; primarily GBSInfectious; primarily GBS Amniotic Fluid aspirationAmniotic Fluid aspiration Viral etiologyViral etiology Surfactant inactivationSurfactant inactivation

GBS PneumoniaGBS Pneumonia

CONGENITAL MALFORMATIONSCONGENITAL MALFORMATIONS

Choanal AtresiaChoanal Atresia Tracheal Atresia/stenosisTracheal Atresia/stenosis Chest MassChest Mass

Diaphragmatic herniaDiaphragmatic hernia CCAMCCAM SequestrationSequestration Lobar emphysemaLobar emphysema

CCAMCCAM

Lobar EmphysemaLobar Emphysema

Diaphragmatic HerniaDiaphragmatic Hernia

ChylothoraxChylothorax

Phrenic Nerve ParalysisPhrenic Nerve Paralysis

ACQUIRED DISEASESACQUIRED DISEASES

InfectionsInfections Bronchopulmonary DysplasiaBronchopulmonary Dysplasia Sub-glottic stenosisSub-glottic stenosis Apnea of PrematurityApnea of Prematurity

Early BPDEarly BPD

Progressive BPDProgressive BPD

Late BPDLate BPD

APNEAAPNEA

Definition: cessation of breathing Definition: cessation of breathing for longer than a 15 second period for longer than a 15 second period or for a shorter time if there is or for a shorter time if there is bradycardia or cyanosisbradycardia or cyanosis

Babies at Risk for ApneaBabies at Risk for Apnea

PretermPreterm Respiratory DistressRespiratory Distress Metabolic DisordersMetabolic Disorders InfectionsInfections Cold-stressed babies who are being warmedCold-stressed babies who are being warmed CNS disordersCNS disorders Low Blood volume or low HematocritLow Blood volume or low Hematocrit Perinatal CompromisePerinatal Compromise Maternal drugs in laborMaternal drugs in labor

Anticipation and DetectionAnticipation and Detection

Place at-risk infants on cardio-Place at-risk infants on cardio-respiratory monitorrespiratory monitor

Low heart rate limit (80-100)Low heart rate limit (80-100) Respiratory alarm (15-20 seconds)Respiratory alarm (15-20 seconds)

Treatment Treatment

Determine cause:Determine cause: x-rayx-ray blood sugarblood sugar body and environmental temperaturebody and environmental temperature hematocrithematocrit sepsis work upsepsis work up electrolyteselectrolytes cardiac work upcardiac work up r/o seizurer/o seizure

TreatmentTreatment

CPAPCPAP Theophylline/Caffeine therapyTheophylline/Caffeine therapy Mechanical ventilationMechanical ventilation Apnea monitorApnea monitor