1.Perinatal Asphyxia Dr. Kalpana Malla MD Pediatrics Manipal Teaching HospitalDownload more documents and slide shows on The Medical Post [ www.themedicalpost.net ]

2. PERINATAL ASPHYXIADefinitionAn insult to the fetus or newborn due to lack ofoxygen (hypoxia) and /or lack of perfusion (ischemia) to various organs.Associated withTissue lactic acidosis Hypoventilation Hypercapnea 2 3. PERINATAL ASPHYXIAIncidence1-1.5%20% of perinatal deathsIncreased risk in IDM Toxemic mothers IUGR Breech Postmature 3 4. SEQUENCE OF EVENTS HR..decrease BP...decreaseNormal Resp...Rapid breathing.Pr.Apnea.Irreg.breathingSec.ApneaResuscitationResuscitationNormal Respiration Normal Respiration4 5. ETIOLOGY90% Antepartum/ Intrapartum 10% Postpartum FACTORSMaternal:- Hypertension- chronic / pre-eclampsia - Diabetes, anemia,, malnutrition - Hypoxia-Pulmonary/Cardiac/ - heart Ds, Bronchial asthma 5 6. FACTORSMaternal:HypotensionIntrauterine infectionsProlonged and difficult 2nd stage of labourPlacental: Infarction/fibrosis/abruptionCord Accidents:Prolapse / True knots / compression/Abn. vessels 7. FACTORSFetal: Infection - intrauterine Anemia - Feto-fetal or feto maternaltransfusion IUGR/ Postmaturity - Meconium aspirationtracheal plug by blood mucus Cong malformations - choanalatresia, laryngeal web,D. hernia, TEF,ICH Hydrops fetalis 8. PATHOPHYSIOLOGYDiving reflex: Shunting of blood to brain ,heart, adrenals andaway from gut, kidney, liver, spleen ,skeletalmuscle and skinProgressive asphyxia: Hypoxia, Hypercapnea, acidosis Pulmonary vasoconstriction, R to L shunt Decrease in HR, CO, BP Cerebral edema- Petechial hemorrhage, SIADH, Na- intracellular accumulation8 9. TARGET ORGAN-BRAINHIE:PATHOPHYSIOLOGYHypoxiaAlteration in glucose and energymetabolismloss of autoregulation & decreasedcardiac functionischemiaSevere hypoxia and ischemia failure of oxidativephosphorylation & ATP productionAccumulation of Na, Cl,Ca intracellular and K andexcitatory neurotransmitters extracellularneuronal death 9 10. HIE- PATHOLOGY1. Selective neuronal necrosis - Cerebral and cerebellar cortex, Thalamus, brain stemnuclei2. Focal and multifocal cortical necrosis3. Watershed infarct4. Parasagittal cerebral injury5. Periventricular leucomalacia6. Status murmoratus.10 11. Hypoxic Ischaemic Encephalopathy Most important consequence of perinatalasphyxia Hypoxic ischaemic insult to the brain 25-30% of survivors have permanent damage likeCP and MR. 15-20% with HIE die 12. SARNAT STAGINGFeaturesStage1 Stage 2 Stage3Mild Moderate Severe1.Level ofHyperalertLethargic Stuperousconsciousness Irritable ObtundedComatose2.Neuromuscularcontrol.Muscle toneNHypotonia FlaccidPostureNFlexion DecerebrationReflexes Decreased / Absent3. ReflexesSuck Weak Weak /AbsentAbsent MoroStrong WeakAbsent 12 13. SARNAT STAGINGFeatures Stagee1Stage 2Stage3 Mild ModerateSevere4.Autonomic Gen.sympathetic Gen.Parasymp Both depressedfunction Pupil MydriasisMiosisMidposition RespSpontSpontPeriodic,apnea HRTachycardia bradycardia Variable5.SeizuresNone commonUncommon6.EEG Normal abnormal abnormal7. Duration