Division of PerinatologyDepartment of Child Health Medical SchoolUniversity of Sumatera Utara

DefinitionPerinatal asphyxia is an insult to the fetus/newborn, due to:Lack of oxygen (hypoxia) and/orLack of perfusion (ischemia) to various organ, and may be associated withLack of ventilation (hypercapnia).

DefinitionEssential characteristics: American Academy ofPediatrics (AAP) and the American College OfObstetricians and Gynecologists (ACOG):Profound metabolic or mixed acidemia (pH < 7)Apgar score of 0-3 for >5 minNeurologic manifestations: seizures, hypotonia, coma, or hypoxic ischemic encephalopathy (HIE)Evidence of multiorgan system dysfunction in the immediate neonatal periode.

Incidence1.0-1.5% of total live birth :36 wk : 0.5%~20% of perinatal death

Apgar score (1952)A scoring system to help assessing a neonates transition after birthConceived to report on the state of the newborn and effectiveness of resuscitation.Poor tool for assessing asphyxia

APGAR SCORING

Organ effects of asphyxiaCNSLungCardiovascular systemRenal systemGastrointestinal tractBlood

Consequences of Asphyxia CNSCerebral hemorrhageCerebral edemaHypoxic-ischemic encephalopathySeizures

PathogenesisIntrauterine asphyxiaFetal pO2, pCO2, pH, BPIntracellular edema Cerebral tissue pressureFocal Cerebral blood flowGeneralized brain swelling Intracranial pressureGeneralized cerebral blood flowBrain necrosisIntrauterine asphyxiaFetal pO2, pCO2, pH, BP

Loss of vascular autoregulationCerebral blood flow

Brain Necrosis

Brain swelling

Consequences of Asphyxia LungDelayed onset of respirationRespiratory distress syndrome from surfactant deficiency or dysfunctionPulmonary hemorrhagePersistent pulmonary hypertention

Consequences of Asphyxia Cardiovascular systemShockHypotentionMyocardial necrosisCongestive heart failureVentricular dysfunction

Consequences of Asphyxia Renal systemOliguria-anuriaAcute tubular or cortical necrosisRenal failure

Consequences of Asphyxia Gastrointestinal systemParalytic ileus or delayed (5-7 days) necrotizing enterocolitis.

Consequences of Asphyxia BloodDisseminated intravascular coagulationThrombocytopenia can result from shortened platelet survivalBone Marrow recovers over time

Consequences of Asphyxia MetabolicAcidosisHypoglicemia (hyperinsulinism)HypocalcemiaHyponatremia/ Syndrome of inappropriate antidiuretic hormone secretion (SIADH)

ManagementOptimal management is prevention: identify the fetus being subjected Immediate resuscitation: maintenance of adequate ventilation, oxygenation, perfusion.Correct metabolic acidosis: Volume expander: to sustain tissue perfusionNS or Ringers LactateO neg if (+) evidence of blood lossAlbumin: not recommended Na BicarbonateOnly with adequate ventilation and circulationOnly when CPR is prolonged and the infant remains unresponsiveness1-2 mEq/kg of a 0.5 mEq/L slow IVTemperature: Avoid perinatal hyperthermia

ManagementMaintain a normal serum glucosa level (75-100 mg/dL) to provide adequate substrate for brain metabolism. Avoid hyperglycemia to prevent hyperosmolality and a possible increase in brain lactate levelsControle of seizures: phenobarbital is the drug of choice.Prevention of cerebral edema: fluid restriction (eg. 60 ml/kg)

Neonatal Resuscitation

Primary versus Secondary ApneaPrimary Apnea no respiration decreasing heart rate BP maintained responds to stimulusSecondary Apnea no respiration heart rate very low BP low No response to stimulation

Signs of a Compromised NewbornCyanosisBradycardiaLow blood pressureDepressed respiratory effortPoor muscle tone 2000 AAP/AHA

Preparation for Resuscitation Personnel and EquipmentTrained person to initiate resuscitation at every delivery Recruit additional personnel, for more complex deliveryPrepare necessary equipmentTurn on radiant warmerCheck resuscitation equipmentTeam concept 2000 AAP/AHA

Evaluating the NewbornImmediately after birth, the following questions must be asked: 2000 AAP/AHA

2000 AAP/AHAEvaluationDecisionAction

Initial Steps 2000 AAP/AHA

Provide WarmthPrevent heat loss byPlacing newborn under radiant warmerDrying thoroughlyRemoving wet towel 2000 AAP/AHA

Preventing Heat LossPremature newbornsSpecial problemsThin skinDecreased subcutaneous tissueLarge surface areaAdditional stepsRaise environment temperatureCover with clear plastic sheeting 2000 AAP/AHA

Opening the Airway

Open the airway byPositioning on back or sideSlightly extending neckSniffing positionAligning posterior pharynx, larynx and trachea 2000 AAP/AHA

Suction mouth first, then noseClear Airway: No Meconium Present 2000 AAP/AHA

If meconium present and newborn is vigorousIf: respiratory effort is strongmuscle tone is goodHeart rate > 100/ minThen:Use bulb syringe or large bore catheter to clear mouth and nose

Meconium present and newborn NOT vigorousTracheal suctionAdminister oxygenInsert laryngoscope, use 12F or 14F suction catheter to clear mouthInsert endotracheal tube Attach endotracheal tube to suction sourceApply suction as tube is withdrawnRepeat as necessary 2000 AAP/AHA

Management of Meconium 2000 AAP/AHA

Dry, Stimulate to Breathe, Reposition 2000 AAP/AHA

Tactile Stimulation 2000 AAP/AHAPotentially Hazardous Stimulation shaking slapping the back squeezing the rib cage hot and cold compresses dilating anal sphincter

Resuscitation Flow Diagram 2000 AAP/AHA

Post - Resuscitation Care 2000 AAP/AHA