RESUSCITATION OF A NEWBORN

PRESENTER: L NCHIMBA-HAMUYUNIMODERATOR: DR S MACHONA

BIRTH ASPHYXIA

• Perinatal asphyxia is an insult to the fetus or newborn due to a lack of O2 and/or lack of perfusion (ischemia) to various organs

• Often assoc with tissue acidosis and hypercarbia• There is no universally acceped criteria; features include

acidemia <7.0, persistence of apgars 0 to 3 beyond 5min– neurological manifestations:coma, seizures, hypotonia, HIE– pulmonary: pulm HTN, meconeum asp, surfactant disruption– Metabolic – m. acidosis, hypoglycemia, hypocalcemia, hyponatremia – Renal – oliguria, ARF– GI – Nec, hepatic dysfxn– Hematologic – DIC, thrombocytopenia

PHYSIOLOGY OF ASPHYXIA

• Primary apnea – when an infant is deprived of O2, initially, rapid breathing occurs. If the asphyxia continues, the resp movmts cease, HR begins to fall, neuromuscular tone reduces– Tactile stimulation and exposure to O2 will induce resps

• Secondary apnea- if asphyxia continues, baby devs deep gasping resps, HR continues to fall, BP begins to fall. The infant is now unresponsive to stimulation and will not spontaneously resume resps unless PPV is initiated

• It is important to note that as a result of fetal hypoxia, infant may go thru the phase of primary and secondary apnea in utero and so an apneac neonate at birth may be in either; two situations may be virtually indistinguishable

• Clinical significance: when one is faced with an apneac neonate, assume you are dealing with secondary apnea and be ready to undertake full resuscitation efficiently

PULMONARY CIRCULATION

• An asphyxiated baby has hypoxemia and acidosis such that pulm arterioles remain constricted and ductus arteriosus remains patent; this results in persistent fetal circulation

• In mild asphyxia, it may be possible to iincrease pulmonary blood flow by quickly restoring adequate ventilation

• In severe forms, vent alone is not enough. Metabolic acidosis needs correction so that pulm vessels open and blood flow to the lungs improve

CARDIAC FUNCTION AND SYSTEMIC CIRCULATION

• In asphyxia, there is redistribution of bloodflow to preserve blood supply to vital organs. There is vasoconstriction in the bowels, kidneys, muscles and skin; thus preserving blood flow to the heart and brain

• As asphyxia prolongs, myocardial function and cardiac output deteriorate and blood flow to all organs is reduced – this sets the stage for progressive organ damage

INITIAL STEPS

Provide warmth Baby should be placed under radiant heat source during

resuscitationPositioning• On her back with neck slightly extended (place rolled blanket /

towel under shoulders)Clear airway • If no meconeum is present, suction mouth and nose (mouth

first) using suction catheter. For meconeum asp., under direct vision using laryngoscope, clear residual meconeum in mouth/pharynx and intubate and suction the trachea and lower airways

EVALUATION

Based on 3 or 4 signs• Respirations• Heart rate• Colour• CRTLow HR is the most important sign for

proceeding to next step

• If the baby has good breathing (RR 40 to 60/min) and HR > 120and has pink color, no further intervention is needed

• If the baby is breathing well, good HR but has central cyanosis, administration of supplemental O2 is indicated

• If the baby is not breathing well, gasping or apneac or HR is < 100, ambubag (PPV)

• Technique for ambubagging…..• Contraindication to ambubagging….• Follow up action after ambubagging:– HR > 100: discontinue ventilation gradually; O2

per nasal catheter– HR 60 to 100: continue ventilating– HR <60: cont ventilating, start chest compressions

CHEST COMPRESSIONS

• Indicated if HR < 60, even after ambubagging• Two techniques– Thumb technique– Two finger technique

• Rate: it is important to ventilate between chest compressions – a vent breath should follow every 3 compressions

• Procedure…..

ENDOTRACHEAL INTUBATION

• Requires frequent practice to master• Indications:– When tracheal suction is needed: MSL babies born

flat– When prolonged bag and mask ventilation is

required or is ineffective– When diaphragmatic hernia is suspected

Copyright ©2010 American Heart Association

Kattwinkel, J. et al. Circulation 2010;122:S909-S919

Newborn Resuscitation Algorithm

MEDICATIONS• The majority of neonates needing resuscitation will respond to

ventilation but a few will need medications• Epinephrine

– If HR remains below 60. 1:10000 at 0.3ml/kg IV or via endotracheal route

• Volume expanders– Normal saline bolus of 10ml/kg in CRT>3secs to increase tissue perfusion

• Naloxone– In resp depression with h/o narcotic administration 4hrs before delivery

• Sodium bicarbonate– For prolonged asphyxia, documented acidosis even after the use of

epinephrine and vol. expanders. Bicarbonate therapy must be preceded and accompanied by ventilation

MEDICATIONS

• Other medications used to improve perfusion of the organs include PLASMA and DOPAMINE.

• There is no role for dexamethasone, calcium gluconate, mannitol, atropine

   Postresuscitation Care 

• Babies who require resuscitation are at risk for deterioration after their vital signs have returned to normal. Once adequate ventilation and circulation have been established, the infant should be maintained in, or transferred to an environment where close monitoring and anticipatory care can be provided.

• Naloxone

• Glucose

• Induced Therapeutic Hypothermia