Neonatal asphyxia: circulation, resuscitation readiness, and Apgar assessment
THE CONTEXT
Asphyxia changes organ perfusion, while unpredictable resuscitation needs require preparation at every delivery.
Circulatory response to asphyxia
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The diving-in reflex redistributes blood from nonvital to vital organs: bowel, kidney, muscle, and skin perfusion decreases, while heart and brain perfusion is relatively preserved.
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Prolonged asphyxia impairs myocardial function and cardiac output, further reducing blood flow to all organs and setting the stage for progressive organ damage.
Preparation and teamwork
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Even with knowledge of risk factors, only half of asphyxia cases can be predicted. Every delivery requires readiness to resuscitate the neonate.
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At least one person must be solely responsible for the neonate and capable of full resuscitation. Anticipated resuscitation may require more than one person.
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Review antepartum and intrapartum risk factors, anticipate emergencies, assemble the team, and choose a leader who assigns roles according to members' competence.
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Use closed-loop communication, in which the listener repeats the message. Check equipment and supplies and seek additional help when required.
Role of Apgar scores
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The Apgar score objectively evaluates the newborn's condition and is generally recorded at 1 and 5 minutes after birth.
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Resuscitation must start before the 1-minute score is assigned. Apgar scores do not determine the need for resuscitation; serial scores assess the response.
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If the 5-minute score is below 7, obtain extended scores every 5 minutes for up to 20 minutes.