Multiorgan System Failure from Perinatal Asphyxia

Perinatal asphyxia is one of the most devastating complications associated with the process of birth. Medical complications that arise from this condition affect not only the brain, but also many other organ systems critical for the maintenance of life. An increased understanding of the multifactorial nature of this disease will help all health care workers to improve care for patients with this condition. Perinatal asphyxia or perinatal depression is a condition due to lack of oxygen resulting in impending or actual cessation of life around the time of birth. It is a common disorder with an incidence of 2-4 per 1000 term newborns. Both short and long-term outcomes for this disorder are very poor. Infants who present with hypoxic-ischemic encephalopathy secondary to perinatal asphyxia have a very high mortality with 15%-20% of these infants dying during the newborn period. Out of the survivors, over 25% have permanent severe neurological deficits. The definition of perinatal asphyxia is complex and requires that all of the following criteria be met (AAP/ ACOG Guidelines for Perinatal Care). 1) Presence of metabolic or mixed acidosis with a pH < 7.00 in the umbilical artery. 2) An Apgar score of 3 or less for longer than 5 minutes. 3) The presence of neurologic sequelae such as seizures, coma or hypotonia in the immediate neonatal period. 4) Multisystem organ dysfunction in one or more of the following systems: cardiovascular, gastrointestinal, hematologic, pulmonary, or renal. There are numerous risk factors that allow a health care worker to anticipate the possibility of the delivery of an asphyxiated or depressed newborn. However, not all infants with these risk factors are depressed at birth. Still, there is an increased association of these factors with the need for neonatal resuscitation at birth. Some of the major antepartum factors associated with this risk include: maternal age > 35 yrs, maternal diabetes, pregnancy-induced hypertension, fetal anemia, bleeding in the 2nd or 3rd trimester, polyhydramnios, oligohydramnios, premature rupture of membranes, intra-uterine infection, post-dates gestation, multiple gestation, small for gestational age or intrauterine growth restriction, maternal substance abuse, fetal malformations, decreased fetal activity and no prenatal care. Some of the major intrapartum factors associated with this risk include: emergency cesarean section, breech presentation, premature labor, prolonged rupture of membranes > 24 hrs, intrauterine infection, precipitous labor, prolonged labor > 24 hrs, prolonged 2nd stage of labor >2 hrs, nonreassuring fetal heart rate patterns, general anesthesia, maternal analgesia with narcotics within 4 hrs of delivery, meconium stained amniotic fluid, prolapsed cord, placenta previa and abruptio placentae. Multisystem organ dysfunction occurs from the lack of blood flow to the kidneys, liver and gastrointestinal tract in an initial attempt to preserve cerebral and cardiac blood flow. As this “dive reflex” begins to fail the cerebral and cardiac systems soon become affected. Organ failure ensues from the lack of oxygen delivery to the tissues as a consequence of hypoxemia—not enough oxygen in the blood or from ischemia—inadequate delivery of oxygenated blood to the tissues from low cardiac output or anemia. Multiple organ systems are affected by perinatal asphyxia with 82% of neonates incurring injury to one or more organs. These include the brain (72%), kidneys (42%), lungs (26%), heart (29%), bone marrow (<20%), bowel (29%), and liver (<20%).