Lynne D. Willett

Intrauterine herpes simplex virus infections

Neonatal herpes simplex virus (HSV) infection is usually acquired at birth, although a few infants have had findings suggestive of intrauterine infection. We describe 13 babies who had clinical manifestations of intrauterine HSV infection, including skin lesions and scars at birth (12), chorioretinitis (eight), microcephaly (seven), hydranencephaly (five), and microphthalmia (two). All infants had combinations of these defects. Infection was proved by viral isolation in each case; all isolates were HSV-2. Two infants died during the first week of life; 10 of the surviving infants had severe neurologic sequelae, and one infant was blind. Four mothers experienced an apparent primary genital HSV infection, and one had recurrent infection, at varying times during gestation. The remaining women denied a history of symptoms of genital HSV infection. These findings indicate that intrauterine HSV infection can occur as a consequence of either primary or recurrent maternal infection and has severe consequences for the fetus.

Risk of hypoventilation in premature infants in car seats

We examined 30 newborn infants for respiratory compromise before, during, and after placement in a recommended car seat restraining device. Twelve infants were premature with a history of apnea, eight were premature without known apnea, and 10 were born at term. Both premature groups had significant decreases in oxygen saturation while in the car seat (P less than 0.01) and more frequent desaturation episodes less than 80% (P less than 0.001). Premature infants with a history of apnea had more bradycardia events (P less than 0.05). No normal term infant had any of these problems. In addition, oxygen saturation trended downward from baseline for all premature infants during the recovery interval (P = 0.07). We conclude that currently available car seats may place premature infants at risk for significant hypoxia and ventilatory compromise.

Outcome of cardiopulmonary resuscitation in the neonatal intensive care unit

This retrospective review of 83 infants undergoing CPR in the neonatal ICU of a teaching hospital found that 12 (14%) patients were discharged from the hospital and seven (8%) were alive at least 1 yr after discharge. Of these seven, five appeared neurologically intact. From another perspective, 41% (12/29) of the patients who survived at least 24 h after CPR were discharged alive. Factors significantly (p less than .05) associated with poor outcome included sepsis, oliguria 24 h before and/or after arrest, prematurity, and intraventricular hemorrhage. Variables significantly (p less than .05) related to good outcome were the need for intubation during resuscitation and the diagnosis of major congenital anomalies. Intraventricular hemorrhage was the single most powerful variable in the regression analysis. Outcome statistics from this study were strikingly similar to currently available adult data.

Theophylline treatment in the neonate with apnea: effect on growth hormone, thyroid hormone and TRH induced TSH secretion.

Caffeine has been shown to markedly alter growth hormone (GH), thyroid stimulating hormone (TSH), and thyroid hormones in animal studies. Similar studies in the human are lacking. To determine the effect of theophylline treatment on endocrine function in neonates with apnea, 10 infants were studied prospectively pretreatment, immediately following therapeutic blood levels of theophylline, at 2, 4, and 6 weeks thereafter and finally 2 weeks after discontinuation of theophylline. T4, free T4, T3, GH, and basal and stimulated TSH were measured at each study period. Results show no significant difference consequent to theophylline therapy on basal thyroid or GH secretion and thyrotropin-releasing hormone (TRH) induced TSH response at any study interval. We conclude there is no evidence to suspect abnormality occurring in growth, thyroid function and GH secretion in neonates receiving theophylline for breathing disorders.

Plasma Fentanyl Levels in Infants Undergoing Extracorporeal Membrane Oxygenation

Plasma levels of fentanyl were analyzed in 12 infants undergoing extracorporeal membrane oxygenation who received a fentanyl bolus (5 to 10 micrograms/kg) followed by infusion at 1 to 6.3 micrograms/kg/hr. Fentanyl levels, averaging 11 samples/infant, were measured by radioimmunoassay (mean 19.7 +/- 35.7 ng/ml; n = 140). Eight of the infants, all with a primary diagnosis other than congenital diaphragmatic hernia, survived with relatively short (< 7 days) courses on extracorporeal membrane oxygenation; this group of infants did not develop tolerance to fentanyl and could be maintained on infusion rates of < 5 micrograms/kg/hr throughout. The four infants with congenital diaphragmatic hernia had longer extracorporeal membrane oxygenation runs and three did not survive; their plasma fentanyl levels were consistently higher and while the infusion rates were higher early on extracorporeal membrane oxygenation, they did not exceed 7 micrograms/kg/hr and actually decreased after 5 days on extracorporeal membrane oxygenation. Five infants (42%) received lorazepam in addition to fentanyl for at least one sampling time. The fentanyl infusion dose and plasma level were higher in the congenital diaphragmatic hernia nonsurvivors who did not receive lorazepam (p < 0.001). A decrease in fentanyl clearance correlated with renal dysfunction (p < 0.01). A bolus of fentanyl followed by infusion of relatively low doses (1 to 5 micrograms/kg/hr) provides adequate analgesia for infants on extracorporeal membrane oxygenation, particularly when it is supplemented with intravenous lorazepam whenever needed to control infant movement.