Plasma beta-endorphin in neonates: effect of prematurity, gender, and respiratory status.

A consecutive cohort of 87 infants (46 infants less than 37 weeks gestational age and 41 term infants greater than or equal to 37 weeks gestation) admitted to the Neonatal Intensive Care Unit (NICU) and a convenience cohort of 27 term well babies at the University of Nebraska Medical Center (Omaha, NE) were evaluated for plasma beta-endorphin (beta E) levels during the first 4 h after birth. Demographic data, maternal history, and respiratory status at the time of sampling as well as development of documented apneic episodes during the initial hospitalization were analyzed for all infants. All NICU infants had higher plasma beta E levels than the control infants. Premature infants had significantly higher neonatal plasma beta E levels than term infants in either the control or NICU groups, but the response was gender specific; premature males had higher plasma beta E than premature females (P = 0.008). Perinatal stress, including respiratory problems, was associated with the increase in plasma beta E, but prematurity and being male were significantly predictors of an elevated plasma beta E level. Immaturity in respiratory control, as evaluated by the development of documented apneic episodes during the infant's initial hospitalization, did not correlate with an elevated perinatal plasma beta E level.

Rhabdomyolysis and myoglobinemia in neonates.

Serial myoglobin determinations were made in 20 neonates during the first week of life to determine whether birth asphyxia results in ischemic damage to muscle with the subsequent pathologic release of myoglobin. Serum myoglobin values were significantly elevated in asphyxiated infants compared with control infants. High myoglobin values correlated with a longer duration of oliguria in the neonatal intensive care unit population. The value of urine dipstick testing for myoglobinuria screening was also evaluated. Infants with elevated myoglobin values were more likely to have a strongly positive urine dipstick for occult blood in the first 48 hours of life. These data suggest that ischemic damage to muscle with pathologic release of myoglobin occurs in the neonatal period and that urine dipstick testing provides a reasonable screening examination for myoglobinuria.

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.

Prostaglandin F1 alpha levels during and after neonatal extracorporeal membrane oxygenation.

Infants receiving extracorporeal membrane oxygenation therapy undergo long-term cardiopulmonary bypass, are systemically heparinized, and frequently receive platelet transfusions. Prostacyclin is a powerful inhibitor of platelet aggregation as well as a potent vasodilator. The levels of its stable metabolite prostaglandin F1 alpha increase significantly in children undergoing cardiopulmonary bypass during heart operations but decrease to preoperative levels after bypass. To determine the effect of long-term bypass on prostacyclin levels, multiple plasma samples were analyzed in 10 human neonates both during extracorporeal membrane oxygenation therapy and within 24 hours after extracorporeal membrane oxygenation. Prostaglandin F1 alpha, the stable metabolite of prostacyclin, was quantitated by radioimmunoassay in picograms per milliliter. Prostaglandin F1 alpha levels were elevated while the patients received extracorporeal membrane oxygenation therapy but decreased with duration of extracorporeal membrane oxygenation. In most infants, prostaglandin F1 alpha levels rose again during weaning from extracorporeal membrane oxygenation and remained elevated for 24 hours after extracorporeal membrane oxygenation. Extracorporeal membrane oxygenation course influenced circulating prostaglandin F1 alpha levels. Fluctuating prostaglandin F1 alpha levels are of clinical significance in the management of vasomotor tone and platelet function, common problems in the care and the prevention of hemorrhage in these critically ill infants.

Serum concentrations of prostacyclin and thromboxane in children before, during, and after cardiopulmonary bypass.

Twenty-six consecutive pediatric patients undergoing reparative procedures necessitating cardiopulmonary bypass were prospectively studied to determine changes in serum levels of 6-keto-prostaglandin F1 alpha and thromboxane B2. Cardiac lesions included acyanotic lesions (five patients), obstructive lesions (10 patients), and right-to-left shunts (11 patients). There was a significant (p less than 0.05) increase in 6-keto-prostaglandin F1 alpha from preoperative levels measured at the time of arterial and venous cannula insertion. This concentration was maintained throughout cardiopulmonary bypass and remained significantly elevated (p less than 0.001) in the recovery room, but returned to preoperative levels by the morning after the operation. Preoperative levels of thromboxane B2 varied widely and were not significantly different from intraoperative levels. The postoperative levels of thromboxane B2, however, were significantly different (p less than 0.05) from the intraoperative levels. In the pediatric age group undergoing cardiopulmonary bypass, 6-keto-prostaglandin F1 alpha and thromboxane B2 change during bypass but do not significantly differ when preoperative levels are compared to postoperative values.

Outbreak of vancomycin-resistant Enterococcus faecium in a neonatal intensive care unit.

An outbreak of vancomycin-resistant Enterococcus faecium involving 28 infants in a neonatal intensive care unit was observed. Successful control of the outbreak was achieved following use of patient and staff cohorting, contact isolation precautions, patient and environmental surveillance cultures, environmental decontamination, molecular typing, introduction of an alcohol-based hand disinfectant, and decreased use of vancomycin.

Neurosonographic findings in infants treated by extracorporeal membrane oxygenation (ECMO).

Extracorporeal membrane oxygenation (ECMO) is an approved therapy for some neonates who have respiratory failure that is due to hyaline membrane disease, meconium aspiration, persistent pulmonary hypertension, congenital diaphragmatic hernia, or sepsis. The major complication of this therapy is hemorrhage, with intracranial hemorrhage having the highest morbidity and mortality. Seizures, incisional bleeding and bleeding in the pleural space, hypoxic-ischemic encephalopathy, renal failure, and cardiovascular complications account for most of the other complications. Cranial sonography provides an ideal imaging modality for baseline evaluation and daily follow-up; however, computed tomography and magnetic resonance imaging, because of better sensitivity, are important for assessment after ECMO. The changes in intracranial blood flow related to ECMO can be noninvasively evaluated by Doppler ultrasound modalities.

Infant home apnea monitoring: a practical review.

Home apnea monitoring is highly controversial. A system for determining which infants are at risk, who to monitor, how long to monitor and when to discontinue home monitors has been presented. This view is based on our clinical experience and review of the literature.

Primary transcatheter treatment of congenital pulmonary arteriovenous malformation causing cyanosis of the newborn.

We report on successful transcatheter therapy of congenital pulmonary arteriovenous malformation resolving persistent cyanosis and obviating the need for surgical pneumonectomy or lobectomy.