Indomethacin-induced urinary flow rate reduction in the ovine fetus is associated with reduced free water clearance and elevated plasma arginine vasopressin levels.

OBJECTIVE: The purpose of our study was to explore the urinary responses of the ovine fetus to indomethacin levels comparable with those used therapeutically in the human fetus. STUDY DESIGN: After a 1-hour control period, chronically catheterized ovine fetuses between 125 and 139 days of gestation were given an intravenous bolus of indomethacin (0.05 mg/kg estimated fetal weight) followed by a 0.0025 mg/kg/min continuous infusion for 5 hours. The experimental group (n = 9) was compared with a vehicle-only infusion group (n = 10). RESULTS: There was a sustained 55.7% +/- 9.5% (mean +/- SEM) decrease in urinary output by 2 hours of indomethacin infusion (p < 0.00001, analysis of variance). Urinary osmolality, potassium, and chloride concentrations underwent sustained increases during the infusion period (p < 0.005). Free water clearance decreased by 67.5% +/- 12.0% (p < 0.001). Fetal arterial pressure increased only transiently (p < 0.05), and increases in venous pressure (p = 0.013) and heart rate (p < 0.0001) were sustained. Fetal plasma arginine vasopressin concentration increased during indomethacin infusion (p < 0.05) and was correlated with the fall in urinary flow rate and free water clearance (p = 0.002). During vehicle infusion no significant changes were observed in any of the variables. CONCLUSIONS: Our data indicate that the fetus undergoes antidiuresis when exposed to low levels of indomethacin and that the observed antidiuresis is mediated by a decrease in free water clearance. The reduction in free water clearance may be mediated by increases in plasma arginine vasopressin concentrations.     

Auditory responsiveness of premature infants utilizing visual reinforcement audiometry (VRA).

The purpose of this investigation was to study the relationship between visual reinforcement audiometry (VRA) performance and age (i.e., corrected and mental) with 60 premature infants. VRA performance was classified as unacceptable, marginal, or acceptable based on conditionability and number of responses obtained before habituation to the task. The results indicated that mental age and corrected age were significantly related to VRA performance. It was found that a corrected age of 8 mo and/or a mental age of 6 mo is typically required for acceptable performance using VRA. A lack of responsiveness to the VRA procedure at these ages would most likely be due to hearing loss as opposed to a general developmental delay. The data from this study would not support a large scale behavioral hearing screening program for premature infants below 8 mo corrected age or 6 mo mental age.     

System divorces on rise. Unscrambling deals is messy and contentious

The mass merger movement of the 1990s has hit the wall. More and more systems are taking a hard look at what their expensive deals have wrought, and are finding they don't like what they see. Disbanding systems are facing messy problems, and there are many questions as to whether de-merged hospitals can make it on their own.     

In utero intussusception producing ileal atresia and meconium peritonitis with and without free air

Two cases of intestinal atresia due to in utero intussusception are reported. Meconium peritonitis occurred in both cases and in one free air in the peritoneal cavity was also found. Both were managed successfully by resection and end-to-end anastomosis. The intussusceptions were discovered on gross and microscopic examination of the distal ileal segment. These two cases and 33 from the literature are reviewed to determine major features of this seemingly unusual occurrence. The atresia was limited to the ileum and jejunum in all cases and involved the ileum in 77%. The atresia was limited to the gap and fibrous-connecting-cord types in all cases, with the gap type slightly more frequent (57%). In all but 1 of the 35 cases (97%), the intussusceptum was found in the small-bowel segment distal to the atresia; in only 2 were free air and calcium deposits identified at birth on X-ray studies of the abdomen. Prematurity was encountered in only 14% of the 35 cases, suggesting that intussusceptum-induced midgut atresia occurs late in pregnancy. The occurrence of two cases in 2 years in Torrance, California, and three cases in 3 years in Helsinki, Finland, suggest that this occurrence must be more frequent than the sparse incidence reported in the literature would indicate. It is suggested that careful gross and microscopic examination of the small-bowel segment just distal to the atresia be carried out in all cases of jejunoileal atresia of gap or cord types to determine the true incidence and clinical nature of this type of in utero intussusception-induced jejunoileal atresia.