Comparison of the effect of three doses of a synthetic surfactant on the alveolar-arterial oxygen gradient in infants weighing > or = 1250 grams with respiratory distress syndrome. American Exosurf Neonatal Study Group II.

The effect of a 50% increment or decrement in the recommended 5 ml/kg dose of a commercially available surfactant (Exosurf Neonatal) on the alveolar-arterial oxygen gradient was investigated in a multicenter, double-blind, placebo-controlled rescue trial conducted at 15 hospitals in the United States. Two doses of three different volumes (2.5, 5.0, and 7.5 ml/kg) were compared with two 5.0 ml/kg doses of air in 281 infants weighing > or = 1250 gm who had respiratory distress syndrome requiring mechanical ventilation and an arterial/alveolar oxygen ratio < 0.22. The first dose was given between 2 and 24 hours of age, and the second dose was given 12 hours later to all infants who still required mechanical ventilation. Infants were stratified at entry by gender and the magnitude of the arterial/alveolar oxygen ratio. The air placebo arm of the study was terminated early when reductions in mortality rates were proved in another rescue trial of this surfactant in infants with the same birth weights. For the first 48 hours, administration of a 2.5 ml/kg dose of surfactant provided less improvement in the alveolar-arterial oxygen gradient than doses of 5.0 and 7.5 ml/kg, which were equivalent. Similar results were observed in mean airway pressure (p < 0.05). There were no significant differences among the three dosage groups in mortality rate, air leak, bronchopulmonary dysplasia, and other complications of prematurity. There were no pulmonary hemorrhages in any group. Reflux of surfactant occurred more frequently in the 5.0 and 7.5 ml/kg groups. These results indicate that more sustained improvements in oxygenation are provided, with equal safety, by the standard two 5.0 ml/kg rescue doses of this surfactant than by the 2.5 ml/kg dose. No further benefit is gained from two larger doses given 12 hours apart.

Non-nutritive sucking does not increase blood levels of gastrin, motilin, insulin and insulin-like growth factor 1 in premature infants receiving enteral feedings.

Non-nutritive sucking in premature infants accelerates weight gain for unclear reasons. The effects of non-nutritive sucking on enteral hormone secretion may augment digestion and/or absorption of nutrients. Blood concentrations of gastrin, motilin, insulin and insulin-like growth factor-1 were measured before and 72 h after the initiation of nasogastric feedings in 21 premature infants randomly assigned to either a non-nutritive suckling or control group. Gastrin and motilin concentrations increased significantly after feedings in all infants (mean +/- SEM) (gastrin, 41 +/- 4 to 73 +/- 9 pg/ml, p < 0.01; motilin, 141 +/- 5 to 181 +/- 3 pg/ml, p < 0.01) Pre- and post-feed insulin concentrations were greater in the non-nutritive sucking group receiving bolus feeds than in control infants who were bolus-fed (P < 0.01). Non-nutritive sucking in premature infants does not appear to alter blood concentrations of motilin, gastrin, insulin or insulin-like growth factor-1 three days after initiation of feedings. If changes in the secretion of these hormones are induced by non-nutritive sucking, they may be at a local paracrine level.

Concurrent administration of albumin with total parenteral nutrition in sick newborn infants.

The effects of concurrent administration of albumin with total parenteral nutrition were studied in 12 premature newborns (birth weight 1.26 +/- 0.1 kg [mean +/- SEM] and gestational age 30 +/- 0.8 weeks [mean +/- SEM]) compared with a control group of 12 premature newborns (birth weight 1.17 +/- 0.2 kg and gestational age 29 +/- 0.1 weeks) who received total parenteral nutrition. All newborns had a plasma albumin level below 3 g/dL and were in cardiorespiratory distress requiring assisted ventilation. Albumin supplementation of total parenteral nutrition resulted in a sustained increase in serum albumin concentration as well as increased mean arterial blood pressures in the study group. Slow albumin infusion had no observed effect on the severity of respiratory distress. Study group infants regained birth weight earlier than control group infants. These data suggest that the concurrent administration of albumin may be clinically beneficial in critically ill newborn infants.

A randomized comparison of assisted vaginal delivery by obstetric forceps and polyethylene vacuum cup.

The assisted vaginal delivery methods of rigid obstetric forceps and polyethylene vacuum cup extraction were compared in a prospective, randomized study. The 99 women studied had all completed 35 full weeks' gestation, required attempted assisted vaginal delivery, and were randomly assigned to either attempted forceps or vacuum-assisted delivery. All presentations were cephalic, with stations ranging from +1 to +4. Neonates were evaluated at 24 hours by neonatal staff. The infants underwent intracranial ultrasound screening during the first 24 hours of life and ophthalmologic examination within 48 hours. Vaginal delivery was successful with the intended method in 83% of vacuum-assisted deliveries and in 78% of forceps deliveries (not statistically significant). Neonatal retinal hemorrhage was found in 17 and 38% (P less than .043) of the randomized forceps and vacuum deliveries, respectively. No intraventricular hemorrhage was found. Apart from associations between vacuum-assisted delivery and mild hyperbilirubinemia and neonatal retinal hemorrhage (of uncertain clinical significance), and between assisted forceps delivery and an increased potential for facial injury, neonatal outcomes did not differ significantly. Maternal outcomes also did not differ significantly. No significant differences in safety or efficacy were found between polyethylene cup vacuum extraction and rigid obstetric forceps-assisted vaginal delivery in this population of predominantly low-pelvic assisted deliveries. Patients delivered by sequential use of forceps after vacuum or by vacuum after failed forceps application did not suffer significantly increased morbidity relative to those delivered by forceps or vacuum alone. Use of alternate or sequential methods allowed an overall cesarean rate of 3% in this population.

Continuous infusion of insulin in hyperglycemic low-birth weight infants receiving parenteral nutrition with and without lipid emulsion.

The efficiency of a continuous infusion of insulin in improving glucose tolerance was compared in two groups of very low-birth weight infants (mean +/- SEM birth weights 757 +/- 40 vs 828 +/- 80 g and gestational ages 27.6 +/- 0.7 vs. 27.2 +/- 0.5 weeks) receiving total parenteral nutrition with and without the addition of lipid emulsion to the nutrition regimen. The mean +/- SEM cumulative doses of insulin (0.87 +/- 0.1 vs 1.15 +/- 0.3 U/kg) and hours required to decrease the blood glucose level to 120 mg/dL (9.1 +/- 0.8 vs 9.5 +/- 1.0 hours) were similar. Insulin was delivered with a syringe pump used for other routine purposes in the neonatal intensive care unit. Continuous intravenous insulin infusion is an effective, inexpensive, safe method for maintaining glucose homeostasis in low-birth weight infants who develop hyperglycemia as a consequence of total parenteral nutrition.

Infusion of total parenteral nutrition via the umbilical artery.

The administration of total parenteral nutrition through umbilical artery catheters in 48 neonates (birth weight 1.7 +/- 0.58 kg) was compared with administration via central venous catheters in 26 infants (birth weight 2.05 +/- 0.89 kg). There was no significant difference in the amount of calories delivered (72 +/- 12 vs 78 +/- 18 cal/kg/day) or in the mean daily weight gain (16.6 +/- 13.3 vs 18 +/- 13.9 g/day). The incidence of sepsis was significantly lower in the umbilical artery catheter group (10.4% vs 15.4%) but there was no significant difference in the rate of infection when adjustment was made for number of days of catheter life (1 per 224 days of catheter life in the umbilical artery group vs 1 per 199 days in the central venous catheter group). Other major complications included transient hypertension in 2 (4%) of the 48 umbilical artery catheter infants and in 1 (3.8%) of the central venous catheter group, aortic thrombosis in 1 (2%) of the 48 umbilical artery catheter infants and a tricuspid vegetation in 1 (3.8%) of the central venous catheter group. Results suggest that the umbilical artery is a reasonable route for the infusion of total parenteral nutrition in low birth weight infants who require arterial access for blood gas analysis. Use of the umbilical artery catheter for parenteral alimentation may avoid the need for surgical placement of central venous lines and the risk of the attendant complications. Nevertheless, safer routes and improved methods of infusion of parenteral infusion must continue to be developed.

Prenatal relationship of surfactant lipid and protein constituents in infants with respiratory distress syndrome: a preliminary communication.

The prenatal relationships between surfactant disaturated phosphatidylcholine (DSPC) and surfactant-associated proteins of preterm infants with respiratory distress syndrome (RDS) have not been well documented. In the present study we measured the concentration of DSPC, surfactant glycoproteins (GP), and surfactant proteolipids (PLP) in amniotic fluids obtained within 6 hours prior to delivery of 16 newborn infants with gestational ages between 27 and 32 weeks. In control infants of 27-32 weeks gestation without RDS, the values of DSPC, GP, and PLP per milliliter of amniotic fluid were 20 +/- 2.9 micrograms, 684 +/- 115.3 ng and 289 +/- 62.5 ng, respectively. These values were significantly higher, threefold for PLP, fourfold for DSPC, and fivefold for GP, than amniotic fluid levels in infants with RDS. The findings support the concept that immaturity of surfactant in RDS involves both phospholipids and surfactant-associated proteins. Measurements of surfactant lipid-protein complex appear to enhance the reliability for identifying prenatally, infants at risk of developing hyaline membrane disease. More extensive studies are warranted to assess the usefulness of these assays for clinical application.

Serum concentrations of growth hormone, insulin, free thyroxine, thyrotropin, and cortisol in very-low-birth-weight infants receiving total parenteral nutrition.

Serum concentrations of growth hormone, insulin, free thyroxine, thyrotropin, cortisol, and glucose were measured during four time periods (0 to 4, 5 to 11, 12 to 18, and greater than or equal to 19 days of life) in 16 mechanically ventilated very-low-birth-weight infants (mean [+/- SD] birth weight, 1017 +/- 196 g) receiving total parenteral nutrition and in 21 very-low-birth-weight infants not requiring mechanical ventilator support (mean [+/- SD] gestational age, 30 +/- 1.7 weeks; mean [+/- SD] birth weight, 1149 +/- 210 g) fed enterally. There were no significant differences in the serum concentrations of the hormones or in the glucose levels between the two groups at any time interval. Present data demonstrate no significant difference in the serum concentration of glucose, insulin, growth hormone, cortisol, free thyroxine, and thyrotropin between very-low-birth-weight infants fed enterally and those maintained on a regimen of total parenteral nutrition.

Clot lysis for thrombosed central venous catheters in pediatric patients.

Central venous catheters (CVC) in pediatric patients provide a reliable method for administration of total parenteral nutrition and chemotherapy. Catheter thrombotic occlusion is a major complication and, until recently, the only therapeutic option was removal and surgical replacement of the catheter. Two fibrinolytic agents, streptokinase and urokinase, have been used successfully in adults to dissolve the clots. Few side effects have been reported when these agents were administered for this purpose. The Physician's Desk Reference advises against the use of such agents in the pediatric population. However, several reports of successful use of these agents in pediatric patients have been reported. They have also been infused systemically to relieve both arterial and venous thrombi. We prospectively evaluated the safety and efficacy of thrombolytic drugs in infants and children with CVCs who were receiving parenteral nutrition and/or hemodialysis. Abbokinase was used on 14 occasions to unclot silastic catheters in 10 pediatric patients. All catheters restored to patency were cleared within 50 minutes with an average clearance time of 19.3 minutes. Only one catheter could not be salvaged. Protime levels were obtained whenever possible before and after administration of the abbokinase. No significant elevations were noted after abbokinase administration. No allergic reactions or other complications occurred. Abbokinase was found to clear clotted central lines in a shorter time frame than has previously been reported in this patient population.

Computed tomography demonstration of cerebral calcification in postasphyxial encephalopathy.

Postasphyxial, diffuse cerebral calcification was demonstrated by computed tomographic (CT) brain scans in two infants. Calcification was seen in the white matter in both patients and in the basal ganglia in one. The neurologic outcome was poor in both infants.

Group B streptococcal colonization patterns in mothers and their infants.

Maternity patients and their newborn infants were cultured for group B streptococci (GBS) at Tampa General Hospital, Tampa, Fla., from September 1982 to May 1983. Culture swabs were placed into Lim Group B Strep Broth (GIBCO Laboratories, Madison, Wis.) and quantitated for GBS. A strong correlation was found between the numbers of GBS in the maternal vagina and the infant rectum. Infants symptomatic for early-onset GBS disease were delivered by mothers heavily colonized (greater than or equal to 3 X 10(4) GBS per swab) at the vagina. Such mothers were identified as GBS carriers by slide coagglutination and latex agglutination after their broth cultures had been incubated for 5 h. These data indicate that maternity patients at high risk of delivering infants heavily colonized with GBS and potentially symptomatic for early-onset GBS disease can be rapidly and selectively identified.

Elimination of multiple reactions of the Phadebact Streptococcus coagglutination test.

Strong multiple reactions often occur with the Phadebact Streptococcus test when the culture contains blood. These reactions interfere with the identification of the Lancefield groups of streptococci. Group B streptococci from the vagina of pregnant women are difficult to identify by slide coagglutination because of the frequent presence of blood on culture swabs. Elimination of these multiple reactions caused by blood would permit rapid identification of group B streptococci in pregnant women. Vaginal broth cultures were examined to determine the cause of multiple reactions with slide coagglutination and to eliminate them from the testing procedure. Of 245 maternal broth cultures, 135 (55%) yielded multiple reactions when tested by coagglutination. Such reactions were either eliminated or greatly diminished by heating the broth sample to 90 degrees C for 10 min. It was also found that globulins in the serum may be responsible for multiple reactions with blood. This heating protocol will permit vaginal broth cultures to be rapidly tested for group B streptococci by slide coagglutination.

Rapid identification of pregnant women heavily colonized with group B streptococci.

Pregnant women admitted to Tampa General Hospital, Tampa, Fla., were cultured for group B streptococci (GBS). Culture swabs were placed into enriched, selective Todd-Hewitt medium and were quantitated for GBS. The broth cultures were tested by slide coagglutination before incubation and after 5 and 20 h of incubation. Fifty-four (27%) of the 201 maternity patients cultured were positive for GBS and were identified as such by slide coagglutination. A strong correlation was found between the magnitudes of colonization and the times required to identify the broth cultures as GBS positive. Cultures from mothers heavily colonized (mean concentrations of 3 X 10(4) GBS per culture swab or greater) were identified after 5 h or less of incubation. Mothers lightly colonized with GBS (mean concentrations of 2 X 10(2) GBS per culture swab) were identified only after their broth cultures had been incubated for 20 h.