CONTEXT: Prone sleeping by infants has been associated with an increased risk of sudden infant death syndrome. OBJECTIVE: To document the prevalence of and identify risk factors for prone sleeping during the first 6 months of life. DESIGN: Prospective cohort study. SETTING: Eastern Massachusetts and northwest Ohio. STUDY PARTICIPANTS: A total of 7796 mothers of infants weighing 2500 g or more at birth. MAIN OUTCOME MEASURES: Maternal and infant characteristics related to prone sleeping at 1 month and 3 months of age. RESULTS: Between 1 month and 3 months of age, prone sleeping increased from 18% to 29%. At 1 month, prone sleeping was associated with the following maternal characteristics: non-Hispanic black or Hispanic race/ethnicity, younger age, less education, and higher parity. At 3 months, switching from nonprone to prone position was associated with mother's race/ethnicity of non-Hispanic black (odds ratio [OR], 1.7; 95% confidence interval [CI], 1.2-2.3) or Hispanic (OR, 1.5; 95% CI, 1.1-2.2); younger maternal age (compared with mothers >34 years: 18-24 years, OR, 1.6; 95% CI, 1.2-2.2; <18 years, OR, 2.2; 95% CI, 1.2-4.3); increasing parity (compared with 1 child: 2 children, OR, 1.5; 95% CI, 1.2-1.8; > or =3 children, OR, 1.7; 95% CI, 1.4-2.2); and infant sex (male sex, OR, 1.4; 95% CI, 1.2-1.7). CONCLUSIONS: If infant sleeping practices in the study communities are representative of practices throughout the United States, a substantial number of infants who slept nonprone at 1 month sleep prone at 3 months.

Adult↗

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Liposyn infusion increases plasma prostaglandin concentrations.

To determine whether Liposyn infusion results in increased plasma prostaglandin (PG) concentrations, the following study was performed in 33 adult rabbits with chronically implanted arterial and venous catheters. Plasma PG concentrations were determined by radioimmunoassay for two vasodilators, PGE2 and PGI2 (as measured by its metabolite 6-keto-PGF1 alpha), and two vasoconstrictors, thromboxane (TX) A2 and PGF2 alpha, as measured by their metabolites TXB2 and PGF2 alpha-M, respectively. A 1-hour infusion of Liposyn at 4 ml per kg resulted in statistically significant increases in arterial and venous concentrations of PGE2 and 6-keto-PGF1 alpha (p less than 0.001) and of TXB2 (p less than 0.04). There were no significant changes in PGF2 alpha-M plasma concentrations. Liposyn infusion also resulted in a small but statistically significant increase in PaO2 of 4.7 +/- 1.5 torr (p less than 0.01). It is concluded that Liposyn infusion results in statistically significant increases in plasma concentrations of PGE2, 6-keto-PGF1 alpha, and TXB2.

6-Ketoprostaglandin F1 alpha↗

PubMedDate not supplied

Stimulus parameters for phrenic nerve pacing in infants and children.

Phrenic nerve pacing has been used since 1966 to support breathing in quadriplegics and patients with central hypoventilation syndrome (CHS). Recently, using low-frequency, long-inspiratory-time (Ti) stimulation, phrenic nerve pacing has been used successfully to support breathing 24 hours per day in adults and older children. However, no similar experience exists for infants and young children. Therefore, in 27 studies in 14 infants and children we determined the effects of changing Ti and interpulse interval (the inverse of stimulus frequency) on ventilation. Diaphragmatic action potentials, airflow, tidal volume, PACO2 and SaO2 were measured during sleep. Phrenic nerve pacing proved useful in 13 of 14 patients to support breathing either during wakefulness (n = 7) or during sleep (n = 6). We found that adequate ventilation could be achieved at significantly longer interpulse intervals, 95 +/- 25 (mean +/- SD) ms, and shorter Ti, 580 +/- 80 ms, than previously reported. At an average respiratory rate of 21 +/- 8 breaths/min it was thus possible to maintain adequate ventilation despite a marked reduction in the number of phrenic nerve stimuli. Theoretically, these reductions in phrenic nerve stimulation should minimize the chance of pacing-induced diaphragmatic damage. These results suggest that 24 hour per day phrenic nerve pacing may be a realistic goal in selected infants and children.

Diaphragm↗

PubMedDate not supplied

Laboratory monitoring of parenteral nutrition-associated hepatic dysfunction in infants.

Hepatic dysfunction associated with parenteral nutrition (PN) is a well recognized occurrence. In order to define the temporal inter-relationships of direct bilirubin to other laboratory parameters, total and direct bilirubin, serum glutamic-pyruvic transaminase (SGPT), serum glutamic-oxaloacetic transaminase (SGOT), and alkaline phosphatase were measured prior to beginning PN and then weekly throughout the duration of PN in 60 consecutive neonates. Cholestatic jaundice (ChJ), defined as a direct bilirubin greater than or equal to 2.0 mg/dl, developed in 11 (33%) of 33 infants receiving PN for at least 2 weeks. Direct bilirubin was the most sensitive and earliest indicator of ChJ. SGOT and SGPT values in the ChJ group were not statistically different from the non-ChJ group until 2 weeks after the onset of cholestasis. Although there was a progressive increase in alkaline phosphatase during the course of PN, the increase was not greater in the ChJ group. In summary, direct bilirubin is the only laboratory indicator of hepatic status that need be determined serially in parenterally alimented infants. Although SGPT and SGOT may be helpful in characterizing hepatic dysfunction once ChJ has occurred, alkaline phosphatase levels do not reliably assess PN-associated liver injury.

Alanine Transaminase↗