Transcutaneous oxygen tension during nonnutritive sucking in preterm infants.

The effects of nonnutritive sucking on transcutaneous oxygen tension, heart rate, and respiratory rate were studied sequentially in 14 sleeping preterm infants breathing room air. Transcutaneous oxygen tension increased during nonnutritive sucking in infants between 32 and 35 weeks postconceptional age, but not in those between 36 and 39 weeks. This response was not associated with a change in respiratory rate or sleep state, although heart rate tended to increase. These data offer further support for the beneficial effects of nonnutritive sucking in preterm infants.

Outbreak of Serratia marcescens infection in a neonatal intensive care unit.

We report an outbreak of Serratia marcescens infection in the neonatal intensive care unit of a community hospital. The outbreak involved eight neonates, (five infected and three colonized), one of whom died. Pulsed-field gel electrophoresis confirmed that all isolates were identical strains. Cohorting and isolation of the infected neonates helped to control the outbreak. No environmental source of infection was found.

Meter-dosed, inhaled beclomethasone initiated at birth to prevent bronchopulmonary dysplasia.

OBJECTIVE: To examine the hypothesis that meter-dosed, inhaled beclomethasone administered to premature infants, beginning at birth and continuing in a tapering dosage schedule over the first 12 days of life, decreases the occurrence of bronchopulmonary dysplasia (BPD), at 36 wks corrected gestational age. DESIGN: Prospective, randomized, double-blind, placebo-controlled, small pilot clinical trial. SETTING: Tertiary care, neonatal intensive care unit. PATIENTS: Premature low birth weight neonates (

Decreased ventilation in preterm infants during oral feeding.

As respiratory difficulty may accompany nipple feeding in preterm neonates, we studied the effect of oral feeding on ventilation in 23 preterm infants. The infants composed two groups based on their postconceptional age at the time of study: Group A comprised 12 infants 34 to 35.9 weeks of age, and group B, 11 infants 36 to 38 weeks. Ventilation was measured via a nasal mask pneumotachometer, and sucking pressure via a nipple that also permitted milk delivery; transcutaneous PO2 and PCO2 were continuously monitored. The feeding pattern comprised an initial period of continuous sucking of at least 30 seconds, followed by intermittent sucking bursts for the remainder of the feed. When compared with an initial semi-upright control period, minute ventilation (V1) during continuous sucking fell by 52 +/- 6% (P less than 0.001) and 40 +/- 2% (P less than 0.001) in groups A and B, respectively. This was the result of a decrease in respiratory frequency and tidal volume and was associated with a fall in TcPO2 of 13 +/- 4 mm Hg (P less than 0.01) in group A and 10 +/- 2 mm Hg (P less than 0.01) in group B. During intermittent sucking, V1 and TcPO2 recovered partially only in the more mature infants (group B). At the end of the feed, TcPCO2 have risen by 3 +/- 1 mm Hg (P less than 0.001) in group A and by 2 +/- 2 mm Hg (P less than 0.05) in group B. Thus oral feeding results in an impairment of ventilation during continuous sucking and the subsequent recovery during intermittent sucking is dependent on postconceptional age.

Decrease in airway pressure during high-frequency jet ventilation in infants with respiratory distress syndrome.

Using a crossover study design, we compared a system of high-frequency jet ventilation with appropriate humidification to pressure-limited conventional ventilation in 12 preterm infants with a birth weight of 1.9 +/- 0.6 kg and gestational age of 32 +/- 2 weeks who had severe respiratory distress syndrome. After a control period of conventional ventilation, high-frequency jet ventilation was administered for 1 to 3 hours at a constant rate (250/min) and inspiratory to expiratory time (1:3 or 1:4) in the same fraction of inspired oxygen as during conventional ventilation. Average peak inspiratory pressure decreased from 29 +/- 3 cm H2O during conventional ventilation to 20 +/- 4 cm H2O during high-frequency jet ventilation (P less than 0.001), whereas positive end expiratory pressure was unchanged, resulting in a reduction in mean airway pressure from 14 +/- 3 to 10 +/- 2 cm H2O (P less than 0.001). There was a simultaneous decrease in PaCO2 (39 +/- 4 to 34 +/- 4 mm Hg, P less than 0.01), but PaO2 did not change. These data indicate that short-term high-frequency jet ventilation maintains gas exchange in infants with respiratory distress syndrome despite a lower PIP and Paw, and results in smaller airway pressure swings than during conventional ventilation. Thus, high-frequency jet ventilation may offer hope for reducing barotrauma in this population.

Neonatal cord blood leptin: its relationship to birth weight, body mass index, maternal diabetes, and steroids.

Leptin is a 16-kD protein encoded by the ob/ob (obesity) gene. In rodents it plays a role in obesity, diabetes, fertility, and neuroendocrine function. In humans serum concentrations of leptin correlate with total body fat in both adults and children. We measured cord blood leptin in 186 neonates that included 82 appropriate for gestational age (AGA), 47 large for gestational age (LGA), 20 infants of diabetic mothers, 52 preterm infants, and 15 intrauterine growth-retarded (IUGR) infants. There were 16 pairs of twins. The mothers of 17 preterm infants were treated with steroids before delivery. Leptin (mean +/- SD) concentration in term, AGA infants (39.4 +/- 1.1 wk) with birth weight (BW) of 3.2 +/- 0.3 kg, body mass index (BMI) of 12.6 +/- 1.1 was 4.01 +/- 3.5 ng/mL. BW correlated with cord leptin (p = 0.002) in a multivariate analysis controlling for potential confounders. Both LGA infants and infants of diabetic mothers had higher cord leptin concentration 7.3 +/- 3.8 and 6.1 +/- 4.8 ng/mL, respectively, compared with AGA infants (p < 0.05). Preterm infants had a mean leptin level of 1.8 +/- 0.97 ng/mL and a 3-fold elevation was seen if mothers received steroids antenatally (p = 0.006). IUGR infants had increased leptin (6.5 +/- 3.9 ng/mL, p = 0.03). Concerning the twin pairs, the smaller had a higher leptin level compared with larger twin (4.1 +/- 9.51 versus 2.8 +/- 5.14, p = NS). Neonatal cord leptin concentrations correlate well with BW and BMI. No gender differences were found in cord blood leptin. Maternal obesity had no effect on cord leptin, whereas exogenous maternal steroids increased neonatal leptin concentrations.

Meter-dosed, inhaled beclomethasone attenuates bronchoalveolar oxyradical inflammation in premature infants at risk for bronchopulmonary dysplasia.

The object of this study was to examine the hypothesis that meter-dosed, inhaled beclomethasone administered to premature infants beginning at birth in a tapering dosage schedule over the first 12 days of life attenuates bronchoalveolar lining fluid oxyradical inflammation concomitant with modulation of bronchopulmonary dysplasia. The design of this study was an unblinded, uncontrolled phase I, pilot investigation of inhaled beclomethasone primarily examining safety and administration. The setting was a tertiary care neonatal intensive care unit. Intubated, premature infants were studied longitudinally to 36 weeks corrected gestational age. Meter-dosed, inhaled beclomethasone was administered in a tapering dosage schedule over the first 12 days of life. Endotracheal tube aspirates were collected on Days 2, 4, and 6 of life and assayed for various markers of bronchoalveolar lining fluid oxyradical stress. Infants were also assessed with regards to a number of relevant clinical variables and presence or absence of bronchopulmonary dysplasia at 36 weeks corrected gestational age. Although no differences in clinical outcome were apparent in comparing nine control infants with nine beclomethasone-treated infants, bronchoalveolar lining fluid from control infants exhibited evidence of apparent phospholipid peroxidation (enhanced polyunsaturated fatty acid consumption) on Day 2 of life compared to beclomethasone-treated infants. Significant differences were noted for percent arachidonic acid, total polyunsaturated fatty acids and ratio of polyunsaturated fatty acids, to saturated fatty acids. The ratio of monohydroxyl linolenic acid to native linoleic acid (a more specific marker of lipid peroxidation) as well as myeloperoxidase activity (a marker of neutrophil oxyradical stress) tended to be higher in the control group but did not achieve statistical significance for this small subject number study. No adverse reactions related to meter-dosed, inhaled beclomethasone were noted in the treatment group; most specifically no evidence of hypothalamic-pituitary-adrenal axis suppression was noted in either control or beclomethasone-treated infants. Meter-dosed, inhaled beclomethasone in the dosage schedule utilized was safe and appeared to moderate bronchoalveolar lining fluid phospholipid peroxidation. Small numbers of infants entered into the present investigation preclude comments on clinical efficacy because of the likelihood of a statistical type 2 error. However, additional investigations of inhaled beclomethasone initiated at birth in premature infants at risk for bronchopulmonary dysplasia, enrolling larger number of subjects and perhaps a higher dosage of beclomethasone, are warranted.

A randomized trial comparing povidone-iodine to a chlorhexidine gluconate-impregnated dressing for prevention of central venous catheter infections in neonates.

UNLABELLED: Neonates who require a central venous catheter (CVC) for prolonged vascular access experience high rates of catheter-related bloodstream infection (CRBSI). PURPOSE: A multicenter randomized clinical trial was undertaken to ascertain the efficacy of a novel chlorhexidine-impregnated dressing (Biopatch Antimicrobial Dressing) on the CVC sites of neonates for the prevention of catheter tip colonization, CRBSI, and bloodstream infection (BSI) without a source. Setting. Six level III neonatal intensive care units. Patients Studied. Neonates admitted to study units who would require a CVC for at least 48 hours. METHODS: Eligible infants were randomized before catheter placement to 1 of the 2 catheter site antisepsis regimens: 1) 10% povidone-iodine (PI) skin scrub, or 2) a 70% alcohol scrub followed by placement of a chlorhexidine-impregnated disk over the catheter insertion site. A transparent polyurethane dressing (Bioclusive Transparent Dressing) was used to cover the insertion site in both study groups. Primary study outcomes evaluated were catheter tip colonization, CRBSI, and BSI without an identified source. RESULTS: Seven hundred five neonates were enrolled in the trial, 335 randomized to receive the chlorhexidine dressing and 370 to skin disinfection with PI (controls). Neonates randomized to the antimicrobial dressing group were less likely to have colonized CVC tips than control neonates (15.0% vs 24.0%, relative risk [RR]: 0.6 95% confidence interval [CI]: 0.5-0.9). Rates of CRBSI (3.8% vs 3.2%, RR: 1.2, CI: 0.5-2.7) and BSI without a source (15.2% vs 14.3%, RR: 1.1, CI: 0.8-1.5) did not differ between the 2 groups. Localized contact dermatitis from the antimicrobial dressing, requiring crossover into the PI treatment group, occurred in 15 (15.3%) of 98 exposed neonates weighing