Improved fluid management utilizing humidified incubators in extremely low birth weight infants

To compare fluid and electrolyte management in extremely low birth weight (ELBW) infants nursed in humidified versus nonhumidified incubators. Setting--tertiary intensive care nursery. Subjects--all infants with birth weight < 1000 g admitted 1/95 to 1/99 who were treated with incubators and survived for > 96 hours (N = 155). Intervention--retrospective comparison of daily weights, fluid intakes, urine outputs, and serum electrolytes between group 1 (n = 70, nonhumidified incubators, born 1/95 to 1/97) and group 2 (n = 85, humidified incubators, born 1/97 to 1/99) over the first 4 days after birth. Despite similar daily weight losses between groups, group 1 infants received higher fluid intakes, had lower urine outputs, and had a higher incidence of hypernatremia, hyperkalemia, and azotemia (p < 0.05). Although no differences in mortality or the incidence of patent ductus arteriosus, bronchopulmonary dysplasia, or the overall rate of nosocomial infections were observed, the proportion of gram-negative isolates increased significantly (62%, p < 0.05) following the introduction of humidified incubators. ELBW weight infants nursed in humidified incubators have lower fluid requirements, improved electrolyte balance, and higher urine outputs during the first 4 days after birth compared to those nursed in nonhumidified incubators.