Semipermeable membranes and hypernatremic dehydration in preterms. A randomized-controlled trial

Background: Hypenatremic dehydration is a complication of preterm infants with reportedly high morbility. In preterm infants, this happens due to a combination of low fluid intake, transepidermal water loss (TEWL), and immaturity of kidney function. Semipermeable membranes are self-adhesive membranes that can be applied as an artificial skin to reduce TEWL. Aims: To test the hypothesis that early application of a semipermeable membrane (Tegaderm(TM)) in preterm infants <= 30 weeks could result in a significant reduction of hypenatremia (serum Na > 145 mEq/l) during the first 15 days of life. Study design: Randomized controlled trial (UMIN000010515). Subjects: 164 consecutive newborns with gestational ages <= 30 weeks, absence of congenital skin defects, and duration of admission a 15 days. Patients were randomized to receive semipermeable membrane (n = 82) or no membrane (n =82) for the first 15 days of life. Outcome measures: The primary endpoint of the study was the incidence reduction of hypernatremia (Na > 145 mEq/l). Secondary endpoints included: postnatal weight loss (WL) and time to birth weight (BW) recovery. Results: Incidence of hypernatremia in the control and semipermeable membrane group was 59.7% and 41.6%, respectively (p = 0.030). Postnatal WL was larger in the control group (13.9 +/- 5.6% vs 11.1 +/- 3.4%, p = 0.005) and occurred later than the semipermeable membrane group (5.4 +/- 2.3 vs 4.5 +/- 1.4 days, p = 0.005). Time to BW recovery was also longer for control group (13.5 +/- 4.3 vs 11.9 +/- 3.2 days, p = 0.016). Conclusions: Early application of skin semipermeable membrane to <= 30 week preterm is associated with decreased incidence of hypernatremia, decreased %WL, and earlier BW recovery. No complications were observed with membrane application.