Israel Medical Association Journal

Background: High frequency oscillatory ventilation based on optimal lung volume strategy is one of the accepted modes of ventilatory support for respiratory distress syndrome in very low birth weight infants. In 1999 it was introduced in our unit as the primary ventilation modality for RDS[1].

Objectives: To evaluate if the shift to HFOV[2] influenced the outcome of ventilated VLBW[3] infants in the neonatal intensive care unit of Carmel Medical Center.

Methods: Data were obtained from the medical charts of VLBW infants born at Carmel Medical Center, and late mortality data were taken from the Israel Ministry of Internal Affairs records. A retrospective analysis and a comparison with a historical control group ventilated by the conventional method were performed.

Results: A total of 232 VLBW infants with RDS were mechanically ventilated, from 1995 to 2003: 120 were ventilated using HFOV during the period 1999–2003 and 102 infants using CV[4] during 1995–1999. The mean gestational age of survivors was 27.4 ± 2 weeks in the HFOV group and 28.4 ± 2 in the conventional ventilation group (P = 0.03). The sub-sample of infants with birth weights <1000 g ventilated with HFOV showed higher survival rates than the infants in the conventional ventilation group, 53 vs. 25 (64.6% vs. 44.6%) respectively (P < 0.05). A trend for lower incidence of pulmonary interstitial emphysema was observed in the HFOV group.

Conclusions: The introduction of HFOV based on optimal lung volume strategy proved to be an efficient and safe method of ventilation support for VLBW infants in our unit.

Objectives: To compare the neonatal outcome (survival, intraventricular hemorrhage and bronchopulmonary dysplasia) of inborn and outborn very low birth weight infants, accounting for sociodemographic, obstetric and perinatal variables, with reference to earlier published data.

Methods: We compared 129 premature infants with birth weights of 750–1250 g delivered between 1996 and 2000 in a hospital providing neonatal intensive care to 99 premature babies delivered in a referring hospital. In the statistical analysis, variables with a statistical significant association with the outcome variables and dissimilar distribution in the two hospitals were identified and entered together with the hospital of birth as explanatory variables in a logistic regression.

Results: Accounting for the covariates, the odds ratios (outborns relative to inborns) were 0.31 (95% confidence interval = 0.11–0.86, P = 0.03) for mortality, 1.37 (95%CI[1] = 0.64–2.96, P = 0.42) for severe intraventricular hemorrhage, and 0.86 (95%CI = 0.38–1.97, P = 0.78) for bronchopulmonary dysplasia. The odds ratio for survival without severe intraventricular hemorrhage was 1.10 (95%CI = 0.55–2.20, P = 0.78). Comparing the current results with earlier (1990–94) published data from the same institution showed that mortality decreased in both the outborn and inborn infants (OR[2] = 0.23, 95%CI = 0.09–0.58, P = 0.002 and 0.46; 95%CI = 0.20–1.04, P = 0.06, respectively), but no significant change in the incidence of severe intraventricular hemorrhage or brochopulmonary dysplasia was observed. Increased survival was observed also in these infants receiving surfactant, more so among the outborn. The latter finding could be attributed to the early, pre-transport surfactant administration, implemented only during the current study.

Conclusions: Our data suggest that very low birth weight outborn infants may share an outcome comparable with that of inborn babies, if adequate perinatal care including surfactant administration is provided prior to transportation to a tertiary center.