737 - Evaluating the Impact of Ventilation Modes at Admission on Neonatal Intensive Care Unit Outcomes in Tiny Babies Born at 22 -24 Weeks Gestation

Publication Number: 2719.737

Chloe I. Gray, Mercer University School of Medicine, Macon, GA, United States; Joleen Dako, Mercer University School of Medicine, Fayetteville, GA, United States

Background: Advances in research and technology have improved the outcomes of preterm infants born at 22 - 24 weeks gestation in recent years, however, bronchopulmonary dysplasia (BPD) continues to be a leading cause of mortality in children younger than 5 years. Preterm lungs are susceptible to injury by mechanical ventilation, oxygen and infection. High-frequency oscillatory ventilation (HFOV) maintains constant mean airway pressure at low tidal volumes and is thought to cause less pulmonary injury and barotrauma when compared to conventional mechanical ventilation (CMV). There is a paucity of data in this growing population of extremely premature infants regarding optimization of lung growth and avoiding damage and negative outcomes.

Objective: To describe outcomes of preterm infants born at 22 - 24 weeks' gestation according to mode of ventilation on admission when comparing HFOV to CMV in the neonatal intensive care unit (NICU).

Design/Methods: This was a retrospective chart review of premature infants born at 22- 24 weeks' gestation at a regional medical center. Infants born outside the hospital were excluded from the study. Respiratory outcomes such as BPD, severity of BPD, duration of mechanical ventilation and oxygen days were evaluated. We also evaluated other outcomes such as intraventricular hemorrhage (IVH), retinopathy of prematurity (ROP), sepsis, length of stay (LOS) and mortality. Fisher exact test, independent t-test and multivariable logistic regression were used in our statistical analysis.

Results: Of the 65 infants included in the study, 44.6% were placed on HFOV while 55.4% were placed on CMV on admission. Infants admitted on HFOV were smaller (p = 0.004) and more premature (p = 0.001) than infants on CMV. After adjusting for gestational age and birth weight, there were no differences in the incidence of BPD, composite outcome of BPD/death or mortality among the two groups. Infants admitted on HFOV had higher odds of moderate or severe BPD (aOR 10.83; 95% CI:1.22 - 96.09; p = 0.032) and longer lengths of stay for survivors (95% CI: 2.7 - 47.5 days, p = 0.029) after adjusting for gestational age and birth weight. We observed higher rates of ROP for babies on CMV; however, they had milder disease compared to infants on HFOV.

Conclusion(s): Infants born at 22 - 24 weeks' gestation admitted on HFOV were observed to have more severe BPD and longer lengths of NICU stay. Additional studies are needed to identify potential unmeasured confounders that may explain these observations.

Table 1: Demographics and Characteristics of Infants Born at 22 -24 Weeks' Gestation by Initial Mode of Ventilation after admission to the Neonatal Intensive Care Unit (NICU)


Table 2: Outcomes of Infants Born at 22 - 24 Weeks Gestation by Initial Mode of Ventilation after admission to the Neonatal Intensive Care Unit (NICU)


Table 3: Multivariable Logistic Regression Analysis of Outcomes for Babies 22 -24 Weeks Gestation admitted to High Frequency Oscillatory Ventilator (HFOV) versus Conventional Ventilator (CMV) Adjusting for Gestational Age and Birth Weight