Impact of prolonged mechanical ventilation in very low birth weight infants

초록

Objective: Prolonged mechanical ventilation (MV) is associated with numerous complications. This study aimed to evaluate in-hospital consequences of prolonged invasive MV support in very low birth weight (VLBW) infants. Methods: Using national data from the Korean Neonatal Network, we reviewed medical records of VLBW infants who survived at least 4 weeks (n=2921), born from January 2013 to December 2014. Results: The cumulative MV duration was significantly correlated with the severity of bronchopulmonary dysplasia (BPD) (P<0.001; rho=0.72). The mortality was increased consistently according to the cumulative duration of invasive MV (P<0.001; r=0.95), reached up to 50% when the MV was continued over 3 months. This progressive increase of mortality according to the MV duration was remarkable in infants with severe BPD compared to mild or moderate BPD (P<0.001). Under correction of gestational age and birth weight, the cumulative duration of MV was significantly correlated with extension of hospital stay (P<0.001; r=0.75) and parenteral nutrition (P<0.001; r=0.65). And in regards to achievement of proper growth at the discharge point, the longer duration of MV was associated with the smaller Z-score at weight (P<0.001; r=-0.15), height (P<0.001; r=-0.33) and head circumference (P<0.001; r=-0.30). In logistic regression analysis, pulmonary hemorrhage was significantly associated with the MV more than 4 weeks (14.8% vs. 1.7%, P=0.001; OR 3.61, 95% CI=1.72-7.58), and infants required the MV more than 4 weeks were significantly prone to have severe retinopathy of prematurity (P=0.034; OR 1.66, 95% CI=1.04-2.65) and periventricular leukomalacia (P=0.047; OR 1.78, 95% CI=1.01-3.15). Conclusion: The cumulative duration of MV was significantly associated with higher mortality and various severe morbidities in VLBW infants in Korea. Aggressive weaning strategies of invasive MV are required to improve the survival and clinical outcomes of these vulnerable infants.