Effects of ventilation on hearing loss in preterm neonates: Nasal continuous positive pressure does not increase the risk of hearing loss in ventilated neonates

IntroductionThere is increased risk of hearing loss in preterm neonates. This risk is further increased by environmental noise exposure especially from life support equipment such as ventilation. Nasal continuous positive airway pressure (NCPAP) used for respiratory support of preterm neonates is known to be associated with prolonged exposure to high levels of noise. However, there is paucity of information on the effect of NCPAP as compared to mechanical ventilation on hearing loss among preterm neonates.MethodsA retrospective chart review was performed on neonates with birth weight (BW) <1500 g. Association of clinical factors including the use of NCPAP and mechanical ventilation with failure of hearing screen were studied. Those who failed hearing screen were followed for 2 years to observe long term effects of NCPAP on the hearing loss.ResultsOf 344 neonates included in the study, 61 failed hearing screen. Gestational age (p = 0.008), BW (p = 0.03), ventilation (p = 0.02), intrauterine growth retardation (p = 0.02), necrotizing enterocolitis (NEC) (p = 0.02), apnea (p < 0.001), use of vancomycin (p = 0.01) and furosemide (p = 0.01) were associated with failure of hearing screen. On multivariate analysis, ventilation (OR 4.56, p = 0.02), apnea (OR 2.2, p < 0.001) and NEC (OR 2.4, p = 0.02) were predictors of failed hearing screen. As compared to those not ventilated, the odds of failing hearing screen was 4.53 (p < 0.01) and 4.59 (p < 0.01) for those treated with NCPAP and mechanical ventilation respectively, with there being no difference between these two ventilatory modalities. Of the 61 neonates, 42 were followed for 2 years, of which 19 had confirmed hearing loss. Among these 19 neonates, there was no difference (p = 0.12) between those who were treated with NCPAP or with mechanical ventilation.ConclusionThere is no increase in the hearing loss in preterm neonates treated with NCPAP as compared to mechanical ventilation despite being exposed to higher environmental noise generated by the NCPAP.