Background: Aerosol administration is increasingly being used as a therapeutic intervention for mechanically ventilated preterm infants. However, the effects of inhalation therapy on retinopathy of prematurity (ROP) have not yet been explored.
Methods: A retrospective cohort study was conducted in a tertiary level neonatal intensive care unit (NICU) from 2011 to 2013. All preterm infants with a gestational age (GA) of 24~29 weeks receiving invasive intubation for more than 1 week in the NICU were included. Infants with severe congenital anomalies were excluded. ROP was defined as stage II or greater according to medical records by ophthalmologists. A multivariate logistic regression model was used to estimate the risk of ROP in relation to inhalation therapy after adjusting for confounders.
Results: In total, 205 infants were enrolled in this study, including 154 with inhalation therapy and 51 without inhalation therapy. Univariate analyses showed an association of inhalation with the following characteristics: sex (p = 0.047), GA (p = 0.029), sepsis (p = 0.047), bronchopulmonary dysplasia (BPD) (p < 0.001), and ROP (p = 0.001). Furthermore, logistic regression analysis indicated that inhalation therapy was an independent risk factor for ROP (odds ratio (OR) = 2.639; 95% confidence interval (CI) = 1.050~6.615). In addition, infants with a GA of 24~25 weeks (OR = 6.063; 95% CI = 2.482~14.81) and 26~27 weeks (OR = 3.825; 95% CI = 1.694~8.638) were at higher risk of ROP than those with a GA of 28~29 weeks. Other factors - including sex, sepsis, BPD, and delivery mode - did not carry significant risk.
Conclusion: Aerosol therapy with pure oxygen delivery is associated with ROP. Clinicians should exercise great caution when conducting aerosol therapy with excess oxygen in mechanically ventilated preterm infants.
Keywords: Aerosol therapy; GA; HFV; ROP; iNO.