The Effect of Volume Guarantee Ventilation on the Incidence of Retinopathy of Prematurity

Newer technologies in neonatal ventilation such as combining volume guarantee with other modes of ventilation could reduce some complications of artificial ventilation by reducing the duration of ventilation and oxygen needs and fluctuations. Retinopathy of prematurity (ROP) is a multifactorial problem mainly affecting preterm infants with different risk factors. Although gestational age (GA) is the main risk factor for ROP, oxygen saturation and fluctuations, arterial pressure of carbon dioxide, and some other parameters of ventilation such as ventilation duration have great impacts on ROP incidence and severity. One hundred and twelve infants with birthweight (BW) under 2000 g or GA under 36 weeks that needed artificial ventilation after admission to the neonatal intensive care unit were randomly assigned into two groups. In the first group, neonates underwent synchronized intermittent mandatory ventilation (SIMV), pressure support ventilation (PSV), or SIMV + PSV with volume guarantee (VG); and in the second group, neonates received ventilation without VG mode. All of the survived infants had ophthalmologic examination at the proper age by a retinal subspecialist to find the different stages of ROP. Mean duration of ventilation was reduced using VG mode from 74.08 ± 47.99 to 47.91 ± 30.47 hours (P < 0.05). The oxygen requirement was less in the ones underwent VG modes and the peak fractional inspired oxygen (FiO2) was higher in infants receiving SIMV + PSV without VG compared to that of infants ventilated with VG mode (52.8 ± 18.4 vs. 40.3 ± 13.0, respectively). The difference between highest and lowest FiO2 was more in the group ventilated without VG (∆FiO2 = 9.52 in the group I and 18.30 in the group II, P < 0.05). Fluctuation of arterial pressure of carbon dioxide (PaCO2) was less prominent in the VG group as compared to the ones ventilated without VG and the mean difference between maximum and minimum PaCO2 was 7.16 in the group I and 13.36 in the group II (P < 0.05). Only three infants were diagnosed with ROP in the group I (with VG mode) in comparison with eight infants in the group II (odds ratio (OR) = 3.25, 95% confidence interval (CI): 1.13 - 9.36). Severe ROP needing treatment was diagnosed in one infant in the group I vs. four infants in the group II (OR = 3, 95%CI: 0.63 - 14.23). ROP incidence in preterm infants could be reduced using VG mode of ventilation, since it is a safer ventilation mode in neonates due to reduction in the mean duration of ventilation, peak FiO2 requirement, and PaCO2 fluctuation.