Effects of Synchronized Intermittent Mandatory Ventilation Versus Pressure Support Plus Volume Guarantee Ventilation in the Weaning Phase of Preterm Infants

Objective: To compare the effects and short-term outcomes of pressure support ventilation with volume guarantee versus synchronized intermittent mandatory ventilation in the weaning phase of very low-birth weight infants with respiratory distress syndrome. Design: Randomized controlled prospective study. Setting: Tertiary care neonatal unit. Patients: A total of 60 premature infants who were less than 33 weeks' gestation and/or less than 1,500 g birth weight and received mechanical ventilation because of respiratory distress syndrome were studied. Interventions: All infants were ventilated from the time of admission with synchronized intermittent positive pressure ventilation mode after surfactant treatment for respiratory distress syndrome and then switched to pressure support ventilation with volume guarantee or synchronized intermittent mandatory ventilation mode in the weaning phase. The ventilatory variables and neonatal outcomes were recorded in each group. Measurements and Main Results: The mean peak inflation pressure was higher in synchronized intermittent mandatory ventilation group (p < 0.001) and the mean airway pressure was higher in pressure support ventilation with volume guarantee group (p = 0.03), whereas mean tidal volume and respiratory rates were similar in both groups. The prevalence of postextubation atelectasis was higher in synchronized intermittent mandatory ventilation group, but the difference was not statistically significant (p = 0.08). No differences were found in the prevalence of reintubation, patent ductus arteriosus, intraventricular hemorrhage, retinopathy of prematurity, bronchopulmonary dysplasia, and pneumothorax between the groups. Conclusions: Pressure support ventilation with volume guarantee mode may be a safe and feasible mode during the weaning phase of very low-birth weight infants on mechanical ventilation support for respiratory distress syndrome with respect to reducing the frequency of postextubation atelectasis and using less peak inflation pressure.