Effect of high-frequency oscillatory ventilation with intermittent sigh breaths on carbon dioxide levels in neonates.

Background: High-frequency oscillatory ventilation (HFOV) minimizes ventilator-induced lung injuries. Spontaneous sigh breathing may augment the functional residual capacity, increase lung compliance, and recruit atelectatic alveoli.

Purpose: To evaluate the difference in the partial pressure of carbon dioxide (PaCO2) in neonates receiving invasive HFOV as the primary mode of respiratory support before versus after sigh breaths (Sighs).

Methods: This prospective study was conducted between January and December 2023. Intubated preterm and term neonates who underwent HFOV with an available arterial line were enrolled in this study after informed parental consent was obtained. Sighs were set at a frequency of 3 breaths/min and pressure of 5 cm H2O above the mean airway pressure for 2 hours. Arterial blood gas was collected before and after Sighs and analyzed using two dependent tests.

Results: Thirty neonates with a mean gestational age of 33.6±4.1 weeks and median date of intervention of 1.88 (interquartile range, 0.87-3.79) days were enrolled. The mean PaCO2 level was significantly lower in the HFOV with Sighs group (45.2±6.6 mm Hg) versus the HFOV alone group (48.8±3.1 mm Hg) with a mean difference (MD) of -3.6 mm Hg (95% confidence interval [CI], -6.3 to -0.9; P=0.01). Subgroup analyses indicated the ability of Sighs to reduce the PaCO2 level in neonates with respiratory distress syndrome (n=15; MD [95% CI] = -4.2 [-8.2 to -0.2] mm Hg; P=0.04).