Objective: To compare the effect of combining assist/control with volume-guarantee (AC+VG) vs synchronized intermittent mandatory ventilation with VG (SIMV+VG) on tidal volume (V(T)), peak inspiratory pressure (PIP), mean airway pressure (MAP), respiratory rate, heart rate, oxygen saturation (SpO(2)), and minute volume (MV) in preterm infants.
Study design: A total of 12 infants were randomized to receive AC+VG, followed by SIMV+VG, or the opposite sequence for four alternating 2-hour periods.
Results: Airway pressure of machine breaths was higher during SIMV. MV and V(Te) were similar, but more variable during synchronized intermittent mandatory ventilation. The V(Te) of unsupported breaths during SIMV was lower than machine breaths of SIMV and AC. There was more tachycardia and tachypnea with a lower and more variable SpO(2) during SIMV.
Conclusions: SIMV+VG is associated with higher work of breathing indicated by tachycardia, tachypnea and lower SpO(2) compared to AC+VG. VG appears to be more effective when combined with AC than with SIMV.