Background and objective: The aim of this prospective, randomized and crossover study was to assess the role of a relatively new mode of mechanical ventilation, biphasic intermittent positive airway pressure (BIPAP) in comparison to another well established one, pressure-support ventilation (PSV) in surgical intensive care patients.
Methods: 24 generally stable patients, breathing on their own after short-term (< 24 hours) postoperative controlled mechanical ventilation (CMV) were randomized to start on either PSV or BIPAP, and indirect calorimetry measurements were performed after 1 hour adaptation period at two time intervals; immediately after the investigated ventilatory mode was started and 1 hour later. Statistics included a two-tailed paired t-test to compare the two sets of different data, p < 0.5 was considered significant.
Results: Oxygen consumption (VO2), energy expenditure (EE), Carbon dioxide production (VCO2), and respiratory quotient (RQ) did not differ significantly between the two groups. There were also no significant differences regarding respiratory rate (RR), minute volume (MV) and arterial blood gas analysis (ABGs). Both modes of ventilation were well tolerated by all patients.
Conclusion: PSV and BIPAP can be used for weaning patients comfortably in surgical intensive care after short-term postoperative ventilation. BIPAP may have the credit of being smoother than PSV where no patient effort is required.