Functional residual capacity-guided alveolar recruitment strategy after endotracheal suctioning in cardiac surgery patients

Abstract

To determine whether the results of functional residual capacity measurements after endotracheal suctioning could guide the decision to perform an alveolar recruitment maneuver and thus improve lung function. Prospective, randomized, controlled interventional study. Intensive care unit of a university hospital. Fifty-nine mechanically ventilated patients within 2 hrs after elective cardiac surgery without preexisting lung diseases. Patients received a standard suctioning procedure with disconnection of the ventilator (20 secs, 14 F catheter, 200 cm H2O negative pressure). Prospectively, patients were stratified into two groups by the postsuctioning functional residual capacity value (group A: functional residual capacity >94% of baseline; group B: functional residual capacity <94% of baseline). Both groups were randomized into either a recruitment maneuver (RM) group (positive end-expiratory pressure 15 cm H2O, peak inspiratory pressure 35-40 cm H2O for 30 secs, group RM) or a non-RM group, in which ventilation was resumed without an RM (group NRM), resulting in four groups. Functional residual capacity and arterial blood gases were recorded for up to 1 hr. In addition, distribution of ventilation was measured by means of electrical impedance tomography. The RM had an impact on distribution of ventilation, functional residual capacity, and oxygenation in patients with a decrease of functional residual capacity after suctioning. In contrast, the RM showed no impact on these parameters in patients with no decrease of functional residual capacity after suctioning. By measurements of functional residual capacity after endotracheal suctioning, patients profiting from a consecutive recruitment maneuver could be identified. Guiding the recruitment strategy on changes of functional residual capacity may improve patient care.