Selective recruitment maneuvers for lobar atelectasis: effects on lung function and central hemodynamics: an experimental study in pigs.

We investigated whether selective lung recruitment of a lobar collapse would improve oxygenation and lung volume as well as a general (global) lung recruitment maneuver, with fewer circulatory side effects. In 10 ventilated, anesthetized pigs, a bronchial blocker was inserted in the right lower lobe, which was selectively lavaged to create a dense lobar collapse. The pigs were randomized into two orders of lung recruitment maneuvers (40 cm H2O airway pressure for 30 s): either a selective lung recruitment maneuver (using the inner lumen of the bronchial blocker) followed by a general lung recruitment maneuver, or vice versa. Median end-expiratory lung volume and median Pao2 increased significantly by approximately 100 mL and 16 kPa, respectively, with no significant differences between the two recruitment methods. There were no circulatory changes during the selective lung recruitment maneuver, but during the general lung recruitment maneuver, mean arterial blood pressure decreased significantly by 36 (21, 41) mm Hg (median, 25th and 75th percentiles), cardiac output by 2.1 (1.6, 2.5) L/min and left ventricular end-diastolic area by 4.4 (3.5, 4.5) cm2. In conclusion, a selective recruitment maneuver improved lung function similar to a general lung recruitment maneuver but without any circulatory side effects.