Lung recruitment maneuver depresses hemodynamics in patients following cardiac surgery

Objective: Aim of the study was the evaluation of the impact of lung recruitment maneuvers on the hemodynamics following cardiac surgery procedures. Methods: The prospective randomized study included 80 adult patients undergoing coronary artery bypass surgery from 01/2009 till 09/2009. Patients were randomized to two duration's of lung recruitment maneuvers (25 cmH 2 O airway pressure for 10s and 45cm H 2 O for 10s) immediately after arriving on ICU. Swan Ganz catheter measurement was used to calculate cardiac output, and arterial blood pressure were monitored continuously. Systemic and pulmonary arterial blood gases were sampled before and after each lung recruitment maneuver to determine the intrapulmonary shunt. Results: Left ventricular end-diastolic areas decreased significantly during both the 10-s and the 20-s lung recruitment maneuvers. Cardiac output was 5.6±0.8l/min at baseline, decreasing by 3.0±1.1l/min and 3.6±1.2l/min during lung recruitment maneuvers of 10 and 20s, respectively. Shunt decreased from 20±5% to 15±6% after the first lung recruitment maneuver and from 15±6% to 12±5% after the second. Conclusions: Lung recruitment maneuvers markedly reduced cardiac output and left ventricular end-diastolic areas in hemodynamically stable patients following cardiac surgery.