Early postoperative 30° lateral positioning after coronary artery surgery:: influence on cardiac output

Aims and objectives. We investigated whether: (i) Early postoperative lateral position after coronary artery bypass surgery may have a negative influence on the cardiac output and (ii) Whether turning procedures cause practical problems. Background. Directly following surgery, coronary artery bypass patients are not receiving routine turning every two hours to prevent pressure ulcers, because a negative influence on hemodynamic parameters is assumed. Design. Clinical trial. Methods. Fifty-five coronary artery bypass patients were randomly assigned to four intervention regimens and underwent a two-hour period of 30 degrees lateral position. Fourteen patients in supine position served as a reference group. We hypothesized that 30 degrees lateral position does not cause a relevant change in the cardiac output. Results. Turning the patients did not have any significant influence on the cardiac index, not even in the patients in a poor hemodynamic condition. The cardiac index in 30 degrees lateral position and supine position two to eight hours postoperatively after coronary artery bypass surgery is statistically bioequivalent. No clinically relevant deviations from preset 'safe' values for mean arterial pressure, right atrial pressure, pulmonary artery wedge pressure and pulmonary arterial pressure were observed, which would require ending the lateral position. There were no practical problems hindering the turning regimen, not even in the patients with an intra-aortic balloon pump. Conclusions. Early postoperative turning of coronary artery bypass surgery patients in lateral position is an easy and feasible procedure that does not influence the cardiac index not even in patients receiving antihypertensive or inotropic/vasopressor therapy. Further research is needed to find out whether our findings are also valid in other patient groups and other position conditions. Relevance to clinical practice. If there are no strict contra-indications, lateral position has to be considered to prevent complications of continuous supine position within two hours after coronary artery bypass surgery patients have been admitted to the intensive care unit.