Reliability of estimation of pulmonary artery wedge pressures during coronary artery bypass surgery

The ability to reliably estimate pulmonary artery wedge pressure measurements using the clinical and basic cardiovascular parameters was assessed in fifty-six patients having elective coronary artery bypass surgery. The patients were divided into three groups: Group 1 had normal left ventricular function (22 patients), Group 2 had moderate left ventricular dysfunction (20 patients) and Group 3 had more severe left ventricular dysfunction (14 patients). The percentages of correct pulmonary artery wedge pressure estimations were 55%, 56% and 52% in Groups 1, 2 and 3 respectively. We conclude that pulmonary artery wedge pressure measurements can only be reliably estimated from the clinical situation and basic cardiovascular parameters on about 50% of occasions and that the reliability of the estimation does not vary between groups with different left ventricular performance.