Continuous cardiac output measurement: pulse contour analysis vs thermodilution technique in cardiac surgical patients

We have analysed the clinical agreement between two methods of continuous c ardiac output measurement: pulse contour analysis (PCCO) and a continuous t hermodilution technique (CCO), were both compared with the intermittent bol us thermodilution technique (BCO). Measurements were performed in 26 cardia c surgical patients (groups 1 and 2, 13 patients each, with an ejection fra ction >45% and <45%, respectively) at 12 selected times. During operation, mean differences (bias) between PCCO-BCO and CCO-BCO did not differ in eith er group. However, phenylephrine-induced increases in systemic vascular res istance (SVR) by approximately 60% resulted in significant differences. Sig nificantly higher absolute bias values of PCCO-BCO compared with CCO-BCO we re also found early after operation in the ICU. Thus PCCO and CCO provided comparable measurements during coronary bypass surgery. After marked change s in SVR, further calibration of the PCCO device is necessary.