Comparison of two semicontinuous cardiac output pulmonary artery cathetersafter valvular surgery

Objective: To compare semicontinuous cardiac output (CCO) with bolus cardia c output (BCO), in the immediate postoperative period after valvular surger y, under hypothermic cardiopulmonary bypass with two CCO pulmonary artery c atheters, based on the pulsed warm thermodilution technique, i.e., Opti-Q f rom Abbott or IntelliCath from Baxter-Edwards (Abbott and Baxter groups, re spectively). Design: Prospective study, Setting: University hospital. Patients: Forty-four adult patients scheduled for mitral and/or aortic valv e surgery were randomized into two groups, Tricuspid or pulmonary valvulopa thy diagnosed by echocardiography was excluded. Interventions: Cardiac output was measured every 20 mins during the 3 posto perative hrs, BCO was the mean of three boluses (10 mL) of an ice-cold sali ne solution injected within 3 sees. CCO was the mean of two CCO values obta ined in normal mode immediately before and after BCO measurements. Measurements and Main Results: Two groups of 22 patients underwent 198 pair s of cardiac output measurements. The mean difference or bias was calculate d as the difference between BCO and CCO, and precision was the so of the me an bias, The limits of agreement were defined as bias +/-2 SD, A two-sample Wilcoxon's test was used for comparison of bias and precision in sinus and non-sinus rhythm, and stable and unstable mean arterial pressure in each g roup and between the two pulmonary artery catheters, The coefficient of cor relation was also calculated. Bias +/- precision was 0.066 +/- 0.526 L/min, r(2) = .83, for the Abbott group, and 0.015 +/- 0.490 L/min, r(2) = .85 (n ot significant), for the Baxter group, There was no significant difference within and between groups for bias and precision in sinus and non-sinus rhy thm, nor in stable and unstable mean arterial pressure. Conclusions: This study, during the immediate postoperative period in valvu lar surgery under hypothermic cardiopulmonary bypass, showed a satisfactory correlation between CCO and BCO with the two systems.