EVALUATION OF A NEW SEMICONTINUOUS CARDIAC-OUTPUT SYSTEM IN THE INTENSIVE-CARE UNIT

Purpose: A new semi-continuous thermodilution cardiac output (CCO) sys tem has been developed recently (Opti-Q(TM) and Q-vue(TM) Abbott criti cal care system). The aim of this study was to compare the accuracy an d reproducibility of this new device;with conventional ice-bolus therm odilution cardiac output (BCO). Methods: Fifteen critically ill patien ts who needed pulmonary artery catheterization were prospectively inve stigated. Eighty seven paired data using BCO and CCO methods were comp ared, Reproducibility was assessed from 90 BCO and 87 CCO determinatio ns by calculation of the mean standard error (SEM) and according to la nd and Altman methodology, Results: The BCO and CCO ranged from 2.46 t o 11.20 L.min(-1) and from 1.75 to 10.05 L.min(-1) respectively, Bias (mean difference between BCO and CCO) was null (0.002 L.min(-1), P = 0 .98), precision (SD of the bias) was 0.74 L.min(-1) and the limits of agreement (mean difference +/- 1.96 SD)ranged from -1.45 to 1.45 L.min (-1). The threshold to consider two cardiac outputs as different (3 x SEM) was equivalent for BCO and CO (0.54 and 0.465 L.min(-1) respectiv ely. According to the Bland and Altman method, reproducibility of CCO was greater than that of BCO: bias of repeated measurements of BCO and CCO were 0.15 L.min(-1) (P < 0.05) and 0.047 L.min(-1) (NS), respecti vely, Conclusion: Compared with BCO, this new device was accurate but cannot be considered as interchangeable regarding the limits of agreem ent, Reproducibility of CCO was superior to BCO.