Introduction: Previous investigators reported a satisfactory agreement between arterial (or transthoracic) (BCOart [PiCCO, Pulsion]) and standard pulmonary artery bolus thermodilution (BCOpulm) in critically ill patients [1,2]. It is unknown, however, whether BCOart is also reliable under the condition of intra-aortic balloon counterpulsation (IABP). It was the aim of this study to approve accuracy of BCOart in patients subjected to IABP.
Method: Eight patients, 37 to 80 (mean 54.8) years old, scheduled for IABP prior to coronary artery bypass surgery were included. A thin thermistor was introduced through the pressure channel to the tip of the 8Fr IABP device, and the pump rate set at 1:1. Cardiac output (CO) was assessed under haemodynamic steady state conditions before surgery and hourly for 8 to 10 hours after admission to the intensive care unit. BCOpulm and BCOart were determined using the average cardiac output (CO) value after 3 to 5 right atrial bolus injections of 10 (BCOpulm) or 15mL (BCOart) iced saline, respectively. Agreement of BCOart and BCOpulm was assessed by Bland Altman analysis.
Results: Seventy-three data pairs were obtained. Mean BCOpulm was 6.41 (range 4.0 to 10.1) and mean BCOart 6.64 (4.0 to 10.1) L/min. Bias was +0.24L/min, the limits of agreement (±2SD) ± 1.8 L/min, and the mean error (2SD/mean [(BCOpulm + BCOart)/2] 27.6%. At BCOpulm <6 L/min, bias was +0.48 L/min, the limits of agreement ± 0.86 L/min and the mean error 15.9%, whereas at BCOpulm >6L/min, bias was + 0.06 L/min, the limits of agreement ± 2.2 L/min and the mean error 29.9%.
Conclusion: In accordance with previous reports in patients without IABP , the agreement we found between BCOart and BCOpulm during IABP was satisfactory. In the sub group of CO values <6 L/min, the overestimation of BCOart was higher but with better precision.
1 Sakka SG, Reinhart K, Meier-Hellmann A. Comparison of pulmonary artery and arterial thermodilution cardiac output in critically ill patients. Intensive Care Med.
2 Della-Rocca G, Costa MG, Coccia C, et al. Cardiac output monitoring: aortic transpulmonary thermodilution and pulse contour analysis agree with standard thermodilution methods in patients undergoing lung transplantation. Can J Anaesth.