S100β after coronary artery surgery: association with lipid peroxidation and neurocognitive scores
None of the currently available pulmonary artery (PA) catheters allows instantaneous and continuous measurement of pulmonary blood flow. At best, the socalled continuous cardiac output (CO) catheters (and associated software) indicate continuously an averaged value of CO measured over several minutes. A new catheter has been introduced recently, and animal experiments have shown that it allows instantaneous detection of changes in pulmonary blood flow. In this catheter, blood flow is derived
... flow is derived from the power required to maintain a temperature gradient between two thermistors that are insulated differently. The technology also allows the clinician to measure CO using the standard thermodilution technique. The aim of the present study was to demonstrate the clinical safety and efficacy of this new PA catheter. Methods: After local research ethics committee approval and informed consent, 20 patients undergoing elective coronary artery bypass grafting were enrolled in this study. The TruCCOMS PA catheter (Aortech International, Bellshill, Scotland) was floated after induction of anaesthesia, through a 9 Fr introducer. CO was measured continuously after arrival in the intensive care unit and for a period of up to 20 h. CO was also determined by using a standardized thermodilution technique at a minimum of 10 time points (as the average of up to six thermodilution curves), each separated by at least 1 h. Haemodynamics were recorded before each measurement of CO by thermodilution. Statistical analysis included Pearson correlation and a Bland-Altman analysis for assessing agreement between the two methods of clinical measurement . Results: A total of 174 paired results of continuous and thermodilution recordings of CO were obtained in 16 patients. The Pearson correlation was 0.63. Bland-Altman analysis showed a bias of 0.63 l/min and a precision of 0.95 l/min, with 95% limits of agreement from -1.15 to +2.67 l/min. This compares favourably with values obtained for other commercially available CO monitors. Reference 1. Bland JM, Altman DG: Statistical methods for assessing agreement between two methods of clinical measurement. Lancet 1986, i:307-310.