Analyzing Arterial Pressure Waveform for Cardiac Output Measurement in Valvular Heart Surgery Patients

Abstract

Thermodilution via pulmonary artery catheter (PAC) is commonly accepted as gold standart method for cardiac output measurements. The new method Flotrac/VigileoTM system calculates cardiac output (CO) by analyzing arterial pressure waveform and has recently been marketed which have the ability to monitor CO noninvasively. In this study we compared Flotrac/VigileoTM (FV) in patients undergoing valvular heart surgery with pulmonary artery cardiac output measurement. Nineteen patients, who would undergo isolated valve replacement surgery were included into the study. All patients were monitored with PAC and FV monitoring systems. Cardiac outputs were measured at four different stages of the operation: After induction of anesthesia (T1), before cannulation (T2), after cardiopulmonary bypass (T3) and after sternal closure (T4). There was no difference between demografic data of patients. CO measurements obtained with the FV system were higher for the T1, and T4 measurements; lower for the T2 and T3 than did those obtained with the PAC. For all measurement stages, good agreements were found between two methods as shown by Bland-Altman statistics. Although many studies are reported for the evaluation of the FV in the operating theatre we could find no studies that have examined this method in isolated valvular heart surgery patients. We compared two different CO measurement methods: FV and PAC in valve replacement surgery patients. The CO values provided by FV were similar to the PAC values that may be considered as gold standart. We concluded that FV is easier to use and less invasive than PAC and would be a good choice in determining CO in patients who will have valvular cardiac surgery.