Comparison of cardiac output derived from FloTrac/Vigileo and impedance cardiography during major abdominal surgery

Objectives Impedance cardiography (ICG) is a noninvasive technique that provides reasonably accurate measurements of cardiac output, but the usefulness of ICG in patients undergoing open abdominal surgery has not been validated. Methods Cardiac output was measured while patients underwent open gastrectomy using an ICG monitor (niccomo; ICG-CO); the results were compared with those measured using a FloTrac/Vigileo monitor (Flo-CO), which measures cardiac output by analysing the arterial waveform. Data collection commenced at the beginning of anaesthetic induction and continued until the patient was awake. Data were compared using the Bland-Altman analysis, and the clinical significance of the difference between the two methods was evaluated by calculating the percentage error (%). Results Eleven patients were monitored during surgery. The bias of the Flo-CO and ICG-CO values was -0.45l/min. The upper and lower limits of agreement were 0.96l/min and -1.85l/min, respectively. The percentage error was 28.5%. Electrocautery induced interference that transiently impaired the performance of the ICG monitor. Conclusions ICG provided useful information in evaluating the cardiac output of patients during abdominal surgery.