H. Paarmann, J. Schön, W. Schmidt, H. Heinze, K.-U. Berger, B. Sedemund-Adib, M. Bechtel, M. Heringlake, H. V. Groesdonk
[Applied Cardiopulmonary Pathophysiology 15: 55-61, 2011]
Purpose: Approximately 1% of patients require temporary circulatory support due to cardiogenic shock following cardiac surgery. These patients are at risk of a mismatch between oxygen delivery and demand and carry a substantial mortality and morbidity risk. Mixed venous oxygen saturation (SvO2) is the still the “gold standard” for the determination of the ratio between systemic oxygen delivery and consumption (DO2/VO2 ratio) in cardiac surgery patients. A noninvasive technique is thought to be cerebral near-infrared spectroscopy determining cerebral oxygen saturation (ScO2). The present analysis aims to compare ScO2 and SvO2 in adult patients undergoing ECMO therapy for postoperative cardiogenic shock.
Methods: Data were collected hourly for the first 24 hours postoperatively. Each patient was equipped with a pulmonary artery catheter (PAC) connected to a Vigilance II® monitor (Edwards Lifesciences, Irvine, USA) for continuous determination of SvO2 and an INVOS 5100 monitoring system (Somanetics, Troy, USA) to determine ScO2. Data were analyzed by parametric testing and Bland-Altman analysis.
Results: 10 consecutive patients were included in this prospective, observational study. SvO2 and ScO2 did not differ significantly throughout the observation period. Bland-Altman analysis showed a mean difference (bias) of 2,37 % and limits of agreement of 13,72 % to -8,99 %
Conclusions: These data suggest that ScO2 does not differ significantly from SvO2 in patients undergoing ECMO therapy for postoperative cardiogenic shock and may thus be a noninvasive alternative to monitor the DO2/VO2 ratio during this condition.
Key words: cardiac surgery, near-infrared spectroscopy, pulmonary artery catheter, mixed venous oxygen saturation, cerebral oxygen saturation
Heinrich V. Groesdonk, M.D.
Intensive Care Unit
Department of Thoracic and Cardiovascular Surgery
University of Saarland