Low and “supranormal” central venous oxygen saturation and markers of tissue hypoxia in cardiac surgery patients: a prospective observational study

• Published in: Intensive care medicine Vol. 37; no. 1; pp. 52 - 59
• Main Authors: Perz, Suzanne, Uhlig, Thomas, Kohl, Matthias, Bredle, Donald L., Reinhart, Konrad, Bauer, Michael, Kortgen, Andreas
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer-Verlag 01.01.2011; Springer; Springer Nature B.V
• Subjects: Aged; Anesthesia. Intensive care medicine. Transfusions. Cell therapy and gene therapy; Anesthesiology; Biological and medical sciences; Biomarkers - blood; Cardiac patients; Cardiac Surgical Procedures; Catheters; Cell Hypoxia; Coronary vessels; Critical care; Critical Care Medicine; Emergency and intensive cardiocirculatory care. Cardiogenic shock. Coronary intensive care; Emergency Medicine; Female; Health aspects; Heart surgery; Hospital patients; Humans; Hyperoxia - blood; Hypoxia; Hypoxia - blood; Intensive; Intensive care; Intensive care medicine; Lactates; Male; Medical research; Medical sciences; Medicine; Medicine & Public Health; Medicine, Experimental; Middle Aged; Mortality; Observational studies; Original; Oxygen - blood; Oxygen saturation; Pain Medicine; Patients; Pediatrics; Pneumology/Respiratory System; Postoperative Complications - blood; Prospective Studies; Reference Values; Sepsis; Surgery; Germany; Organ failure; Gastric tonometry; Lactate; ScvO; Systemic inflammation; Stomach; Oxygen; Intensive care; Digestive system; Saturation; Cardiovascular disease; Inflammation; Lactates; Surgery; Hypoxia; Tonometry; Lactic acid; Resuscitation
• ISSN: 0342-4642; 1432-1238
• DOI: 10.1007/s00134-010-1980-8

Purpose To characterize incidence of low, normal and “supranormal” central venous oxygen saturation (ScvO 2 ) and the relation to markers of tissue hypoxia, course and outcome in cardiac surgery patients. Methods Prospective, observational study in a university multidisciplinary 50-bed intensive care unit including 205 consecutive patients undergoing elective cardiac surgery. Data were split into training and test data sets and subjected to 50 replications of fivefold cross-validation to estimate lower and upper bounds of ScvO 2 indicative of impaired tissue oxygenation. Results Both low (≤60.8%) and supranormal (≥77.4%) ScvO 2 were associated with an unfavorable course, while the logistic EuroSCORE for risk adjustment was comparable between groups. Incidences of abnormal ScvO 2 were 13.2% low and 30.7% supranormal. Patients with low ScvO 2 and an uneventful course initially presented with normal lactate levels, whereas patients with supranormal ScvO 2 displayed consistently higher serum lactate levels. High ScvO 2 values were associated with the use of β-mimetics and signs of systemic inflammation. Mortality rates were comparable for patient populations presenting either low (14.8%) or supranormal ScvO 2 (7.9%) and higher than normals (0%, p  < 0.001). Lactate was comparably increased in patients that ultimately died, irrespective whether they had low or supranormal ScvO 2 values. In contrast, neither low nor supranormal ScvO 2 was associated with altered gastric pCO 2. Conclusions High ScvO 2 is an under-recognized warning sign for impaired tissue oxygenation in the peri-operative period. Including values ≥77.4% as ‘normal’ impaired performance of ScvO 2 monitoring to predict a complicated perioperative course.