High central venous saturation after cardiac surgery is associated with increased organ failure and long-term mortality: an observational cross-sectional study

Abstract

IntroductionCentral venous saturation (ScvO2) monitoring has been suggested to address the issue of adequate cardiocirculatory function in the context of cardiac surgery. The aim of this study was to determine the impact of low (L) (<60%), normal (N) (60%-80%), and high (H) (>80%) ScvO2 measured on intensive care unit (ICU) admission after cardiac surgery.MethodsWe conducted a retrospective, cross-sectional, observational study at three ICUs of a university hospital department for anaesthesiology and intensive care. Electronic patient records of all adults who underwent cardiac surgery between 2006 and 2013 and available admission measurements of ScvO2 were examined. Patients were allocated to one of three groups according to first ScvO2 measurement after ICU admission: group L (<60%), group N (60%-80%), and group H (>80%). Primary end-points were in-hospital and 3-year follow-up survival.ResultsData from 4,447 patients were included in analysis. Low and high initial measurements of ScvO2 were associated with increased in-hospital mortality (L: 5.6%; N: 3.3%; H: 6.8%), 3-year follow-up mortality (L: 21.6%; N: 19.3%; H: 25.8%), incidence of post-operative haemodialysis (L: 11.5%; N: 7.8%; H: 15.3%), and prolonged hospital length of stay (L: 13 days, 9–22; N: 12 days, 9–19; H: 14 days, 9–21). After adjustment for possible confounding variables, an initial ScvO2 above 80% was associated with adjusted hazard ratios of 2.79 (95% confidence interval (CI) 1.565-4.964, P <0.001) for in-hospital survival and 1.31 (95% CI 1.033-1.672, P = 0.026) for 3-year follow-up survival.ConclusionsPatients with high ScvO2 were particularly affected by unfavourable outcomes. Advanced haemodynamic monitoring may help to identify patients with high ScvO2 who developed extraction dysfunction and to establish treatment algorithms to improve patient outcome in these patients.Electronic supplementary materialThe online version of this article (doi:10.1186/s13054-015-0889-6) contains supplementary material, which is available to authorized users.

Systematic review of the association of venous oxygenation and outcome in adult hospitalized patients

“…SmvO 2 below 55-70% and ScvO 2 below 60% have consistently been associated with higher morbidity in cardiac patients and in general ICU patients (Table 2: Venous saturation and morbidity). 24,29,40,47 Similar observations have been done in patients undergoing abdominal surgery, although the cut-off values for ScvO 2 were consistently higher than for those in cardiac surgery. 20,21,30,42 Consequently, a low SmvO 2 and ScvO 2 has in the majority of studies been associated with increased use of post-operative ventilatory support and increased length of stay in the ICU.…”

“…2,9,12,[20][21][22][23][24][28][29][30]40,42,47 In patients undergoing abdominal surgery, ScvO 2 below 70-75% was associated with increased morbidity. The main results of our study were that values of SmvO 2 or ScvO 2 below 55-70% in cardiac patients and in patients admitted to general ICUs were associated with increased mortality, morbidity and length of stay in ICU.…”

“…2,9,[20][21][22]47 Cut-off values for low SmvO 2 and ScvO 2 in cardiac patients were used in the range 55-70% and 60-75% respectively. 2,9,[20][21][22]47 In the largest patient cohort to date, patients with SmvO 2 below 60% in the perioperative period during coronary artery bypass grafting operation (CABG), had significantly higher 30-day and 5-year mortality rates. 21 Similar observations have been done in certain subsets of cardiac patients (pulmonary arterial hypertension), 10 whereas contradictory observations have been done in the general ICU populations, demonstrating both strong 11,12,24 and no correlation 23 between SvO 2 and mortality.…”

“…One study associated high SmvO 2 (> 70%) in cardiac patients with increased 6-month and 1-year mortality. 47 Measurement of SvO 2 in patients with sepsis has gained widespread interest based on a number of observational studies, in which the majority have demonstrated an association between low SmvO 2 or ScvO 2 and mortality. 47 Measurement of SvO 2 in patients with sepsis has gained widespread interest based on a number of observational studies, in which the majority have demonstrated an association between low SmvO 2 or ScvO 2 and mortality.…”

Diagnostic and therapeutic medical devices for safer blood management in cardiac surgery: systematic reviews, observational studies and randomised controlled trials

“…This is not implausible: cerebral venous oxygen saturation, as measured by NIRS, may be influenced by multiple factors that result in high values in the presence of tissue hypoxia. Supranormal oxygen delivery or alternatively diminished tissue oxygen utilisation in states in which cerebral autoregulation is impaired, as is frequently observed during CPB, 253,254 may result in spuriously high values. Our observation that, despite the low frequency of cerebral desaturation, 41% of participants had dysfunction of at least one organ system supports this hypothesis.…”