Preoperative blood glucose concentrations and postoperative outcomes after elective non-cardiac surgery: an observational study.

BACKGROUND: The association between preoperative blood glucose (BG) concentration and outcomes after non-cardiac surgery and the impact of the diabetes diagnosis status remain unclear. We tested two hypotheses: that preoperative BG is related to surgical outcomes; and that this relationship depends on the diabetes diagnosis status of the patient. METHODS: We retrospectively analysed data on 61 536 consecutive elective non-cardiac surgery patients treated at our tertiary care facility. Logistic regression models were used to test the hypotheses before and after adjustment for baseline patient characteristics. Our primary outcome was a composite of in-hospital serious complications and mortality. A second primary outcome was 1 yr mortality. RESULTS: The crude incidence of the composite in-hospital outcome was significantly related to preoperative BG (P<0.001), but not after covariable adjustment (P=0.40). This relationship did not significantly differ between patients with and without diagnosed diabetes (P=0.09). One year mortality was significantly related to preoperative BG, both univariably (P<0.001) and after covariable-adjustment (P<0.001). Patients with diagnosed diabetes and preoperative euglycaemia generally had worse 1 yr mortality than those without diabetes at the same BG {e.g. odds ratio (OR) [95% confidence interval (CI)] of 1.27 (1.06, 1.53) at 6 mmol litre(-1) (108 mg dl(-1)), P=0.003}. Conversely, hyperglycaemic patients with diagnosed diabetes displayed a significantly lower 1 yr mortality than hyperglycaemic patients without diabetes [OR (95% CI) of 0.58 (0.44, 0.77) at 12 mmol litre(-1) (216 mg dl(-1)), P<0.001]. CONCLUSIONS: For elective non-cardiac surgery, preoperative hyperglycaemia should be given greater consideration in patients without diabetes than in those with diagnosed diabetes.

Association between preoperative statin therapy and postoperative change in glomerular filtration rate in endovascular aortic surgery.

BACKGROUND: Acute kidney injury during endovascular aortic repair can result in a reduction in the postoperative glomerular filtration rate (GFR). The 'pleiotropic' effects of statins offer a potential mechanism of reducing the postoperative decline in the GFR. We therefore tested the hypothesis that in patients undergoing endovascular aortic repair, the GFR decreases less in patients taking preoperative statins than in those who do not. METHODS: A cohort investigation of 501 consecutive patients who underwent endovascular aortic repair between June 2005 and March 2007 in an academic tertiary care centre. Multivariable linear regression was used to assess the association between the statin use and the postoperative GFR, after adjusting for the baseline GFR and other confounding covariables selected using a stepwise criterion. RESULTS: The statin use was not associated with a change in the postoperative GFR (P=0.94); the difference (95% confidence interval) in the mean postoperative GFR (statins minus no statins) was estimated at 0.1 (-3.1, +3.4) ml min(-1) 1.73 m(-2). A decrease in the GFR of ≥ 25% (the threshold to diagnose contrast-induced nephropathy) developed in 26 of 192 patients given statins before operation (13.5%) compared with 36 of 296 patients who were not taking statins (12.2%). CONCLUSIONS: Statin therapy is not associated with a statistically significant change in the mean postoperative GFR in patients undergoing endovascular aortic surgery, nor a reduction in the risk of a GFR decline of >25%.

Central venous pressure during the post-anhepatic phase is not associated with early postoperative outcomes following orthotopic liver transplantation.

BACKGROUND: Fluid management during orthotopic liver transplantation poses unique challenges for the anesthesiologist. Maintenance of hypovolemia as indicated by low central venous pressure has been associated with reduced blood loss and improved outcomes in some studies, but with higher 30-day mortality and increased incidence of renal dysfunction in others. The primary aim was to evaluate the association of central venous pressure management after liver allograft reperfusion with immediate postoperative patient outcomes. METHODS: This was a retrospective investigation evaluating the intraoperative and postoperative records of 144 consecutive patients who underwent orthotopic liver transplantation at a single institution. RESULTS: We did not find any important association between central venous pressure management after graft reperfusion and postoperative patient outcomes. Specifically, these data do not support the hypothesis that maintenance of lower central venous pressure during the post-anhepatic phase of orthotopic liver transplantation is associated with improved immediate postoperative allograft function (except for a steeper decrease in post operative days 1-3 in 2 of the 3 liver function test: alanine aminotransferase and bilirubin) or overall patient survival, graft survival, composite graft/patient survival, intensive care length of stay, hospital length of stay or the occurrence of infections. CONCLUSION: Maintaining a lower central venous pressure during the post-anhepatic phase during orthotopic liver transplantation is not associated with any benefit in terms of immediate postoperative allograft function, graft survival or patient survival.

Circulating-water garment or the combination of a circulating-water mattress and forced-air cover to maintain core temperature during major upper-abdominal surgery.

BACKGROUND: A recent heat-balance study in volunteers suggested that greater efficacy of circulating-water garments (CWGs) results largely from increased heat transfer across the posterior skin surface since heat transfer across the anterior skin surface was similar with circulating-water and forced-air. We thus tested the hypothesis that the combination of a circulating-water mattress (CWM) and forced-air warming prevents core temperature reduction during major abdominal surgery no worse than a CWG does. METHODS: Fifty adult patients aged between 18 and 85 yr old, undergoing major abdominal surgery, were randomly assigned to intraoperative warming with a combination of forced-air and a CWM or with a CWG (Allon ThermoWrap). Core temperature was measured in the distal oesophagus. Non-inferiority of the CWM to the CWG on change from baseline to median intraoperative temperature was assessed using a one-tailed Student's t-test with an equivalency buffer of -0.5°C. RESULTS: Data analysis was restricted to 16 CWG and 20 CWM patients who completed the protocol. Core temperature increased in both groups during the initial hours of surgery. We had sufficient evidence (P=0.001), to conclude that the combination of a CWM and forced-air warming was non-inferior to a CWG in preventing temperature reduction, with mean (95% CI) difference in the temperature change between the CWM and the CWG groups (CWM-CWG) of 0.46°C (-0.09°C, 1.00°C). CONCLUSIONS: The combination of a CWM and forced-air warming is significantly non-inferior in maintaining intraoperative core temperature than a CWG. TRIAL REGISTRY: This trial has been registered at clinical trials.gov, identifier: NCT 00651898.