Effect of perioperative insulin infusion on surgical morbidity and mortality: systematic review and meta-analysis of randomized trials.7.
OBJECTIVE
To conduct a systematic review and meta-analysis of randomized controlled trials (RCTs) to evaluate the effect of perioperative insulin infusion on outcomes important to patients.


METHODS
We used 6 search strategies including an electronic database search of MEDLINE, EMBASE, and Cochrane CENTRAL, from their inception up to May 1, 2006, and included RCTs of perioperative insulin infusion (with or without glucose targets) measuring outcomes in patients undergoing any surgery. Pairs of reviewers working independently assessed the methodological quality and characteristics of included trials and abstracted data on perioperative outcomes (ie, outcomes that occurred during hospitalization or within 30 days of surgery).


RESULTS
We identified 34 eligible trials. In the 14 trials that assessed mortality, there were 68 deaths among 2192 patients randomized to insulin infusion compared with 98 deaths among 2163 patients randomized to control therapy (random-effects pooled relative risk, 0.69; 95% confidence interval [CI], 0.51-0.94; 99% CI, 0.46-1.04; I2, 0%; 95% CI, 0.0%-47.4%). Hypoglycemia increased in the intensively treated group (20 trials, 119/1470 patients in insulin infusion vs 48/1476 patients in control group; relative risk, 2.07; 95% CI, 1.29-3.32; 99% CI, 1.09-3.88; I2, 31.5%; 95% CI, 0.0%-59.0%). No significant effect was seen in any other outcomes. The available mortality data represent only 40% of the optimal information size required to reliably detect a plausible treatment effect; potential methodological and reporting biases weaken inferences.


CONCLUSIONS
Perioperative insulin infusion may reduce mortality but increases hypoglycemia in patients who are undergoing surgery; however, mortality results require confirmation in large and rigorous RCTs.
Gandhi
Gunjan Y
GY
Division of Endocrinology, Diabetes, Metabolism and Nutrition, Mayo Clinic, 200 First St SW, Rochester, MN 55905, USA. gandhi.gunjan@mayo.edu
Murad
M Hassan
MH
Flynn
David N
DN
Erwin
Patricia J
PJ
Cavalcante
Alexandre B
AB
Bay Nielsen
Henning
H
Capes
Sarah E
SE
Thorlund
Kristian
K
Montori
Victor M
VM
Devereaux
P J
PJ
D006801:Humans; D007004:Hypoglycemic Agents / Q000008:administration & dosage*; D007262:Infusions, Intravenous; D007328:Insulin / Q000008:administration & dosage*; D009017:Morbidity / Q000639:trends; D009864:Ontario / Q000453:epidemiology; D019990:Perioperative Care / Q000379:methods*; D011183:Postoperative Complications / Q000453:epidemiology* / Q000517:prevention & control*; D016032:Randomized Controlled Trials as Topic; D013514:Surgical Procedures, Operative; D015996:Survival Rate / Q000639:trends
D007004:Hypoglycemic Agents; D007328:Insulin