Insulin resistance despite tight glucose control is associated with mortality in critically ill surgical patients.
BACKGROUND
The hyperglycemic state following trauma and surgery is related partially to insulin resistance (IR). The objective is to determine if critically ill surgical patients vary in their extent of IR and is IR associated with mortality.


METHODS
Prospective observational study in trauma and surgical intensive care units. There were 925 ventilated, critically ill surgical patients who were placed on an automated euglycemia protocol. A mathematic multiplier (M) employed by the protocol was used as a measure of IR. Outcome, phenotypic, laboratory, and treatment variables were analyzed.


RESULTS
54,141 entries for glucose (mg/dl) and M were analyzed. Median glucose was 118mg/dL, with 45% of values between 80-110mg/dL, 81% between 80-150 mg/dL, and 0.2% less than 40 mg/ dL. M varied by 42 fold over the entire population, and by an average of 11-fold among individual patients. The median blood glucose was not different between groups (118 mg/dl for survivors and 118 mg/dl for non-survivors, P = 0.36). The median insulin dose and M were significantly higher in non-survivors (4.1 U/hr versus 3.4 U/hr, P = 0.005; 0.061 versus 0.058, P = 0.02).


CONCLUSIONS
There was a large amount of variation in insulin resistance, as measured by an adapting multiplier, both across the population and within patients. In the setting of tight glucose control measures of glucose control (median blood glucose and percent in range) do not differentiate between patients who lived and died while measures of insulin resistance (median insulin dose and multiplier) do, suggesting that the insulin resistance is a better predictor of outcome.
Mowery
Nathan T
NT
Department of Surgery, Vanderbilt University Medical Center, Nashville, Tennessee, USA. nmowery@wfubmc.edu
Dortch
Marcus J
MJ
Dossett
Lesly A
LA
Norris
Patrick R
PR
Diaz
Jose J
JJ
Morris
John A
JA
May
Addison K
AK
D001786:Blood Glucose / Q000032:analysis*; D016638:Critical Illness / Q000401:mortality*; D005260:Female; D006801:Humans; D006943:Hyperglycemia / Q000401:mortality; D007333:Insulin Resistance / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D014947:Wounds and Injuries / Q000601:surgery
D001786:Blood Glucose