Insulin Resistance Heralds Positive Cultures after Severe Injury

Abstract

"Insulin resistance heralds positive cultures after severe injury." Surgical infections. 10,6. 503-509. (2009 Background: Insulin resistance and hyperglycemia are common in acutely injured patients, and associated with poor outcomes. In the era of tight glucose control, measures of insulin responsiveness (IR) may provide a better indicator of patient status than does the serum glucose concentration. We hypothesized that measures of IR during tight glycemic control protocols are associated with infection and may be more predictive than the serum glucose concentration.Methods: All critically injured, mechanically ventilated patients undergo protocolized tight glycemic control with the aid of a computer-based system that calculates the insulin dose using an adapting multiplier (insulin dose ¼ [blood glucose -60)ÂM). Consecutive patients on protocol were studied to identify the incidence of positive sterile-site or quantitative bronchoalveolar lavage cultures (>10 4 colony-forming units=mL). Patients were stratified by presence and number of positive cultures and analyzed by both serum glucose measures and measures of IR (average multiplier and average insulin infusion rate). Results: During the six-month study period, 356 patients were placed on the tight glycemic control protocol. Of these, 101 patients had 192 positive cultures. Patients with positive cultures required significantly more hourly insulin than those without a positive culture (3.7 vs. 2.8 units=h; p ¼ <0.001). Logistic regression showed the insulin dose (odds ratio 2.1; 95% confidence interval 1.6, 3.0; p ¼ <0.001) and the adapting multiplier to be independent predictors of the patient having a positive culture among other factors associated with nosocomial infection. Conclusions: Insulin resistance, quantified by hourly insulin dose and median multiplier, confers a higher risk of systemic nosocomial infection. Patients with positive cultures actually had lower admission and median blood glucose values over their intensive care unit stays, highlighting the decreased value of this measure as a predictor of outcome in the setting of tight glucose control. A greater insulin requirement suggesting resistance may be used as a marker of a higher risk of nosocomial infection.

Undiagnosed medical comorbidities in the uninsured

“…Stress insulin resistance heralds infections in trauma patients 27 and strongly associates with increased mortality following TBI. 28 Trauma patients who fail to reach early euglycemia have increased mortality.…”

Insulin Resistance in Critically Injured Adults: Contribution of Pneumonia, Diabetes, Nutrition, and Acuity

“…T rauma induces a cascade of increasing stress hormone and cytokine concentrations implicated in the pathogenesis of insulin resistance (IR) and stress hyperglycemia [1][2][3][4][5][6][7]. Impaired immune function associated with these acute abnormalities in glucose metabolism may result in elevated infectious morbidity and mortality rates [2,3,5,[7][8][9][10][11][12][13][14][15][16][17][18][19].…”

“…Impaired immune function associated with these acute abnormalities in glucose metabolism may result in elevated infectious morbidity and mortality rates [2,3,5,[7][8][9][10][11][12][13][14][15][16][17][18][19]. The risk of death in both critically ill surgical and trauma patients is increased in the setting of poor glycemic control [2,3,5,[7][8][9][10][11][12][13][14][15][16][17][18][19], particularly if hyperglycemia is not corrected quickly [1][2][3][4][5][6][7].…”

“…The effective glycemic control facilitated by these protocols may prevent infection-induced hyperglycemia; in fact, infected patients may have better glycemic control than their non-infected counterparts [7]. Thus, in the setting of tight glucose control, measures of insulin provision and resistance are better signals of infection than hyperglycemia [2][3][4][5][6][7]10,11,13,15,17].…”

“…The multiplier is electronically adjusted incrementally as the patient's IR changes. Insulin resistance, as measured by M or other means, is strongly correlated with infection and death in the setting of glycemic control [2,[7][8][9]12,14,16,18,19].…”