The glucoregulatory benefits of glucagon-like peptide-1 (7-36) amide infusion during intensive insulin therapy in critically ill surgical patients: a pilot study.

OBJECTIVES: Intensive insulin therapy for tight glycemic control in critically ill surgical patients has been shown to reduce mortality; however, intensive insulin therapy is associated with iatrogenic hypoglycemia and increased variability of blood glucose levels. The incretin glucagon-like peptide-1 (7-36) amide is both insulinotropic and insulinomimetic and has been suggested as an adjunct to improve glycemic control in critically ill patients. We hypothesized that the addition of continuous infusion of glucagon-like peptide-1 to intensive insulin therapy would result in better glucose control, reduced requirement of exogenous insulin administration, and fewer hypoglycemic events. DESIGN: Prospective, randomized, double-blind, placebo-controlled clinical trial. SETTING: Surgical or burn ICU. PATIENTS: Eighteen patients who required intensive insulin therapy. INTERVENTIONS: A 72-hour continuous infusion of either glucagon-like peptide-1 (1.5 pmol/kg/min) or normal saline plus intensive insulin therapy. MEASUREMENTS AND MAIN RESULTS: The glucagon-like peptide-1 cohort (n = 9) and saline cohort (n = 9) were similar in age, Acute Physiology and Chronic Health Evaluation score, and history of diabetes. Blood glucose levels in the glucagon-like peptide-1 group were better controlled with much less variability. The coefficient of variation of blood glucose ranged from 7.2% to 30.4% in the glucagon-like peptide-1 group and from 19.8% to 56.8% in saline group. The mean blood glucose coefficient of variation for the glucagon-like peptide-1 and saline groups was 18.0% ± 2.7% and 30.3% ± 4.0% (p = 0.010), respectively. The 72-hour average insulin infusion rates were 3.37 ± 0.61 and 4.57 ± 1.18 U/hr (p = not significant). The incidents of hypoglycemia (≤ 2.78 mmol/L) in both groups were low (one in the glucagon-like peptide-1 group, three in the saline group). CONCLUSIONS: Glucagon-like peptide-1 (7-36) amide is a safe and efficacious form of adjunct therapy in patients with hyperglycemia in the surgical ICU setting. Improved stability of blood glucose is a favorable outcome, which enhances the safety of intensive insulin therapy. Larger studies of this potentially valuable therapy for glycemic control in the ICU are justified.

Noise levels in a burn intensive care unit.

INTRODUCTION: Increased noise levels in hospitals, critical care units, and peri-operative areas have been associated with higher levels of sleep deprivation and patient stress. The World Health Organization (WHO) guidelines stipulate a limit of 35 decibels (dB(A)) equivalent continuous sound level (LEq) during the day and 30 dB(A) LEq at night in patients' rooms. To date, no quantitative studies of noise levels have been performed in burn units. The objective of this study was to quantify noise levels in a burn critical care unit to ascertain compliance with guidelines in order to minimize this potential insult. METHODS: An A-weighted sound pressure level meter was used to measure the ambient noise levels in a burn intensive care unit. Maximum and minimum sound pressure levels were measured at 30-min intervals on 10 days over a 1 month period. Measurements were obtained during shift changes and random times during the day and night-time. Descriptive statistical analyses were performed, to calculate means and standard deviations. Noise measurements at specified times were compared using analysis of variance (ANOVA). RESULTS: Mean dB(A) LEq values for shift changes, day, and night-time were 65.9 ± 2.8, 65.7 ± 2.6, and 60.9 ± 5.2 dB(A), respectively. There was no significant difference in dB(A)(max) or dB(A)(min) between shift changes, day or night-time (p>0.05). However, night-time minimum values were consistently lower. There was no significant difference between sound pressure level (SPL) inside and outside patients' rooms (p>0.05) at any time. CONCLUSIONS: Irrespective of time or location, the mean dB(A) LEq in the burn unit was significantly greater than World Health Organization (WHO), National Institute for Occupational Safety and Health (NIOSH), and the Environmental Protection Agency (EPA) recommendations. Guidelines for decreasing noise exposure are necessary to reduce potential negative effects on patients, visitors, and staff.

Glucose metabolism in burn patients: the role of insulin and other endocrine hormones.

Severe burn causes a catabolic response with profound effects on glucose and muscle protein metabolism. This response is characterized by hyperglycemia and loss of muscle mass, both of which have been associated with significantly increased morbidity and mortality. In critically ill surgical patients, obtaining tight glycemic control with intensive insulin therapy was shown to reduce morbidity and mortality and has increasingly become the standard of care. In addition to its well-known anti-hyperglycemic action and reduction in infections, insulin promotes muscle anabolism and regulates the systemic inflammatory response. Despite a demonstrated benefit of insulin administration on the maintenance of skeletal muscle mass, it is unknown if this effect translates to improved clinical outcomes in the thermally injured. Further, insulin therapy has the potential to cause hypoglycemia and requires frequent monitoring of blood glucose levels. A better understanding of the clinical benefit associated with tight glycemic control in the burned patient, as well as newer strategies to achieve and maintain that control, may provide improved methods to reduce the clinical morbidity and mortality in the thermally injured patient.

Intensive insulin therapy confers a similar survival benefit in the burn intensive care unit to the surgical intensive care unit.

BACKGROUND: In contrast to the benefits of intensive insulin therapy (IIT) in the surgical intensive care unit (SICU), its benefits in the burn ICU (BICU) remain unclear. Furthermore, IIT and tight glycemic control has received little attention in elderly ICU patients. METHODS: We evaluated the normalization of blood glucose level with IIT in BICU and SICU patients. From October 2006 to July 2007, 970 patients were admitted to our BICU and our SICU. A total of 79 of these patients met criteria for initiation of IIT, 37 of who required IIT for at least 72 hours. Data were analyzed to determine if tight glycemic control (blood glucose < or =150 mg/dL by day 3) is associated with reduced morbidity and mortality. RESULTS: Tight control was better achieved in SICU patients (45%) than in BICU patients (33%). Daily insulin requirements were approximately 2-fold greater in SICU patients compared with BICU patients (P < .05). Tight control in both SICU and BICU patients was associated with a decreased incidence of sepsis compared with poor glycemic control (10% vs 58% and 60% vs 70%, respectively) and a decreased mortality rate (0 vs 58% and 20% vs 50%; SICU vs BICU, respectively). The percentage of total body surface area burned in BICU patients was 10% and 45% in the < or =150 and >150 mg/dL groups. Mortality rate in the poor control group was >10-fold greater than that of the tight control group; for patients > or =65 years of age, mortality was nearly double than that of patients <65 years of age. The greatest mortality rate (62%) was seen in patients >65 years of age with poor control. CONCLUSION: Tight control with IIT is associated with an increased survival rate in both BICU and SICU patients. Age is associated with survival, with patients older than 65 years of age having the greatest mortality rate.

Numerical and clinical accuracy of a continuous glucose monitoring system during intravenous insulin therapy in the surgical and burn intensive care units.

BACKGROUND: Intensive insulin therapy (IIT) for glycemic control in critically ill patients has been shown to be beneficial. Continuous glucose monitoring systems (CGMSs) have been approved as an adjunct to complement standard glucose monitoring in type 2 diabetes mellitus. This study was designed to evaluate the accuracy of a real-time CGMS (DexCom STS) in the intensive care unit (ICU). We also evaluated its reliability and accuracy using a hyperinsulinemic-euglycemic and a hyperglycemic clamp study. METHODS: Nineteen patients were enrolled in this 7-day study [13 = surgical intensive care unit (SICU), 6 = burn intensive care unit (BICU)]. The patients were on IIT for at least 2 h prior the subcutaneous sensor insertion. Mean age and body mass index for SICU and BICU patients were 60.3 +/- 3.7 and 64.5 +/- 6.2 years and 36.6 +/- 5.0 and 33.85 +/- 3.4 kg/m2, respectively. DexCom accuracy was analyzed separately for the Johnson & Johnson (J&J) calibration finger sticks, Roche Accucheck finger sticks, and the Hitachi 917 analyzer measurements on serum using Clarke error grid analysis and Bland-Altman analysis. In the clamp studies, 20 patients were enrolled, and the data were analyzed similarly. RESULTS: There were 1065 pairs of DexCom-Accucheck, 232 pairs of DexCom-J&J, and 84 pairs of DexCom-Hitachi in ICU patients. For DexCom-Accucheck, 68.26% of the pairs fell into zone A, 31.83% into zone B, and 0.75% into zone C. There were no values in zones D or E. From the 1102 matching DexCom-Beckman pairs in clamp studies, 42.29% were in zone A, 55.90% were in zone B, and 4.08% were in zone C. CONCLUSIONS: Despite the high percentage of measurements in zones A and B, underestimation of hypoglycemia by DexCom measurements makes it an unreliable device in the ICU setting.