Search

Objectives: Insulin administration lowers plasma potassium concentration by augmenting intracellular uptake of potassium. The effect of insulin administration on renal potassium excretion is unclear. Some studies suggest that insulin has an antikaliuretic effect although plasma potassium levels were poorly controlled. Since the introduction of glycemic control in the intensive care unit, insulin use has increased. We examined the relation between administered insulin and renal potassium excretion in critically ill patients under computer-assisted glucose and potassium regulation., Design: Prospective observational study., Setting: Twelve-bed surgical intensive care unit of a university teaching hospital., Patients: Consecutive intensive care unit patients., Interventions: Potassium and glucose levels were regulated by a computer-assisted decision support system. Both potassium and insulin were continuously administered by syringe pump., Measurements and Main Results: Renal potassium excretion was measured daily in the 24-hr urine collections. The 24-hr urinary samples of patients with kidney failure or on renal replacement therapy were excluded. Multivariate analysis with potassium excretion as the dependent variable was performed. In 178 consecutive patients, 1,456 24-hr urinary samples, were analyzed. Mean ± SD plasma potassium was 4.2 ± 0.3 mmol/L, with 79 ± 46 mmol/d of potassium administered and a mean insulin dose of 53 ± 38 U/day. Renal potassium excretion was 126 ± 51 mmol/day. After multivariate analysis correcting for relevant variables (including diuretics, pH, potassium levels and renal sodium excretion), insulin administration was independently and positively associated with renal potassium excretion. Other significant variables were potassium levels, potassium administration, renal sodium and chloride excretion, creatinine clearance, diuretic therapy, pH, known diabetes and intensive care unit admission day (R = .52; p <. 001)., Conclusion: Insulin administration is associated with an increase in the renal potassium excretion in critically ill patients.

Background: Early delivery of calories is important in critically ill patients, and the administration of parenteral nutrition (PN) is sometimes required to achieve this goal. However, PN can induce acute hyperglycemia, which is associated with adverse outcome. We hypothesized that initiation of PN using a rapid "step-up" approach, coupled with a computerized insulin-dosing protocol, would result in a desirable caloric intake within 24 hours without causing hyperglycemia., Methods: In our surgical intensive care unit (ICU), glucose is regulated by a nurse-centered computerized glucose regulation program. When adequate enteral feeding was not possible, PN was initiated according to a simple step-up rule at an infusion rate of 10 mL/h (approximately 10 kcal/h) and subsequently increased by steps of 10 mL/h every 4 hours, provided glucose was <10 mmol/L, until the target caloric intake (1 kcal/kg/h) was reached. All glucose levels and insulin doses were collected during the step-up period and for 24 hours after achieving target feeding., Results: In all 23 consecutive patients requiring PN, mean intake was 1 kcal/kg/h within 24 hours. Of the 280 glucose samples during the 48-hour study period, mean ± standard deviation glucose level was 7.4 ± 1.4 mmol/L. Only 4.5% of glucose measurements during the step-up period were transiently ≥10 mmol/L. After initiating PN, the insulin requirement rose from 1.1 ± 1.5 units/h to 2.9 ± 2.5 units/h (P < .001)., Conclusions: This proof of concept study shows that rapid initiation of PN using a step-up approach coupled with computerized glucose control resulted in adequate caloric intake within 24 hours while maintaining adequate glycemic control.

The avid consumption of glucose with concomitant lactate production by malignant cells, even under aerobic conditions, is called the Warburg effect, or aerobic glycolysis. This metabolic state is a final common pathway that apparently serves various invasive purposes. As most invasive tumours display the Warburg effect, this has proven of great clinical importance in detecting malignancies with 18-fluorine 2-deoxyglucose positron emission tomography (FDG-PET) scans. However, using the Warburg effect to target malignancies has proven more difficult. Since hypoglycaemia has been shown to be tumouricidal for cancers that display the Warburg effect, various schemes to block glucose utilization have been investigated. But in vivo it is difficult to selectively target glucose utilization in malignant cells without harming normal cells. Cancer cells produce large amounts of lactate under the Warburg effect, without fully oxidizing it to CO(2). In contrast normal cells can completely oxidize lactate under aerobic conditions. Recent studies have demonstrated that vital organs such as the brain, heart, liver, kidneys and muscle are capable of oxidizing lactate as a fuel alternative to glucose. It has also been shown that during hypoglycaemia intravenous lactate can serve as a salvage fuel in man. Other clinical studies showed that patients can effectively metabolize large amounts of exogenous lactate. All this appears to reflect the recently recognized major physiological role of lactate as a glucose alternative. Consequently, lactate is the most logical candidate to serve as a salvage fuel when local or systemic hypoglycemia is induced. Thus, we hypothesize that the combination of hypoglycaemia induced by insulin and concomitant lactate administration will selectively suppress cancers manifesting the Warburg effect, since such cancers will have great difficulty in metabolizing lactate. This metabolic therapy could be modulated in many ways both in amplitude, in duration and in timing with respect to other therapies. The validated isolated limb perfusion (ILP) model for sarcoma appears an attractive model to evaluate local therapy with insulin and lactate and test its (adjuvant) tumouricidal effects in animals and man. Such effects could be evaluated with modern metabolic detection techniques such as FDG-PET and magnetic resonance imaging in local models both in animals and humans. Subsequently the systemic effects of hypoglycaemia combined with sodium lactate administration could be evaluated.

Objective: Intensive insulin therapy is associated with the risk of hypoglycemia and increased costs of material and personnel. We therefore evaluated the safety and efficiency of a computer-assisted glucose control protocol in a large population of critically ill patients., Design and Setting: Observational cohort study in three intensive care units (32 beds) in a 1,300-bed university teaching hospital., Patients: All 2,800 patients admitted to the surgical, neurosurgical, and cardiothoracic units; the study period started at each ICU after implementation of Glucose Regulation for Intensive Care Patients (GRIP), a freely available computer-assisted glucose control protocol., Measurements and Results: We analysed compliance in relation to recommended insulin pump rates and glucose measurement frequency. Patients were on GRIP-ordered pump rates 97% of time. Median measurement time was 5min late (IQR 20min early to 34 min late). Hypoglycemia was uncommon (7% of patients for mild hypoglycemia, < 3.5mmol/l; 0.86% for severe hypoglycemia, < 2.2 mmol/l). Our predefined target range (4.0-7.5 mmol/l) was reached after a median of 5.6 h (IQR 0.2-11.8) and maintained for 89% (70-100%) of the remaining stay at the ICU. The number of measurements needed was 5.9 (4.8-7.3) per patient per day. In-hospital mortality was 10.1%., Conclusions: Our computer-assisted glucose control protocol provides safe and efficient glucose regulation in routine intensive care practice. A low rate of hypoglycemic episodes was achieved with a considerably lower number of glucose measurements than used in most other schemes.

Background: Tight glucose control by intensive insulin therapy has become a key part of critical care and is an important field of study in acute coronary care. A balance has to be found between frequency of measurements and the risk of hypoglycemia. Current nurse-driven protocols are paper-based and, therefore, rely on simple rules. For safety and efficiency a computer decision support system that employs complex logic may be superior to paper protocols., Methods: We designed and implemented GRIP, a stand-alone Java computer program. Our implementation of GRIP will be released as free software. Blood glucose values measured by a point-of-care analyzer were automatically retrieved from the central laboratory database. Additional clinical information was asked from the nurse and the program subsequently advised a new insulin pump rate and glucose sampling interval., Results: Implementation of the computer program was uneventful and successful. GRIP treated 179 patients for a total of 957 patient-days. Severe hypoglycemia (< 2.2 mmol/L) only occurred once due to human error. With a median (IQR) of 4.9 (4.2-6.2) glucose measurements per day the median percentage of time in which glucose fell in the target range was 78%. Nurses rated the program as easy to work with and as an improvement over the preceding paper protocol. They reported no increase in time spent on glucose control., Conclusion: A computer driven protocol is a safe and effective means of glucose control at a surgical ICU. Future improvements in the recommendation algorithm may further improve safety and efficiency.

Objective: To find out if there is an association between hyperglycaemia and mortality in mixed ICU patients.Design and Setting: Retrospective cohort study over a 2-year period at the medical ICU of a university hospital.Measurements: Admission glucose, maximum and mean glucose, length of stay, mortality, insulin therapy and Apache-II score.Results: In 1085 consecutive patients, ICU- and hospital mortality were 20 and 25%, respectively. The total number of blood glucose measurements was 10.012. Admission glucose was 7.9 +/- 4.5 mmol/l (mean +/- SD), mean glucose 7.5 +/- 2.9 and maximum glucose 10.0 +/- 5.4 mmol/l. Median ICU length of stay (LOS) was 3.0 days (range 2.0-6.0 days, IQR), and hospital LOS was 16 days (range 7-32 days). In 28% of patients insulin treatment was started. Median Apache-II score was 13. 68% of patients were mechanically ventilated. Univariate analysis showed an association with ICU mortality for mean glucose (non-survivors 8.6 +/- 4.3 vs 7.2 +/- 2.4 survivors), maximum glucose (11.7 +/- 5.9 vs 9.6 +/- 5.2, non-survivors vs survivors, respectively), use of insulin (mortality 29 vs 17% in patients not using insulin) and age (61 vs 55.7 years). Gender and a history of diabetes mellitus were not associated with mortality. In a multivariate model, the Apache-II score was the only variable associated with mortality independent of other variables, including mean blood glucose.Conclusion: In this retrospective study mean glucose level was not an independent risk factor for mortality in mixed ICU patients. [ABSTRACT FROM AUTHOR]

Background: Favorable clinical outcomes have been observed with glucose-insulin-potassium infusion (GIK) in acute myocardial infarction (MI). The mechanisms of this beneficial effect have not been delineated clearly. GIK has metabolic, anti-inflammatory and profibrinolytic effects and it may preserve the ischemic myocardium. We sought to assess the effect of GIK infusion on infarct size and left ventricular function, as part of a randomized controlled trial. Methods: Patients (n = 940) treated for acute MI by primary percutaneous coronary intervention (PCI) were randomized to GIK infusion or no infusion. Endpoints were the creatinine kinase MB-fraction (CK-MB) and left ventricular ejection fraction (LVEF). CK-MB levels were determined 0, 2, 4, 6, 24, 48, 72 and 96 hours after admission and the LVEF was measured before discharge. Results: There were no differences between the two groups in the time course or magnitude of CK-MB release: the peak CK-MB level was 249 ± 228 U/L in the GIK group and 240 ± 200 U/L in the control group (NS). The mean LVEF was 43.7 ± 11.0 % in the GIK group and 42.4 ± 11.7% in the control group (P = 0.12). A LVEF ≤ 30% was observed in 18% in the controls and in 12% of the GIK group (P = 0.01). Conclusion: Treatment with GIK has no effect on myocardial function as determined by LVEF and by the pattern or magnitude of enzyme release. However, left ventricular function was preserved in GIK treated patients. [ABSTRACT FROM AUTHOR]