Safety and feasibility of an insulin adjustment protocol to maintain blood glucose concentrations within a narrow range in critically ill patients in an Australian level III adult intensive care unit.

OBJECTIVE Recent data have shown a link between normal blood glucose levels and improved outcomes in intensive care patients. We wished to develop an insulin adjustment protocol for an adult intensive care unit to maintain blood glucose concentrations safely within a narrow range. METHODS After a 6 month introductory period, an observational study was conducted during a 10 month period in an Australian level III intensive care unit to assess the safety and feasibility of an insulin adjustment protocol to maintain blood glucose concentrations safely within a narrow range. The protocol included a variable insulin infusion, a constant caloric source and frequent blood glucose level monitoring to detect and prevent hypoglycaemia. RESULTS Over the 10 month period a total of 148 patients were studied using the protocol and represented 13 % of all intensive care unit admissions during this period. In total, there were 12,623 patient hours 'on protocol', with 5,603 blood glucose levels performed. The mean morning blood glucose level was 6.5 mmol/L and 49% of blood glucose levels were within the target range of 4.1 - 7.0 mmol/L. There were four recorded incidents of hypoglycaemia, defined as a blood glucose level of less than 2.2 mmol/L, the lowest at 1.5 mmol/L being the only symptomatic episode. The incidence of hyperglycaemia (blood glucose level > 10 mmol/L) was 13 % of all blood glucose level measurements. CONCLUSIONS The insulin adjustment protocol with a constant caloric source and frequent blood glucose level monitoring was found to be safe and feasible in maintaining blood glucose concentrations within a narrow range in a mixed adult intensive care unit population.