Effectiveness of insulin solution: a comparison between different times for maintaining the solution

Hyperglycemia is frequent in the critically ill patient, and is a risk factor for unfavorable clinical outcomes, including mortality. During the recent years, intensive blood glucose control using intravenous insulin infusion has gained a prominent role in the critically ill patient management. There is important concern on insulin solution continued efficacy over the time, as little the literature available on this subject is poor. Lack of evidence is known to lead to inappropriate practices. This study aimed to compare the blood glucose levels between two different protocols in an intensive care unit in Porto Alegre, using the same solution concentration and two different replacement times during the first 24 hours, and additionally to assess the protocol-related hypoglycemia rate.

The medical charts of 80 patients under insulin therapy for over 24 hours during 2008 were revised; 40 patients had their insulin solution replaced every 6 hours and for 40 patients the insulin solution was replaced after 24 hours.

The causes for admission to the intensive care unit included more frequently hypertensive (68.8%) and diabetic (45%) patients. No significant capillary blood glucose differences were seen for the every 6 or 24 hours solution replacement groups. Only 3 mild hypoglycemia cases were observed in the every 6 hours replacement group, and no hypoglycemia was seen in the 24 hours replacement group.

We concluded that keeping insulin infusion, replacing the solution every 24 hours is feasible. However, longer infusion time studies are required to check for possible hypoglycemic events as insulin therapy advances.