PURPOSE: Glucose control is a major therapeutic focus in critically ill patients. Although morbidity and mortality benefits of normalization of blood glucose are generally accepted, there remains concern about hypoglycemia. During the implementation of a computerized insulin protocol in the adult ICUs of our hospital network, we investigated the factors and possible causes of hypoglycemic events and associated clinical sequelae.
METHODS: From May 3, 2005-March 31, 2006, coincident with dissemination of a computerized intravenous insulin glucose control protocol to the adult ICUs of Intermountain Health Care, all glucometer values of patients treated with the protocol (target range 80-110mg/dl) were reviewed five times per week. We investigated all glucometer blood glucose values ≤ 50 mg/dl (hypoglycemia) to determine potential reasons for the low value. Evaluation criteria were developed prior to the dissemination and consistently applied throughout the time of this report.
RESULTS: 1,898 patients (76,995 observations) were reviewed. Hypoglycemia occurred in 199 (10.5%) patients for a total of 260 events (0.34%). Clinical sequelae occurred in 29 of 260 events (11.2%). Of these, blood pressure changes of ± 10mmHg (systolic or mean) occurred 28 times (15 decreases, 13 increases) and one patient experienced a mental status change. Clinical problems contributing to hypoglycemic episodes were: diagnosis of diabetes 72 (27.7%), renal failure 21 (8.1%), or liver failure 13 (5%). Medications thought to contribute to hypoglycemia were steroids and/or vaso-active infusions 35 (13.5%), and insulin administration not directed by the protocol 46 (17.7%). 78 hypoglycemic events (30.0%) were associated with late glucose measurements (greater than 30 minutes) and 18 events (6.9%) were associated with disregard of protocol instructions.
CONCLUSION: The use of a computerized insulin protocol resulted in a low rate of hypoglycemia. Clinical sequelae were minimal, perhaps because of timely discovery and treatment. We found important factors associated with hypoglycemia. These factors have been used to educate bedside clinicians.
CLINICAL IMPLICATIONS: Discovery of factors related to hypoglycemia will potentiate the benefit and minimize the risk of glucose control.
DISCLOSURE: Vanessa Washington, None.