Causes of Hyperglycemia and Hypoglycemia in Adult Inpatients

Wendy D. Smith; Almut G. Winterstein; Thomas Johns; Eric Rosenberg; Brian C. Sauer


Am J Health Syst Pharm. 2005;62(7):714-719. 

In This Article

Abstract and Introduction

Purpose: The underlying causes of hyperglycemia and hypoglycemia in adult medical and surgical inpatients were studied.
Methods: Hyperglycemic and hypoglycemic events occurring in adult medical and surgical patients admitted between February and July 2003 to a tertiary care hospital were identified prospectively from automated daily printouts of abnormal blood glucose levels generated by the hospital laboratory. Information on the causes of a random sample of events was ascertained within 24 hours through chart review and provider and patient interviews. Narratives were presented to an expert committee to assess the causes of each event and preventability.
Results: Eighteen of 24 hypoglycemic events and 26 of 26 hyperglycemic episodes were considered preventable. Failure to adjust antidiabetic drugs in response to decreases in oral intake and unexpected deviation from normal hospital routine were the most common factors contributing to hypoglycemia. Hyperglycemia was most often associated with an unwillingness of providers to take responsibility for diabetes management and the exclusive use of sliding-scale insulin regimens.
Conclusion: Hyperglycemia and hypoglycemia in medical and surgical inpatients were mostly related to inadequate prescribing, monitoring, and communication practices.

The significance of medication errors and their negative impact on public health are well documented.[1] The prevalence of medication errors in hospitalized patients has been estimated to be 1-10%.[2] One of the most common high-risk areas for medication errors and preventable adverse drug events (ADEs) appears to be the use of insulin and the overall management of diabetes mellitus in acute care. The 2001 report of Medmarx, a national database for hospital medication error reporting, identified insulin as the medication most frequently involved in harmful medication errors, especially errors in dosage, errors of omission, and prescribing errors.[3] A comprehensive review of published reports of preventable ADEs stated that insulin and antidiabetic medications are among the top 10 medications associated with preventable ADEs in the inpatient setting.[2]

Multiple retrospective and prospective studies have been performed to establish the significance of glucose control in the acute care setting and to identify risk factors associated with poor glucose control.[4,5,6,7,8,9,10,11,12] However, few studies have been published characterizing medication errors and suggesting potential areas for quality improvement initiatives relevant to glucose control in acute care.[13,14,15] These studies -- which lacked a systematic assessment of causes of hypoglycemia and failed to address hyperglycemia -- suggested establishing a check system whereby one nurse prepares the dose and another nurse reviews it, storing insulin and heparin separately, avoiding the use of the abbreviation U for units, and using independent check systems for infusion rates and concentration settings.[13,14] Despite wide-spread efforts to make these changes, the incidence of medication errors involving insulin remains high.

It remains unclear if targeting slips and lapses, errors caused by misreading or miswriting, or other oversights will accomplish a significant improvement in diabetes patient outcomes in hospitals. It is also unknown whether these types of errors account for the largest portion of causes of preventable hyperglycemia and hypoglycemia. To date, no study has been designed to systematically determine the underlying causes of both hyperglycemia and hypoglycemia in hospitalized patients.

The purpose of this study was to identify and quantify the underlying causes of hyperglycemia and hypoglycemia in adult medical and surgical patients.