Surprising result after evaluating a nurse-driven guideline on blood glucose management

Introduction

Whether blood glucose management is a cornerstone in reducing ICU mortality is still under debate. Nevertheless, conscientious glucose regulation by intensive insulin therapy has become an indicator in the evaluation of the medical quality of ICUs in the Netherlands. In recent years, however, there have been several reports of increased hypoglycemic events and clinical harm due to stringent glucose regulation [1].

The general ICU in our hospital consists of two units with a comparable patient population with separate nursing staff but the same medical staff. Both units work with the same nurse-driven guideline for the blood glucose management providing some liberty in the decision-making process. The frequency of glucose measurement with a point-of-care device is left to the nurses' discretion. A glucose level of 4.5 to 7 mmol/l was set as the target value on both wards.

Methods

After 2 years the total number of tests done on each ward, the achieved average glucose level, and the number of hypoglycemic events (glucose <2.5 mmol/l) and hyperglycemic events (glucose >8 mmol/l) according to our hospital laboratory database were evaluated.

Results

Unit 1 had a total of 700 patients with 5,717 ICU-days and performed 27,218 tests according to an average of 4.8 tests/patient/day. Unit 1 achieved an average glucose level of 6.9 mmol/l with 0.6% hypoglycemia and 32% hyperglycemia. Unit 2 had a total of 504 patients with 5,384 ICU-days and performed 39,400 tests according to an average of 7.3 tests/patient/day. Unit 2 achieved an average glucose level of 6.4 mmol/l with 0.9% hypoglycemia and 20% hyperglycemia.

Conclusion

Using a nurse-driven protocol, both units achieved comparable and satisfying average glucose levels with acceptable numbers of hypoglycemic events. There was a striking difference in the number of tests performed between the two wards depending on interpretation of the same guideline.