Description and evaluation of a glycemic management protocol for patients with diabetes undergoing heart surgery

To evaluate a protocol for glycemic management in the treatment of postoperative heart patients with diabetes in the setting of a community hospital.

The protocol included a standardized guideline in tabular form for nurse-implemented insulin infusion ("drip") therapy for postoperative glycemic control. At the time of discontinuation of the insulin drip, the glycemic status of patients with diabetes was managed by the endocrine department. Overall, 29 patients were assessed without and 29 patients with use of the protocol in a community hospital.

From postoperative days 0 through 4, use of the protocol resulted in a greater number of blood glucose determinations, a trend toward greater utilization of insulin drip therapy without a significant increase in the number of patients treated with insulin drip, and no change in the frequency of hypoglycemic episodes. During the same time interval, the percentages of postoperative days during which at least one blood glucose value equaled or exceeded 250 mg/dL were 27.5% without the protocol and 16.8% with use of the protocol (P = 0.0318). The principal finding of the study was reduction in the percentage of postoperative days during which mean blood glucose values equaled or exceeded 200 mg/dL to less than half the previously observed frequency-from 38.4% without the protocol to 16.8% with the protocol (P = 0.0001). The effectiveness of the insulin drip component of the protocol is suggested by a trend, shown on postoperative days 2 through 4, of 70 patient days with mean blood glucose levels <200 mg/dL (58 of these days without insulin drip therapy) and 15 patient days with mean blood glucose values > or =200 mg/dL (none of these days associated with same-day insulin drip therapy).

A standardized approach to insulin drip therapy, in combination with subspecialty consultation for follow-up glycemic management with use of subcutaneous administration of insulin, can improve glycemic control in postoperative heart patients without continuation of insulin drip therapy outside the critical-care unit. The trends observed on postoperative days 2 through 4, that most patients maintained glycemic control without insulin drip therapy and that all failures of glycemic control occurred among patients who no longer received insulin drip therapy, suggest the possibility of developing criteria for selection of patients for continuation of insulin infusion outside the critical-care unit.