To ensure timely adjustments to your patient’s regimen, make sure that all your orders for insulin administration are accompanied by provisions for revising the dosing regimen when changes in patient status occur. (Protocols for managing both hypo- and hyperglycemia should, of course, be part of your orders as well.)
No heightened hypoglycemia risk with basal/bolus regimen
A basal/bolus insulin regimen is more aggressive than a sliding-scale protocol, and fear of hypoglycemia has historically kept physicians from using it.1 The Randomized Study of Basal/Bolus Insulin Therapy in the inpatient management of patients with type 2 diabetes (RABBIT 2), published in 2007, addressed this concern. The researchers compared blood glucose levels for inpatients on a sliding-scale insulin regimen with those of patients on a basal/bolus regimen and found no difference in the frequency of hypoglycemia.7 None of the participants were critically ill.
The study did show, however, that those on the sliding-scale regimen had higher mean fasting and random blood glucose levels than those on the basal/bolus regimen. Of patients on the basal/bolus regimen, 66% reached the target—a mean blood glucose <140 mg/dL—vs 38% of those on the sliding-scale regimen. What’s more, 14% of those on the traditional regimen never achieved levels <240 mg/dL, whereas all of those in the basal/bolus group did. The mean daily insulin dose was significantly higher for those on the basal/bolus plan vs the sliding scale regimen (42 vs 12.5 units, respectively).7
RABBIT 2 provides clear evidence of significant improvement in glycemic control among inpatients on a basal/bolus insulin regimen, but patient-oriented outcomes have yet to be measured. However, emerging evidence of the impact of hyperglycemia on morbidity and mortality among diabetes patients in intensive care18,19 has led the American College of Endocrinology5 and the Society of Hospital Medicine, among others, to recommend using basal/bolus insulin in the management of inpatients with diabetes.
IV insulin’s role—and is it expanding?
IV insulin is the treatment of choice for patients in diabetic ketoacidosis, but recent research suggests that it may also be the preferred approach to diabetes management in other critically ill patients, as well as in those undergoing surgery.18-20
In a study comparing outcomes of surgical ICU patients managed with IV insulin during the perioperative and postoperative periods with surgical patients on conventional diabetes management, Van den Berghe found a 45% reduction in mortality rates among those receiving insulin infusions (4.6% of those on IV insulin died, compared with 8% of those receiving subcutaneous insulin). The use of IV insulin therapy also decreased the time spent in intensive care, although it did not shorten the overall length of stay.19
Regular insulin is used most often for insulin infusions. Some trials with ultra–short-acting insulin have been done, but the findings were inconclusive.
Your patient is leaving: Ease the transition
For inpatients with diabetes, discharge planning includes a transition, from insulin to oral agents, perhaps, and from maintaining glucose control based on a hospital schedule to adjusting to the patterns of daily life at home. Particular care is required for patients who will be transitioned from IV to subcutaneous insulin. IV insulin has a half-life of only 10 minutes, so the initial subcutaneous dose should be administered about 1 hour prior to discontinuation of the infusion. Failure to plan accordingly may result in significant hyperglycemia and associated complications.17,21
Research suggests that patients be switched to their outpatient diabetes management plan at least 24 hours before discharge, a protocol that was followed in Mr. H’s case. He remained in the hospital for 5 days. After myocardial infarction was ruled out, Mr. H underwent a nuclear medicine cardiac stress test for which he needed to be NPO. When testing was completed, Mr. H resumed a diabetic diet, and discharge planning began. Since his diabetes was not well controlled on admission and he required >20 units of insulin per day in the hospital, Mr. H’s physician opted to include long-acting insulin at bedtime in his outpatient regimen. On the day before Mr. H was scheduled to leave the hospital, the physician discontinued the short-acting mealtime insulin and restarted oral metformin twice daily, closely monitoring the patient’s glucose levels until discharge. The physician told Mr. H to schedule a follow-up visit within a week so that his new outpatient regimen could be reviewed.
Ideally, a diabetes nurse specialist will be available, not only to get involved in discharge planning, but also to provide patient education, care, and advice. Researchers found that hospital stays for patients with diabetes were shortened (8 days vs 11 days) when a diabetes nurse specialist was involved in their care. The patients were also more knowledgeable and satisfied.22