Drs. Kirkman and Juneja (1) are correct in pointing out the discrepancies between the text and the algorithm figures for post hyperglycemic crises management in our articles on hyperglycemic crises (2,3). We regret the confusion surrounding this issue and have corrected this omission in Figs. 1 and 2, as described below.
As stated in the text, as soon as the patient is able to tolerate fluids and/or meals, we recommend treatment with a multidose regimen of short- and intermediate/long–acting insulin after resolution of the hyperglycemic crisis. To maintain adequate plasma insulin levels and prevent recurrence of diabetic ketoacidosis (DKA) and/or hyperglycemia, subcutaneous (SC) insulin should be given 1–2 h before the insulin infusion is discontinued.
After the resolution of DKA or hyperosmolar hyperglycemic state (HHS), some patients may be unable to take oral nourishment. While NPO (not eating), they should receive intravenous (IV) insulin infusion or be temporarily treated every 4 h with SC regular insulin based on blood glucose levels. SC regular insulin is given in 5-unit increments for every 50 mg/dl increase in blood glucose above 150 mg/dl for up to 20 units for a blood glucose of 300 mg/dl. In our experience, the above dosage of insulin every 4 h, while the patient is NPO and receiving glucose and insulin, has not resulted in hypoglycemia or relapse of hyperglycemia and/or ketoacidosis. It should be emphasized that such a step is only temporary and is by no means a replacement for intermediate/long–acting insulin along with multiple-dose regular insulin. This statement was omitted in Figs. 1 and 2 of the position paper (2) and Figs. 4 and 5 in the technical review (3). The figures will be modified as follows for DKA and HHS:
Check electrolytes, BUN [blood urea nitrogen], creatinine and glucose every 2–4 h until stable. After resolution of DKA, if the patient is NPO, continue IV insulin and supplement with SC regular insulin as needed. When the patient can eat, initiate a multidose insulin regimen and adjust as needed [see text for details]. Continue IV insulin infusion for 1–2 h after SC insulin is begun to ensure adequate plasma insulin levels. Continue to look for precipitating cause(s).
Check electrolytes, BUN, creatinine and glucose every 2–4 h until stable. After resolution of HHS, if the patient is NPO, continue intravenous insulin and supplement with SC regular insulin as needed [see text]. When the patient can eat, initiate SC insulin or previous treatment regimen and assess metabolic control. Continue to look for precipitating cause(s).
In the second letter, Dr. Lorber (4) expresses his concern that sliding scale insulin is reactive rather than proactive and that it fails to account for individual variability in insulin sensitivity. We believe that the use of continuous fixed sliding scale insulin as monotherapy should be discouraged; however, the transient use of supplemental regular insulin alone or in combination with long-acting insulin is effective in the recovery phase of hyperglycemic crises (5,6). A different issue is the use of sliding scale insulin for the routine management of diabetes, which has been a subject of controversy in the literature. Historically, the term “sliding scale insulin” has evoked concerns by clinicians regarding the risk of hypoglycemia and hyperglycemia that may result from a lack of attention to daily blood glucose patterns. Obviously, any insulin regimen requires frequent assessments and adjustments; therefore, using a fixed sliding scale as the only treatment to control blood glucose is counterproductive.
Another criticism is that a sliding scale insulin regimen simply “chases” the blood glucose rather than prevents hyperglycemia through the use of a proactive insulin plan. The latter statement is without supported evidence. On the contrary, the benefit of an insulin bolus preprandially based on a flexible schedule using rapid-acting insulin either via an insulin pump or injection has been well demonstrated (7,8,9); however, a static dose of insulin has resulted in very poor glucose control. The current use of sliding scale insulin incorporates a more sophisticated approach to optimizing blood glucose control that considers not only the ambient blood glucose level but also the variables that will affect the blood glucose level over the next 1–4 h. Therefore, the intent of a flexible sliding scale is one that varies depending on content of meal, time of day, premeal blood glucose, etc. This, however, does not remove the responsibility from the clinician or the patient for acting on consistent pre- or postprandial elevations in blood glucose levels.
A flexible regimen may be the most important approach in controlling postprandial peaks in blood glucose. Therefore, it behooves us to look carefully at the subject of “sliding scale” insulin before summarily dismissing it as a harmful intervention. Whatever term we choose to use, the use of a sliding scale or supplemental insulin algorithm is an invaluable tool in the management and education of the patient requiring insulin for glucose control.
Article Information
We are grateful to Drs. Kirkman, Juneja, and Lorber for their constructive comments.
References
Address correspondence and reprint requests to Abbas E. Kitabchi, University of Tennessee Health Science Center, Department of Medicine, 951 Court Ave., Room 335M, Memphis, TN 38163. E-mail: akitabchi@utmem.edu
