Should we use sliding-scale insulin as monotherapy for hospitalized diabetic patients?
Slide-scale insulin (SSI) is a method to correct hyperglycemia through frequent dosing of short acting insulin based on a patient’s blood glucose and pre-set rubric. When blood glucose is low little or no insulin is given and when blood glucose is elevated higher doses are administered. A recent publication by the Journal of Hospital Medicine addresses this common practice of managing hospitalized diabetic patients with SSI alone.
Where did this practice of SSI as monotherapy come from?
- First popularized by Joslin in 1934 it remains a popular strategy. In 2007 a survey of 44 hospitals found 43% of non-critically ill patients with hyperglycemia were treated with SSI alone.
- Inpatient providers not wanting to cause hypoglycemia may sometimes as a more conservative and convenient given ready-made order sets
Key Points
- SSI monotherapy does not replicate normal pancreatic physiology of basal insulin secretion indirectly suppressing hepatic gluconeogenesis nor meal-associated insulin stimulated uptake glucose uptake.
- SSI monotherapy is ineffective and potentially harmful. SSI is a reactive strategy and in two large systematic review has never been shown to prevent hyperglycemia in hospitalized patients.
- Patients on SSI monotherapy were at a 3-fold increased risk of developing hyperglycemia vs. SSI with other forms of insulin and may be more likely to have increased hospital length of stay.
- Basal insulin added to SSI when dosed carefully does not increase the risk of hypoglycemia.
- What should you do instead?
- A weight-based dosing basal plus prandial and correctional insulin regimen. The RABBIT 2 trial, involving T2DM patients, used a total daily dose of 0.4 units / kg for patients with blood sugar ≤200 mg/dL and 0.5 units/kg for those with higher initial glucose levels. Half of the total daily dose given to basal and other half divided among meals. Caution with patients > 70 yo, impaired GFR, or on fluctuating steroid doses.
- For the insulin naïve or patients whose home diabetic regimen is in question, it could be reasonable start with SSI as monotherapy for 24 hours to inform subsequent insulin dosing. This “dose finding” method has not been validated in the literature.
Ambrus DB, O’Connor MJ. Things We Do For No Reason: Sliding-Scale Insulin as Monotherapy for Glycemic Control in Hospitalized Patients. J Hosp Med. 2019 Feb 1;14(2):114-116. doi: 10.12788/jhm.3109. Epub 2018 Nov 28. PMID: 30534639.
Kristen Lee MD, PGY3