Subcutaneous Insulin Protocol for DKA Shows Significant Decrease in ICU Need

Vincent X. Liu, MD, MSc

Recent data suggest that a protocol based on subcutaneous insulin for diabetic ketoacidosis (DKA) treatment had associations with a significant decrease in both intensive care unit need and readmission.

The protocol additionally appeared to be safe for patients with DKA, showing no associated increases in the incidence of hypoglycemia during hospitalizations or in 30-day mortality.

“Our results suggest that an [subcutaneous] insulin-driven protocol including the selection of optimal patients can be used effectively in treating DKA, although these results should be confirmed in future prospective studies,” wrote study author Vincent X. Liu, MD, MSc, Kaiser Permanente Division of Research.

Standard therapy for DKA in the United States has included continuous intravenous regular insulin until resolution of ketoacidosis, managed in the ICU for close monitoring. Meanwhile, subcutaneous insulin could decrease the ICU needs, but data remain limited.

The current study examined the outcomes of patients with DKA treated with subcutaneous insulin protocol in place of IV insulin infusion, followed by rapid-acting insulin injections given over longer periods than previously examined.

Between January 2010 - January 2016, all hospitals in an integrated healthcare system in California used a standardized electronic health record (EHR) order set for treating DKA. At the start of 2016, the intervention hospital implemented a DKA protocol using subcutaneous insulin as primary treatment for all adult (≥18 years), nonpregnant patients.

The pre implementation period was defined as January 2010 - December 2015 and the post implementation as January 2017 - December 2019. Investigators compared the outcomes between the periods at the intervention site versus other system facilities through a difference-in-difference approach.

Outcomes of interest included mortality within 30 days of hospital admission, hospital readmission within 30 days of discharge, and overall hospital length of stay.

The study included a total of 7989 DKA hospitalizations, with 4739 hospitalizations (59.3%) occurring during pre implementation and 3250 (40.7%) occurring during post implementation. The overall mean age of patients was 42.3 years and included 4137 hospitalizations (51.8%) occurring among female patients.

Prior to implementation, data show subcutaneous insulin was the first insulin administered in 40 intervention site hospitalizations (13.4%), compared to 651 control (14.7%) hospitalizations. After implementation, a total of 98 hospitalizations (80.3%) received subcutaneous insulin first at the intervention site, compared with 402 hospitalizations (12.8%) at control sites.

Through the first 48 hours of hospitalization, the total number of insulin units administered at the intervention site did not differ between the preimplementation and postimplementation periods (122.5 versus 126.2 units), while they increased at standard care sites (109.6 versus 121.9 units).

Additionally, using difference-in-difference regression, data show the adjusted rate ratio for ICU admission was lower at the intervention site compared with the standard care sites at 0.43 (95% CI, 0.33 - 0.56), a 57% reduction compared with control. Moreover, the adjusted rate ratio for 30-day readmission was also lower at 0.50 (95% CI, 0.25 - 0.99), a 50% reduction.

Investigators observed no significant changes in hospital length of stay (0.97; 95% CI, 0.76 - 1.23) and rates of death.

The study, “Evaluation of Outcomes Following Hospital-Wide Implementation of a Subcutaneous Insulin Protocol for Diabetic Ketoacidosis,” was published in JAMA Network Open.