Predictors of Iatrogenic Hypoglycemia in Treatment of Hyperkalemia
Do A, Naffouj S, Modi K, Hammoudeh R, Miller J, and Dabbagh MF. Predictors of Iatrogenic Hypoglycemia in Treatment of Hyperkalemia. J Gen Intern Med 2019; 34(2):S321.
J Gen Intern Med
Background: Hypoglycemia is a potential adverse outcome that could complicate the treatment of hyperkalemia with insulin administration. Treatment needs to be individualized for patients' specific characteristics to avoid iatrogenic hypoglycemia. Our study aimed to identify characteristics that could increase the risk of hypoglycemia. Methods: A retrospective study at a large tertiary institution was conducted from December 2016 to November 2017. A chart review was performed on adult patients who received subcutaneous insulin and intravenous glucose for treatment of hyperkalemia (potassium > 5 mmol/L) while present in the emergency department or inpatient setting. Patients who received insulin for the treatment of hyperglycemia were excluded. Data including demographics, insulin dose, and laboratory values were collected. The cohort was divided into two groups; patients who developed hypoglycemic events (defined as serum glucose < 70 mg/dL) and those who did not. Univariate and multivariate analysis was performed. The primary outcome was incidence of hypoglycemia. The secondary outcome was identifying predictors of hypoglycemia. Results: 1156 consecutive patients with hyperkalemia who were treated with insulin were analyzed. Mean age was 61 years, 59% were males, and 61% were African American. 69% had chronic kidney disease, and of those 32.7% were on hemodialysis. The mean dose of insulin administered was 0.105 +0.05 units/kg for a median pre-treatment potassium level of 5.9 mmol/L. 17.8% of patients developed hypoglycemia (N=206). The median pre-treatment glucose level was 126 mg/dL, and mean hypoglycemia level was 53 mg/dL. On multivariate analysis age (p=0.0328), pre-treatment glucose level (p< 0.0001), and insulin dosing (p=0.0032) were significant predictors of hypoglycemia. For every 10-year increase in age, the risk of hypoglycemia increased by an odds ratio (OR) of 1.128. For every 10 mg/dL increase in the pre-treatment glucose level, the odds of developing hypoglycemia were reduced by an OR of 0.929. For every 0.025 units/kg increase of insulin dosing above the 0.1 units/kg usually administered, the OR for hypoglycemia was increased by 1.006. There was a significant difference in the rates of hypoglycemic events between the emergency department (24.2%) compared to the general practice units (18.4%) and intensive care units (12.8%) (p< 0.001). There was no relationship between insulin dose and pre-treatment glucose (R2= 0.0006). Conclusions: Patients with older age, lower pre-treatment glucose and higher insulin doses were at increased risk of developing hypoglycemia following treatment of hyperkalemia with insulin. Clinicians should more regularly evaluate baseline glucose levels when treating hyperkalemia with insulin to prevent iatrogenic hypoglycemia.