An order set for insulin administration reduced hypoglycemia among inpatients being treated for hyperkalemia, a recent study found.
The observational, prospective study included adult nonobstetric patients treated for acute hyperkalemia (serum potassium ≥5.1 mEq/L) on medical, ICU, and surgical units at the University of California, San Francisco, Medical Center between January 2016 and September 2017. Results were published in the February Journal of Hospital Medicine.
In January 2016, the hospital implemented an initial hyperkalemia treatment order set, which added blood glucose checks before insulin injection and at one, two, four, and six hours after insulin. In March 2017, it was replaced with a new order set, which added weight-based dosing of insulin, alerts to identify patients at higher risk of hypoglycemia, and tools to guide decision making based on blood glucose levels. The study compared 225 insulin orders made under the old order set with 145 issued under the new one.
Under the first order set, the iatrogenic hypoglycemia rate (defined as a glucose level <70 mg/dL [3.9 mmol/L]) was 21%, with 92% of episodes occurring within three hours of first insulin treatment. The study identified some risk factors for hypoglycemia: decreased renal function (serum creatinine >2.5 mg/dL), a high dose of insulin (>0.14 units/kg), and retreatment when blood glucose was below 140 mg/dL (7.8 mmol/L). Under the updated order set, the rate of iatrogenic hypoglycemia decreased to 10%. Rates of severe hypoglycemia (glucose level <40 mg/dL [2.2 mmol/L]) were 5% and 2% under the respective order sets.
The study also showed a trend toward improved hyperglycemia rates and significantly decreased serum potassium levels under the revised order set. The latter might have been due to weight-based dosing of insulin, the study authors speculated.
“Prior studies have likely underestimated the incidence of hyperkalemia treatment-associated hypoglycemia as glucose levels are rarely checked within three hours of insulin administration,” they wrote. The authors noted that greater adherence to the order set would probably have provided even more improvement in glycemic control. In all five of the 14 hypoglycemic events under the updated order set, a recommended bolus of dextrose was not provided at the appropriate time. The order set generally was only used for about 75% of hyperkalemia patients, and adherence to the glucose checks was suboptimal, the authors noted.
Such frequent glucose monitoring during hyperkalemia treatment (two checks in a six-hour window) may be difficult in some clinical environments, but checking blood sugar before insulin administration and within four hours after should be a priority, they said. The authors also noted that they plan to update their order set with a best practice alert about the additional recommended dextrose bolus.