Iatrogenic hypoglycaemia following glucose-insulin infusions for the treatment of hyperkalaemia.

OBJECTIVES To study the incidence of, and risk factors for, iatrogenic hypoglycaemia following GwI infusion in our institution. Context Hyperkalaemia is a life-threatening biochemical abnormality. Glucose-with-insulin (GwI) infusions form standard management, but risk iatrogenic hypoglycaemia (glucose ≤ 3.9mmol/L). Recently updated UK guidelines include an additional glucose infusion in patients with pre-treatment capillary blood glucose (CBG) <7.0 mmol/L. DESIGN Retrospective analysis of outcomes for GwI infusions prescribed for hyperkalaemia from 1st January-28th February 2019, extracted from the Newcastle-upon-Tyne Hospitals NHS Foundation Trust electronic platform (eRecord). Participants 132 patients received 228 GwI infusions for hyperkalaemia. Main outcome measures Incidence, severity and time-to-onset of hypoglycaemia. RESULTS Hypoglycaemia incidence was 11.8%. At least 1 hypoglycaemic episode occurred in 18.2% of patients with 6.8% having at least 1 episode of severe hypoglycaemia (<3.0 mmol/L). Most episodes (77.8%) occurred within 3 hours of treatment. Lower pre-treatment CBG(5.9 mmol/L [4.1 mmol/L - 11.2 mmol/L],; versus 7.6 mmol/L [3.7 mmol/L - 31.3 mmol/L], p = 0.000) was associated with hypoglycaemia risk. A diagnosis of type 2 diabetes and treatment for hyperkalaemia within the previous 24 hours were negatively associated. CONCLUSIONS Within our inpatient population, around 1 in 8 GwI infusions delivered as treatment for hyperkalaemia resulted in iatrogenic hypoglycaemia. Higher pre-treatment CBG and a diagnosis of type 2 diabetes were protective, irrespective of renal function. Our findings support the immediate change to current management, either with additional glucose infusions, or by using glucose-only infusions in patients without diabetes. These approaches should be compared via a prospective randomised study.