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

Abstract

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 ≤ 3.9 mmol/L). Recently updated UK guidelines include an additional glucose infusion in patients with pretreatment capillary blood glucose (CBG) < 7.0 mmol/L.

Design: Retrospective analysis of outcomes for GwI infusions prescribed for hyperkalaemia from 1 January to 28 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 h of treatment. Lower pretreatment 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 = .000) was associated with hypoglycaemia risk. A diagnosis of type 2 diabetes and treatment for hyperkalaemia within the previous 24 h were negatively associated.

Conclusions: Within our inpatient population, around 1 in 8 GwI infusions delivered as treatment for hyperkalaemia resulted in iatrogenic hypoglycaemia. Higher pretreatment 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 randomized study.

Keywords: dextrose; glucose-with-insulin; hyperkalaemia; hypoglycaemia.