Use of lispro insulin for treatment of diabetic ketoacidosis in cats

Objectives: The aim of this study was to evaluate the efficacy and safety of lispro insulin for the treatment of feline diabetic ketoacidosis (DKA). Times to resolution of hyperglycaemia, ketosis and acidosis were compared between cats treated with continuous rate infusion (CRI) of lispro insulin and cats treated with CRI of regular insulin. Methods: Client-owned cats with naturally occurring DKA, newly diagnosed with diabetes mellitus (DM) or already receiving treatment for DM, were included. Diagnosis of DKA involved the presence of at least two clinical signs consistent with DKA (eg, polyuria/polydipsia, anorexia, severe lethargy, vomiting and dehydration), blood glucose (BG) concentration >13.9 mmol/l (>250 mg/dl), blood beta hydroxybutyrate (BHB) concentration >2.5 mmol/l and venous pH <7.3 or bicarbonate <15 mEq/l. Cats were treated with a standard protocol of an intravenous (IV) CRI of regular insulin (group R) or lispro insulin (group L). The time to resolution of DKA was defined as the time interval from when the IV CRI of insulin began until marked hyperglycaemia (BG >13.9 mmol/l [>250 mg/dl]), ketosis (BHB concentration >1 mmol/l) and acidosis (venous pH <7.3 and/or bicarbonate <15 mEq/l) resolved. Results: Eighteen DKA cases (nine per group) were enrolled into the study. There were no significant differences in the median time to resolution of three variables (hyperglycaemia, ketosis and acidosis) between the two groups. Two cats in group R developed hypoglycaemia during the CRI of insulin. One cat in group L and three cats in group R developed hypophosphataemia, which required phosphate supplementation. Conclusions and relevance: IV CRI of lispro insulin has few side effects and appears to be as effective as IV CRI of regular insulin in the treatment of cats with DKA.