Treatment strategies for hyperkalemia secondary to urethral obstruction in 50 male cats: 2002-2017.

ABSTRACT

OBJECTIVES: The aims of this study were to describe the potassium-lowering treatment strategies used to manage moderate-to-severe hyperkalemia in male cats with urethral obstruction (UO); to determine how much dextrose was required per unit of insulin to prevent hypoglycemia; to determine whether early initiation of a dextrose continuous rate infusion (CRI) prevented hypoglycemia; and to determine whether in-hospital mortality was associated with presenting plasma potassium concentration ([K+]). METHODS: The medical records of male cats presenting with a [K+] ⩾7.0 mEq/l due to UO that had another [K+] measured within 6 h were reviewed retrospectively. All [K+] values within the first 6 h, blood glucose concentrations, treatments for hyperkalemia and survival to discharge were recorded. Analyses were performed to test for associations between dextroseinsulin ratios or method of dextrose administration and the development of hypoglycemia; and for presenting [K+] and mortality. Normally distributed groups of continuous data were compared with a t-test and categorical data were compared with a Fisher's exact test. RESULTS: Fifty cats were included. Mean presenting [K+] was 8.9 ± 1.0 mEq/l, while the mean final [K+] within 6 h was 6.6 ± 1.4 mEq/l. Forty-two (84%) cats were treated with intravenous fluids and 40 (80%) were treated with dextrose and insulin. Median dextroseinsulin ratio was 2 g/u (range 0.4-100). No dextroseinsulin ratio was found to protect against hypoglycemia, and 3/8 cats that became hypoglycemic had received ⩾2 g dextrose per unit of insulin. There was no association between the early initiation of a dextrose-containing CRI and avoidance of hypoglycemia. No association was found between presenting [K+] and mortality. CONCLUSIONS AND RELEVANCE While no specific dextroseinsulin ratio was found to protect against hypoglycemia, there is evidence that the commonly recommended dextroseinsulin ratio of 2 g/u may be inadequate in preventing hypoglycemia in every cat. Severity of hyperkalemia was not associated with mortality.