Profound hypokalemia causing respiratory failure in a cat with hyperaldosteronism

Abstract

Objective: Description of acute respiratory failure in a cat due to profound hypokalemia associated with primary hyperaldosteronism. Case summary: A cat was presented with weakness and paraparesis that deteriorated rapidly into acute ventilatory failure. The serum potassium concentration declined despite intravenous fluid therapy. Positive pressure ventilation was required to support ventilatory function. A functional adrenocortical adenoma was found at necropsy in conjunction with a serum aldosterone concentration of greater than 3329 pmol/L. New or unique information provided: Respiratory failure secondary to profound hypokalemia is a rare, although recognized, condition. There are few reports that focus on this aspect of respiratory failure in the veterinary literature and primary hyperaldosteronism has not been reported as a cause of respiratory failure in cats.

Successful use of short‐term mechanical ventilation to manage respiratory failure secondary to profound hypokalemia in a cat with hyperaldosteronism

“…In addition, the hypokalemia can be severe enough to cause respiratory muscle paralysis that necessitates mechanical ventilation. In 2007, the first case of respiratory failure in a cat secondary to profound hypokalemia due to hyperaldosteronism was described in the veterinary literature 27 . However, that cat was euthanized at the owner's request within an hour of starting positive pressure ventilation due to the development of a pneumothorax.…”

“…In 2007, the first case of respiratory failure in a cat secondary to profound hypokalemia due to hyperaldosteronism was described in the veterinary literature. 27 However, that cat was euthanized at the owner's request within an hour of starting positive pressure ventilation due to the development of a pneumothorax. A definitive diagnosis of primary hyperaldosteronism was made postmortem based on a banked serum sample (aldosterone 43329 pmol/L) and the finding of a right-sided adrenal mass on necropsy.…”

Electrolyte Evaluation

“…18,31 Clinical signs of hypokalemia generally occur with serum potassium concentrations ≤2.5 mEq/L and include generalized weakness characterized classically by cervical ventriflexion that can progress to paralysis and respiratory difficulties, inability to concentrate urine, anorexia, vomiting, and decreased bowel motility. 24,26,32 Cardiac conduction abnormalities can occur and mani fest on ECG by a depressed ST segment, decreased amplitude or inversion of the T wave, increased P wave amplitude, and prolonged PR and QRS intervals. 24 Mul tiple arrhythmias may also occur.…”

Serum aldosterone and cortisol concentrations before and after suppression with fludrocortisone in cats

“…15,23 In contrast, in cats, suspicion of PHA arises with identification of hypokalemia, hypertension, and elevated plasma aldosterone concentration; diagnosis ultimately relies on identification of a discrete tumor within the adrenal glands. 1,2,4,[7][8][9]14,17,[19][20][21] However, in the absence of a discrete tumor, such as in cats with adrenocortical nodular hyperplasia, minimal or no adrenal gland changes may be detected via ultrasound. 10 In fact, in humans, following a diagnosis of PHA, further testing such as a computed tomography scan and adrenal vein blood sampling is conducted to differentiate between unilateral and bilateral hyperplasia, adenoma or adenocarcinoma.…”

“…Primary hyperaldosteronism (PHA) in cats has been reported in the veterinary literature since 1983, but with increasing frequency over the past decade. 1,2,4,7–10,14,17,19–21 It is an important feline disease because of significant associated morbidity and mortality attributable to resultant hypokalemia and hypertension. Furthermore, it has been implicated as a mediator of progression of renal disease 10 and hypertension 11 in cats.…”