The EFFECTS OF PROCEDURE DURATION AND ATIPAMEZOLE ADMINISTRATION ON HYPERKALEMIA IN TIGERS (PANTHERA TIGRIS) AND LIONS (PANTHERA LEO) ANESTHETIZED WITH Α-2 AGONISTS

Hyperkalaemia during two consecutive anaesthetics in an aggressive Bengal cat

“…The recovery was uneventful, and the cat regained a normal HR (160 bpm) and blood pressure (MAP 82 mm Hg) 5 minutes following administration. Unfortunately, it was impossible to monitor potassium in the post‐operative period due to the temperament of the cat, but it is feasible that the atipamezole would have contributed to alleviation of the hyperkalaemia if medetomidine was a contributing factor in its development 13,15,17,18 …”

“…The occurrence of hyperkalaemia under general anaesthesia is a well-known complication in wild felids. The disorder has been recognised in seven different species [13][14][15][16][17][18] and in up to 20% of a population composed mainly of anaesthetised tigers, cheetahs and cougars. 32 However, the phenomenon has not been reported to the same extent in domestic cats.…”

“…44 Additionally, high doses of alpha-2 agonists tend to prolong the inhibition of insulin release in domestic cats; the maximum decrease in plasma insulin concentration and the peak in plasma glucose concentration occur at approximately 1 and 2 hours, respectively, 44 and similar findings were found in large felids. 13,18 The combination of hypoinsulinaemia and hyperglycaemia with hyperkalaemia is well described in nondomestic cats, with the inhibition of insulin secretion mediated by medetomidine seeming to play an important role. 13,16 Therefore, these drugs should be considered an important potential factor in the development of hyperkalaemia.…”

“…Unfortunately, it was impossible to monitor potassium in the post-operative period due to the temperament of the cat, but it is feasible that the atipamezole would have contributed to alleviation of the hyperkalaemia if medetomidine was a contributing factor in its development. 13,15,17,18 The effect of alpha-2 adrenoreceptor agonists on the secretion of cortisol in cats has been described. Xylazine and medetomidine cause a decrease of plasma cortisol, but it is unclear whether this effect is alpha-2 adrenoreceptor related, with recent studies suggesting the involvement of imidazoline receptors.…”

“…Ketamine was also administered as part of premedication, and almost all large felids that develop hyperkalaemia under general anaesthesia receive ketamine for immobilisation but always in combination with an alpha-2 adrenergic agonist. [13][14][15][16][17][18] There is no direct link reported between ketamine and potassium homeostasis, and consequently, it is unlikely that ketamine played a role in the development of hyperkalaemia.…”