Hyperkalemia during general anesthesia in two Greyhounds

Abstract

CASE DESCRIPTION A 36-kg (79-lb) castrated male Greyhound (dog 1) and a 25-kg (55 lb) spayed female Greyhound (dog 2) underwent general anesthesia for dental care with similar perianesthetic protocols on multiple occasions from 2013 to 2016. Both dogs had periodontal disease but were otherwise deemed healthy. Both dogs developed clinically relevant hyperkalemia, with signs including loss of P waves on ECG tracings, during multiple anesthetic events. CLINICAL FINDINGS Dog 1 developed hyperkalemia during 2 of 2 anesthetic events, with ECG changes noted during the first event. Dog 2 developed hyperkalemia during 3 of 4 anesthetic events, with ECG changes identified during the second and third events. Serum potassium concentration for both dogs was within the reference range prior to and between anesthetic events. No underlying etiopathogenesis for hyperkalemia was identified for either dog.

Repeated hyperkalaemia during two separate episodes of general anaesthesia in a nine-year-old, female neutered greyhound

“…The fact that many greyhounds have ear tattoos post racing has allowed for tracing of genotype. The underlying pathophysiology is yet to be elicited and warrants further investigation, although the prevalence is reported at 38 per cent in a group of 95 dogs, with 80 per cent occurring at greater than 120 minutes of anaesthesia and the rest at less than 90 minutes 23. This time frame fits with the case reported here and may explain the hyperkalaemia seen.…”

“…With other, currently unpublished, reports of greyhounds developing hyperkalaemia when anaesthetised, a genetic predisposition to this condition should be considered whenever a greyhound is scheduled for general anaesthesia. This presentation has been described in the literature using the term ‘sudden intraoperative hyperkalaemia of greyhounds’4 or ‘anaesthesia-induced hyperkalaemia in Greyhounds’ 23. The suggestion is that a familial component may play a role, with duration of general anaesthesia being an inciting cause.…”

Recurrent Hyperkalemia During General Anesthesia in a Dog

“…There are also human case reports documenting hyperkalemia after a single bolus of propofol at an average dose (14,15). There have been a few recent case reports published describing development of perioperative hyperkalemia in dogs and all of these patients received propofol (2)(3)(4). However, aside from the case reported by Mallard et al (3), none of the dogs developed signs supportive of PRIS except for hyperkalemia and did not receive a continuous rate infusion.…”

“…There are also reports of veterinary species-specific problems such hyperkalemic periodic paralysis in Quarter Horses (6) [also reported in a dog (7)], episodic hyperkalemia in Greyhounds (8), and unexplained hyperkalemia in non-domestic felids (9). There was a recent case series documenting repeated intra-operative hyperkalemia in two Greyhounds where the inciting cause was not identified (2). Greyhounds reportedly have significantly lower than average basal aldosterone levels, which may have contributed to the development of hyperkalemia or to their inability to rapidly and/or effectively respond to increases in serum potassium when they occurred.…”

“…It is an uncommon intra-operative complication but can occur secondary to a variety of causes. Recently, there have been increased reports of the development of hyperkalemia in canine patients under anesthesia (2)(3)(4). This case report describes the development of repeated severe hyperkalemia under general anesthesia in a dog of which the cause remains unknown.…”