Anaesthesia recovery quality after racemic ketamine or S-ketamine administration to male cats undergoing neutering surgery

Abstract

Postoperative anaesthesia recovery and analgesia qualities were compared in cats anaesthetised with racemic ketamine (RS-ket) or S-ketamine (S-ket) undergoing orchiectomy. Twenty client-owned male cats received medetomidine (0.03 mg/kg) and S-ket (6 mg/kg; n = 10) or RS-ket (10 mg/kg; n = 10), all intramuscularly. After routine orchiectomy, animals received atipamezole (0.15 mg/kg) intramuscularly. Thirty and 60 min after atipamezole administration, one observer unaware of the treatment identity evaluated analgesia using a visual analogue scale (VAS) and, by means of four points scales, sedation, unprovoked behaviour and behavioural reactions to external stimuli. Cats with a VAS > or = 15 mm were to receive butorphanol. Times to sternal and standing positions were recorded. After 60 min, cats were given carprofen (4 mg/kg) subcutaneously. Anaesthesia with S-ket, at 60% of the RS-ket dose, provided faster recoveries. At 60 min, undisturbed cats in S-ket group had a trend towards fewer behavioural changes. Cats in RS-ket group were more sedate at 30 min and responded with a lower intensity to external stimulation. Immediate postoperative analgesia was considered adequate for both groups and no cat required butorphanol administration.

Evaluation of three chemical immobilization protocols in golden‐headed lion tamarins (Leontopithecus chrysomelas) undergoing vasectomy surgery

“…50 Some studies show that ketamine S(+) presented a better clearance and, consequently, lower effective period and a faster anesthetic recovery. 51,52 In a report comparing equal doses of racemic and S(+) ketamine associated with midazolam in common marmosets did not see any difference as to induction and recovery times. 8 However, they observed that animals that received the racemic ketamine presented a longer period of immobilization.…”

“…Cats treated with dexmedetomidine presented a longer recovery period, but with better quality, smoother, and with better movement control . Some studies show that ketamine S(+) presented a better clearance and, consequently, lower effective period and a faster anesthetic recovery …”

Comparison of racemic ketamine and S-ketamine as agents for the induction of anaesthesia in goats

“…Based on studies in rats, mice and man it has been suggested that, in comparison to the racemate, the dose of S-ketamine should be reduced by 50-70% for anaesthetic use (Ryder et al 1978;White et al 1985). In recent years S-ketamine has been introduced in veterinary practice and its use has been reported in horses, dogs, cats and laboratory animals (Muir & Hubbell 1988;Larenza et al 2008aLarenza et al , 2009Rossetti et al 2008).…”

Efeitos anestésicos da administração intranasal ou intramuscular de cetamina S+ e midazolam em pomba-rola (Streptotelia sp.)

“…Em medicina, é muito utilizada como medicação pré-anestésica pela via intranasal, com boa eficácia e sem efeitos adversos para sedação em crianças (Diaz 1997). A cetamina S+ é o enantiômero levógiro da cetamina racêmica e apresenta maior afinidade a receptores NMDA, maior potência analgésica e menos efeitos adversos com menores doses quando comparada a cetamina racêmica (Duque et al 2008, Larenza et al 2008a, 2008b. Pelas características peculiares da cetamina S+, optou-se, no presente estudo, pela utilização da menor dose deste fármaco (20mg/kg) preconizada para anestesia de pombos.…”

“…Esta discrepância entre resultados pode ser decorrente da grande variedade intra e interespécies de pássaros (Samour et al 1984), considerando que diferentes famílias de pássaros foram avaliadas nos outros estudos, o que pode resultar em particularidades na biotransformação dos fármacos e na ação farmaco-lógica destes. Outra diferença importante é que a dose da cetamina S+ deste estudo (20mg/kg) foi metade da dose utilizada em periquitos (40 mg/kg), o que também poderia justificar a menor duração de ação nos pombos, apesar de alguns autores afirmarem que a cetamina S+, por apresentar maior efeito analgésico e maior potência, pode ter sua dose reduzida como o observado para gatos, cães e pôneis (Duque et al 2008, Larenza et al 2008a, 2008b.…”