Anesthetic and physiologic effects of tiletamine, zolazepam, ketamine, and xylazine combination (TKX) in feral cats undergoing surgical sterilization

Abstract

Tiletamine (12.5 mg), zolazepam (12.5 mg), ketamine (20 mg), and xylazine (5 mg) (TKX; 0.25 ml, IM) combination was evaluated as an anesthetic in 22 male and 67 female adult feral cats undergoing sterilization at high-volume sterilization clinics. Cats were not intubated and breathed room air. Oxygen saturation (SpO(2)), mean blood pressure (MBP), heart rate (HR), respiration rate (RR), and core body temperature were recorded. Yohimbine (0.25 ml, 0.5 mg, IV) was administered at the completion of surgery. TKX produced rapid onset of lateral recumbency (4+/-1 min) and surgical anesthesia of sufficient duration to complete surgical procedures in 92% of cats. SpO(2) measured via a lingual pulse oximeter probe averaged 92+/-3% in male cats and 90+/-4% in females. SpO(2) fell below 90% at least once in most cats. MBP measured by oscillometry averaged 136+/-30 mm Hg in males and 113+/-29 mm Hg in females. MBP increased at the onset of surgical stimulation suggesting incomplete anti-nociceptive properties. HR averaged 156+/-19 bpm, and RR averaged 18+/-8 bpm. Neither parameter varied between males and females or over time. Body temperature decreased significantly over time, declining to 38.0+/-0.8 degrees C at the time of reversal in males and 36.6+/-0.8 degrees C at the time of reversal in females. Time from anesthetic reversal to sternal recumbency was prolonged (72+/-42 min). Seven cats (8%) required an additional dose of TKX to maintain an adequate plane of anesthesia at the onset of surgery, and this was associated with significantly longer recovery times (108+/-24 min).

Contenção farmacológica do gato-do-mato-pequeno, Leopardus tigrinus, para colheita de sêmen, pela associação de tiletamina zolazepam e xilazina

“…Pachaly et al (2002a) descreveram tempos médios de anestesia menores, com retorno à consciência em 90,90±39,10 minutos com dosagens similares de tiletamina + zolazepam (6,94mg/kg) e maiores de xilazina (2,77mg/ kg). Cistola et al (2004) relataram o uso de um protocolo anestésico similar em gatos domésticos, porém com a associação de cloridrato de cetamina além dos farmacos descritos, com tempo anestésico de 72,0±42,0 minutos, e reversão por ioimbina, que diminui o tempo de recuperação anestésica. Ambos os trabalhos revelaram segurança no uso dessas associações farmacológicas, sendo relatada por Pachaly et al (2002a) apenas uma intercorrência em gato-do-mato-pequeno, com quadro de distúrbio psicomotor incluindo tremores, obnubilação e ataxia, posteriormente estabilizado.…”

“…Houve diferença significativa (pd"0,05) entre P1 e P2, sendo que em P2 a FR média foi superior à observada em P1. As médias, entretanto, mantiveram-se dentro de níveis aceitáveis para o procedimento anestésico, embora Pachaly et al (2002c) e Cistola et al (2004) tenham relatado freqüências respiratórias um pouco menores para gato-maracajá e gato doméstico (29,87±7,23 e 18,00±8,00 MRPM, respectivamente). Uma hipótese explicativa seria o menor controle da sensibilidade dolorosa, identificado em P2 após a eletroejaculação, que poderia propiciar elevação da FR.…”

“…Pachaly et al (2002c) descreveram valores de 122,13±16,55 batimentos por minuto para freqüência cardíaca em gato-maracajá anestesiado com protocolo similar. Cistola et al (2004) encontraram valores de 156±19 BPM em gatos domésticos submetidos a anestesia dissociativa.…”

“…O quadro foi estabilizado e o paciente se recuperou da anestesia, sendo encaminhado para tratamento clínico da insuficiência cardíaca. O cloridrato de ioimbina, na dose de 0,5mg por animal, foi descrito por Cistola et al (2004), para reversão do protocolo anestésico associan-do tiletamina, zolazepam, cetamina e xilazina em cirurgias de castração em gatos domésticos.…”

Continuous infusion in adult females dogs submitted to ovariohysterectomy with midazolam-xylazine and/or medetomidine pre-treated with methotrimeprazine and buprenorphine

“…This reduction was more relevant in G1 although with greater values as compared to G2. This behavior can be based on the depressing effect of xylazine on f 23,24 . The relationship between V T and f showed that the greatest alteration was related to xylazine confirming, once again, the compensatory phenomenon.…”