The use of propofol and sevoflurane for surgical anaesthesia in New Zealand White rabbits

Abstract

New Zealand White (NZW) rabbits (n ¼ 34) received intravenous propofol (16 + 5 mg/kg) for induction of anaesthesia followed by maintenance with sevoflurane (4.0 + 0.5%) in oxygen. All animals underwent ovariohysterectomy. Heart rate, respiratory rate, haemoglobin oxygen saturation, end-tidal carbon dioxide concentration, end-tidal sevoflurane concentration and oesophageal temperature were monitored every 5 min. Time from induction of anaesthesia to tracheal extubation and sternal recumbency were recorded as was the quality of recovery. Direct arterial blood pressure values (mmHg) were recorded every 5 min from 19 rabbits and 22 arterial blood gases analyses were performed (11 postintubation and 11 at the time of recovery). Propofol produced smooth induction of anaesthesia without production of apnoea. Intubation was successfully performed in all but one rabbit in an average of 4 + 3 min from the beginning of propofol administration. No ventilatory support was required during the anaesthetic period. Respiratory rate averaged 51 + 8 bpm and end-tidal CO 2 (kPa) was 4.0 + 0.5 mmHg during anaesthesia. Blood gas values were maintained within normal limits and average mean arterial blood pressure was 73.4 + 7.9 mmHg. Time to regain the swallowing reflex following discontinuation of sevoflurane was 2 + 1 min and time to sternal recumbency was 8 + 0.3 min. No anaesthetic-related mortality occurred and all animals recovered uneventfully. Propofolsevoflurane anaesthesia produced a good quality of surgical anaesthesia for ovariohysterectomy and stable cardiopulmonary conditions. Propofol-sevoflurane anaesthesia in young healthy NZW rabbits appears to be an effective and practically useful method of anaesthesia.

Use of arterial blood gas analysis as a superior method for evaluating respiratory function in pet rabbits (Oryctolagus cuniculus)

“…Mean values of arterial pH reported previously have ranged between 7.26 and 7.46 which are comparable with the values reported here (mean 7.45) (Burnett and Itano 1989, Egbrink and others 1989, Flecknell and others 1990, Rich and others 1990, Barzago and others 1992, Sakai and others 1999, Allweiler and others 2010, Schroeder and Smith 2011. )…”

“…The values obtained in the present study (mean 33.2) are lower than those previously reported in anaesthetised rabbits but are comparable with those values published for conscious rabbits (Egbrink and others 1989, Flecknell and others 1990, Rich and others 1990, Barzago and others 1992, Sakai and others 1999, Toal and Gul 2006, Allweiler and others 2010). This may be due to hyperventilation, which was noted clinically in all the conscious rabbits in this study; however, no data was collected on respiratory rate.…”

Preanesthesia, Anesthesia, Analgesia, and Euthanasia

“…Degree of sedation or anesthesia, as well as alteration of physiologic variables, depends upon infusion rate and time of day of administration. Allweiler et al (2010) describe such administration to unsedated, pre-oxygenated rabbits. Pedal withdrawal reflexes and preanesthetic levels of heart rate, respiratory rate, mean arterial pressure, and end tidal CO 2 were preserved (Ko et al, 1992).…”

“…Sevoflurane use in the rabbit has now been wellcharacterized (Scheller et al, 1988;Allweiler et al, 2010;Flecknell et al, 1999). The MAC for this agent in rabbits as determined by tail clamp is 3.7% (Scheller et al, 1988).…”

“…The MAC for this agent in rabbits as determined by tail clamp is 3.7% (Scheller et al, 1988). In rabbits being ovariohysterectomized, propofol induction followed by sevoflurane maintenance (4.0 ± 0.5%) provided surgical anesthesia with cardiopulmonary stability and a return to sternal recumbency within 8 min of sevoflurane termination (Allweiler et al, 2010). A number of studies have characterized the hemodynamic and ventilatory response of sevoflurane-anesthetized rabbits to infusion of various sedative-hypnotic (propofol, midazolam) and analgesic (remifentanyl, dexmedetomidine) agents (Nishizawa et al, 2012;Chang et al, 2009;Sazuka et al, 2012;Koshika et al, 2011).…”