Bigby Sarah E, Beths Thierry, Bauquier Sébastien, Carter Jennifer E
Department of Veterinary Medicine, University of Cambridge, Cambridge, England, UK.
Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Werribee, VIC, Australia.
Vet Anaesth Analg. 2017 Nov;44(6):1267-1275. doi: 10.1016/j.vaa.2017.03.005. Epub 2017 May 2.
To evaluate the effect of rate of administration of propofol or alfaxalone on induction dose requirements and incidence of postinduction apnea (PIA) in dogs following premedication with methadone and dexmedetomidine.
Prospective, randomized clinical trial.
Thirty-two healthy American Society of Anesthesiologists class I client-owned dogs (seven females, 25 males), aged between 5 and 54 months, weighing between 2.0 and 48.2 kg.
Dogs were premedicated intramuscularly with 0.5 mg kg methadone and 5 μg kg dexmedetomidine. Thirty minutes after premedication, dogs were preoxygenated for 5 minutes before the induction agent was administered intravenously via a syringe driver until orotracheal intubation was achieved. Dogs were randomized to receive alfaxalone 0.5 mg kg minute (A-Slow), alfaxalone 2 mg kg minute (A-Fast), propofol 1 mg kg minute (P-Slow), or propofol 4 mg kg minute (P-Fast). Oxygen saturation of hemoglobin (SpO), end-tidal carbon dioxide and respiratory rate were monitored. If PIA (≥30 seconds without a breath) occurred, the time to the first spontaneous breath was measured. If SpO decreased below 90%, the experiment was stopped and manual ventilation initiated.
The mean±standard deviation induction doses of alfaxalone and propofol were lower in the A-Slow [A-Slow 0.9±0.3 mg kg, A-Fast 2.2±0.5 mg kg (p≤0.001)] and P-Slow [P-Slow 1.8±0.6 mg kg, P-Fast 4.1±0.7 mg kg (p≤0.001)] groups, respectively. The incidence of PIA was 25% for the A-Slow and P-Slow groups and 100% for the A-Fast and P-Fast groups (p = 0.007).
Both propofol and alfaxalone following methadone and dexmedetomidine premedication caused PIA. Induction dose requirement and incidence of PIA were affected by the rate of administration of both drugs. When possible, propofol and alfaxalone doses should be reduced and administered slowly to reduce PIA.
评估在美沙酮和右美托咪定预处理后，丙泊酚或阿法沙龙的给药速度对犬诱导剂量需求及诱导后呼吸暂停（PIA）发生率的影响。
前瞻性随机临床试验。
32只健康的美国麻醉医师协会I级客户拥有的犬（7只雌性，25只雄性），年龄在5至54个月之间，体重在2.0至48.2千克之间。
犬肌肉注射0.5毫克/千克美沙酮和5微克/千克右美托咪定进行预处理。预处理30分钟后，在通过注射器驱动器静脉注射诱导剂直至进行气管插管前，犬预充氧5分钟。犬被随机分为接受0.5毫克/千克·分钟阿法沙龙（A-慢）、2毫克/千克·分钟阿法沙龙（A-快）、1毫克/千克·分钟丙泊酚（P-慢）或4毫克/千克·分钟丙泊酚（P-快）。监测血红蛋白氧饱和度（SpO）、呼气末二氧化碳和呼吸频率。如果发生PIA（呼吸暂停≥30秒），测量首次自主呼吸的时间。如果SpO降至90%以下，停止实验并开始人工通气。
阿法沙龙和丙泊酚的平均±标准差诱导剂量在A-慢组[A-慢0.9±0.3毫克/千克，A-快2.2±0.5毫克/千克（p≤0.001）]和P-慢组[P-慢1.8±0.6毫克/千克，P-快4.1±0.7毫克/千克（p≤0.001）]中分别较低。A-慢组和P-慢组的PIA发生率为25%，A-快组和P-快组为100%（p = 0.007）。
美沙酮和右美托咪定预处理后，丙泊酚和阿法沙龙均会引起PIA。两种药物的给药速度均会影响诱导剂量需求和PIA发生率。可能的情况下，应降低丙泊酚和阿法沙龙的剂量并缓慢给药以减少PIA。
