Matthews N S, Hartsfield S M, Hague B, Carroll G L, Short C E
Texas Veterinary Medical Center, Texas A & M University, College Station 77843-4474, USA.
Vet Surg. 1999 May-Jun;28(3):196-201. doi: 10.1053/jvet.1999.0196.
To evaluate propofol for induction and maintenance of anesthesia, after detomidine premedication, in horses undergoing abdominal surgery for creation of an experimental intestinal adhesion model.
Prospective study.
Twelve horses (424 +/- 81 kg) from 1 to 20 years of age (5 females, 7 males).
Horses were premedicated with detomidine (0.015 mg/kg i.v.) 20 to 25 minutes before induction, and a propofol bolus (2 mg/kg i.v.) was administered for induction. Propofol infusion (0.2 mg/kg/min i.v.) was used to maintain anesthesia. The infusion rate was adjusted to maintain an acceptable anesthetic plane as determined by muscle relaxation, occular signs, response to surgery, and cardiopulmonary responses. Oxygen (15 L/min) was insufflated through an endotracheal tube as necessary to maintain the SpO2 greater than 90%. Systolic (SAP), mean (MAP), and diastolic (DAP) arterial pressures, heart rate (HR), electrocardiogram (ECG), respiratory rate (RR), SpO2 (via pulse oximetry), and nasal temperature were recorded at 15 minute intervals, before premedication and after induction of anesthesia. Arterial blood gas samples were collected at the same times. Objective data are reported as mean (+/-SD); subjective data are reported as medians (range).
Propofol (2.0 mg/kg i.v.) induced anesthesia (mean bolus time, 85 sec) within 24 sec (+/-22 sec) after the bolus was completed. Induction was good in 10 horses; 2 horses showed signs of excitement and these two inductions were not smooth. Propofol infusion (0.18 mg/kg/min +/- 0.04) was used to maintain anesthesia for 61 +/- 19 minutes with the horses in dorsal recumbency. Mean SAP, DAP, and MAP increased significantly over time from 131 to 148, 89 to 101, and 105 to 121 mm Hg, respectively. Mean HR varied over time from 43 to 45 beats/min, whereas mean RR increased significantly over anesthesia time from 4 to 6 breaths/min. Mean arterial pH decreased from a baseline of 7.41 +/- 0.07 to 7.30 +/- 0.05 at 15 minutes of anesthesia, then increased towards baseline values. Mean PaCO2 values increased during anesthesia, ranging from 47 to 61 mm Hg whereas PaO2 values decreased from baseline (97 +/- 20 mm Hg), ranging from 42 to 57 mm Hg. Muscle relaxation was good and no horses moved during surgery: Recovery was good in 9 horses and acceptable in 3; mean recovery time was 67 +/- 29 minutes with 2.4 +/- 2.4 attempts necessary for the horses to stand.
Detomidine-propofol anesthesia in horses in dorsal recumbency was associated with little cardiovascular depression, but hypoxemia and respiratory depression occurred and some excitement was seen on induction.
Detomidine-propofol anesthesia is not recommended for surgical procedures in horses if dorsal recumbency is necessary and supplemental oxygen is not available (eg, field anesthesia).
评估在进行腹部手术以建立实验性肠粘连模型的马匹中，在给予右美托咪定进行术前用药后，丙泊酚用于诱导和维持麻醉的效果。
前瞻性研究。
12匹马（体重424±81千克），年龄1至20岁（5匹雌性，7匹雄性）。
在诱导前20至25分钟，给马匹静脉注射右美托咪定（0.015毫克/千克）进行术前用药，然后静脉注射丙泊酚推注剂量（2毫克/千克）进行诱导。使用丙泊酚输注（0.2毫克/千克/分钟静脉输注）维持麻醉。根据肌肉松弛程度、眼部体征、对手术的反应以及心肺反应来调整输注速率，以维持可接受的麻醉平面。必要时通过气管内导管吹入氧气（15升/分钟），以维持脉搏血氧饱和度（SpO2）大于90%。在术前用药前和麻醉诱导后，每隔15分钟记录收缩压（SAP）、平均动脉压（MAP）、舒张压（DAP）、心率（HR）、心电图（ECG）、呼吸频率（RR）、SpO2（通过脉搏血氧饱和度测定）和鼻腔温度。同时采集动脉血气样本。客观数据以平均值（±标准差）报告；主观数据以中位数（范围）报告。
丙泊酚（2.0毫克/千克静脉注射）在推注完成后24秒（±22秒）内诱导麻醉（平均推注时间为85秒）。10匹马诱导效果良好；2匹马出现兴奋迹象，这两次诱导不平稳。使用丙泊酚输注（0.18毫克/千克/分钟±0.04）将马匹仰卧位维持麻醉达61±19分钟。平均SAP、DAP和MAP随时间显著升高，分别从131毫米汞柱升至148毫米汞柱、从89毫米汞柱升至101毫米汞柱、从105毫米汞柱升至121毫米汞柱。平均HR随时间从43次/分钟变化至45次/分钟，而平均RR在麻醉期间从4次/分钟显著增加至6次/分钟。平均动脉pH值在麻醉15分钟时从基线的7.41±0.07降至7.30±0.05，然后向基线值升高。麻醉期间平均动脉血二氧化碳分压（PaCO2）值升高，范围为47至61毫米汞柱，而动脉血氧分压（PaO2）值从基线（97±20毫米汞柱）下降至范围为42至57毫米汞柱。肌肉松弛良好，手术期间无马匹移动：9匹马恢复良好，3匹马恢复可接受；平均恢复时间为67±29分钟，马匹站立需要2.4±2.4次尝试。
马匹仰卧位时右美托咪定 - 丙泊酚麻醉导致的心血管抑制较小，但出现了低氧血症和呼吸抑制，且诱导时出现了一些兴奋现象。
如果需要马匹仰卧位且无法提供补充氧气（如野外麻醉），不建议在马匹手术中使用右美托咪定 - 丙泊酚麻醉。
