Marntell Stina, Nyman Görel, Funkquist Pia, Hedenstierna Göran
Department of Large Animal Clinical Sciences, Faculty of Veterinary Medicine, Swedish University of Agricultural Sciences, Uppsala, Sweden.
Vet Anaesth Analg. 2005 Mar;32(2):83-93. doi: 10.1111/j.1467-2995.2004.00178.x.
To study pulmonary gas exchange and cardiovascular responses to sedation achieved with romifidine and butorphanol (RB) alone, or combined with acepromazine, and during subsequent tiletamine-zolazepam anaesthesia in horses.
Six (four males and two females) healthy Standardbred trotters aged 3-12 years; mass 423-520 kg.
Randomized, cross-over, experimental study.
Horses were anaesthetized on two occasions (with a minimum interval of 1 week) with intravenous (IV) tiletamine-zolazepam (Z; 1.4 mg kg(-1)) after pre-anaesthetic medication with IV romifidine (R; 0.1 mg kg(-1)) and butorphanol (B; 25 microg kg(-1) IV). At the first trial, horses were randomly allocated to receive (protocol ARBZ) or not to receive (protocol RBZ) acepromazine (A; 35 microg kg(-1)) intramuscularly (IM) 35 minutes before induction of anaesthesia. Each horse was placed in left lateral recumbency and, after tracheal intubation, allowed to breathe room air spontaneously. Respiratory and haemodynamic variables and ventilation-perfusion (; multiple inert gas elimination technique) ratios were determined in the conscious horse, after sedation and during anaesthesia. One- and two-way repeated-measures anova were used to identify within- and between-technique differences, respectively.
During sedation with RB, arterial oxygen tension (PaO(2)) decreased compared to baseline and increased mismatch was evident; there was no O(2) diffusion limitation or increase in intrapulmonary shunt fraction identified. With ARB, PaO(2) and remained unaffected. During anaesthesia, intrapulmonary shunt occurred to the same extent in both protocols, and mismatching increased. This was less in the ARBZ group. Arterial O(2) tension decreased in both protocols, but was lower at 25 and 35 minutes of anaesthesia in RBZ than in ARBZ. During sedation, heart rate (HR) and cardiac output (Qt) were lower while arterial-mixed venous oxygen content differences and haemoglobin concentrations were higher in RBZ compared with ARBZ. Total systemic vascular resistance, mean systemic, and mean pulmonary arterial pressures were higher during anaesthesia with RBZ compared to ARBZ.
Acepromazine added to RB generally improved haemodynamic variables and arterial oxygenation during sedation and anaesthesia. Arterial oxygenation was impaired as a result of increased shunt and mismatch during anaesthesia, although acepromazine treatment reduced disturbances and falls in PaO(2) to some extent. Haemodynamic variables were closer to baseline during sedation and anaesthesia when horses received acepromazine. Acepromazine may confer advantages in healthy normovolaemic horses.
研究单独使用罗米芬定和布托啡诺（RB）或联合乙酰丙嗪镇静时以及随后在马进行替来他明-唑拉西泮麻醉期间的肺气体交换和心血管反应。
6匹（4匹雄性和2匹雌性）3至12岁健康的标准赛马；体重423 - 520千克。
随机、交叉、实验性研究。
马在两次麻醉（间隔至少1周）时，先静脉注射罗米芬定（R；0.1毫克/千克）和布托啡诺（B；25微克/千克静脉注射）进行麻醉前给药，然后静脉注射替来他明-唑拉西泮（Z；1.4毫克/千克）。在第一次试验中，马被随机分配在麻醉诱导前35分钟肌肉注射（IM）乙酰丙嗪（A；35微克/千克）（方案ARBZ）或不注射（方案RBZ）。每匹马置于左侧卧位，气管插管后，让其自主呼吸室内空气。在清醒马、镇静期间和麻醉期间测定呼吸和血流动力学变量以及通气-灌注（；多惰性气体消除技术）比值。分别使用单向和双向重复测量方差分析来确定技术内和技术间的差异。
在RB镇静期间，动脉血氧分压（PaO₂）与基线相比降低，且通气/血流不匹配明显增加；未发现O₂扩散受限或肺内分流分数增加。使用ARB时，PaO₂未受影响。在麻醉期间，两种方案中肺内分流程度相同，且不匹配增加。ARBZ组这种情况较轻。两种方案中动脉血氧张力均降低，但在麻醉25分钟和35分钟时，RBZ组的PaO₂低于ARBZ组。在镇静期间，与ARBZ组相比，RBZ组心率（HR）和心输出量（Qt）较低，而动脉-混合静脉血氧含量差和血红蛋白浓度较高。与ARBZ组相比，RBZ麻醉期间总全身血管阻力、平均体循环和平均肺动脉压更高。
在RB中添加乙酰丙嗪通常可改善镇静和麻醉期间的血流动力学变量和动脉氧合。尽管乙酰丙嗪治疗在一定程度上减少了干扰和PaO₂下降，但麻醉期间由于分流增加和通气/血流不匹配导致动脉氧合受损。当马接受乙酰丙嗪时，镇静和麻醉期间血流动力学变量更接近基线。乙酰丙嗪可能对健康的血容量正常的马具有优势。
