PDF(Pubmed)
Abstract：
BACKGROUND: When inhalant anesthetic equipment is not available or during upper airway surgery, intravenous infusion of one or more drugs are commonly used to induce and/or maintain general anesthesia. Total intravenous anesthesia (TIVA) does not require endotracheal intubation, which may be more difficult to achieve in rabbits. A range of different injectable drug combinations have been used as continuous infusion rate in animals. Recently, a combination of ketamine and propofol (ketofol) has been used for TIVA in both human patients and animals. The purpose of this prospective, blinded, randomized, crossover study was to evaluate anesthetic and cardiopulmonary effects of ketofol total intravenous anesthesia (TIVA) in combination with constant rate infusion (CRI) of midazolam, fentanyl or dexmedetomidine in eight New Zealand White rabbits. Following IV induction with ketofol and endotracheal intubation, anesthesia was maintained with ketofol infusion in combination with CRIs of midazolam (loading dose [LD]: 0.3 mg/kg; CRI: 0.3 mg/kg/hr; KPM), fentanyl (LD: 6 µg/kg; CRI: 6 µg/kg/hr; KPF) or dexmedetomidine (LD: 3 µg/kg; CRI: 3 µg/kg/hr; KPD). Rabbits in the control treatment (KPS) were administered the same volume of saline for LD and CRI. Ketofol infusion rate (initially 0.6 mg kg- 1 minute- 1 [0.3 mg kg- 1 minute- 1 of each drug]) was adjusted to suppress the pedal withdrawal reflex. Ketofol dose and physiologic variables were recorded every 5 min.
RESULTS: Ketofol induction doses were 14.9 ± 1.8 (KPM), 15.0 ± 1.9 (KPF), 15.5 ± 2.4 (KPD) and 14.7 ± 3.4 (KPS) mg kg- 1 and did not differ among treatments (p > 0.05). Ketofol infusion rate decreased significantly in rabbits in treatments KPM and KPD as compared with saline. Ketofol maintenance dose in rabbits in treatments KPM (1.0 ± 0.1 mg/kg/min) and KPD (1.0 ± 0.1 mg/kg/min) was significantly lower as compared to KPS (1.3 ± 0.1 mg/kg/min) treatment (p < 0.05). Ketofol maintenance dose did not differ significantly between treatments KPF (1.1 ± 0.3 mg/kg/min) and KPS (1.3 ± 0.1 mg/kg/min). Cardiovascular variables remained at clinically acceptable values but ketofol infusion in combination with fentanyl CRI was associated with severe respiratory depression.
CONCLUSIONS: At the studied doses, CRIs of midazolam and dexmedetomidine, but not fentanyl, produced ketofol-sparing effect in rabbits. Mechanical ventilation should be considered during ketofol anesthesia, particularly when fentanyl CRI is used.
RESULTS: Ketofol induction doses were 14.9 ± 1.8 (KPM), 15.0 ± 1.9 (KPF), 15.5 ± 2.4 (KPD) and 14.7 ± 3.4 (KPS) mg kg- 1 and did not differ among treatments (p > 0.05). Ketofol infusion rate decreased significantly in rabbits in treatments KPM and KPD as compared with saline. Ketofol maintenance dose in rabbits in treatments KPM (1.0 ± 0.1 mg/kg/min) and KPD (1.0 ± 0.1 mg/kg/min) was significantly lower as compared to KPS (1.3 ± 0.1 mg/kg/min) treatment (p < 0.05). Ketofol maintenance dose did not differ significantly between treatments KPF (1.1 ± 0.3 mg/kg/min) and KPS (1.3 ± 0.1 mg/kg/min). Cardiovascular variables remained at clinically acceptable values but ketofol infusion in combination with fentanyl CRI was associated with severe respiratory depression.
CONCLUSIONS: At the studied doses, CRIs of midazolam and dexmedetomidine, but not fentanyl, produced ketofol-sparing effect in rabbits. Mechanical ventilation should be considered during ketofol anesthesia, particularly when fentanyl CRI is used.
摘要：
背景：当吸入麻醉设备不可用时或在上气道手术期间，静脉输注一种或多种药物通常用于诱导和/或维持全身麻醉。全静脉麻醉（TIVA）不需要气管插管，这在兔子中可能更难实现。一系列不同的可注射药物组合已被用作动物中的连续输注速率。最近,氯胺酮和丙泊酚(酮泊酚)的组合已用于人类患者和动物的TIVA.这个前景的目的，失明,随机化，交叉研究的目的是评估酮泊酚全静脉麻醉（TIVA）联合咪达唑仑恒定速率输注（CRI）的麻醉和心肺效果，8只新西兰白兔的芬太尼或右美托咪定。在静脉内诱导和气管插管后,麻醉维持与咪达唑仑的CRIs（负荷剂量[LD]：0.3mg/kg；CRI：0.3mg/kg/hr；KPM），芬太尼（LD：6µg/kg；CRI：6µg/kg/hr；KPF）或右美托咪定（LD：3µg/kg；CRI：3µg/kg；KPD）。对照处理(KPS)中的兔施用相同体积的用于LD和CRI的盐水。调整酮泊酚输注速率(最初0.6mgkg-1分钟-1[每种药物0.3mgkg-1分钟-1])以抑制踏板退缩反射。每5分钟记录酮泊酚剂量和生理变量。
结果：酮泊酚诱导剂量为14.9±1.8（KPM），15.0±1.9(KPF),15.5±2.4（KPD）和14.7±3.4（KPS）mgkg-1，在治疗之间没有差异（p>0.05）。与生理盐水相比，在KPM和KPD治疗中，兔的酮泊酚输注速率显着降低。与KPS(1.3±0.1mg/kg/min)治疗相比,治疗中KPM(1.0±0.1mg/kg/min)和KPD(1.0±0.1mg/kg/min)在兔中的酮泊酚维持剂量显著更低(p<0.05)。KPF（1.1±0.3mg/kg/min）和KPS（1.3±0.1mg/kg/min）治疗之间的酮泊酚维持剂量没有显着差异。心血管变量保持在临床上可接受的值，但输注氯酚与芬太尼CRI联合使用会导致严重的呼吸抑制。
结论：在研究剂量下，咪达唑仑和右美托咪定的CRIs，但不是芬太尼,在家兔体内产生了保留酮剂的作用。在氯氟醚麻醉期间应考虑机械通气,特别是当使用芬太尼CRI时。
结果：酮泊酚诱导剂量为14.9±1.8（KPM），15.0±1.9(KPF),15.5±2.4（KPD）和14.7±3.4（KPS）mgkg-1，在治疗之间没有差异（p>0.05）。与生理盐水相比，在KPM和KPD治疗中，兔的酮泊酚输注速率显着降低。与KPS(1.3±0.1mg/kg/min)治疗相比,治疗中KPM(1.0±0.1mg/kg/min)和KPD(1.0±0.1mg/kg/min)在兔中的酮泊酚维持剂量显著更低(p<0.05)。KPF（1.1±0.3mg/kg/min）和KPS（1.3±0.1mg/kg/min）治疗之间的酮泊酚维持剂量没有显着差异。心血管变量保持在临床上可接受的值，但输注氯酚与芬太尼CRI联合使用会导致严重的呼吸抑制。
结论：在研究剂量下，咪达唑仑和右美托咪定的CRIs，但不是芬太尼,在家兔体内产生了保留酮剂的作用。在氯氟醚麻醉期间应考虑机械通气,特别是当使用芬太尼CRI时。
