Objective

To evaluate the efficacy and cardiopulmonary effects of ketamine–midazolam for chemical restraint, isoflurane anesthesia and tramadol or methadone as preventive analgesia in spotted pacas subjected to laparoscopy.

Study design

Prospective placebo-controlled blinded trial.

Animals

A total of eight captive female Cuniculus paca weighing 9.3 ± 0.9 kg.

Methods

Animals were anesthetized on three occasions with 15 day intervals. Manually restrained animals were administered midazolam (0.5 mg kg^–1) and ketamine (25 mg kg^–1) intramuscularly. Anesthesia was induced and maintained with isoflurane 30 minutes later. Tramadol (5 mg kg^–1), methadone (0.5 mg kg^–1) or saline (0.05 mL kg^–1) were administered intramuscularly 15 minutes prior to laparoscopy. Heart rate (HR), respiratory rate, mean arterial pressure (MAP), peripheral oxygen saturation (SpO₂), end-tidal CO₂ partial pressure (Pe′CO₂), end-tidal concentration of isoflurane (Fe′Iso), pH, PaO₂, PaCO₂, bicarbonate (HCO₃⁻), anion gap (AG) and base excess (BE) were monitored after chemical restraint, anesthesia induction and at different laparoscopy stages. Postoperative pain was assessed by visual analog scale (VAS) for 24 hours. Variables were compared using anova or Friedman test (p < 0.05).

Results

Chemical restraint was effective in 92% of animals. Isoflurane anesthesia was effective; however, HR, MAP, pH and AG decreased, whereas Pe′CO₂, PaO₂, PaCO₂, HCO₃⁻ and BE increased. MAP was stable with tramadol and methadone treatments; HR, Fe′Iso and postoperative VAS decreased. VAS was lower for a longer time with methadone treatment; SpO₂ and AG decreased, whereas Pe′CO₂, PaCO₂ and HCO₃⁻ increased.

Conclusions and clinical relevance

Ketamine–midazolam provided satisfactory restraint. Isoflurane anesthesia for laparoscopy was effective but resulted in hypotension and respiratory acidosis. Tramadol and methadone reduced isoflurane requirements, provided postoperative analgesia and caused hypercapnia, with methadone causing severe respiratory depression. Thus, the anesthetic protocol is adequate for laparoscopy in Cuniculus paca; however, methadone should be avoided.

中文翻译：

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化学抑制、异氟醚麻醉和美沙酮或曲马多作为经腹腔镜检查的斑点美洲豹（Cuniculus paca）预防性镇痛的评估

客观的

评估氯胺酮-咪达唑仑用于化学抑制、异氟醚麻醉和曲马多或美沙酮作为腹腔镜检查的斑点帕卡斯预防性镇痛的功效和心肺作用。

学习规划

前瞻性安慰剂对照盲试验。

动物

总共八只圈养雌性Cuniulus paca，重 9.3 ± 0.9 公斤。

方法

动物以 15 天的间隔麻醉 3 次。手动约束的动物肌肉注射咪达唑仑（0.5 mg kg ^–1）和氯胺酮（25 mg kg ^–1）。30分钟后用异氟醚诱导并维持麻醉。在腹腔镜检查前 15 分钟肌肉注射曲马多 (5 mg kg ^–1 )、美沙酮 (0.5 mg kg ^–1 ) 或生理盐水 (0.05 mL kg ^–1 )。心率 (HR)、呼吸频率、平均动脉压 (MAP)、外周血氧饱和度 (SpO ₂ )、呼气末 CO ₂分压 (P e' CO ₂ )、异氟醚呼气末浓度 (F e'Iso)、pH、PaO ₂、PaCO ₂、碳酸氢盐（HCO ₃ ^-）、阴离子间隙（AG）和碱过量（BE）在化学约束、麻醉诱导和不同腹腔镜检查阶段进行监测。术后疼痛通过视觉模拟量表 (VAS) 评估 24 小时。使用方差分析或弗里德曼检验比较变量( p < 0.05)。

结果

化学抑制对 92% 的动物有效。异氟醚麻醉有效；然而，HR、MAP、pH 和 AG 降低，而Pe ' CO ₂、PaO ₂、PaCO ₂、HCO ₃ ^-和 BE 增加。曲马多和美沙酮治疗后 MAP 稳定；HR、F e' Iso 和术后 VAS 降低。美沙酮治疗的 VAS 在较长时间内较低；SpO ₂和AG 降低，而P e' CO ₂、PaCO ₂和HCO ₃ ^-增加。

结论和临床相关性

氯胺酮-咪达唑仑提供了令人满意的抑制。腹腔镜检查异氟醚麻醉有效，但会导致低血压和呼吸性酸中毒。曲马多和美沙酮减少了异氟醚的需求，提供术后镇痛并引起高碳酸血症，美沙酮引起严重的呼吸抑制。因此，麻醉剂协议是足够的腹腔镜Cuniculus帕卡; 但是，应避免使用美沙酮。