Objective

To evaluate the analgesic efficacy and safety of tumescent local anesthesia (TLA) in cats undergoing unilateral mastectomy.

Study design

Prospective clinical trial.

Animals

A total of 12 ovariohysterectomized female cats.

Methods

All animals were premedicated with pethidine (4 mg kg^–1) intramuscularly (IM), followed by induction of anesthesia with propofol (5 mg kg^–1) intravenously and maintenance with isoflurane in oxygen. A refrigerated TLA solution (15 mL kg^–1, 8 °C) was injected using a Klein cannula. The solution was composed of 0.5 mL of epinephrine (1 mg mL^–1) and 40 mL of 2% lidocaine added to 210 mL lactated Ringer’s solution (final lidocaine concentration 0.32%). Heart and respiratory rates, systolic arterial blood pressure, temperature and oxygen saturation were measured during anesthesia. Blood samples were collected from the jugular vein for measurement of plasma lidocaine concentration using high performance liquid chromatography. Postoperative pain scores were evaluated hourly for 6 hours. Analgesic rescue was performed with tramadol (2 mg kg^–1) IM and meloxicam (0.15 mg kg^–1) subcutaneously.

Results

Plasma lidocaine concentration peaked at 90 minutes after injection of TLA, but no concentration considered toxic for the species was measured. The median postoperative analgesia time was 6 hours after injection of TLA.

Conclusions

This study found that TLA prevented sympathetic response to noxious stimuli during anesthesia and provided satisfactory postoperative analgesia in cats submitted to total unilateral mastectomy, with no apparent signs of toxicity.

Clinical relevance

TLA can prevent sympathetic stimulation resulting from noxious stimuli during anesthesia, promoting good intraoperative conditions, proving to be a viable addition to analgesia in cats submitted to a total unilateral mastectomy.

中文翻译：

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猫单侧乳房切除术肿胀局部麻醉的评估

客观的

评估肿胀局部麻醉（TLA）对接受单侧乳房切除术的猫的镇痛效果和安全性。

学习规划

前瞻性临床试验。

动物

共 12 只卵巢子宫切除的雌性猫。

方法

所有动物都预先用哌替啶 (4 mg kg ^–1 ) 肌肉注射 (IM)，然后用异丙酚 (5 mg kg ^–1 ) 静脉内诱导麻醉，并在氧气中用异氟醚维持。使用 Klein 套管注入冷冻的 TLA 溶液（15 mL kg ^–1，8 °C）。该溶液由 0.5 mL 肾上腺素 (1 mg mL ^–1) 和 40 mL 2% 利多卡因添加到 210 mL 乳酸林格氏溶液中（最终利多卡因浓度为 0.32%）。在麻醉期间测量心脏和呼吸频率、收缩动脉血压、温度和氧饱和度。从颈静脉收集血样用于使用高效液相色谱法测量血浆利多卡因浓度。术后疼痛评分每小时评估一次，持续 6 小时。使用曲马多 (2 mg kg ^–1 ) IM 和美洛昔康 (0.15 mg kg ^–1 ) 皮下进行镇痛救援。

结果

血浆利多卡因浓度在注射 TLA 后 90 分钟达到峰值，但未检测到被认为对该物种有毒的浓度。中位术后镇痛时间为注射 TLA 后 6 小时。

结论

该研究发现，TLA 可防止麻醉期间对有害刺激的交感神经反应，并为接受全单侧乳房切除术的猫提供令人满意的术后镇痛，没有明显的毒性迹象。

临床相关性

TLA 可以防止麻醉期间由有害刺激引起的交感神经刺激，促进良好的术中条件，证明是对接受全单侧乳房切除术的猫镇痛的可行补充。