Objective

To describe the anesthetic and adverse effects of an injectable anesthetic protocol in dogs as part of a high-volume sterilization program under field conditions in Belize.

Study design

Prospective, observational, field study.

Animals

A total of 23 female and eight male dogs (14.2 ± 7.7 kg; age ≥ 8 weeks).

Methods

Using a volume per kg-based dose chart, dogs were administered ketamine (4.5 mg kg⁻¹), medetomidine (0.04 mg kg⁻¹) and hydromorphone (0.09 mg kg⁻¹) intramuscularly. After induction of anesthesia, an endotracheal tube was inserted and dogs were allowed spontaneous breathing in room air. Monitoring included peripheral oxygen saturation (SpO₂), mean arterial pressure (MAP), heart rate (HR), respiratory rate, rectal temperature and end-tidal carbon dioxide (Pe′CO₂). Meloxicam (0.2 mg kg⁻¹) was administered subcutaneously after surgery. Data were analyzed with linear models and chi-square tests (p < 0.05).

Results

Onset of lateral recumbency (3.4 ± 2 minutes) was rapid. Desaturation (SpO₂ < 90%) was observed at least once in 64.5% of dogs and was more frequent in large dogs (p = 0.019). Hypercapnia (Pe′CO₂ ≥ 50 mmHg; 6.7 kPa) was observed in 48.4% of dogs. MAP was 111 ± 19 mmHg, mean ± standard deviation. Hypertension (MAP ≥ 120 mmHg), bradycardia (HR ≤ 60 beats minute⁻¹) and tachycardia (HR ≥ 140 beats minute⁻¹) were observed in 45.2%, 16.1% and 3.3% of dogs, respectively. Hypotension and hypothermia were not observed. Sex was not significantly associated with any complication. Return of swallowing reflex and time to standing were 71 ± 23 and 152 ± 50 minutes after injection, respectively. Return of swallowing was significantly longer in large dogs.

Conclusions and clinical relevance

At the doses used, ketamine–medetomidine–hydromorphone was effective in dogs for high-volume sterilization. In this field setting, adverse effects included hypoventilation, hypoxemia and prolonged recovery.

中文翻译：

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氯胺酮-美托咪定-氢吗啡酮在野外条件下高质量，高产量的外科手术消毒程序中对狗的麻醉作用。

目的

描述在伯利兹野外条件下，作为大剂量消毒程序的一部分，可注射麻醉剂对狗的麻醉和不良反应。

学习规划

前瞻性，观察性，实地研究。

动物

共有23只雌狗和8只雄狗（14.2±7.7千克；年龄≥8周）。

方法

使用基于每千克体积的剂量表，通过肌肉内向狗施用氯胺酮（4.5 mg kg ^-1），美托咪定（0.04 mg kg ^-1）和氢吗啡酮（0.09 mg kg ^-1）。麻醉诱导后，插入气管导管，让狗在室内空气中自发呼吸。监测包括外周氧饱和度（SPO ₂），平均动脉压（MAP），心脏速率（HR），呼吸速率，直肠温度和呼气末二氧化碳（P E' CO ₂）。术后皮下注射美洛昔康（0.2 mg kg ^-1）。用线性模型和卡方检验分析数据（p <0.05）。

结果

侧卧位起病迅速（3.4±2分钟）。在64.5％的狗中至少观察到一次去饱和（SpO ₂ <90％），并且在大型狗中更常见（p  = 0.019）。高碳酸血症（P E' CO ₂ ≥50毫米汞柱; 6.7千帕）在狗的48.4％观察到。MAP为111±19 mmHg，平均值±标准偏差。高血压（MAP≥120 mmHg），心动过缓（HR≤60次/分^-1）和心动过速（HR≥140次/分^-1））分别在45.2％，16.1％和3.3％的狗中观察到。未观察到低血压和体温过低。性别与任何并发症均无明显关联。注射后，吞咽反射的恢复和站立时间分别为71±23和152±50分钟。大型犬的吞咽时间明显更长。

结论与临床意义

在使用剂量的情况下，氯胺酮-美托咪定-氢吗啡酮对狗进行大批量消毒是有效的。在这种田间环境中，不良反应包括换气不足，低氧血症和恢复时间过长。