蛛网膜下腔注射高压阿片类药物对马的镇痛作用。

Natalini Cláudio C, Polydoro Alexandre da S, Linardi Renata L

Equine Health Studies Program, Department of Veterinary Clinical Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA 70803, USA.

Am J Vet Res. 2006 Jun;67(6):941-6. doi: 10.2460/ajvr.67.6.941.

OBJECTIVE

To evaluate the effects of subarachnoidally administered hyperbaric morphine, buprenorphine, and methadone on avoidance threshold to noxious electrical stimulation of the perineal, sacral, lumbar, and thoracic regions in horses.

ANIMALS

6 healthy adult horses.

PROCEDURES

Horses were assigned to receive subarachnoid administration of hyperbaric morphine (0.01 mg/kg), buprenorphine (0.001 mg/kg), methadone (0.01 mg/kg), or 10% dextrose solution in equal volumes (5 mL). Electrical stimulation was applied every 10 minutes for 60 minutes and every 30 minutes for 120 minutes after subarachnoid injection over the dermatomes of the perineal, sacral, lumbar, and thoracic regions, and the avoidance threshold voltage was recorded. Heart and respiratory rate, blood gas tensions, serum electrolyte concentrations, and sedative effects were also evaluated.

RESULTS

Administration of 10% dextrose solution did not change the avoidance threshold. Morphine and methadone significantly increased the avoidance threshold by 10 minutes after injection, which lasted until 120 minutes after subarachnoid administration in the perineal, sacral, lumbar, and thoracic regions. Profound analgesia (avoidance threshold > 40 V) was achieved in all regions. Buprenorphine also significantly increased the avoidance threshold by 10 minutes (36 V) after injection, which lasted 60 minutes and was considered moderate. Heart rate, blood pressure, respiratory rate, and blood gas tensions stayed within reference range. No ataxia, signs of sedation, or CNS excitement were observed.

CONCLUSIONS AND CLINICAL RELEVANCE

Subarachnoid administration of hyperbaric morphine or methadone produces intense analgesia for 120 minutes over the dermatomes of the perineal, sacral, lumbar, and thoracic areas without cardiorespiratory depression, ataxia, or CNS excitement in horses.

目的

评估蛛网膜下腔注射高压吗啡、丁丙诺啡和美沙酮对马会阴、骶、腰和胸部区域有害电刺激回避阈值的影响。

动物

6匹健康成年马。

步骤

将马分为四组，分别接受蛛网膜下腔注射等体积（5 mL）的高压吗啡（0.01 mg/kg）、丁丙诺啡（0.001 mg/kg）、美沙酮（0.01 mg/kg）或10%葡萄糖溶液。蛛网膜下腔注射后，在会阴、骶、腰和胸部区域的皮节上，每隔10分钟施加电刺激60分钟，之后每隔30分钟施加电刺激120分钟，并记录回避阈值电压。同时评估心率、呼吸频率、血气张力、血清电解质浓度和镇静效果。

结果

注射10%葡萄糖溶液未改变回避阈值。吗啡和美沙酮在注射后10分钟显著提高了回避阈值，在蛛网膜下腔注射后120分钟内，会阴、骶、腰和胸部区域的回避阈值持续升高。所有区域均实现了深度镇痛（回避阈值>40 V）。丁丙诺啡在注射后10分钟也显著提高了回避阈值（36 V），持续60分钟，被认为是中度镇痛。心率、血压、呼吸频率和血气张力均保持在参考范围内。未观察到共济失调、镇静迹象或中枢神经系统兴奋。