Mendez-Angulo Jose L, Granados Maria M, Modesto Rolf, Serrano-Rodriguez Juan M, Funes Francisco J, Quiros Setefilla, Gomez-Villamandos Rafael J, Zaldívar Sara, Trumble Troy N
Department of Animal Medicine and Surgery, University of Córdoba, Córdoba, Spain.
Veterinary Population Medicine Department, University of Minnesota, St. Paul, MN, USA.
Equine Vet J. 2020 Sep;52(5):743-751. doi: 10.1111/evj.13236. Epub 2020 Feb 21.
Local anaesthetics are being combined clinically with amikacin in intravenous regional limb perfusion (IVRLP), with limited knowledge on the analgesia provided and its onset and duration of action after tourniquet application and release.
To evaluate the systemic clinical effect, limb withdrawal to nociceptive stimulation, and plasma and synovial fluid concentrations after IVRLP with lidocaine or mepivacaine in standing sedated horses.
Prospective, controlled, randomised, cross-over study.
Six healthy adult horses were sedated and received IVRLP with lidocaine, mepivacaine or saline (negative control), or perineural anaesthesia of the medial and lateral palmar and palmar metacarpal nerves (positive control) in one forelimb with a 3-week washout period between trials. Electrical and mechanical stimuli were used to test nociceptive threshold of the limb before and after IVRLP/perineural anaesthesia. For lidocaine and mepivacaine trials, blood was collected from the jugular vein and synovial fluid from the radiocarpal joint before, during and out to 24 hours after IVRLP. Drug concentrations were measured using high-performance liquid chromatography.
Nociceptive thresholds for lidocaine, mepivacaine and perineural anaesthesia trials were significantly increased compared with saline and baseline values at 10, 20 and 30 minutes, with no differences between anaesthetic trials. During this time, horses had lower heart rates than IVRLP with saline. After tourniquet release at 30 minutes, nociceptive thresholds for lidocaine and mepivacaine trials gradually returned to baselines, whereas perineural anaesthesia trial remained unchanged out to an hour. Plasma lidocaine and mepivacaine concentrations were ≤50 ng/mL while the tourniquet was in place, significantly increasing 10 minutes after tourniquet release. Maximal lidocaine and mepivacaine concentrations in synovial fluid were reached 25 minutes after IVRLP injection.
Amikacin was not included in the perfusate.
Similar to perineural anaesthesia, IVRLP with lidocaine or mepivacaine provides anti-nociception to the distal limb in standing sedated horses while a tourniquet is applied with concentrations remaining below toxic levels in plasma and synovial fluid.
局部麻醉药在临床中与阿米卡星联合用于静脉区域肢体灌注（IVRLP），但对于止血带应用和松开后所提供的镇痛效果及其起效和作用持续时间的了解有限。
评估在站立镇静的马匹中进行利多卡因或甲哌卡因IVRLP后的全身临床效果、肢体对伤害性刺激的退缩反应以及血浆和滑液浓度。
前瞻性、对照、随机、交叉研究。
六匹健康成年马进行镇静，在一个前肢接受利多卡因、甲哌卡因或生理盐水（阴性对照）的IVRLP，或正中神经和尺神经以及掌骨掌侧神经的神经周围麻醉（阳性对照），试验之间有3周的洗脱期。在IVRLP/神经周围麻醉前后，使用电刺激和机械刺激来测试肢体的伤害性阈值。对于利多卡因和甲哌卡因试验，在IVRLP前、期间以及至IVRLP后24小时从颈静脉采集血液，并从桡腕关节采集滑液。使用高效液相色谱法测量药物浓度。
与生理盐水和基线值相比，利多卡因、甲哌卡因和神经周围麻醉试验的伤害性阈值在10、20和30分钟时显著升高，但麻醉试验之间无差异。在此期间，马匹的心率低于接受生理盐水IVRLP时。在30分钟松开止血带后，利多卡因和甲哌卡因试验的伤害性阈值逐渐恢复到基线，而神经周围麻醉试验在1小时内保持不变。止血带在位时，血浆利多卡因和甲哌卡因浓度≤50 ng/mL，止血带松开10分钟后显著升高。IVRLP注射后25分钟达到滑液中利多卡因和甲哌卡因的最大浓度。
灌注液中未包含阿米卡星。
与神经周围麻醉相似，在站立镇静的马匹中应用止血带时，利多卡因或甲哌卡因的IVRLP可为远端肢体提供抗伤害感受，且血浆和滑液中的浓度保持在毒性水平以下。
