Objective

To investigate the effect of metamizole on physiologic variables in calves undergoing surgical extirpation of the navel during anaesthesia using xylazine, ketamine and isoflurane.

Study design

Double-blind, randomized trial.

Animals

A total of 26 calves.

Methods

Calves with uncomplicated umbilical hernias and otherwise clinically healthy were randomly allocated to one of two groups: the control group (CG) and metamizole group (MG). All calves were administered meloxicam (0.5 mg kg^–1) intravenously (IV) 150 minutes before skin incision (SI). Animals were premedicated with xylazine (0.2 mg kg^–1) intramuscularly 50 minutes before SI. Anaesthesia was induced with ketamine (2 mg kg^–1) IV 30 minutes before SI and maintained with isoflurane in oxygen. MG calves were given metamizole (40 mg kg^–1) IV 60 minutes before SI. CG calves were administered an equivalent volume of saline. Heart rate (HR) and mean arterial blood pressure (MAP) were recorded from 5 minutes before SI until the end of anaesthesia (60 minutes after SI). Blood samples for determination of the plasma cortisol concentration (PCC) were drawn 60 minutes before SI and at 5, 30, 60, 150, and 510 minutes after SI.

Results

In both groups, PCC increased during surgery and decreased after surgery. PCC was consistently lower in MG than in CG and was significantly (p = 0.0026) lower at 150 minutes after SI in the MG. Overall, the mean PCC in MG was 10.9 nmol L^–1 lower than that in CG (p = 0.01). In both groups, HR decreased during anaesthesia, whereas MAP increased, albeit with no statistically significant (p > 0.05) differences between groups.

Conclusions and clinical relevance

Our study results suggest that a single preoperative dose of metamizole may have a positive impact on intra- and immediate postoperative analgesia by reducing PCC when used as an indicator of nociception.

中文翻译：

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在小牛脐部手术期间使用安乃近作为额外的镇痛剂。

 客观的

目的 研究安乃近对使用赛拉嗪、氯胺酮和异氟醚麻醉期间接受脐摘除手术的犊牛生理变量的影响。

 研究设计

双盲、随机试验。

 动物

共有26头小牛。

 方法

患有无并发症脐疝且临床健康的犊牛被随机分配到两组中的一组：对照组（CG）和安乃近组（MG）。所有犊牛在切皮 (SI) 前 150 分钟静脉注射 (IV) 美洛昔康 (0.5 mg kg ^–1 )。 SI前50分钟给动物肌内注射赛拉嗪(0.2 mg kg ^–1 )。 SI 前 30 分钟用氯胺酮 (2 mg kg ^-1 ) IV 诱导麻醉，并用氧气中的异氟烷维持。 MG 犊牛在 SI 前 60 分钟静脉注射安乃近 (40 mg kg ^–1 )。 CG小牛被给予等体积的盐水。从 SI 前 5 分钟到麻醉结束（SI 后 60 分钟）记录心率 (HR) 和平均动脉血压 (MAP)。在SI前60分钟和SI后5、30、60、150和510分钟抽取血样用于测定血浆皮质醇浓度(PCC)。

 结果

两组中，PCC 在手术期间均增加，而手术后则减少。 MG 中的 PCC 始终低于 CG 中的 PCC，并且在 MG 中 SI 后 150 分钟时显着降低 ( p = 0.0026)。总体而言，MG 中的平均 PCC 比 CG 中低 10.9 nmol L ^–1 ( p = 0.01)。在两组中，麻醉期间 HR 下降，而 MAP 增加，尽管组间没有统计学显着性差异 ( p > 0.05)。

结论和临床相关性

我们的研究结果表明，术前单剂量安乃近可能通过减少 PCC 作为伤害感受指标，对术中和术后即刻镇痛产生积极影响。