Küls Nina, Blissitt Karen J, Shaw Darren J, Schöffmann Gudrun, Clutton Richard E
Department for Anaesthesiology and Perioperative Care, The Veterinary University of Vienna, Vienna, Austria.
Royal (Dick) School of Veterinary Studies, Easter Bush Veterinary Centre, The University of Edinburgh, Roslin, Midlothian, UK.
Vet Anaesth Analg. 2017 Sep;44(5):1198-1207. doi: 10.1016/j.vaa.2016.11.009. Epub 2017 Mar 25.
To evaluate skin temperature increase as an early predictive measure for evaluating epidural and femoral-sciatic block success in dogs.
Prospective clinical trial.
A total of 29 dogs undergoing orthopaedic surgery on one hindlimb.
Dogs were anaesthetized and placed into lateral recumbency with the affected limb uppermost and the coat was clipped. Baseline infrared thermographic images (T0) of the affected limb, of the paw pad of the affected leg and of the ipsilateral paw pad were taken. Subsequently, dogs were administered either an epidural (EPI; n=11) or a femoral-sciatic block (FS; n=18) using bupivacaine 1 mg kg. Then, 2 minutes after placement of the block, thermographic images were obtained every 3 minutes for a total of four measurements (T1-T4) and surgery was commenced. Rescue analgesia consisting of fentanyl 1 μg kg was administered if needed. A regional block was considered successful if the dose of fentanyl administered was less than the lower 95% confidence interval of the geometric mean of the total fentanyl used in each group. A ≥ 1 °C increase of skin temperature was considered as the minimum increase required for detection of a successful block.
A total of 12 out of 18 blocks in the FS and eight of 11 in the EPI group were considered successful based on fentanyl consumption. Out of these, only four of 12 in the FS and one of eight in the EPI group developed an increase in temperature of ≥ 1 °C. Contrarily, four of six of the nonsuccessful cases in the FS and three of three in the EPI group developed an increase in temperature of ≥ 1 °C.
Contrary to reports in humans, thermography did not indicate regional block success prior to surgery in dogs. However further studies under more controlled conditions are needed to determine whether thermography can be used to indicate failure of regional blockade.
评估皮肤温度升高作为评估犬硬膜外阻滞和股-坐骨神经阻滞成功与否的早期预测指标。
前瞻性临床试验。
共29只接受一侧后肢骨科手术的犬。
对犬进行麻醉，使其侧卧，患侧肢体在上，并剃去手术部位毛发。拍摄患侧肢体、患侧爪垫及同侧爪垫的基线红外热成像图（T0）。随后，使用1mg/kg布比卡因对犬进行硬膜外阻滞（EPI；n = 11）或股-坐骨神经阻滞（FS；n = 18）。在阻滞实施2分钟后，每3分钟获取一次热成像图，共进行4次测量（T1 - T4），然后开始手术。必要时给予1μg/kg芬太尼进行补救镇痛。如果给予的芬太尼剂量低于每组所用芬太尼总量几何平均数的95%置信区间下限，则认为区域阻滞成功。皮肤温度升高≥1℃被视为检测到成功阻滞所需的最小升高幅度。
根据芬太尼用量，FS组18例阻滞中有12例、EPI组11例中有8例被认为成功。其中，FS组12例中的4例和EPI组8例中的1例体温升高≥1℃。相反，FS组6例未成功病例中的4例以及EPI组3例未成功病例中的3例体温升高≥1℃。
与人类的报道相反，热成像在犬手术前并未显示区域阻滞成功。然而，需要在更严格控制的条件下进行进一步研究，以确定热成像是否可用于指示区域阻滞失败。
