Department of Orthopaedic Surgery, Horsens Regional Hospital, Horsens, Denmark.
Aarhus Microdialysis Research Group, Orthopaedic Research Unit, Aarhus University Hospital, Aarhus N, Denmark.
APMIS. 2021 Apr;129(4):225-231. doi: 10.1111/apm.13121. Epub 2021 Feb 23.
This study aimed to evaluated ischemic metabolites in subcutaneous tissue, skeletal muscle, and calcaneal cancellous bone before, during, and after tourniquet application in a simultaneous paired comparison of tourniquet-exposed and non-tourniquet-exposed legs. Ten patients scheduled for hallux valgus or hallux rigidus surgery were included. Microdialysis catheters were placed to simultaneously and continuously sample the metabolites glucose, lactate, pyruvate, and glycerol bilaterally for 12 h in subcutaneous tissue, skeletal muscle, and calcaneal cancellous bone. A tourniquet was applied on the leg planned for surgery (inflation time: 15 min, mean tourniquet duration time (range): 65 (58;77) min). During tourniquet inflation, a 2- to 3-fold increase of the mean lactate/pyruvate ratio was found for all investigated tissues in the tourniquet-exposed leg compared with the non-tourniquet-exposed leg. The lactate/pyruvate ratio recovery time after tourniquet release was within 30 min for skeletal muscle, 60 min for subcutaneous tissue, and 130 min for calcaneal cancellous bone. Only the tourniquet-exposed skeletal muscles were found to be ischemic during tourniquet inflation, defined by a significant increase of the lactate/pyruvate ratio exceeding the ischemic cutoff level of 25; however, this level decreased below 25 immediately after tourniquet release. The glycerol ratio increased instantly after inflation in the tourniquet-exposed leg in skeletal muscle and subcutaneous tissue, and recovered within 60 (skeletal muscle) and 130 min (subcutaneous tissue) after tourniquet release. These findings suggest that applying tourniquet for approximately 1 h results in limited tissue ischemia and cell damage in subcutaneous tissue, skeletal muscle, and calcaneal cancellous bone.
本研究旨在评估止血带应用前后，同时比较止血带暴露侧和非止血带暴露侧腿部，在皮下组织、骨骼肌和跟骨松质骨中缺血代谢物的变化。纳入 10 例拟行拇外翻或僵硬拇趾手术的患者。双侧皮下组织、骨骼肌和跟骨松质骨中同时连续放置微透析导管，持续 12 小时采样代谢物葡萄糖、乳酸、丙酮酸和甘油。在计划手术的腿部施加止血带（充气时间：15 分钟，平均止血带使用时间（范围）：65（58；77）分钟）。在止血带充气期间，与非止血带暴露侧相比，止血带暴露侧所有组织的平均乳酸/丙酮酸比值增加了 2-3 倍。止血带释放后，骨骼肌中乳酸/丙酮酸比值的恢复时间在 30 分钟内，皮下组织中为 60 分钟，跟骨松质骨中为 130 分钟。只有止血带充气时暴露的骨骼肌才会发生缺血，定义为乳酸/丙酮酸比值显著增加，超过 25 的缺血临界值；然而，这一水平在止血带释放后立即下降至 25 以下。在止血带充气后，骨骼肌和皮下组织中暴露于止血带的骨骼肌和皮下组织中甘油比立即增加，并在止血带释放后 60（骨骼肌）和 130 分钟（皮下组织）内恢复。这些发现表明，应用止血带约 1 小时会导致皮下组织、骨骼肌和跟骨松质骨中的组织缺血和细胞损伤有限。
