Schroeder D, Hill G L
Department of Surgery, Auckland Hospital, New Zealand.
Aust N Z J Surg. 1991 Oct;61(10):774-9.
We attempted to define the site of muscle action accounting for the apparent muscle weakness occurring with postoperative fatigue. A model of the normal pathway of muscle contraction is presented. A series of studies, designed to separate the elements of the pathway, was performed on 38 patients undergoing major abdominal surgery. Central fatigue was measured with Christensen's analogue, voluntary strength by grip strength, perceived effort by grading the difficulty of a set work load, involuntary muscle function by ulnar nerve stimulation, and muscle bulk represented by total body nitrogen, measured by in vivo neuron activation analysis. Fatigue increased for the first 2 weeks after operation, was back to pre-operative levels within 1 month, and improved further at 3 months. Grip strength fell after operation and returned to pre-operative levels within 3 months. Perceived effort rose after operation and returned to pre-operative levels by 3 months. Involuntary muscle function was unaffected by operation. Similarly, total body nitrogen fell in the first 2 weeks after operation but was improved on baseline levels at 3 months. However, there was no consistent correlation between the movement patterns of any of the muscle parameters and fatigue. The results suggest that fatigue after surgery is not accompanied by any muscular defect, and that the apparent muscular weakness is probably a secondary phenomenon to the central fatigue.
我们试图确定导致术后疲劳时出现明显肌肉无力的肌肉作用部位。本文提出了一个肌肉收缩正常途径的模型。对38例接受腹部大手术的患者进行了一系列旨在分离该途径各要素的研究。采用克里斯滕森模拟法测量中枢疲劳，通过握力测量自愿力量，通过对设定工作量的难度进行分级来感知努力程度，通过尺神经刺激测量非自主肌肉功能，并用体内神经元激活分析测量以全身氮表示的肌肉量。术后前2周疲劳加剧，1个月内恢复到术前水平，3个月时进一步改善。握力术后下降，3个月内恢复到术前水平。术后感知努力程度上升，3个月时恢复到术前水平。非自主肌肉功能不受手术影响。同样，术后前2周全身氮含量下降，但3个月时恢复到基线水平。然而，任何肌肉参数的运动模式与疲劳之间均无一致的相关性。结果表明，术后疲劳并不伴有任何肌肉缺陷，明显的肌肉无力可能是中枢疲劳的继发现象。
