Coppolino Giuseppe, Bolignano Davide, Parisi Sergio, Aloisi Emanuele, Romeo Adolfo, Quartarone Angelo, Buemi Michele
Department of Internal Medicine, University of Messina, Messina, Italy.
Ther Apher Dial. 2007 Oct;11(5):375-81. doi: 10.1111/j.1744-9987.2007.00503.x.
Dramatic removal of potassium during hemodialysis sessions can induce changes in the electrical properties of nerve cells or muscle fibers, which may underlie neuromuscular symptoms referred by end-stage renal disease patients. The primary aim of our study was to investigate the effects of acetate-free biofiltration (AFB) on the amplitude of compound motor action potential (cMAP) obtained after stimulation of the ulnar nerve at the wrist. The secondary aim was to compare the effect of two different potassium removal modalities on cMAP amplitude and to analyze the effects on muscular force by specific dynamometric tests. Twenty-eight patients received dialysis for 4 h, 3 times per week, first with standard AFB with constant potassium (AFB) and then with AFB with a variable concentration of potassium in the dialysis bath (AFB(K)). The amplitude of cMAP was determined after ulnar nerve stimulation at the wrist at different time intervals: at the start of dialysis; at 15, 45, 90, and 120 min after beginning the session; and at the end of treatment. At the same time intervals, muscle force generation was determined using a dynamometer. Finally, we measured plasma electrolytes, intraerythrocytic potassium, and the electrical membrane potential at rest (REMP) of the erythrocytic membrane. The main finding of this study was a significant reduction of cMAP amplitude in the first 45 min after AFB, which paralleled the reduction in serum potassium levels. Moreover, there was a reduction of muscular strength determined with dynamometric measurements. Potassium removal induced by the two different modalities of AFB may significantly affect myocardial and fibromuscular cells by modulating the electrochemical balance of cell membranes. The transient alteration of the electrical properties on voluntary striated muscle fibers may contribute to the brief reduction in muscular strength we detected in patients who underwent AFB. AFB(K) can minimize the negative effects of standard AFB treatment on neuromuscular excitability, most likely through a more gentle variation of potassium levels during dialysis.
血液透析过程中钾的急剧清除可引起神经细胞或肌纤维电特性的改变，这可能是终末期肾病患者出现神经肌肉症状的原因。我们研究的主要目的是探讨无醋酸盐生物滤过（AFB）对腕部刺激尺神经后复合运动动作电位（cMAP）振幅的影响。次要目的是比较两种不同的钾清除方式对cMAP振幅的影响，并通过特定的测力计测试分析对肌肉力量的影响。28例患者每周进行3次、每次4小时的透析，首先采用含恒定钾的标准AFB（AFB），然后采用透析液中钾浓度可变的AFB（AFB(K)）。在不同时间间隔对腕部尺神经进行刺激后测定cMAP振幅：透析开始时；透析开始后15、45、90和120分钟；以及治疗结束时。在相同时间间隔，使用测力计测定肌肉力量产生情况。最后，我们测量了血浆电解质、红细胞内钾以及红细胞膜静息电膜电位（REMP）。本研究的主要发现是，AFB后最初45分钟内cMAP振幅显著降低，这与血清钾水平的降低平行。此外，通过测力计测量发现肌肉力量有所下降。两种不同方式的AFB诱导的钾清除可能通过调节细胞膜的电化学平衡而显著影响心肌和纤维肌肉细胞。随意横纹肌纤维电特性的短暂改变可能导致我们在接受AFB治疗的患者中检测到的肌肉力量短暂下降。AFB(K)可以将标准AFB治疗对神经肌肉兴奋性的负面影响降至最低，最有可能是通过透析过程中钾水平更平缓的变化实现的。
