Neuromuscular electrical stimulation may attenuate muscle proteolysis after cardiovascular surgery: A preliminary study

Objective To explore the efficacy of postoperative neuromuscular electrical stimulation (NMES) on muscle protein degradation and muscle weakness in patients after cardiovascular surgery. Methods Sixty-one patients underwent NMES daily from postoperative days (PODs) 1 to 5 in addition to postoperative mobilization program (NMES group), and 41 patients underwent postoperative mobilization program only (non-NMES group). The primary outcome was the concentration of 3-methylhistidine (3-MH) in 24-hour urine corrected for urinary creatinine content (3-MH/Cre) from PODs 1 to 5. The secondary outcomes were knee extensor isometric strength (KEIS) and handgrip strength at POD 7. Results Baseline characteristics such as age, sex, preoperative body mass index, hemoglobin, handgrip strength, KEIS, surgery type, cardiopulmonary bypass time, and immediate postoperative interleukin-6 were not different between the groups. Urinary 3-MH/Cre was increased significantly in both groups; however, urinary 3-MH/Cre in the NMES group peaked earlier compared with that in the non-NMES group. KEIS at POD 7 was significantly greater in the NMES group (median [interquartile range], 0.40 kg/weight [0.33-0.45] in the NMES group vs 0.23 kg/weight [0.15-0.36] in the non-NMES group; P < .01). Handgrip strength at POD 7 was also significantly greater in the NMES group (median [interquartile range], 32 kg [24.5-35.3] in the NMES group vs 24 kg [16.0-30.0] in the non-NMES group; P < .01). Conclusions This study demonstrated that NMES might attenuate skeletal muscle protein degradation and muscle weakness after cardiovascular surgery. A cause-effect relationship between NMES and functional preservation would be a future challenging issue.