Preoperative respiratory muscle training combined with aerobic exercise improves respiratory vital capacity and daily life activity following surgical treatment for myasthenia gravis

Abstract

Objective The effects of preoperative respiratory muscle training (RMT) on postoperative complications in patients surgically treated for myasthenia gravis (MG) remain unclear. The present study therefore evaluated the effects of preoperative moderate-to-intense RMT and aerobic exercise, when added to respiratory physiotherapy, on respiratory vital capacity, exercise capacity, and duration of hospital stay in patients with MG. Methods Eighty patients with MG scheduled for extended thymectomy were randomly divided into two groups. The 40 subjects in the study group (SG) received preoperative moderate-to-intense RMT and aerobic exercise in addition to respiratory physiotherapy, whereas the 40 subjects in the control group (CG) received only chest physiotherapy. Respiratory vital capacity (as determined by VC, FVC, FEV1, FEV1/FVC, and PEF) and exercise capacity (as determined by the 6-min walk test [6 MWT]) were measured pre- and postoperatively and before discharge. The duration of hospital stay and activity of daily living (ADL) were also determined. Results Demographic and surgical characteristics, along with preoperative vital capacity and exercise capacity, were similar in the two groups. In the CG, VC (p = 0.001), FVC (p = 0.001), FEV1 (p = 0.002), PEF (p = 0.004), and 6MWT (p = 0.041) were significantly lower postoperatively than preoperatively, whereas the FEV1/FVC ratio did not differ significantly. Postoperative VC (p = 0.012), FVC (p = 0.030), FEV1 (p = 0.014), and PEF (p = 0.035) were significantly higher in the SG than in the CG, although 6MWT results did not differ. ADL on postoperative day 5 was significantly higher in the SG than in the CG (p = 0.001). Conclusion RMT and aerobic exercise can have positive effects on postoperative respiratory vital capacity and daily life activity, and would enhance recovery after surgery in MG patients.

Summary of the best evidence for the prevention and management of myasthenic crisis after thymectomy

“…One RCT was retrieved from the PubMed database. In the evaluation of the RCT ( 24 ), item 6, which concerned the “possibility of selective reporting of study results”, was evaluated as “unclear”; however, all the other items were evaluated as “low risk”. The study designs were complete, the overall quality was high, and this study was approved for inclusion.…”

“…Recommendation 5. Respiratory muscle training should be performed before surgery, including the use of lip breathing, abdominal breathing, and three-ball breathing trainers (the training amount is three balls per inhalation); training for 15 minutes, 3 times a day for 5 days, combined with aerobic exercise (up and down stairs) ( 16 , 24 ). (Evidence level: 5b; recommendation: A).…”

“…Recommendation 6. Chest physical therapy should be conducted (expectoration should be practiced 3 times a day for 15 minutes each time, for 5 days), forced exhalation expectoration should be practiced (3 times a day for 15 minutes each time, for 5 days), and smoking should cease for >2 weeks ( 16 , 24 ). (Evidence level: 1c; recommendation: A).…”

“…Recommendation 7. Limb muscle strength training using the United States Thera elastic band (red, moderate intensity), and aerobic exercise (10 times a day, three times each time, 1 minute rest) should be performed ( 24 ). (Evidence level: 1c; recommendation: B).…”

“…Recommendation 20. The patient should be instructed to use a breathing trainer (with the inspiratory pressure set to 30% of the maximum oral inspiratory pressure), and practice lip breathing, and abdominal breathing ( 24 ). (Evidence level: 5b; recommendation: A).…”