Postoperative inspiratory muscle training in addition to breathing exercises and early mobilization improves oxygenation in high-risk patients after lung cancer surgery: a randomized controlled trial.
OBJECTIVE
The aim was to investigate whether 2 weeks of inspiratory muscle training (IMT) could preserve respiratory muscle strength in high-risk patients referred for pulmonary resection on the suspicion of or confirmed lung cancer. Secondarily, we investigated the effect of the intervention on the incidence of postoperative pulmonary complications.


METHODS
The study was a single-centre, parallel-group, randomized trial with assessor blinding and intention-to-treat analysis. The intervention group (IG, n = 34) underwent 2 weeks of postoperative IMT twice daily with 2 × 30 breaths on a target intensity of 30% of maximal inspiratory pressure, in addition to standard postoperative physiotherapy. Standard physiotherapy in the control group (CG, n = 34) consisted of breathing exercises, coughing techniques and early mobilization. We measured respiratory muscle strength (maximal inspiratory/expiratory pressure, MIP/MEP), functional performance (6-min walk test), spirometry and peripheral oxygen saturation (SpO2), assessed the day before surgery and again 3-5 days and 2 weeks postoperatively. Postoperative pulmonary complications were evaluated 2 weeks after surgery.


RESULTS
The mean age was 70 ± 8 years and 57.5% were males. Thoracotomy was performed in 48.5% (n = 33) of cases. No effect of the intervention was found regarding MIP, MEP, lung volumes or functional performance at any time point. The overall incidence of pneumonia was 13% (n = 9), with no significant difference between groups [IG 6% (n = 2), CG 21% (n = 7), P = 0.14]. An improved SpO2 was found in the IG on the third and fourth postoperative days (Day 3: IG 93.8 ± 3.4 vs CG 91.9 ± 4.1%, P = 0.058; Day 4: IG 93.5 ± 3.5 vs CG 91 ± 3.9%, P = 0.02). We found no association between surgical procedure (thoracotomy versus thoracoscopy) and respiratory muscle strength, which was recovered in both groups 2 weeks after surgery.


CONCLUSIONS
Two weeks of additional postoperative IMT, compared with standard physiotherapy alone, did not preserve respiratory muscle strength but improved oxygenation in high-risk patients after lung cancer surgery. Respiratory muscle strength recovered in both groups 2 weeks after surgery.
NCT01793155.
Department of Physiotherapy and Occupational Therapy, Aalborg University Hospital, Aalborg, Denmark Faculty of Medicine and Health, Surgery, Örebro University, Örebro, Sweden bcb@rn.dk.
Barbara Cristina
BC
Brocki
Department of Cardiothoracic Surgery, Aalborg University, Aalborg, Denmark Department of Clinical Medicine, Aalborg University, Aalborg, Denmark.
Jan Jesper
JJ
Andreasen
KU Leuven Faculty of Kinesiology and Rehabilitation Sciences, Leuven, Belgium Respiratory Rehabilitation and Respiratory Division, University Hospital Leuven, Leuven, Belgium.
Daniel
D
Langer
Faculty of Medicine and Health, Surgery, Örebro University, Örebro, Sweden.
Domingos Savio R
DS
Souza
Faculty of Medicine and Health, Surgery, Örebro University, Örebro, Sweden.
Elisabeth
E
Westerdahl
D000368:Aged; D000369:Aged, 80 and over; D001945:Breathing Exercises / Q000379:methods* / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000401:mortality* / Q000503:physiopathology / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D053580:Muscle Strength / Q000502:physiology; D011182:Postoperative Care / Q000379:methods* / Q000706:statistics & numerical data*; D011183:Postoperative Complications; D012132:Respiratory Muscles / Q000502:physiology; D016896:Treatment Outcome
Inspiratory muscle training; Lung cancer; Physiotherapy; Postoperative; Pulmonary complications; Surgery