title: Deep breathing exercises performed 2 months following cardiac surgery: a randomized controlled trial.
abstract: OBJECTIVE
  Postoperative breathing exercises are recommended to cardiac surgery patients. Instructions concerning how long patients should continue exercises after discharge vary, and the significance of treatment needs to be determined. Our aim was to assess the effects of home-based deep breathing exercises performed with a positive expiratory pressure device for 2 months following cardiac surgery.
  
  
  METHODS
  The study design was a prospective, single-blinded, parallel-group, randomized trial. Patients performing breathing exercises 2 months after cardiac surgery (n = 159) were compared with a control group (n = 154) performing no breathing exercises after discharge. The intervention consisted of 30 slow deep breaths performed with a positive expiratory pressure device (10-15 cm H2O), 5 times a day, during the first 2 months after surgery. The outcomes were lung function measurements, oxygen saturation, thoracic excursion mobility, subjective perception of breathing and pain, patient-perceived quality of recovery (40-Item Quality of Recovery score), health-related quality of life (36-Item Short Form Health Survey), and self-reported respiratory tract infection/pneumonia and antibiotic treatment.
  
  
  RESULTS
  Two months postoperatively, the patients had significantly reduced lung function, with a mean decrease in forced expiratory volume in 1 second to 93 ± 12% (P< .001) of preoperative values. Oxygenation had returned to preoperative values, and 5 of 8 aspects in the 36-Item Short Form Health Survey were improved compared with preoperative values (P< .01). There were no significant differences between the groups in any of the measured outcomes.
  
  
  CONCLUSIONS
  No significant differences in lung function, subjective perceptions, or quality of life were found between patients performing home-based deep breathing exercises and control patients 2 months after cardiac surgery.
authors.affiliation: School of Health and Medical Sciences, Örebro University, Örebro, Sweden (Dr Westerdahl); Departments of Physiotherapy (Dr Westerdahl and Mr Jonsson), Cardiothoracic Surgery (Dr Westerdahl and Mr Jonsson), and Occupational and Environmental Medicine (Ms Bryngelsson), Örebro University Hospital, Örebro, Sweden; and Physiotherapy, Department of Neuroscience (Dr Urell and Dr Emtner), and Respiratory Medicine and Allergology (Dr Emtner) and Clinical Physiology (Dr Hedenström), Department of Medical Sciences, Uppsala University, Uppsala, Sweden.
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Westerdahl
authors.forename: Charlotte
authors.initials: C
authors.lastname: Urell
authors.forename: Marcus
authors.initials: M
authors.lastname: Jonsson
authors.forename: Ing-Liss
authors.initials: IL
authors.lastname: Bryngelsson
authors.forename: Hans
authors.initials: H
authors.lastname: Hedenström
authors.forename: Margareta
authors.initials: M
authors.lastname: Emtner
mesh_terms: D000368:Aged; D001945:Breathing Exercises / Q000379:methods / Q000523:psychology / Q000706:statistics & numerical data; D006348:Cardiac Surgical Procedures / Q000009:adverse effects / Q000534:rehabilitation*; D005260:Female; D006331:Heart Diseases / Q000503:physiopathology / Q000523:psychology / Q000601:surgery; D006801:Humans; D008297:Male; D008875:Middle Aged; D008991:Monitoring, Physiologic / Q000379:methods; D011183:Postoperative Complications / Q000503:physiopathology / Q000517:prevention & control*; D011184:Postoperative Period; D011788:Quality of Life; D012129:Respiratory Function Tests; D016896:Treatment Outcome