title: Deep breathing exercises with positive expiratory pressure at a higher rate improve oxygenation in the early period after cardiac surgery--a randomised controlled trial.
abstract: OBJECTIVE
  In addition to early mobilisation, a variety of breathing exercises are used to prevent postoperative pulmonary complications after cardiac surgery. The optimal duration of the treatment is not well evaluated. The aim of this study was to determine the effect of 30 versus 10 deep breaths hourly, while awake, with positive expiratory pressure on oxygenation and pulmonary function the first days after cardiac surgery.
  
  
  METHODS
  A total of 181 patients, undergoing cardiac surgery, were randomised into a treatment group, performing 30 deep breaths hourly the first postoperative days, or into a control group performing 10 deep breaths hourly. The main outcome measurement arterial blood gases and the secondary outcome pulmonary function, evaluated with spirometry, were determined on the second postoperative day.
  
  
  RESULTS
  Preoperatively, both study groups were similar in terms of age, SpO(2), forced expiratory volume in 1s and New York Heart Association classification. On the second postoperative day, arterial oxygen tension (PaO(2)) was 8.9 ± 1.7 kPa in the treatment group and 8.1 ± 1.4 kPa in the control group (p = 0.004). Arterial oxygen saturation (SaO(2)) was 92.7 ± 3.7% in the treatment group and 91.1 ± 3.8% in the control group (p = 0.016). There were no differences in measured lung function between the groups or in compliance to the breathing exercises. Compliance was 65% of possible breathing sessions.
  
  
  CONCLUSIONS
  A significantly increased oxygenation was found in patients performing 30 deep breaths the first two postoperative days compared with control patients performing 10 deep breaths hourly. These results support the implementation of a higher rate of deep breathing exercises in the initial phase after cardiac surgery.
authors.affiliation: Department of Neuroscience, Physiotherapy, Uppsala University, Uppsala, Sweden; Physiotherapy Section, University Hospital, Uppsala, Sweden; Department of Cardiothoracic Anaesthesiology, University Hospital, Uppsala, Sweden.
authors.forename: Charlotte
authors.initials: C
authors.lastname: Urell
authors.forename: Margareta
authors.initials: M
authors.lastname: Emtner
authors.forename: Hans
authors.initials: H
authors.lastname: Hedenström
authors.forename: Arne
authors.initials: A
authors.lastname: Tenling
authors.forename: Marie
authors.initials: M
authors.lastname: Breidenskog
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Westerdahl
mesh_terms: D000368:Aged; D001945:Breathing Exercises; D002245:Carbon Dioxide / Q000097:blood; D006348:Cardiac Surgical Procedures / Q000009:adverse effects / Q000534:rehabilitation*; D005260:Female; D006801:Humans; D008171:Lung Diseases / Q000209:etiology / Q000517:prevention & control; D008297:Male; D008875:Middle Aged; D010100:Oxygen / Q000097:blood; D010313:Partial Pressure; D011175:Positive-Pressure Respiration / Q000295:instrumentation / Q000379:methods*; D011182:Postoperative Care / Q000379:methods*; D015656:Respiratory Mechanics / Q000502:physiology; D016896:Treatment Outcome
chemical_list: D002245:Carbon Dioxide; D010100:Oxygen