Deep breathing exercises with positive expiratory pressure at a higher rate improve oxygenation in the early period after cardiac surgery--a randomised controlled trial

Eur J Cardiothorac Surg. 2011 Jul;40(1):162-7. doi: 10.1016/j.ejcts.2010.10.018. Epub 2010 Dec 10.


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.

Publication types

  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Breathing Exercises*
  • Carbon Dioxide / blood
  • Cardiac Surgical Procedures / adverse effects
  • Cardiac Surgical Procedures / rehabilitation*
  • Female
  • Humans
  • Lung Diseases / etiology
  • Lung Diseases / prevention & control
  • Male
  • Middle Aged
  • Oxygen / blood
  • Partial Pressure
  • Positive-Pressure Respiration / instrumentation
  • Positive-Pressure Respiration / methods*
  • Postoperative Care / methods*
  • Respiratory Mechanics / physiology
  • Treatment Outcome


  • Carbon Dioxide
  • Oxygen