title: Respiratory muscle strength is not decreased in patients undergoing cardiac surgery.
abstract: BACKGROUND
  Postoperative pulmonary impairments are significant complications after cardiac surgery. Decreased respiratory muscle strength could be one reason for impaired lung function in the postoperative period. The primary aim of this study was to describe respiratory muscle strength before and two months after cardiac surgery. A secondary aim was to describe possible associations between respiratory muscle strength and lung function.
  
  
  METHODS
  In this prospective observational study 36 adult cardiac surgery patients (67 ± 10 years) were studied. Respiratory muscle strength and lung function were measured before and two months after surgery.
  
  
  RESULTS
  Pre- and postoperative respiratory muscle strength was in accordance with predicted values; MIP was 78 ± 24 cmH2O preoperatively and 73 ± 22 cmH2O at two months follow-up (p = 0.19). MEP was 122 ± 33 cmH2O preoperatively and 115 ± 38 cmH2O at two months follow-up (p = 0.18). Preoperative lung function was in accordance with predicted values, but was significantly decreased postoperatively. At two-months follow-up there was a moderate correlation between MIP and FEV1 (r = 0.43, p = 0.009).
  
  
  CONCLUSIONS
  Respiratory muscle strength was not impaired, either before or two months after cardiac surgery. The reason for postoperative lung function alteration is not yet known. Interventions aimed at restore an optimal postoperative lung function should focus on other interventions then respiratory muscle strength training.
authors.affiliation: Department of Neuroscience: Physiotherapy, Uppsala University, BOX 593/BMC, SE-751 24, Uppsala, Sweden. charlotte.urell@neuro.uu.se.
authors.forename: Charlotte
authors.initials: C
authors.lastname: Urell
authors.affiliation: Department of Neuroscience: Physiotherapy, Uppsala University, BOX 593/BMC, SE-751 24, Uppsala, Sweden.|Department of Medical Sciences: Respiratory, Allergy and Sleep Research, Uppsala University, Akademiska sjukhuset, Uppsala, SE-751 85, Sweden.
authors.forename: Margareta
authors.initials: M
authors.lastname: Emtner
authors.affiliation: Department of Medical Sciences: Clinical Physiology, Uppsala University, Akademiska sjukhuset, SE-751 85, Uppsala, Sweden.
authors.forename: Hans
authors.initials: H
authors.lastname: Hedenstrom
authors.affiliation: Department of Medical Sciences: Clinical Physiology, Uppsala University, Akademiska sjukhuset, SE-751 85, Uppsala, Sweden.|Faculty of Medicine and Health, Örebro University, UFC, P.O. BOX 1613, SE-701 16, Region Örebro County, Örebro, Sweden.
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Westerdahl
mesh_terms: D000368:Aged; D001945:Breathing Exercises; D006348:Cardiac Surgical Procedures / Q000009:adverse effects*; D005260:Female; D006801:Humans; D008168:Lung / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D053580:Muscle Strength / Q000502:physiology*; D011184:Postoperative Period; D011446:Prospective Studies; D012132:Respiratory Muscles / Q000502:physiology*
keywords: Cardiac surgery; Lung function; Median sternotomy; Respiratory muscle strength