title: Dyspnea response following bilateral thoracoscopic staple lung volume reduction surgery.
abstract: OBJECTIVE
  Lung volume reduction surgery (LVRS) has shown promise for treating patients with severe emphysema in recent clinical trials. However, response following surgery is difficult to assess due to frequent discrepancies between subjective and objective outcomes. We evaluated the relationship between improvement in dyspnea and pulmonary function response in 145 consecutive patients with inhomogeneous emphysema enrolled in a bilateral thoracoscopic lung volume reduction protocol in order to assess predictors of improved dyspnea outcome and correlation of subjective and objective improvement measures.
  
  
  METHODS
  Baseline complete pulmonary function testing, spirometry, gas exchange, plethysmography, gas dilution lung volumes, along with resting dyspnea index determinations were performed preoperatively, and repeated short term (mean, 33 days; n=129) and long term (>6 months; mean, 276 days; n=84) following surgery.
  
  
  RESULTS
  Improvement in FEV1 percent predicted was significantly associated with improvement in dyspnea scores, though considerable variability exists (r=0.04, p<0.01, short term; r=0.4, p=0.1, long term). In this preselected patient group, those with the extreme degrees of hyperinflation may have less improvement in dyspnea following LVRS than those with milder preoperative hyperinflation. Greater improvement in dyspnea short term and long term was seen in patients with lower presenting residual volume/total lung capacity ratios (r=0.4, p=0.02, short term; r=0.4, p<0.05, long term).
  
  
  CONCLUSIONS
  Bilateral thoracoscopic staple LVRS results in significant objective and subjective improvement in patients with severe emphysema and hyperinflation. There was considerable variability between improvement in dyspnea and improvement in spirometry, and preoperative predictors of response may differ between these outcome variables. Further studies are needed to define the long-term implications of these findings.
authors.affiliation: Division of Pulmonary Medicine, UC Irvine Medical Center, Orange, Calif 92668, USA. mbrenner@bli.uci.edu
authors.forename: M
authors.initials: M
authors.lastname: Brenner
authors.forename: R J
authors.initials: RJ
authors.lastname: McKenna
authors.forename: A F
authors.initials: AF
authors.lastname: Gelb
authors.forename: R J
authors.initials: RJ
authors.lastname: Fischel
authors.forename: B
authors.initials: B
authors.lastname: Yoong
authors.forename: J
authors.initials: J
authors.lastname: Huh
authors.forename: K
authors.initials: K
authors.lastname: Osann
authors.forename: J C
authors.initials: JC
authors.lastname: Chen
mesh_terms: D000368:Aged; D002423:Cause of Death; D004417:Dyspnea / Q000503:physiopathology* / Q000601:surgery; D005069:Evaluation Studies as Topic; D005500:Follow-Up Studies; D005541:Forced Expiratory Volume / Q000502:physiology; D005544:Forecasting; D006801:Humans; D007902:Length of Stay; D008137:Longitudinal Studies; D008170:Lung Compliance / Q000502:physiology; D008176:Lung Volume Measurements; D017060:Patient Satisfaction; D010991:Plethysmography; D011013:Pneumonectomy / Q000379:methods*; D011656:Pulmonary Emphysema / Q000503:physiopathology / Q000601:surgery*; D011659:Pulmonary Gas Exchange / Q000502:physiology; D012115:Residual Volume / Q000502:physiology; D012129:Respiratory Function Tests; D013147:Spirometry; D017792:Surgical Stapling; D013906:Thoracoscopy; D014109:Total Lung Capacity / Q000502:physiology; D016896:Treatment Outcome