title: Lung function 12 months following emphysema resection.
abstract: OBJECTIVE
  To investigate the mechanism of airflow limitation before and 6 and 12 months after targeted emphysematous resection in 10 male patients aged 67 +/- 8 years (mean +/- SD) with very severe COPD undergoing bilateral thoracoscopic stapling techniques.
  
  
  METHODS
  Lung function, including static lung elastic recoil, was measured 2 weeks before and 6 and 12 months after surgery.
  
  
  RESULTS
  Twelve months after surgery, there was a significant (p < 0.001) reduction in total lung capacity (TLC), 9.5 +/- 0.3 L (mean +/- SEM) to 8.5 +/- 0.3 L, functional residual capacity, and residual volume. Airway conductance and FEV1, 0.71 +/- 0.1 L (mean +/- SEM) to 0.95 +/- 0.1 L, improved significantly (p < 0.01). Lung elastic recoil increased markedly at TLC from 11.7 +/- 0.7 cm H2O (mean +/- SEM) to 15.0 +/- 1.0 cm H2O (p < 0.01) as did maximum expiratory airflow in every patient. However, when compared with data obtained in each patient at 6 months, lung volumes are significantly increased, and expiratory airflow and lung elastic recoil pressures are significantly reduced (p < or = 0.05). Analysis of maximum expiratory flow-static elastic recoil pressure curve indicates conductance of the S airway segment (Gs) increased from 0.20 +/- 0.03 L/s/cm H2O (mean +/- SEM) to 0.28 +/- 0.04 L/s/cm H2O (p < 0.02), and critical transmural pressure in the collapsible segment (Ptm') decreased from 3.2 +/- 0.2 cm H2O (mean +/- SEM) to 2.5 +/- 0.2 cm H2O (p < 0.01).
  
  
  CONCLUSIONS
  The improvement in maximal expiratory airflow can be attributed primarily to increased lung elastic recoil and its secondary effect on enlarging airway diameter causing increased airway conductance, increased Gs, and decreased Ptm'. The improvement in lung function and elastic recoil peaks at 6 months.
authors.affiliation: Department of Medicine, Lakewood (California) Regional Medical Center, University of California, Los Angeles, School of Medicine, USA.
authors.forename: A F
authors.initials: AF
authors.lastname: Gelb
authors.forename: M
authors.initials: M
authors.lastname: Brenner
authors.forename: R J
authors.initials: RJ
authors.lastname: McKenna
authors.forename: N
authors.initials: N
authors.lastname: Zamel
authors.forename: R
authors.initials: R
authors.lastname: Fischel
authors.forename: J D
authors.initials: JD
authors.lastname: Epstein
mesh_terms: D000368:Aged; D000403:Airway Resistance; D005500:Follow-Up Studies; D005541:Forced Expiratory Volume; D006801:Humans; D008170:Lung Compliance; D008297:Male; D008448:Maximal Expiratory Flow Rate; D008875:Middle Aged; D011013:Pneumonectomy; D011656:Pulmonary Emphysema / Q000503:physiopathology / Q000601:surgery*; D015656:Respiratory Mechanics; D014109:Total Lung Capacity