title: Relation between preoperative inspiratory lung resistance and the outcome of lung-volume-reduction surgery for emphysema.
abstract: BACKGROUND
  Surgery to reduce lung volume has recently been reintroduced to alleviate dyspnea and improve exercise tolerance in selected patients with emphysema. A reliable means of identifying patients who are likely to benefit from this surgery is needed.
  
  
  METHODS
  We measured lung resistance during inspiration, static recoil pressure at total lung capacity, static lung compliance, expiratory flow rates, and lung volumes in 29 patients with chronic obstructive lung disease before lung-volume-reduction surgery. The changes in the forced expiratory volume in one second (FEV1) six months after surgery were related to the preoperatively determined physiologic measures. A response to surgery was defined as an increase in the FEV1 of at least 0.2 liter and of at least 12 percent above base-line values.
  
  
  RESULTS
  Of the 29 patients, 23 had some improvement in FEV1 including 15 who met the criteria for a response to surgery. Among the variables considered, only preoperative lung resistance during inspiration predicted changes in expiratory flow rates after surgery. Inspiratory lung resistance correlated significantly and inversely with improvement in FEV1 after surgery (r=-0.63, P<0.001). A preoperative criterion of an inspiratory resistance of 10 cm of water per liter per second had a sensitivity of 88 percent (14 of 16 patients) and a specificity of 92 percent (12 of 13 patients) in identifying patients who were likely to have a response to surgery.
  
  
  CONCLUSIONS
  Preoperative lung resistance during inspiration appears to be a useful measure for selecting patients with emphysema for lung-volume-reduction surgery.
authors.affiliation: Division of Pulmonary and Critical Care Medicine, Brigham and Women's Hospital, Boston, MA 02115, USA.
authors.forename: E P
authors.initials: EP
authors.lastname: Ingenito
authors.forename: R B
authors.initials: RB
authors.lastname: Evans
authors.forename: S H
authors.initials: SH
authors.lastname: Loring
authors.forename: D W
authors.initials: DW
authors.lastname: Kaczka
authors.forename: J D
authors.initials: JD
authors.lastname: Rodenhouse
authors.forename: S C
authors.initials: SC
authors.lastname: Body
authors.forename: D J
authors.initials: DJ
authors.lastname: Sugarbaker
authors.forename: S J
authors.initials: SJ
authors.lastname: Mentzer
authors.forename: M M
authors.initials: MM
authors.lastname: DeCamp
authors.forename: J J
authors.initials: JJ
authors.lastname: Reilly
mesh_terms: D000328:Adult; D000368:Aged; D000403:Airway Resistance; D005260:Female; D005541:Forced Expiratory Volume; D006801:Humans; D016014:Linear Models; D008168:Lung / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D011013:Pneumonectomy; D011379:Prognosis; D011656:Pulmonary Emphysema / Q000503:physiopathology* / Q000601:surgery*; D016896:Treatment Outcome; D014797:Vital Capacity