title: Is long-term functional outcome after lung volume reduction surgery predictable?
abstract: OBJECTIVE
  The aim of this retrospective study was to analyze which preoperative parameters might predict a persistent improvement in forced expiratory volume in 1 s (FeV1) 1 year after surgery.
  
  
  METHODS
  Seventy consecutive lung volume reduction surgery (LVRS) patients (age, 56.5+/-1.2 years) with a follow-up period of at least 1 year were analyzed (from September 1994 to September 1997). The patients were described by lung function tests, blood gas analysis, ventilatory mechanics (intrinsic positive endexpiratory pressure (PEEP)) and morphometric data (degree of heterogeneity, DHG; degree of hyperinflation, DHI; severity of parenchymal destruction, SPD) preoperatively. Based on the postoperative course of FeV1 (percentual increase compared with preoperative values, % increase), patients were divided into four groups: group A, (n=21) no improvement (FeV1</=20% increase); group B, (n=10) FeV1>/=20% increase, which declined to preoperative values after 1 year; group C, (n=18) FeV1, 20-40% increase, sustaining at 1 year; group D, (n=21) FeV1>/=40% increase, sustaining at 1 year. The statistics comprised of analysis of variance (ANOVA) and chi-square testing, with values presented as means+/-SEM.
  
  
  RESULTS
  No differences were found for lung function parameters (FeV1: 27.7+/-2.7, 26.0+/-2.5, 23. 9+/-2.2 and 23.9+/-1.9% predicted, in groups A, B, C and D, respectively). Arterial blood gas levels preoperatively revealed significant differences between the groups; the arterial pO(2) was 66.2+/-1.2 mmHg in groups A+B compared with 61.8+/-1.5 mmHg in groups C+D (P=0.030). The arterial pCO(2) was 39.2+/-1.1 mmHg in groups A+B compared with 43.3+/-1.5 mmHg in groups C+D (P=0.038). The morphometric data had a strong trend towards higher heterogeneity in groups C and D. Marked DHI was found in 59 and 81% of patients in groups A+B versus C+D, respectively (P=0.121). Marked DHG was present in 22 and 54% of patients in groups A+B versus C+D, respectively (P=0.010).
  
  
  CONCLUSIONS
  Preoperative arterial pO(2) and pCO(2), and the DHG are predictors for long-term benefit after LVRS with regard to the FeV1, 1 year postoperatively.
authors.affiliation: Department of Cardio-thoracic Surgery, University of Vienna, Währinger Gürtel 18-20, 1090, Vienna, Austria. wilfried.wisser@akh-wien.ac.at
authors.forename: W
authors.initials: W
authors.lastname: Wisser
authors.forename: O
authors.initials: O
authors.lastname: Senbaklavaci
authors.forename: C
authors.initials: C
authors.lastname: Ozpeker
authors.forename: M
authors.initials: M
authors.lastname: Ploner
authors.forename: T
authors.initials: T
authors.lastname: Wanke
authors.forename: E
authors.initials: E
authors.lastname: Tschernko
authors.forename: E
authors.initials: E
authors.lastname: Wolner
authors.forename: W
authors.initials: W
authors.lastname: Klepetko
mesh_terms: D000704:Analysis of Variance; D001784:Blood Gas Analysis; D016009:Chi-Square Distribution; D005260:Female; D005500:Follow-Up Studies; D005541:Forced Expiratory Volume; D006801:Humans; D008297:Male; D008875:Middle Aged; D011013:Pneumonectomy / Q000379:methods*; D011237:Predictive Value of Tests; D011300:Preoperative Care; D011656:Pulmonary Emphysema / Q000175:diagnosis / Q000503:physiopathology* / Q000601:surgery*; D011659:Pulmonary Gas Exchange; D012129:Respiratory Function Tests; D012189:Retrospective Studies; D012720:Severity of Illness Index; D016896:Treatment Outcome