title: Exercise ventilatory inefficiency and mortality in patients with chronic obstructive pulmonary disease undergoing surgery for non-small-cell lung cancer.
abstract: OBJECTIVE
  Surgical resection is the treatment of choice to cure patients with non-small-cell lung cancer (NSCLC); nevertheless, the assessment of the lower limit of surgical tolerance remains difficult. Ventilatory inefficiency (measured as the ventilation to CO(2) production ratio (V'(E)/V'(CO2) slope) is a survival predictor in pulmonary hypertension (PH) and chronic heart failure (CHF) and is considered a marker of PH in chronic obstructive pulmonary disease (COPD). The aim of this study was to investigate the role of V'(E)/V'(CO2) slope as preoperative mortality and morbidity predictor in COPD patients submitted to lung resection for NSCLC and considered operable according to current standards.
  
  
  METHODS
  A retrospective analysis was performed in 145 consecutive COPD patients with lung cancer (128 males and 17 females), with a mean age of 64 years (range: 41-82 years) who were referred for preoperatory evaluation. Because of bronchial obstruction or reduced pulmonary diffusion capacity for carbon monoxide (D(L,CO)), all these patients were considered operable only after a cardiopulmonary exercise test showed a preserved cardiopulmonary function.
  
  
  RESULTS
  A total of 98 lobectomies, eight bilobectomies and 39 pneumonectomies (13 left and 26 right) were performed. Twenty-one patients (14.5%) suffered severe cardio-respiratory complications; 15/106 patients (14.2%) after lobectomy/bilobectomy and 6/39 (15.4%) after pneumonectomy. Five patients (3.4%) died within 30 days after surgery (3/106 after lobectomy/bilobectomy (2.8%) and 2/39 after pneumonectomy (5.1%)). Considering all functional parameters before surgery and the postoperative predicted values, a logistic regression analysis individuated the V'(E)/V'(CO2) slope as the only independent mortality predictor (odds ratio (OR): 1.24 z=2.77; p<0.007). The V'(O2 peak) was instead the best predictor for the occurrence of severe cardiopulmonary postoperative complications (OR: 0.05, z=-2.39, p<0.02).
  
  
  CONCLUSIONS
  In COPD patients, a high V'(E)/V'(CO2) slope before lung resection is an independent mortality predictor even in the presence of an acceptable cardiopulmonary performance. COPD patients with high V'(E)/V'(CO2) slope before surgery must be carefully screened to exclude pulmonary hypertension, especially before surgical procedures with large parenchymal exeresis.
authors.affiliation: SSD Laboratorio di Fisiopatologia Respiratoria e Centro del Sonno, AOU San Luigi Orbassano, Torino, Italy. r.torchio@inrete.it
authors.forename: Roberto
authors.initials: R
authors.lastname: Torchio
authors.forename: Marco
authors.initials: M
authors.lastname: Guglielmo
authors.forename: Roberto
authors.initials: R
authors.lastname: Giardino
authors.forename: Francesco
authors.initials: F
authors.lastname: Ardissone
authors.forename: Claudio
authors.initials: C
authors.lastname: Ciacco
authors.forename: Carlo
authors.initials: C
authors.lastname: Gulotta
authors.forename: Aleksandar
authors.initials: A
authors.lastname: Veljkovic
authors.forename: Massimiliano
authors.initials: M
authors.lastname: Bugiani
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002248:Carbon Monoxide / Q000502:physiology; D002289:Carcinoma, Non-Small-Cell Lung / Q000150:complications / Q000601:surgery*; D005080:Exercise Test / Q000379:methods; D005260:Female; D005541:Forced Expiratory Volume / Q000502:physiology; D006801:Humans; D006976:Hypertension, Pulmonary / Q000150:complications / Q000175:diagnosis / Q000503:physiopathology; D008175:Lung Neoplasms / Q000150:complications / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D011013:Pneumonectomy / Q000009:adverse effects / Q000379:methods; D011300:Preoperative Care / Q000379:methods; D029424:Pulmonary Disease, Chronic Obstructive / Q000150:complications* / Q000503:physiopathology; D011659:Pulmonary Gas Exchange / Q000502:physiology; D012129:Respiratory Function Tests / Q000379:methods; D012189:Retrospective Studies; D013147:Spirometry / Q000379:methods
chemical_list: D002248:Carbon Monoxide