title: [Arterial blood gases study in patients with stable chronic obstructive pulmonary disease in accordance with spirometric values].
abstract: OBJECTIVE
  The aim of this study was to evaluate the need to assess arterial blood gases in patients with stable chronic obstructive pulmonary disease (COPD) in accordance with spirometric values.
  
  
  METHODS
  Transverse study in stable COPD patients with spirometry and pulse oximetry assessment. Specific exclusion criteria were: diagnosis of asthma, sleep apnea syndrome or respiratory failure not due to COPD. Diagnostic of respiratory failure was established when pulse oximetry saturation was < or = 92%; we evaluated the best predicted FEV1 cut-off value.
  
  
  RESULTS
  467 patients (age = 64 [8] yr) were evaluated. FEV1 was 44 (14) % predicted. Two patients (1.5%) with FEV1 > 50 % and 29 patients (23.6%) with FEV1 between 41 and 50% had respiratory failure. Sensitivity (0.98) and rate of false-negative (0.98) at a cut-off of 50% predicted value FEV1 was superior to sensitivity (0.75%) and rate of false-negative (0.87) at a cut-off of 40% predicted value FEV1.
  
  
  CONCLUSIONS
  In stable COPD patients, the rate of respiratory failure increases when the predicted value FEV1 is below 50%. Therefore, we recommend this spirometric cut-off to evaluate arterial blood gases.
authors.affiliation: Unidad de Neumología, Hospital Costa del Sol, Marbella, Málaga, España. jfguerra@hcs.es
authors.forename: José
authors.initials: J
authors.lastname: Fernández Guerra
authors.forename: José María
authors.initials: JM
authors.lastname: García Jiménez
authors.forename: Emilio
authors.initials: E
authors.lastname: Perea-Milla López
authors.forename: José Joaquín
authors.initials: JJ
authors.lastname: Cebrián Gallardo
authors.forename: Elena
authors.initials: E
authors.lastname: Mora Ruiz
authors.forename: Luis Felipe
authors.initials: LF
authors.lastname: Moreno Arrastio
mesh_terms: D000368:Aged; D005260:Female; D005541:Forced Expiratory Volume; D006801:Humans; D008297:Male; D008875:Middle Aged; D010092:Oximetry; D011237:Predictive Value of Tests; D029424:Pulmonary Disease, Chronic Obstructive / Q000097:blood* / Q000503:physiopathology; D013147:Spirometry