title: Is hypercapnea a predictor of better survival in the patients who underwent mechanical ventilation for chronic obstructive pulmonary disease (COPD)?
abstract: BACKGROUND
  There are contradictory reports concerning hypercapnia as a predictor of a better outcome in COPD. This study examined the clinical implications of hypercapnea in COPD patients (M:F = 59:19) who required mechanical ventilation.
  
  
  METHODS
  The clinical parameters at the time of MICU admission, the total ventilation time, the APACHE II score and the pulmonary function testing were retrospectively analyzed between the survivors and nonsurvivors.
  
  
  RESULTS
  Univariate analysis showed that compared with the nonsurvivors, the survivors had lower AaDO2 values (59.8 +/- 53.5 vs. 105.0 +/- 73.3 mmHg, p=0.000), higher PaCO2 values (64.9 +/- 16.0 vs. 48.9 +/- 17.8 mmHg, p=0.000), lower APACHE II scores (19.0 +/- 3.8 vs. 24.1 +/- 5.1, p=0.002), the more frequent application of initial noninvasive positive pressure ventilation (44.0 vs. 14.3%, p=0.008), and a lower combined rate of septic shock (4.0 vs. 39.3%, p=0.000). Multivariate analysis revealed that a lower PaCO2 (OR: 0.94, p=0.008), the presence of septic shock (OR: 10.16, p=0.011), a higher APACHE II score (OR: 1.22, p=0.040) and a longer ventilation time (OR: 1.002, p=0.041) were the risk factors for mortality. A lower PaCO2 was also verified as the predictor. for mortality by multivariate analysis when excluding septic shock.
  
  
  CONCLUSIONS
  Hypercapnia at admission is thought to be an independent predictor of better survival for the COPD patients who require mechanical ventilation.
authors.affiliation: Department of Pulmonary and Critical Care Medicine, Ajou University School of Medicine, Suwon, Korea.
authors.forename: Joo Hun
authors.initials: JH
authors.lastname: Park
authors.forename: Younsuck
authors.initials: Y
authors.lastname: Koh
authors.forename: Chae-Man
authors.initials: CM
authors.lastname: Lim
authors.forename: Sang-Bum
authors.initials: SB
authors.lastname: Hong
authors.forename: Yeon Mok
authors.initials: YM
authors.lastname: Oh
authors.forename: Tae Sun
authors.initials: TS
authors.lastname: Shim
authors.forename: Sang Do
authors.initials: SD
authors.lastname: Lee
authors.forename: Woo Sung
authors.initials: WS
authors.lastname: Kim
authors.forename: Dong Soon
authors.initials: DS
authors.lastname: Kim
authors.forename: Won Dong
authors.initials: WD
authors.lastname: Kim
mesh_terms: D018806:APACHE; D000368:Aged; D015415:Biomarkers; D005260:Female; D006801:Humans; D006935:Hypercapnia; D008297:Male; D015999:Multivariate Analysis; D010343:Patient Admission; D011379:Prognosis; D029424:Pulmonary Disease, Chronic Obstructive / Q000401:mortality* / Q000628:therapy; D012121:Respiration, Artificial / Q000379:methods; D012131:Respiratory Insufficiency; D012189:Retrospective Studies; D012307:Risk Factors; D016019:Survival Analysis; D016896:Treatment Outcome
chemical_list: D015415:Biomarkers