title: [The value of changes in end-tidal carbon dioxide pressure induced by passive leg raising test in predicting fluid responsiveness in mechanically ventilated patients with septic shock].
abstract: OBJECTIVE
  To test whether the changes of partial end-tidal carbon dioxide pressure (PETCO2) during passive leg raising (PLR) predict fluid responsiveness in mechanically ventilated patients with septic shock.
  
  
  METHODS
  Forty-two mechanically ventilated patients with septic shock admitted from January 2012 to November 2012 were prospectively recruited.Hemodynamic parameters monitored by a pulse indicator continuous cardiac output (PiCCO) device and PETCO2 monitored by an expiratory-CO2 device were studied at baseline, after PLR, and after volume expansion. Fluid responsiveness was defined as an increase in cardiac index (CI) of 15% or greater after volume expansion. The correlation between PLR-induced CI change (ΔCIPLR) and PETCO2 (ΔPETCO2-PLR) was analyzed. The value of ΔPETCO2-PLR to predict fluid responsiveness was evaluated by receiver operating characteristic (ROC) curves.
  
  
  RESULTS
  A total of 42 patients were enrolled in this study, of whom, 24 had a CI increase of ≥ 15% after volume expansion (responders). After PLR, CI and PETCO2 were both significantly increased in the response group compared with baseline [(21.4 ± 12.9)% of CI and (9.6 ± 4.7)% of PETCO2, P < 0.05], while no significant changes were observed (P > 0.05) in the non-response group. Both ΔCIPLR and ΔPETCO2-PLR were significantly higher in responder group than in the non-responder group (both P < 0.05). ΔCI and ΔPETCO2 after PLR were strongly correlated (r = 0.64, P < 0.05). In responders after PLR, the area under ROC curve of ΔPETCO2-PLR was 0.900 ± 0.056 (95%CI 0.775-1.000, P < 0.05). An increase of ≥ 5% in ΔPETCO2-PLR predicted fluid responsiveness with a sensitivity of 88.0% and specificity of 88.2%.
  
  
  CONCLUSIONS
  The change of PETCO2 induced by passive leg raising is a non-invasive and easy way to predict fluid responsiveness in mechanically ventilated patients with septic shock.
authors.affiliation: Department of Critical Care Medicine, Wuxi People's Hospital Affiliated to Nanjing Medical University, Wuxi 214023, China. Email: zangzhizzd@yahoo.com.cn.
authors.forename: Zhi-dong
authors.initials: ZD
authors.lastname: Zang
authors.forename: Jie
authors.initials: J
authors.lastname: Yan
authors.forename: Hong-yang
authors.initials: HY
authors.lastname: Xu
authors.forename: Feng-ming
authors.initials: FM
authors.lastname: Liang
authors.forename: Ting
authors.initials: T
authors.lastname: Yang
authors.forename: Da-peng
authors.initials: DP
authors.lastname: Wang
authors.forename: Fei
authors.initials: F
authors.lastname: Gao
mesh_terms: D000328:Adult; D000368:Aged; D002245:Carbon Dioxide / Q000097:blood*; D005260:Female; D006801:Humans; D035002:Lower Extremity; D008297:Male; D008875:Middle Aged; D012121:Respiration, Artificial; D012772:Shock, Septic / Q000097:blood* / Q000628:therapy
chemical_list: D002245:Carbon Dioxide