title: Risk factors for prolonged ventilation after cardiac surgery using APACHE II, SAPS II, and TISS: comparison of three different models.
abstract: OBJECTIVE
  To identify the risk for prolonged mechanical ventilation in cardiac surgical patients.
  
  
  METHODS
  Prospective study with retrospective combination of a second database.
  
  
  METHODS
  Six hundred and eighty-seven patients after cardiac surgery over a period of 12 months.
  
  
  METHODS
  Demographic data were recorded preoperatively, and surgical procedures intraoperatively using a surgical database designed for quality control. Length of ICU and hospital stay, and hospital outcome were recorded. Severity of illness was assessed daily using APACHE II, SAPS II, and Organ Failure Score. Intensity of treatment and nursing care was monitored by means of the Therapeutic Intervention Scoring System (TISS). Univariate and multivariate analyses were performed using logistic regression. The predictive value of the identified variables was tested by the Wilcoxon test using the receiver operating characteristic curve.
  
  
  RESULTS
  Sixty-two patients (9.0%) were ventilated for > 48 h and accounted for 42.8% of the total costs in the ICU. The pre- and intraoperatively collected data produced a model with weak predictive capacity for prolonged ventilation [area under curve (AUC) 73.22 and 71.08, respectively]. The use of TISS and SAPS postoperatively resulted in an effective model of prediction (AUC 93.76). Adding the occurrence of reoperation, reintubation, emergency transfusion, intraaortic balloon pumping, and need for total parenteral nutrition to the model further improved its predictive capacity (AUC 94.74).
  
  
  CONCLUSIONS
  The present results strongly suggest that data collected postoperatively using established scoring systems as well as documented events of high clinical impact for risk assessment and quality control are reliable predictors of prolonged ventilation.
authors.affiliation: Department of Anesthesiology and Intensive Care, University Hospital Charité, Campus Mitte, Humboldt University of Berlin, Schumannstrasse 20/21, 10098 Berlin, Germany. hartmut.kern@charite.de
authors.forename: H
authors.initials: H
authors.lastname: Kern
authors.forename: U
authors.initials: U
authors.lastname: Redlich
authors.forename: H
authors.initials: H
authors.lastname: Hotz
authors.forename: C
authors.initials: C
authors.lastname: von Heymann
authors.forename: J
authors.initials: J
authors.lastname: Grosse
authors.forename: W
authors.initials: W
authors.lastname: Konertz
authors.forename: W J
authors.initials: WJ
authors.lastname: Kox
mesh_terms: D018806:APACHE; D000368:Aged; D006348:Cardiac Surgical Procedures; D016009:Chi-Square Distribution; D003422:Critical Care / Q000592:standards; D005260:Female; D017052:Hospital Mortality; D006801:Humans; D007902:Length of Stay / Q000706:statistics & numerical data; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012372:ROC Curve; D012121:Respiration, Artificial / Q000706:statistics & numerical data*; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D012720:Severity of Illness Index; D018709:Statistics, Nonparametric