title: A model to predict the immediate postoperative FEV1 following major lung resections.
abstract: OBJECTIVE
  FEV1 measured on the first postoperative day has shown to be a better predictor of complications than traditional ppoFEV1. Therefore, its estimation before operation may enhance risk stratification. The objective of this study was to develop and validate a model to predict FEV1 on the first postoperative day after major lung resection.
  
  
  METHODS
  FEV1 was prospectively measured on the first postoperative day in 272 patients submitted for lobectomy or pneumonectomy at two centers. A random sample of 136 patients was used to develop a model estimating the first day FEV1 by using multiple regression analysis including several preoperative and operative factors. The model was then validated by bootstrap analysis and tested on the other sample of 136 patients.
  
  
  RESULTS
  Factors reliably associated with postoperative first day FEV1 were age (p=0.002), preoperative FEV1 (p<0.0001), the presence of epidural analgesia (p<0.0001), and the percentage of non-obstructed segments removed during operation (p=0.001). The following model estimating the first day postoperative FEV1 was derived: -2.648+0.295 x age+0.371 x FEV1+8.216 x epidural analgesia - 0.338 x percentage of non-obstructed segments removed during operation. In the validation set, the mean predicted first day postoperative FEV1 value did not differ from the observed one (42.6 vs 42.0, respectively; p=0.3) and the plot of the observed versus the predicted first day FEV1 showed a satisfactory calibration.
  
  
  CONCLUSIONS
  We developed a model predicting the first day postoperative FEV1. If future analyses will prove its role in stratifying the early postoperative risk, it may be integrated in preoperative evaluation algorithms to refine risk stratification.
authors.affiliation: Unit of Thoracic Surgery, Umberto Io Regional Hospital, Ancona, Italy. alexit_2000@yahoo.com
authors.forename: Alessandro
authors.initials: A
authors.lastname: Brunelli
authors.forename: Gonzalo
authors.initials: G
authors.lastname: Varela
authors.forename: Gaetano
authors.initials: G
authors.lastname: Rocco
authors.forename: Laura
authors.initials: L
authors.lastname: Socci
authors.forename: Nuria
authors.initials: N
authors.lastname: Novoa
authors.forename: Tindaro
authors.initials: T
authors.lastname: Gatani
authors.forename: Michele
authors.initials: M
authors.lastname: Salati
authors.forename: Antonello
authors.initials: A
authors.lastname: La Rocca
mesh_terms: D000368:Aged; D005260:Female; D005541:Forced Expiratory Volume / Q000502:physiology*; D006801:Humans; D008171:Lung Diseases / Q000601:surgery*; D008297:Male; D008954:Models, Biological; D011013:Pneumonectomy / Q000379:methods*; D011182:Postoperative Care / Q000379:methods; D011184:Postoperative Period; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012044:Regression Analysis; D018570:Risk Assessment