title: An aggregate score to predict the risk of large pleural effusion after pulmonary lobectomy.
abstract: OBJECTIVE
  The volume of pleural effusion is one of the determinants of chest drain removal following pulmonary resection. Recent research suggests that values up to 400 ml/day are safe. The objective of this study was to develop an aggregate risk score to identify patients at higher risk of developing a large pleural effusion (LPE) (>400 ml/day) on postoperative day 2 (POD2) after pulmonary lobectomy.
  
  
  METHODS
  An observational study on 229 consecutive patients was conducted prospectively in two European centres (June 2012-September 2013). All patients underwent pulmonary lobectomy for lung cancer (thoracotomy: 131, video-assisted thoracic surgery: 98) and managed by single chest tube connected to an electronic-regulated suction device. Exclusion criteria were chest wall or diaphragm resection and postoperative-assisted mechanical ventilation. To build the aggregate score, variables were initially screened by univariable analysis, and then used in stepwise logistic regression analysis (validated by bootstrap). The scoring system was developed by proportional weighing of the significant predictor estimates, and patients were grouped in classes of incremental risk according to their total score.
  
  
  RESULTS
  The incidence of LPE on POD2 was 23% (53 of 229 patients). The independent risk factors associated with LPE on POD2 were age greater than 70 years (P = 0.01, bootstrap frequency 71%), a lower lobectomy (P = 0.03, bootstrap frequency 59%) and presence of COPD (P = 0.02, bootstrap frequency 63%). Each predictor received a weighted score of 1, and patients were grouped into three risk classes showing an incremental risk of LPE (P < 0.001): Class A (Score 0) 5 LPE in 66 patients, 7.5%; Class B (Score 1) 19 LPE in 88 patients, 22%; Class C (Score >1) 29 LPE in 75 patients, 39%.
  
  
  CONCLUSIONS
  The aggregate score is a reliable tool for identifying high-risk patients for LPE and assists in the selection of patients that can safely proceed to chest drain removal early after surgery.
authors.affiliation: St James's University Hospital, Leeds, UK hristovarr@gmail.com.
authors.forename: Ralitsa
authors.initials: R
authors.lastname: Hristova
authors.affiliation: St James's University Hospital, Leeds, UK.
authors.forename: Cecilia
authors.initials: C
authors.lastname: Pompili
authors.affiliation: St James's University Hospital, Leeds, UK.
authors.forename: Sofina
authors.initials: S
authors.lastname: Begum
authors.affiliation: Ospedali Riuniti Ancona, Ancona, Italy.
authors.forename: Michele
authors.initials: M
authors.lastname: Salati
authors.affiliation: St James's University Hospital, Leeds, UK.
authors.forename: Manos
authors.initials: M
authors.lastname: Kefaloyannis
authors.affiliation: St James's University Hospital, Leeds, UK.
authors.forename: Vasileios
authors.initials: V
authors.lastname: Tentzeris
authors.affiliation: St James's University Hospital, Leeds, UK.
authors.forename: Kostas
authors.initials: K
authors.lastname: Papagiannopoulos
authors.affiliation: St James's University Hospital, Leeds, UK.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Brunelli
mesh_terms: D000367:Age Factors; D000368:Aged; D015505:Chest Tubes; D005260:Female; D006801:Humans; D015994:Incidence; D008175:Lung Neoplasms / Q000601:surgery; D008297:Male; D010996:Pleural Effusion / Q000453:epidemiology / Q000209:etiology*; D011013:Pneumonectomy / Q000009:adverse effects* / Q000379:methods; D011446:Prospective Studies; D018570:Risk Assessment / Q000379:methods; D012307:Risk Factors
keywords: Chest drainage; Complications; Lobectomy; Patient safety; Pleural effusion; Scoring system