title: How to distinguish an active air leak from a pleural space effect.
abstract: OBJECTIVE
  We aimed to distinguish a pleural space effect from an active air leak, using a digital chest drain system that provided continuous air flow and pleural pressure checks.
  
  
  METHODS
  between March 2010 and October 2011, we employed 144 digital drains for 138 thoracic surgical procedures.
  
  
  RESULTS
  We observed 18 (12.5%) active air leaks, among which 4 (2.8%) were prolonged air leaks characterized by high differential pleural pressure due to increased mean expiratory pressure (>1 cm H(2)O; p<0.0001), and 3 (2.1%) late air leaks, all long-lasting (p<0.0001), predicted by pressure curve divergence before the air flow appearance. We also reported 25 (17.4%) pleural space effects characterized by a high differential pleural pressure, but mainly due to a lower mean inspiratory pressure (<20 cm H(2)O; p<0.0001), and especially related to surgical pleurodesis procedures (p<0.0003) and wide lung resections (p<0.0002); there was no increasing pneumothorax after provocative clamping.
  
  
  CONCLUSIONS
  A digital chest drain system, ensuring continuous air flow and pleural pressure measurement, could clearly identify a pleural space effect, avoiding the frequent misinterpretation of an active air leak, and allowing safe removal of the chest tube at the right time.
authors.affiliation: Department of Thoracic Surgery, I.R.C.C.S.–C.R.O.B. Basilicata Regional Cancer Institute, Rionero in Vulture, Italy. d.marasco@inwind.it
authors.forename: Rita Daniela
authors.initials: RD
authors.lastname: Marasco
authors.forename: Gabriella
authors.initials: G
authors.lastname: Giudice
authors.forename: Cosimo
authors.initials: C
authors.lastname: Lequaglie
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000388:Air; D004322:Drainage; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D035422:Pleural Cavity; D011183:Postoperative Complications / Q000175:diagnosis*; D011446:Prospective Studies; D019616:Thoracic Surgical Procedures; D055815:Young Adult