title: Do atmospheric conditions influence the first episode of primary spontaneous pneumothorax?
abstract: OBJECTIVE
  Several studies suggest that changes in airway pressure may influence the onset of primary spontaneous pneumothorax (PSP). The aim of this study was to investigate the influence of atmospheric changes on the onset of the first episode of PSP.
  
  
  METHODS
  We retrospectively analysed cases of pneumothorax admitted to our department between 1 January 2009 and 31 October 2013. Patients with recurrent pneumothorax, traumatic pneumothorax, older than 35 years or presenting history of underlying pulmonary disease were excluded. Meteorological data were collected from the Météo-France archives. Variation (Δ) of mean atmospheric pressure, and relative humidity, were calculated for each day between the day at which symptoms began (D-day), the day before first symptoms (D-1), 2 days before the first symptoms (D-2) and 3 days before the first symptoms (D-3).
  
  
  RESULTS
  Six hundred and thirty-eight cases of pneumothorax were observed during the period of this study; 106 of them (16.6%) were a first episode of PSP. We did not observe any significant differences between days with or without PSP admission for any of the weather parameters that we tested. We could not find any thresholds in the variation of atmospheric pressure that could be used to determine the probability of PSP occurrence.
  
  
  CONCLUSIONS
  Variation of atmospheric pressure, relative humidity, rainfall, wind speed and temperature were not significantly related to the onset of the first episode of PSP in healthy patients. These results suggest that the scientific community should focus on other possible aetiological factors than airway pressure modifications.
authors.affiliation: Department of Thoracic Surgery, University Hospital of Caen, Caen, France heyndrickx-m@chu-caen.fr.
authors.forename: Maxime
authors.initials: M
authors.lastname: Heyndrickx
authors.affiliation: Department of Thoracic Surgery, University Hospital of Caen, Caen, France.
authors.forename: Jean-Philippe
authors.initials: JP
authors.lastname: Le Rochais
authors.affiliation: Department of Thoracic Surgery, University Hospital of Caen, Caen, France.
authors.forename: Philippe
authors.initials: P
authors.lastname: Icard
authors.affiliation: LETG-Caen Géophen Laboratory, UMR 6554 CNRS, University of Caen Basse-Normandie, Caen, France.
authors.forename: Olivier
authors.initials: O
authors.lastname: Cantat
authors.affiliation: Department of Pulmonary Medicine, University Hospital of Caen, Caen, France.
authors.forename: Gérard
authors.initials: G
authors.lastname: Zalcman
mesh_terms: D000328:Adult; D001274:Atmospheric Pressure; D005260:Female; D005602:France / Q000453:epidemiology; D006801:Humans; D008297:Male; D011030:Pneumothorax / Q000453:epidemiology / Q000209:etiology*; D012189:Retrospective Studies; D018570:Risk Assessment / Q000379:methods*; D012307:Risk Factors; D013696:Temperature; D014887:Weather; D055815:Young Adult
keywords: Atmospheric pressure; Pneumothorax; Weather