title: Pleural Hypercarbia After Lung Surgery Is Associated With Persistent Alveolopleural Fistulae.
abstract: BACKGROUND
  Persistent air leak (PAL) > 5 days due to alveolopleural fistulae is a leading cause of morbidity following surgical resection. Elevated CO2 levels reportedly inhibit alveolar epithelial cell proliferation and impair wound healing in vitro. Because the injured lung surface is in direct communication with the pleural cavity, we investigated whether the pleural gaseous milieu affected lung healing.
  
  
  METHODS
  Oxygen and CO2 levels in pleural gas were determined prospectively in consecutive patients (N = 116) undergoing lung resection by using an infrared spectroscopy-based analyzer. Poisson and logistic regression analyses were used to determine the relationship between time to resolution of air leaks and pleural oxygen and CO2. In addition, patients with pleural CO2 concentrations ? 6% on postoperative day 1 (n = 20) were alternatively treated with supplemental oxygen and extrapleural suction to reduce the pleural CO2 levels.
  
  
  RESULTS
  Poisson analyses revealed that every 1% increase in CO2 was associated with a delay in resolution of air leak by 9 h (95% CI, 7.1 to 10.8; P < .001). Linear regression showed that every 1% increase in CO2 increased the odds of PAL by 10-fold (95% CI, 2.2 to 47.8; P = .003). In patients with pleural CO2 ? 6%, a reduction in CO2 promoted resolution of air leak (6.0 ± 1.2 vs 3.4 ± 1.1 days; P < .001).
  
  
  CONCLUSIONS
  Pleural hypercarbia seems to be associated with persistent alveolopleural fistulae following lung resection. Analysis of pleural gases could allow for better chest tube management following lung resection. Patients with intrapleural hypercarbia seem to benefit from supplemental oxygen and suction, whereas patients who do not have hypercarbia can be maintained on water seal drainage.
authors.affiliation: Division of Thoracic Surgery, Department of Surgery, Northwestern University, Chicago, IL. Electronic address: abharat@nm.org.
authors.forename: Ankit
authors.initials: A
authors.lastname: Bharat
authors.affiliation: Division of Thoracic Surgery, Department of Surgery, Northwestern University, Chicago, IL.
authors.forename: Nicole
authors.initials: N
authors.lastname: Graf
authors.affiliation: Division of Thoracic Surgery, Department of Surgery, Northwestern University, Chicago, IL.
authors.forename: Andrew
authors.initials: A
authors.lastname: Mullen
authors.affiliation: Division of Thoracic Surgery, Department of Surgery, Northwestern University, Chicago, IL.
authors.forename: Jacob
authors.initials: J
authors.lastname: Kanter
authors.affiliation: Bluhm Cardiovascular Institute, Northwestern University, Chicago, IL.
authors.forename: Adin-Cristian
authors.initials: AC
authors.lastname: Andrei
authors.affiliation: Division of Pulmonary and Critical Care Medicine, Department of Medicine, Northwestern Medicine, Northwestern University, Chicago, IL; Jesse Brown Veterans Affairs Medical Center, Chicago, IL.
authors.forename: Peter H S
authors.initials: PH
authors.lastname: Sporn
authors.affiliation: Division of Thoracic Surgery, Department of Surgery, Northwestern University, Chicago, IL.
authors.forename: Malcolm M
authors.initials: MM
authors.lastname: DeCamp
authors.affiliation: Division of Pulmonary and Critical Care Medicine, Department of Medicine, Northwestern Medicine, Northwestern University, Chicago, IL.
authors.forename: Jacob I
authors.initials: JI
authors.lastname: Sznajder
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D006935:Hypercapnia / Q000209:etiology / Q000517:prevention & control*; D008297:Male; D008875:Middle Aged; D010102:Oxygen Inhalation Therapy; D010995:Pleural Diseases / Q000175:diagnosis / Q000209:etiology*; D011013:Pneumonectomy / Q000009:adverse effects*; D011446:Prospective Studies; D011650:Pulmonary Alveoli; D016156:Respiratory Tract Fistula / Q000175:diagnosis / Q000209:etiology*; D013396:Suction
keywords: lung; lung injury; thoracic surgery