title: Acid regurgitation associated with persistent cough after pulmonary resection: an observational study.
abstract: BACKGROUND
  Following a pulmonary resection, some patients suffer from persistent coughing, which may have a relationship with acid regurgitation. Since few physiological studies have been reported regarding this issue, we conducted the present observational study.
  
  
  METHODS
  Persistent cough after pulmonary resection (CAP) was defined as non-productive coughing that occurred after a pulmonary resection in patients with stable chest X-ray results and no postnasal drip syndrome, asthma, or history of angiotensin converting enzyme inhibitor administration. A 24-hour esophageal pH monitor was used with patients with coughing (n = 13) and patients with no coughing (n = 4) after undergoing a lobectomy, and the relationship between acid regurgitation and CAP was assessed using symptom association probability.
  
  
  RESULTS
  Based on the results of pH monitoring conducted within 4 weeks of the operation we divided the patients into 3 groups: Type A had frequent gastroesophageal refluxes (>50 occurrences in 24 hours) and frequent coughing (>30 occurrences in 24 hours), Type B had frequent gastroesophageal refluxes and infrequent coughing, and type C had infrequent gastroesophageal refluxes and infrequent coughing. Type A patients (n = 10) were exclusively those with CAP and the symptom association probability was greater than 95%. Five from that group underwent esophageal pH monitoring more than 1 year after surgery and none showed significant improvements in acid regurgitation.
  
  
  CONCLUSIONS
  There was a relationship seen between acid regurgitation and CAP in some patients shortly after surgery, while acid regurgitation remained unimproved after improvement of coughing in most of those 1 year after surgery.
authors.affiliation: Department of Cardiothoracic Surgery, Dokkyo Medical University School of Medicine, Mibu, Tochigi, Japan. sawabata@dokkyomed.ac.jp
authors.forename: Noriyoshi
authors.initials: N
authors.lastname: Sawabata
authors.forename: Shin-ichi
authors.initials: S
authors.lastname: Takeda
authors.forename: Toshiteru
authors.initials: T
authors.lastname: Tokunaga
authors.forename: Masayoshi
authors.initials: M
authors.lastname: Inoue
authors.forename: Hajime
authors.initials: H
authors.lastname: Maeda