title: Effect of prophylactic bronchodilator treatment with intravenous colforsin daropate, a water-soluble forskolin derivative, on airway resistance after tracheal intubation.
abstract: BACKGROUND
  After induction of anesthesia, lung resistance increases. The authors hypothesized that prophylactic bronchodilator treatment with intravenous colforsin daropate, a water-soluble forskolin derivative, before tracheal intubation would result in decreased lung resistance and increased lung compliance after tracheal intubation when compared with placebo medication.
  
  
  METHODS
  Forty-six adult patients were randomized to placebo or colforsin daropate treatment. Patients in the control group received normal saline; patients in the colforsin group received 0.75 microg. kg-1 x min-1 colforsin daropate intravenously until the study ended. Thirty minutes after the study began, the authors administered 5 mg/kg thiamylal and 5 microg/kg fentanyl for induction of general anesthesia and 0.3 mg/kg vecuronium for muscle relaxation. A 15-mg. kg-1. h-1 continuous infusion of thiamylal followed anesthetic induction. Four, 8, 12, and 16 min after tracheal intubation, mean airway resistance (R(awm)), expiratory airway resistance (R(awe)), and dynamic lung compliance (C(dyn)) were measured.
  
  
  RESULTS
  Patients in the colforsin group had significantly lower R(awm) and R(awe) and higher C(dyn) after intubation than those in the control group. Differences in R(awm), R(awe), and C(dyn) between the two groups persisted through the final measurement at 16 min. At 4 min after intubation, smokers had a higher R(awm) and a lower C(dyn) than nonsmokers in the control group. After treatment by intravenous colforsin daropate, R(awm), R(awe), and C(dyn) values were similar for smokers and nonsmokers after tracheal intubation.
  
  
  CONCLUSIONS
  Prophylactic treatment with colforsin daropate produced lower R(awm) and R(awe) and higher C(dyn) after tracheal intubation when compared with placebo medication. Pretreatment before intubation may be beneficial and advantageous for middle-aged smokers.
authors.affiliation: Department of Anesthesia, Chiba Hokusoh Hospital, Nippon Medical School, Japan. hfb01245@nifty.com
authors.forename: Zen'ichiro
authors.initials: Z
authors.lastname: Wajima
authors.forename: Toshiya
authors.initials: T
authors.lastname: Shiga
authors.forename: Tatsusuke
authors.initials: T
authors.lastname: Yoshikawa
authors.forename: Akira
authors.initials: A
authors.lastname: Ogura
authors.forename: Kazuyuki
authors.initials: K
authors.lastname: Imanaga
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Inoue
authors.forename: Ryo
authors.initials: R
authors.lastname: Ogawa
mesh_terms: D000328:Adult; D000403:Airway Resistance / Q000187:drug effects*; D000769:Anesthesia, Inhalation; D001794:Blood Pressure / Q000187:drug effects; D001993:Bronchodilator Agents / Q000627:therapeutic use*; D002395:Catecholamines / Q000097:blood; D005576:Colforsin / Q000031:analogs & derivatives* / Q000627:therapeutic use*; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006439:Hemodynamics / Q000187:drug effects; D006801:Humans; D007442:Intubation, Intratracheal; D008170:Lung Compliance / Q000187:drug effects; D008297:Male
chemical_list: D001993:Bronchodilator Agents; D002395:Catecholamines; C122001:colforsin daropate; D005576:Colforsin