title: The effects on the lower esophageal sphincter of sevoflurane induction and increased intra-abdominal pressure during laparoscopy.
abstract: BACKGROUND
  Today sevoflurane is one of the most frequently used volatile anesthetics. The speed of induction can approach that of intravenous anesthetics, and case reports using sevoflurane induction for emergency anesthesia have been published. The purpose of this study in laparoscopic cholecystectomy patients was to investigate the effects of sevoflurane during inhalation induction on the lower esophageal sphincter pressure (LESP) and barrier pressure (BrP). The effects on lower esophageal sphincter (LES) and BrP of increased intra-abdominal pressure during laparoscopy were also evaluated.
  
  
  METHODS
  We recorded LESP and BrP in nine patients using a Dent sleeve device. Recordings were made before and after inhalation induction of anesthesia with 8% sevoflurane, as well as before and after insufflation of CO(2) into the abdomen.
  
  
  RESULTS
  After induction with sevoflurane, LESP (P= 0.039) and BrP (P= 0.020) decreased. Nevertheless, BrP was kept positive in all patients. Insufflation of CO(2) into the abdomen during laparoscopy induced a significant increase in LESP (P= 0.02) and gastric pressure (P= 0.004). However, there was no significant change in BrP (P= 0.66); it increased in four patients and decreased in five.
  
  
  CONCLUSIONS
  BrP was kept positive in all patients after induction of anesthesia. Therefore, we believe that in combination with cricoid pressure, inhalation induction with sevoflurane might be a safe choice. As the adaptive increase in LESP during laparoscopy was not enough to retain a barrier pressure in all patients, it is important to be aware of the risk of regurgitation throughout the anesthesia.
authors.affiliation: Department of Anesthesiology and Intensive Care, Orebro University Hospital, Orebro, Sweden. kristian.thorn@oebroll.se
authors.forename: K
authors.initials: K
authors.lastname: Thörn
authors.forename: S-E
authors.initials: SE
authors.lastname: Thörn
authors.forename: M
authors.initials: M
authors.lastname: Wattwil
mesh_terms: D000328:Adult; D018685:Anesthetics, Inhalation / Q000009:adverse effects*; D002245:Carbon Dioxide / Q000008:administration & dosage; D017081:Cholecystectomy, Laparoscopic / Q000009:adverse effects* / Q000379:methods; D004333:Drug Administration Routes; D049630:Esophageal Sphincter, Lower / Q000187:drug effects* / Q000502:physiology; D005260:Female; D006801:Humans; D007327:Insufflation / Q000379:methods; D008297:Male; D008365:Manometry; D008738:Methyl Ethers / Q000009:adverse effects*; D008875:Middle Aged; D011312:Pressure; D000077149:Sevoflurane
chemical_list: D018685:Anesthetics, Inhalation; D008738:Methyl Ethers; D002245:Carbon Dioxide; D000077149:Sevoflurane