title: Effect of single oral dose of tramadol on gastric secretions pH.
abstract: BACKGROUND
  Tramadol is an atypical analgesic agent. It has been shown that intramuscular or intravenous injection tramadol is able to inhibit M3 muscarinic receptors. Tramadol is able to mediate smooth muscles contraction and glandular secretions. We have evaluated the effects of single oral dose of tramadol given preoperatively on gastric juices pH in patients electively scheduled for laparoscopic cholecystectomy.
  
  
  METHODS
  Sixty adult, American Society of Anesthesiologist I and II patients scheduled for laparoscopic cholecystectomy were included in the study. Patients were randomly assigned to receive either placebo (n = 30) or oral tramadol 50 mg (n = 30). General anesthesia was induced using propofol, fentanyl and cisatracurium. After induction of anesthesia 5 ml of gastric fluid was aspirated through orogastric tube. The gastric fluid pH was measured using pH meter.
  
  
  RESULTS
  There was no significant difference in the pH between the groups. Gastric pH of the placebo and tramadol groups was 1.97 versus 1.98 (P = 0.092) respectively.
  
  
  CONCLUSIONS
  Preoperatively single oral dose of tramadol was unable to elevate the desired level of gastric acid secretions pH (>2.5). This may be due to pharmacokinetic disparity between the analgesic and pH elevating properties of tramadol.
authors.affiliation: Department of Anesthesia, College of Medicine, King Saud University, Riyadh, Saudi Arabia.
authors.forename: Khan Mueen
authors.initials: KM
authors.lastname: Ullah
authors.affiliation: Department of Anesthesia, College of Medicine, King Saud University, Riyadh, Saudi Arabia.
authors.forename: Mansoor
authors.initials: M
authors.lastname: Aqil
authors.affiliation: Department of Anesthesia, College of Medicine, King Saud University, Riyadh, Saudi Arabia.
authors.forename: Altaf
authors.initials: A
authors.lastname: Hussain
authors.affiliation: Department of Anesthesia, College of Medicine, King Saud University, Riyadh, Saudi Arabia.
authors.forename: Tariq
authors.initials: T
authors.lastname: Al Zahrani
authors.affiliation: Department of Anesthesia, College of Medicine, King Saud University, Riyadh, Saudi Arabia.
authors.forename: Marwan
authors.initials: M
authors.lastname: Hillis
keywords: Gastric pH; M3 muscrinic receptors; tramadol