title: Saliva cyclic GMP increases during anaesthesia.
abstract: BACKGROUND
  Cyclic GMP (cGMP) has been implicated in modulating the effects of general anaesthesia. Changes in cGMP in humans undergoing anaesthesia have not been reported previously.
  
  
  METHODS
  In this pilot study we measured cGMP in the saliva of six healthy volunteers and eight patients undergoing general anaesthesia for minor gynaecological procedures. Samples were obtained using a commercially available sampling device and cGMP was determined with an enzyme immunoassay and results expressed as a cGMP per mg protein.
  
  
  RESULTS
  There was no statistically significant variation in salivary cGMP either day-to-day or between time points in healthy volunteers. Analysis of variance of salivary cGMP of patients undergoing general anaesthesia showed that cGMP increased significantly intraoperatively and returned to preoperative levels after surgery (P=0.03).
  
  
  CONCLUSIONS
  This is the first time that real time in vivo changes in salivary cGMP levels during general anaesthesia in humans have been demonstrated and may allow an alternative technique for measuring depth of anaesthesia in the future.
authors.affiliation: Academic Unit of Anaesthesia and Intensive Care, Institute of Medical Sciences, University of Aberdeen, Aberdeen AB25 2ZD, Scotland, UK.
authors.forename: T
authors.initials: T
authors.lastname: Engelhardt
authors.forename: H F
authors.initials: HF
authors.lastname: Galley
authors.forename: F M
authors.initials: FM
authors.lastname: MacLennan
authors.forename: N R
authors.initials: NR
authors.lastname: Webster
mesh_terms: D000328:Adult; D000768:Anesthesia, General; D015415:Biomarkers / Q000032:analysis; D006152:Cyclic GMP / Q000378:metabolism*; D005260:Female; D006801:Humans; D007432:Intraoperative Period; D016343:Monitoring, Intraoperative / Q000379:methods; D011184:Postoperative Period; D012463:Saliva / Q000378:metabolism*
chemical_list: D015415:Biomarkers; D006152:Cyclic GMP