title: [Evolution of the carboxyhemoglobinemia and methemoglobinemia during endoscopic resection: An observational study].
abstract: OBJECTIVE
  Combustion of organic tissues due to endoscopic resection could induce methemoglobin (MetHb) and carboxyhemoglobin (COHb) formation. The aim of this study is to evaluate MetHb and COHb formation in patients undergoing prostatic or bladder endoscopic procedures.
  
  
  METHODS
  COHb and MetHb measurements were performed in 44 patients at the beginning and end of the procedure. A third measurement was done in patients who stayed more than one hour in the recovery room. Means were compared using Student t-test, simple regressions were used for quantitative variables and ANOVA for categorical variables. Multiple linear regressions were used for multivariate analysis.
  
  
  RESULTS
  COHb increased by 0.5±0.9 % (95 % CI: 0.2 to 0.7 % P=0.001). MetHb increase was 0.0±0.4 % (95 % CI: -0.1 to 0.2 % P=0.552). In univariate analysis, the variables associated with COHb increase are the length of surgery, the amount of irrigation fluid and location (prostate or bladder) of the procedure. In the multivariate model, COHb increase is associated with the amount of liquid and the location.
  
  
  CONCLUSIONS
  MetHb did not increase during endoscopic surgery. In contrast, COHb increases, and can, in some patients, exceed 2-4 %. This could be responsible for a decreased angina threshold in patients with ischemic heart disease.
  
  
  METHODS
  4.
authors.affiliation: Service d'anesthésie, CHU UcL Namur, 1, avenue du Docteur-Gaston-Therasse, 5530 Yvoir, Belgique. Electronic address: laurent.bairy@uclouvain.be.
authors.forename: L
authors.initials: L
authors.lastname: Bairy
authors.affiliation: Service d'anesthésie, cliniques universitaires Saint-Luc, 10, avenue Hippocrate, 1200 Bruxelles, Belgique.
authors.forename: G
authors.initials: G
authors.lastname: Hardy
authors.affiliation: Service d'urologie, CHU Ucl Namur, 1, avenue du Docteur-Gaston-Therasse, 5530 Yvoir, Belgique.
authors.forename: M
authors.initials: M
authors.lastname: Di Gregorio
authors.affiliation: Unité de support scientifique, CHU Ucl Namur, 1, avenue du Docteur-Gaston-Therasse, 5530 Yvoir, Belgique.
authors.forename: B
authors.initials: B
authors.lastname: Bihin
mesh_terms: D000368:Aged; D002263:Carboxyhemoglobin / Q000032:analysis* / Q000096:biosynthesis; D003558:Cystoscopy; D006801:Humans; D008706:Methemoglobin / Q000032:analysis* / Q000096:biosynthesis; D008708:Methemoglobinemia / Q000097:blood; D059035:Perioperative Period; D020728:Transurethral Resection of Prostate
chemical_list: D008706:Methemoglobin; D002263:Carboxyhemoglobin
keywords: Carboxyhemoglobin; Carboxyhémoglobine; Cystoscopie; Cystoscopy; Methemoglobin; Méthémoglobine; Résection transurétrale de la prostate; Transurethral resection of prostate