title: Risk factors for hypoxemia during ambulatory gastrointestinal endoscopy in ASA I-II patients.
abstract: BACKGROUND
  Most studies identify the American Society of Anesthesiology (ASA) classification as the most significant risk factor for hypoxemia. The risk factors operative within ASA I and II patients are not well defined. Therefore, we analyzed prospectively collected data to identify the risk factors of hypoxemia in such patients.
  
  
  METHODS
  A combination of a narcotic and benzodiazepine was used for sedation and oxygen was supplemented if hypoxemia (oxygen saturation <or=90%) developed. Univariate and multivariate analyses were performed and correlations estimated for predetermined clinical variables.
  
  
  RESULTS
  40 of 79 patients (51%) developed hypoxemia, which occurred more frequently in the obese (71%; 10/14) than the nonobese (46%; 30/65) group (P=0.08). On multivariate analysis, the odds ratios (OR) and 95% confidence intervals (CI) for developing hypoxemia were age >or= 60 years 4.5 (1.4-14.3) P=0.01, and incremental 25-mg doses of meperidine 2.6 (1.02-6.6) P = 0.04. Body mass index (BMI) significantly correlated with the number of hypoxemic episodes (rho 0.26, 95% CI 0.04-0.48, P=0.02).
  
  
  CONCLUSIONS
  In ASA I and II patients, BMI significantly correlated with the number of hypoxemic episodes, whereas age >or= 60 years and meperidine dose were significant risk factors for hypoxemia.
authors.affiliation: Department of Gastroenterology and Hepatology, Digestive Disease Institute, Cleveland Clinic Foundation, 9500 Euclid Avenue, A 30, Cleveland, OH 44195, USA.
authors.forename: Mohammed A
authors.initials: MA
authors.lastname: Qadeer
authors.forename: A
authors.initials: A
authors.lastname: Rocio Lopez
authors.forename: John A
authors.initials: JA
authors.lastname: Dumot
authors.forename: John J
authors.initials: JJ
authors.lastname: Vargo
mesh_terms: D000367:Age Factors; D000368:Aged; D000556:Ambulatory Surgical Procedures; D015992:Body Mass Index; D016292:Procedural Sedation / Q000009:adverse effects*; D004305:Dose-Response Relationship, Drug; D016099:Endoscopy, Gastrointestinal; D005260:Female; D006801:Humans; D006993:Hypnotics and Sedatives / Q000009:adverse effects*; D000860:Hypoxia / Q000209:etiology*; D008297:Male; D008614:Meperidine / Q000009:adverse effects*; D008874:Midazolam / Q000009:adverse effects; D008875:Middle Aged; D009765:Obesity / Q000150:complications*; D016017:Odds Ratio; D017060:Patient Satisfaction; D011446:Prospective Studies; D018570:Risk Assessment; D012307:Risk Factors
chemical_list: D006993:Hypnotics and Sedatives; D008614:Meperidine; D008874:Midazolam