title: General anesthesia and exhaled breath hydrogen peroxide.
abstract: To study the role of free radical formation on the impairment of pulmonary function seen with general anesthesia, we measured the hydrogen peroxide (H2O2) concentration in the exhaled breath condensate of 27 patients. Patients were divided into three study groups: a healthy patient group (group 1, n = 15) consisting of ASA physical status 1 and 2 patients undergoing elective noncardiothoracic surgery; a specific anesthetic event group (group 2, n = 6) composed of patients undergoing cardiopulmonary bypass (CPB); and a positive control group (group 3, n = 6) consisting of patients with the adult respiratory distress syndrome (ARDS). The exhaled breath condensate was collected by diverting exhaled breath through a glass condensation coil submerged in an ice/salt water bath. The exhaled breath condensate samples were then assayed using a spectrophotometric method. In group 1, samples were collected before and after the induction of general anesthesia with intravenous drugs, and before and after the administration of the inhalational anesthetics isoflurane (1.5%) (n = 7) or N2O (70%) (n = 8). In group 2, samples were collected pre- and post-CPB, and in group 3, when specific diagnostic criteria for ARDS were met. There was no significantly detectable H2O2 (not significantly different from zero) in any of the samples from the group 1 patients. Similarly, group 2 patients had exhaled breath H2O2 concentrations near zero except for one patient who was positive for the lupus anticoagulant. Group 3 patients had a mean (+/- SE) exhaled breath H2O2 concentration of 0.55 (+/- 0.08) microM, which was significantly greater than zero (P less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Department of Anesthesiology, University of California, San Diego Medical Center 92103-8770.
authors.forename: W C
authors.initials: WC
authors.lastname: Wilson
authors.forename: J F
authors.initials: JF
authors.lastname: Swetland
authors.forename: J L
authors.initials: JL
authors.lastname: Benumof
authors.forename: P
authors.initials: P
authors.lastname: Laborde
authors.forename: R
authors.initials: R
authors.lastname: Taylor
mesh_terms: D000768:Anesthesia, General; D000769:Anesthesia, Inhalation; D000771:Anesthesia, Intravenous; D001944:Breath Tests; D002315:Cardiopulmonary Bypass; D006801:Humans; D006861:Hydrogen Peroxide / Q000032:analysis*; D007530:Isoflurane; D009609:Nitrous Oxide; D011897:Random Allocation; D012128:Respiratory Distress Syndrome / Q000378:metabolism / Q000601:surgery; D013053:Spectrophotometry
chemical_list: D006861:Hydrogen Peroxide; D007530:Isoflurane; D009609:Nitrous Oxide