title: Feasibility of Anesthesia Maintenance With Sevoflurane During Cardiopulmonary Bypass: A Pilot Pharmacokinetics Study.
abstract: OBJECTIVE
  Adequate maintenance of hypnosis during anesthesia throughout surgery using sevoflurane alone was investigated. In addition, sevoflurane pharmacokinetics during cardiopulmonary bypass were analyzed.
  
  
  METHODS
  This was a pilot pharmacokinetic study.
  
  
  METHODS
  Tertiary care university hospital.
  
  
  METHODS
  The study comprised 10 patients aged between 18 and 75 years who underwent elective mitral valve surgery.
  
  
  METHODS
  The end-tidal and sevoflurane plasma concentrations were measured throughout cardiac surgery procedures involving cardiopulmonary bypass. The sevoflurane plasma concentration was measured using gas chromatography. In addition, the ratio between sevoflurane alveolar concentration and inspired concentration over time (FA/FI) was analyzed to describe wash-in and wash-out curves.
  
  
  RESULTS
  Hypnosis was maintained adequately throughout surgery using sevoflurane alone. The bispectral index was maintained between 40 and 60 during cardiopulmonary bypass. The end-tidal sevoflurane was significantly different before and during cardiopulmonary bypass (1.86%±0.54% v 1.30%±0.58%, respectively; p<0.001). However, the sevoflurane plasma concentration was not significantly different before and after cardiopulmonary bypass start-up (40.55 µg/mL [76.62-125.33] before cardiopulmonary bypass and 36.24 µg/mL [56.49-81-42] during cardiopulmonary bypass). This mismatch possibly can be explained by changes that occured after cardiopulmonary bypass start-up, such as reductions of body temperature (36.33°C±0.46°C v 32.98°C±2.38°C, respectively; p<0.001) and hematocrit (35.62%±3.98% v 25.5%±3.08%, respectively; p<0.001). The sevoflurane alveolar concentration varied according to sevoflurane plasma concentration and bispectral index values. No adverse events regarding sevoflurane administration during cardiopulmonary bypass were observed.
  
  
  CONCLUSIONS
  Sevoflurane end-tidal values were reliable indicators of adequate anesthesia during all cardiac surgery procedures involving cardiopulmonary bypass.
authors.affiliation: Department of Anesthesia and Intensive Care, IRCCS San Raffaele Scientific Institute, Milan, Italy.
authors.forename: Roberta
authors.initials: R
authors.lastname: Meroni
authors.affiliation: Department of Anesthesia and Intensive Care, IRCCS San Raffaele Scientific Institute, Milan, Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Gianni
authors.affiliation: Department of Anesthesia and Intensive Care, IRCCS San Raffaele Scientific Institute, Milan, Italy.
authors.forename: Marcello
authors.initials: M
authors.lastname: Guarnieri
authors.affiliation: Department of Anesthesia and Intensive Care, IRCCS San Raffaele Scientific Institute, Milan, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Saglietti
authors.affiliation: Department of Anesthesia and Intensive Care, IRCCS San Raffaele Scientific Institute, Milan, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Gemma
authors.affiliation: Department of Anesthesia and Intensive Care, IRCCS San Raffaele Scientific Institute, Milan, Italy.
authors.forename: Alberto
authors.initials: A
authors.lastname: Zangrillo
authors.affiliation: Department of Anesthesia and Intensive Care, IRCCS San Raffaele Scientific Institute, Milan, Italy. Electronic address: bignami.elena@hsr.it.
authors.forename: Elena
authors.initials: E
authors.lastname: Bignami
mesh_terms: D000328:Adult; D000768:Anesthesia, General / Q000379:methods*; D018685:Anesthetics, Inhalation / Q000008:administration & dosage / Q000097:blood* / Q000493:pharmacokinetics; D002315:Cardiopulmonary Bypass / Q000379:methods*; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D008297:Male; D008738:Methyl Ethers / Q000008:administration & dosage / Q000097:blood* / Q000493:pharmacokinetics; D008875:Middle Aged; D010865:Pilot Projects; D000077149:Sevoflurane
chemical_list: D018685:Anesthetics, Inhalation; D008738:Methyl Ethers; D000077149:Sevoflurane
keywords: anesthesia; bispectral index; cardiopulmonary bypass; kinetics; sevoflurane