title: Propofol fails to attenuate the cardiovascular response to rapid increases in desflurane concentration.
abstract: BACKGROUND
  A rapid increase in desflurane concentration to greater than 1 MAC transiently increases heart rate, arterial blood pressure, and circulating catecholamine concentration. Because propofol decreases sympathetic outflow, it was hypothesized that propofol would blunt these responses.
  
  
  METHODS
  To test this hypothesis, five healthy male volunteers were studied three times. After induction of anesthesia with 2 mg.kg-1 propofol, anesthesia was maintained with 4% end-tidal desflurane in oxygen (0.55 MAC) via an endotracheal tube for 32 min. On separate occasions, in random order, either no propofol or 2 mg.kg-1 propofol was administered either 2 or 5 min before increasing end-tidal desflurane concentration from 4% to 8%.
  
  
  RESULTS
  Without propofol pretreatment, the increase to 8% desflurane transiently increased heart rate (from 63 +/- 3 beats/min to 108 +/- 5 beats/min, mean +/- SEM; P < 0.01), mean arterial pressure (from 73 +/- 1 mmHg to 118 +/- 6 mmHg; P < 0.01), and epinephrine concentration (from 14 +/- 1 pg.ml-1 to 279 +/- 51 pg.ml-1; P < 0.05). There was no significant change in norepinephrine concentration (from 198 +/- 37 pg.ml-1 to 277 +/- 46 pg.ml-1). The peak plasma epinephrine concentration was attenuated by each propofol pretreatment (158 +/- 35 pg.ml-1, propofol given 2 min before, and 146 + 41 pg.ml-1, propofol given 5 min before; P < 0.05), but neither propofol pretreatment modified the cardiovascular or norepinephrine responses.
  
  
  CONCLUSIONS
  Although able to blunt the increase in epinephrine concentration, propofol 2 mg.kg-1 propofol does no attenuate the transient cardiovascular response to a rapid increase in desflurane concentration to greater than 1 MAC.
authors.affiliation: Department of Anaesthesia, Glasgow Royal Infirmary, Scotland, United Kingdom.
authors.forename: M
authors.initials: M
authors.lastname: Daniel
authors.forename: E I
authors.initials: EI
authors.lastname: Eger
authors.forename: R B
authors.initials: RB
authors.lastname: Weiskopf
authors.forename: M
authors.initials: M
authors.lastname: Noorani
mesh_terms: D000328:Adult; D000768:Anesthesia, General / Q000009:adverse effects* / Q000379:methods*; D018686:Anesthetics, Intravenous / Q000494:pharmacology; D001794:Blood Pressure / Q000187:drug effects*; D000077335:Desflurane; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D006339:Heart Rate / Q000187:drug effects*; D006801:Humans; D007530:Isoflurane / Q000009:adverse effects / Q000031:analogs & derivatives* / Q000493:pharmacokinetics; D008297:Male; D017202:Myocardial Ischemia / Q000139:chemically induced / Q000517:prevention & control; D015742:Propofol / Q000494:pharmacology
chemical_list: D018686:Anesthetics, Intravenous; D000077335:Desflurane; D007530:Isoflurane; D015742:Propofol