IS PROPOFOL USED APPROPRIATELY FOR ITS ANTIEMETIC EFFECT?

S385 INTRODUCTION: Propofol based anesthesia has been shown to decrease the incidence of post-operative nausea and vomiting (PONV) compared to inhalational techniques. [1] More recently propofol has been used in subhypnotic doses in an attempt to reduce PONV. [2] In addition many practitioners utilize the so-called "sandwich technique" involving propofol induction of anesthesia, maintenance with volatile agents and the use of propofol again during the last few minutes of a case, in an attempt to reduce PONV and to decrease recovery time. However a previous study has shown that propofol does not reach the plasma concentration necessary to reduce PONV. The purpose of this study was to investigate how practitioners use propofol for its antiemetic effect. METHODS: We surveyed 150 practicing anesthesiologists at the ASA annual meeting (46% academic, 54% private). Questions were asked concerning the use of propofol specifically to reduce PONV. RESULTS: Propofol is used by 84% of the respondents as part of the anesthetic regimen for its antiemetic effect. Table 1 and Table 2 below show how propofol is used (numbers are % of the propofol users).Table 1Table 2DISCUSSION: A large proportion of practicing anesthesiologists use propofol for its antiemetic effect, sometimes in combination with other agents. A surprising number (62.5%) expect propofol to reduce PONV more than 60 min after induction dose. In addition 37% of those using propofol for its antiemetic effect use a "sandwich" technique. This may not be protective against PONV for longer cases. A recent study determined the plasma concentration of propofol associated with a 50% reduction in PONV as 343ng/ml [2], which may not be approached using the above techniques. Propofol should be administered in adequate doses for its antiemetic effect.