VANCOMYCIN DOES NOT ENHANCE HYPOTENSION UNDER ANESTHESIA

The rapid administration of vancomycin is associated with flushing and hypotension, a consequence of histamine release. The manufacturer dis courages administering vancomycin to anesthetized patients, stating th at vancomycin aggravates the hypotensive effects of anesthetics. To te st this, we randomly assigned 36 adults (ASA classes I through III) to one of two groups: preinduction (Preind, n = 19) and postinduction (P ostind, n = 17). Both groups received two different infusions: vancomy cin (1 g/250 mL normal saline) and saline (250 mL normal saline) over 30-60 min. The Preind group received vancomycin before anesthesia was induced and saline was administered immediately after anesthesia was i nduced; for the Postind group, this order was reversed. This was done in a double-blind fashion. The anesthetic induction was standardized b y the intravenous administration of thiopental and vecuronium and anes thetic maintenance by inhalation of nitrous oxide and enflurane. End-t idal enflurane, heart rate (HR), and blood pressure (BP) were measured every 3 min. Independent (unpaired) t-test was used in data analysis. The groups did not differ significantly. We conclude that vancomycin infusion may be given under anesthesia without significant adverse hem odynamic consequences if administered over a 30-60 min period of time.