Ketamine for Intravenous Regional Anesthesia

TLDR

The study evaluated ketamine intravenous regional anesthesia in volunteers at 0.5%, 0.3%, and 0.2% concentrations. Ketamine at 0.5% and 0.3% produced adequate anesthesia, whereas 0.2% was ineffective; the 0.3% dose achieved full blockade but caused unpleasant psychotomimetic effects, so ketamine is not recommended for IVRA unless these side effects are mitigated.

Abstract

We studied ketamine intravenous regional anesthesia of the upper extremity in volunteers using concentrations of 0.5%, 0.3%, and 0.2%. Ketamine 0.5 and 0.3% produced adequate intravenous regional anesthesia. Anesthesia was inadequate when a 0.2% concentration was used. However, although the 0.3% concentration provides complete sympathetic, sensory, and motor blockade when injected into the isolated extremity, unpleasant psychotomimetic effects after the release of the tourniquet limit the usefulness of this use of ketamine. Ketamine cannot be recommended for intravenous regional anesthesia unless these unpleasant side effects are abolished or controlled by means of pharmacologic adjuvants.