A Study for Minimum Volumes of Bicarbonate to Cause Precipitation of the Domestic Lidocaines / 대한마취과학회지

ABSTRACT

BACKGROUND: When local anesthetics for regional anesthesia is used, usually small amounts of bicarbonate are added for rapid onset. This addition gives the mixed solution a more alkaline pH. The following result is an increased unionized form of the local anesthetic and rapid penetration of the drug into tissue. Unfortunately, no data about adequate mixing volumes of domestic lidocaine and bicarbonate is available. METHODS: We examined six mixing pairs of two kinds of 2% lidocaines and three kinds of 8.4% bicarbonates for minimum volumes of bicarbonate to cause a precipitation of 2% 20 ml lidocaine. RESULTS: The mean volumes of bicarbonate to cause precipitation were 1.54 ml for Kwang-Myung lidocaine with Kwang-Myung bicarbonate, 2.90 ml for Kwang-Myung lidocaine with Dae-Won bicarbonate, 2.73 ml for Kwang-Myung lidocaine with Je-Il bicarbonate, 0.97 ml for Je-Il lidocaine with Kwang-Myung bicarbonate, 1.26 ml for Je-Il lidocaine with Dae-Won bicarbonate and 1.39 ml for Je-Il lidocaine with Je-Il bicarbonate. CONCLSIONS We conclude that the Kwang-Myung lidocaine and the Je-Il lidocaine could cause precipitation when mixing with a smaller bicarbonate volume than foreign textbook recommended.