An improved anesthetic nerve block and method is disclosed comprising a local long acting anesthetic and a physiologic carbonate base. The local long acting anesthetic and the physiologic carbonate base are introduced to a living organism and adjacent to a nerve. The local long acting anesthetic and the physiologic carbonate base react to form a precipitated mass around the nerve for creating a local nerve block. The precipitated mass degrades into unionized local anesthetic which penetrates through the nerve membrane and into the axon for creating a prolonged local nerve block.