Anesthesia reference, on demand

Toxicity from local anesthetics is generally treated as additive, so mixing lidocaine and bupivacaine does not raise the ceiling. The combined dose should stay within limits, and a common conservative approach is to sum each drug as a fraction of its own maximum and keep the total at or below 100 percent. Weight-based maximums still apply to each agent, so dose to the more conservative limit and account for the full injected volume.