Local anesthetics are often used for nerve block anesthesia, and there are two common types of local anesthetics: esters and amides. The more common is the amide class, such as lidocaine, bupivacaine and ropivacaine, ropivacaine has ropivacaine hydrochloride and ropivacaine mesylate. Bupivacaine hydrochloride is often used clinically, but this drug is very toxic to nerves and heart, once cardiotoxicity occurs, it is very difficult to resuscitate, so when using, must be carefully observed, if epidural anesthesia, must be tested before pushing anesthetics; nerve block anesthesia must be pumped back before, no blood reflux and then push the drug, to minimize the risk. Once a toxic reaction occurs, it should be resuscitated in time. If you choose nerve block, you must choose the safest drug, especially for inexperienced anesthesiologists who are not skilled in puncture.