A nerve block decreases your pain during and after surgery. It is more effective than pain medications through the IV. Because you have less pain, you will need less oral or IV pain medications, even though you have the medications available to you. Supplement reviews You will have fewer side effects of pain medications, such as respiratory depression, itching, nausea, and somnolence. In addition, you may be able to avoid a general anesthesia. Sometimes, a nerve block is done in addition to a general anesthesia for pain relief after the surgery.