Anesthesia Coding Alert

Answer: These are often coded as trigger point injections because they are directly into the piriformis muscle, but the procedure code does not reflect the reimbursement the physician deserves. The piriformis muscle is very close to the sciatic nerve, but coding it as a sciatic nerve block (64445*, Injection, anesthetic agent; sciatic nerve, single) is incorrect unless the physician actually blocks the sciatic nerve. Coding it as a peripheral nerve block (64450*, ... other peripheral nerve or branch) is better because a peripheral nerve runs through the piriformis muscle.

The original diagnosis (such as ICD-9 355.0, Mononeuritis of lower limb; lesion of sciatic nerve) also helps determine the injection's appropriate code. Reporting these injections is a judgment call, so just be consistent in coding for them.