Anesthesia Coding Alert

Brushing up on vocabulary can help you understand what was done.

Getting familiar with certain terminology will help you gain a better understanding of regional anesthesia for obstetrics and what the codes represent.

An intrathecal injection is one into the spinal canal, more specifically into the sub-arachnoid space so that it reaches the cerebral spinal fluid. You’ll find that several anatomic layers cover the spinal cord.

The “space” just above the cord and the cerebral spinal fluid is called the subarachnoid or subdural space. The area adjacent to or above this is the epidural space.

Whenever the physician punctures the “dura” (the lining of the spinal cord), the instillation of anesthetic carries the risk of getting too high and interfering with maternal respiration. Epidural anesthesia is placed in contact with the dura but does not enter the dura.

Instillation of intrathecal medication is performed in much the same way. A very small dose of an opiate (usually morphine) or an opiate mixed with a local anesthetic can be placed in the same location using the same technique as is done with the epidural. The risks of toxic effects of local anesthetics and the risk of getting “too high” are minimal because of the small dose necessary.