Different Types of Neuraxial Anesthesia
Neuraxial anesthesia refers to a group of regional anesthesia techniques that involve the administration of anesthetic agents near the central nervous system’s neuraxial axis, specifically within the spinal canal. The primary types of neuraxial anesthesia are spinal anesthesia, epidural anesthesia, and combined spinal-epidural (CSE) anesthesia. Each technique has unique applications, benefits, and considerations, making them essential tools in modern anesthesiology 1.
Spinal anesthesia involves injecting a local anesthetic into the cerebrospinal fluid within the subarachnoid space, usually between the L3-L4 or L4-L5 vertebrae, with the patient in a sitting or lateral decubitus position. It provides a rapid onset of sensory and motor blockade within 5-10 minutes, lasting 1-3 hours, depending on the anesthetic administered. Spinal anesthesia is commonly used for lower abdominal, pelvic, and lower extremity surgeries, including cesarean sections and hip replacements. Benefits include a predictable blockade and minimal systemic absorption, while risks include hypotension, post-dural puncture headache, and limited duration of action 2.
Epidural anesthesia involves the injection of local anesthetics into the epidural space, which is located just outside the dura mater. Though both spinal and epidural anesthesia target the spinal cord, the two types of neuraxial anesthesia differ in how close to the spinal cord medication is injected. In epidural anesthesia, a catheter may be placed in the epidural space to allow continuous or intermittent administration of anesthetics. Epidural anesthesia has a slower onset compared to spinal anesthesia, typically taking 15-30 minutes to establish effective blockade, but it can be prolonged by adjusting the infusion of anesthetics through an epidural catheter. Epidural anesthesia is versatile and used for a wide range of surgeries, including thoracic, abdominal, and lower limb procedures, but also for labor analgesia and postoperative pain control. However, they involve technical complexity, potential for failed block, slower onset, and risks such as epidural hematoma or infection 3–5.
CSE anesthesia combines the benefits of both spinal and epidural techniques—initially, a spinal needle is inserted through an epidural needle to deliver a single dose of local anesthetic into the subarachnoid space, after which an epidural catheter is placed for continuous or intermittent administration of anesthetics. CSE provides the rapid onset of spinal anesthesia with the prolonged and adjustable duration of epidural anesthesia: the spinal component offers immediate anesthesia, with the epidural catheter maintaining the blockade. CSE anesthesia is particularly useful for procedures requiring immediate and prolonged anesthesia, such as major abdominal surgeries and labor analgesia 6,7. Advantages include its rapid onset and reliable block from the spinal component, prolonged anesthesia and postoperative analgesia through the epidural catheter, and flexibility. However, it requires a high level of skill and carries risks such as hypotension, post-dural puncture headache, and epidural catheter-related complications 7,8.
The different types of neuraxial anesthesia are spinal, epidural, and combined spinal-epidural techniques, each offering distinct advantages for various surgical and pain management applications. The choice of neuraxial anesthesia depends on factors such as the type and duration of surgery, patient condition, and desired postoperative pain control.
References
1. Regional Anesthetic Blocks – StatPearls – NCBI Bookshelf. Available at: https://www.ncbi.nlm.nih.gov/books/NBK563238/.
2. Spinal Anesthesia – StatPearls – NCBI Bookshelf. Available at: https://www.ncbi.nlm.nih.gov/books/NBK537299/.
3. Epidural Anesthesia – StatPearls – NCBI Bookshelf. Available at: https://www.ncbi.nlm.nih.gov/books/NBK542219/.
4. Epidural – NHS. Available at: https://www.nhs.uk/conditions/epidural/.
5. Epidural: What It Is, Procedure, Risks & Side Effects. Available at: https://my.clevelandclinic.org/health/treatments/21896-epidural.
6. Roofthooft, E., Rawal, N. & Van de Velde, M. Current status of the combined spinal-epidural technique in obstetrics and surgery. Best Pract. Res. Clin. Anaesthesiol. 37, 189–198 (2023).doi: 10.1016/j.bpa.2023.04.004
7. Combined Spinal Epidural (CSE). Available at: https://www.asra.com/news-publications/asra-updates/blog-landing/legacy-b-blog-posts/2019/08/07/combined-spinal-epidural-(cse).
8. Combined spinal–epidural techniques – Continuing Education in Anaesthesia, Critical Care and Pain. Available at: https://www.bjaed.org/article/S1743-1816(17)30496-1/fulltext.