Skip to Main Content


  • Image not available.Spinal, epidural, and caudal blocks are also known as neuraxial anesthesia. Each of these blocks can be performed as a single injection or with a catheter to allow intermittent boluses or continuous infusions.
  • Image not available.Performing a lumbar (subarachnoid) puncture below L1 in an adult (L3 in a child) avoids potential needle trauma to the cord.
  • Image not available.The principal site of action for neuraxial blockade is the nerve root.
  • Image not available.Differential blockade typically results in sympathetic blockade (judged by temperature sensitivity) that may be two segments higher than the sensory block (pain, light touch), which in turn is usually two segments higher than the motor blockade.
  • Image not available.Interruption of efferent autonomic transmission at the spinal nerve roots can produce sympathetic and some parasympathetic blockade.
  • Image not available.Neuraxial blocks typically produce variable decreases in blood pressure that may be accompanied by a decrease in heart rate and cardiac contractility.
  • Image not available.Deleterious cardiovascular effects should be anticipated and steps undertaken to minimize the degree of hypotension. Volume loading with 10–20 mL/kg of intravenous fluid for a healthy patient will partially compensate for the venous pooling.
  • Image not available.Excessive or symptomatic bradycardia should be treated with atropine, and hypotension should be treated with vasopressors.
  • Image not available.Major contraindications to neuraxial anesthesia are patient refusal, bleeding diathesis, severe hypovolemia, elevated intracranial pressure, infection at the site of injection, and severe stenotic valvular heart disease or ventricular outflow obstruction.
  • Image not available.For epidural anesthesia, a sudden loss of resistance is encountered as the needle penetrates the ligamentum flavum and enters the epidural space. For spinal anesthesia, the needle is advanced further through the epidural space and penetrates the dura–subarachnoid membranes as signaled by free flowing cerebrospinal fluid.
  • Image not available.Epidural anesthesia is a neuraxial technique offering a range of applications wider than the typical all-or-nothing spinal anesthetic. An epidural block can be performed at the lumbar, thoracic, or cervical level.
  • Image not available.Epidural techniques are widely used for operative anesthesia, obstetric analgesia, postoperative pain control, and chronic pain management.
  • Image not available.Epidural anesthesia is slower in onset (10–20 min) and may not be as dense as spinal anesthesia.
  • Image not available.The quantity (volume and concentration) of local anesthetic needed for epidural anesthesia is very large compared with spinal anesthesia. Significant toxicity can occur if this amount is injected intrathecally or intravascularly. Safeguards against this include the epidural test dose and incremental dosing.
  • Image not available.Caudal epidural anesthesia is one of the most commonly used regional techniques in pediatric patients.


Wayne Kleinman is the Director of Obstetric Anesthesia, Encino-Tarzana Regional Medical Center, Los Angeles, California.


Spinal, caudal, and epidural blocks were first used for surgical procedures at the turn of the twentieth century (see Chapter 1). These central blocks were widely used prior to the 1940s until increasing reports of permanent neurological injury appeared. However, a large-scale epidemiological study conducted in the 1950s indicated that complications were rare when these blocks were performed skillfully with attention to asepsis and when newer, safer local anesthetics were used. A resurgence in the use of central blocks ensued, and today they are once ...

Want remote access to your institution's subscription?

Sign in to your MyAccess profile while you are actively authenticated on this site via your institution (you will be able to verify this by looking at the top right corner of the screen - if you see your institution's name, you are authenticated). Once logged in to your MyAccess profile, you will be able to access your institution's subscription for 90 days from any location. You must be logged in while authenticated at least once every 90 days to maintain this remote access.


About MyAccess

If your institution subscribes to this resource, and you don't have a MyAccess profile, please contact your library's reference desk for information on how to gain access to this resource from off-campus.

Subscription Options

AccessAnesthesiology Full Site: One-Year Subscription

Connect to the full suite of AccessAnesthesiology content and resources including procedural videos, interactive self-assessment, real-life cases, 20+ textbooks, and more

$995 USD
Buy Now

Pay Per View: Timed Access to all of AccessAnesthesiology

24 Hour Subscription $34.95

Buy Now

48 Hour Subscription $54.95

Buy Now

Pop-up div Successfully Displayed

This div only appears when the trigger link is hovered over. Otherwise it is hidden from view.