Lumbar blockade

A lumbar blockade of the sympathetic nervous system is a methodologically simple procedure, practically free from complications, which has proved to be effective in individual cases. (58)... 

In the caudal form of extradural anesthesia, the agent is introduced through the sacral hiatus above the coccyx. It is particularly applicable to perineal and rectal procedures. Anesthetization of higher anatomical levels is not easily obtained, because the required injection volume can be excessive. Although caudal anesthesia has been used extensively in obstetrics, lumbar epidural blockade is now more commonly used because of the lower dose of drug required in addition, the sacral segments are spared until their anesthesia is required for the delivery. 

Central neural blockade. The anesthetic is injected within the spaces surrounding the spinal cord10 (Fig. 12-2). Specifically, the term epidural nerve blockade refers to injection of the drug into the epidural space—that is, the space between the bony vertebral column and the dura mater. A variation of epidural administration known as a caudal block is sometimes performed by injecting the local anesthetic into the lumbar epidural space via the sacral hiatus (see Fig. 12-2). Spinal nerve blockade refers to injection within the subarachnoid space— that is, the space between the arachnoid membrane and the pia mater. Spinal blockade is also referred to as intrathecal anesthesia because the drug is injected within the tissue sheaths surrounding the spinal cord (intrathecal means within a sheath see Chapter 2). 

In 55 patients, continuous lumbar sympathetic blockade with local anesthetics administered via a catheter to treat sympathetic pain caused a psoas abscess in two patients, both of whom were treated with a continuous infusion of 0.25% bupivacaine (28). It was assumed that the catheter had been dislodged and that the drug had been injected into the psoas muscle or the psoas sheath. Another reason for this complication could have been local trauma due to a hematoma around the vertebrae during the insertion of the needle. The main drawbacks of the technique were the high incidences of infections and displacement of the catheters. 

Horner s syndrome has been reported after lumbar epidural block in two other patients who were having lumbar epidural anesthesia for chronic pain treatment (144). The authors suggested that this complication had probably occurred through anatomical changes in the epidural space, leading to a high degree of sympathetic blockade. 

These agents must be delivered directly to the desired nerve bundle. The delivery is often a problem due to technical issues accessing these anatomical sites, particularly cervical, brachial plexus, lumbar plexus, sciatic, and popliteal blocks. This is commonly the reason for inadequate neural blockade. There maybe other issues precluding needle or catheter placement, such as patient cooperation, infection, or coagulation concerns. 

---