What is the difference between lumbar puncture and epidural anesthesia?

Lumbar puncture is actually a traditional name for subarachnoid puncture.

First of all, subarachnoid puncture mainly refers to an invasive examination operation, which is clinically used to extract cerebrospinal fluid for related examination, but it can also be anesthetized by injecting local anesthetic through subarachnoid puncture (that is, "subarachnoid block" or "spinal anesthesia").

Maybe many people don't understand, isn't subarachnoid block and epidural anesthesia all on the back? Is there a difference between the two?

In fact, these two kinds of anesthesia are collectively called intraspinal anesthesia, and the anatomical level in the spinal canal is ligamentum flavum-dura mater-arachnoid membrane-spinal cord in turn. The epidural space between ligamentum flavum and dura mater is called epidural anesthesia. However, there is a potential anatomical gap between dura mater and arachnoid membrane, which is generally difficult to distinguish in clinic. There is a gap between the arachnoid membrane and the spinal cord, which is called subarachnoid space. So one of the differences between these two anesthesia methods is the difference of drug injection level.

More importantly, the duration, location and dosage of anesthesia in the two groups are also different. Subarachnoid block has the advantages of short anesthesia time, low safe anesthesia site (usually only used for abdominal and below surgical anesthesia) and relatively small dosage (the main complication is headache caused by low intracranial pressure, but the improvement of instruments in recent years has reduced this risk); Epidural anesthesia can support surgery for a long time, and can even be used for postoperative analgesia. The safe anesthesia site is high (even used for neck surgery anesthesia in the early stage), but the dosage is large (and the technical requirements for practitioners are high, which may lead to complications of total spinal anesthesia).