Lidocaine and mepivacaine, which have a faster onset of action and better penetration than other local anesthetics, are especially good for caudal anesthesia, which occurs rather slowly but may be uneven due to the density of connective tissue and possible adhesions or septa in the sacral canal. .
Bupivacaine (Bucain, Anecain, Markain) is now also widely used for caudal anesthesia: although its action comes later, the duration of action is much longer.
The concentration of local anesthetics is the same as for intervertebral access: for reliable surgical anesthesia (with a motor block) – 2% lidocaine, or 2% mepivacaine, or 0.5% bupivacaine; for analgesia (only sensory block), in combination with anesthesia or for postoperative analgesia, a concentration (1% lidocaine, or 1% mepivacaine, or 0.25 % bupivacaine ) is sufficient (and much safer) .
The volume for reliable blockade of all sacral segments in adults is approximately 20 ml (2-3 ml per segment, twice the segment dose for lumbar intervertebral anesthesia). In pregnancy, the dose is less: 16-18 ml can give a block up to T10.
The onset of local anesthetics with caudal anesthesia is mediated than with intervertebral access, and the onset of full effect may require 40 minutes.
Addition of adrenaline provides less absorption of local anesthetics into the bloodstream (especially important for fairly large volumes with caudal anesthesia), acceleration of onset and prolongation of the block duration . So, anesthesia from 2% lidocaine with the addition of adrenaline at a dilution of 1: 200.000 can last up to two hours.
All precautions for local anesthetics are the same as for intervertebral access . section “LOCAL ANESTHETICS FOR EPIDURAL ANESTHESIA”),