What Is a Caudal Block?

A caudal block is a pain relief technique that’s characterized by the injection of certain numbing and anti-inflammatory medications into the lower sacral bone of the spine. It’s most commonly used on infants and children, typically as a means of reducing discomfort after surgery. In rarer cases it’s used on adults, but normally only for more minor procedures; epidural blocks and other stronger anesthetics are more common in these cases. Caudal pain medications are normally administered after the patient has already been anesthetized for the surgery, and it’s main purpose is normally to minimize discomfort in the hours after waking. It’s used exclusively to minimize pain below the umbilical area, and normally has the effect of numbing the legs and lower abdomen for anywhere from six to 10 hours.

Pediatric surgeries often present special challenges in terms of pain relief, in part because of how small patients are in most cases. Only limited doses of pain-abating medication are usually safe, and in many cases it’s difficult for children to adequately express how much pain they’re in. Caudal blocks, which are sometimes also called caudal epidural blocks, are common for surgeries performed on the lower abdomen or legs. It is normally administered via injection into the caudal canal, which sits in the sacral spine, just after the patient has been put under for surgery. When done properly it can reduce both the amount of general anesthetic required for the surgery itself and the amount of pain relief needed once the patient wakes up. This often speeds wake time while improving comfort more generally.

The caudal canal is the sacral part of the spinal canal near the lower spine. A caudal block is given by injection into the caudal canal. It is often used to decrease pain and discomfort following groin surgery or any surgery on the lower abdomen. The patient will be given another form of pain medication to treat discomfort after the block has worn off.

The most common drugs included in the injection are lignocaine 1% and bupivacaine 0.25%, though this can vary slightly depending on the provider, the region, and basic availability. In most cases these should come from single dose ampoules. For children, the dose is calculated based on patient age and weight. For adults, the block is normally dosed at around 20 to 30 ml for an abdomen block and 15 to 20 ml for lower limb blocks.

In all cases these drugs should carefully monitored by a trained anesthesiologist, as an overdose can be fatal. Recommended dosages typically hit a maximum of 2 mg/kg for bupivicaine and 4 mg/kg for lignocaine. If the dose hits a vein intravenously, it can reach toxicity at a much smaller dosage amount.

The effects normally last for about two hours, which covers the length of most minor surgeries. Longer procedures may require an anesthesiologist to re-administer the drugs at appropriate intervals. In most cases patients will slowly regain sensation within 4 hours to 6 hours after the block begins wearing off.

The patient may be unstable due to the loss of sensation and should not try walking without assistance until full sensation has returned. Most patients are unlikely to have good balance or use of their legs and feet until about 6 hours after the procedure. Hot items should also be avoided, because the lack of sensation could cause accidental burns since the patient won’t be able to distinguish something that’s simply warm from something that’s dangerously hot.

Medical professionals should be alerted if the caudal nerve block has caused the patient to suffer discomfort that is not tolerable with other pain medications. The patient should also be able to urinate at least every 8 hours after a caudal block is administered. Discomfort and inability to urinate may be signs that something is more seriously wrong.