Overview of Caudal Anesthesia
Caudal anesthesia is a type of pain control often used in surgeries. It can be used alone or alongside general anesthesia. It is commonly used in children for surgeries in the lower part of the stomach and in adults to manage chronic lower back pain. According to a study that looked at 750 caudal anesthesia procedures done in children, it was found to be successful 96% of the time. The use of special equipment like fluoroscopy and ultrasound, which can help accurately place the needle necessary for this anesthesia, has improved the success rate even further.
Anatomy and Physiology of Caudal Anesthesia
The caudal epidural technique is a medical procedure where doctors access the space around your spinal cord through a gap at the base of your spine, called the sacral hiatus. This is slightly different in adults and children. In adults, the spinal cord ends at the first or second vertebra of the lumbar region (lower back). In children, it ends at the third or fourth vertebra in the lower back and moves up a bit during the first year of life. This switcheroo in young babies means that doctors might sometimes reach the dural sac (the protective outer layer of the spinal cord) while performing this procedure.
The most preferred method of performing this procedure is by using anatomical landmarks to identify the right spot. In adults, doctors often use this method for a one-time treatment because it’s tricky to insert a thin tube (catheter) for ongoing treatment. In children, while the one-time technique is still preferred, it’s a bit easier to put in a catheter if needed. Research has shown that using a catheter in this way for short periods (less than three days) is safe and doesn’t increase the risk of serious or local infections.
Why do People Need Caudal Anesthesia
Caudal anesthesia is a form of treatment used in children for operations below the belly button. These operations can include repairs to a hernia in the groin area, urological treatments, fixing a rare birth defect called anal atresia, and procedures on the legs. This anesthesia can be used on its own, or along with general anesthesia.
Caudal epidural injections may also be used for chronic lower back pain that hasn’t improved with traditional medical treatment. These injections can work particularly well for patients who have pain from both a herniated disk and facet joint problems, where the joints in your spine become painful. However, if the pain is coming only from facet joints, these injections might not be the right solution.
In the past, caudal epidural anesthesia, which involves placing a catheter, was also used in pregnant women for pain relief during the second stage of labor. But, there were problems with its effectiveness, risk of limb paralysis due to large amounts of local anesthetic, and significant drops in blood pressure. Because of these issues, lumbar epidurals, which are in the lower part of the spine, became the standard method for managing pain during labor.
Caudal blocks may be chosen over lumbar epidural blocks as they numb the lower part of the spinal cord and reduce muscle function while limiting disruption to the body’s sympathetic nervous system (which controls the body’s response to stress). They also have a lower chance of causing a dural puncture, which is when a needle accidentally punctures the membrane surrounding the spinal cord.
When a Person Should Avoid Caudal Anesthesia
There are certain circumstances where a type of anesthesia known as caudal anesthesia (anesthesia given in the lower part of your spine) may not be suitable. Among these include: refusal by the patient or their guardian, infection at the spot where the needle would be inserted, severe bleeding disorder, increased pressure in the brain, and allergy to the medications used in the procedure. A raised pressure in the brain could possibly lead to more serious complications after getting this type of anesthesia.
There are also relatively less severe situations, but they still might make caudal anesthesia a bit risky. For instance, spinal stenosis (narrowing of the spaces within your spine) can make complications with the nervous system more likely after using anesthesia techniques in the spine. People with low body fluids might experience lower blood pressure due to the effect of the anesthesia on the blood vessels. If a person has a less serious bleeding disorder, further conversation is needed. The American Society of Regional Anesthesia provides the most recent guidelines in such cases.
A widespread infection might make any type of spinal anesthesia a bit risky due to the possibility of spreading the infection and the risk of vasodilation indicating to low blood pressure. However, anesthesia on the spine is usually safe to perform once a patient is responding well to antibiotic treatment.
In children, there are other conditions doctors need to consider where caudal anesthesia might not be suitable. These include a boil at the base of the spinal cord (pilonidal cyst), abnormal sacral bones (spine bones at your lower back) such as previous issues of spinal cord and covering protruding through a birth defect in the spine (meningomyelocele), or abnormal fusion of the spine (like tethered cord syndrome).
Equipment used for Caudal Anesthesia
To do a caudal epidural block, which is a type of pain relief procedure for the lower body, a doctor needs certain equipment. This includes a syringe that is the right size, a needle or a tube used for obtaining vein access (IV access catheter), the medication needed, a solution to clean the skin such as alcohol, chlorhexidine, or an iodine solution, and personal protective equipment like sterile gloves, a mask, and a head covering.
Using ultrasound, which is a device that uses sound waves to create images, can be helpful in performing a caudal epidural block in both children and adults. According to a study by Shin and others, using ultrasound to locate a part of the lower spine called the sacral hiatus made it easier to carry out the procedure.
The most reliable way to know if a caudal epidural block has worked properly is fluoroscopy-guided method. Fluoroscopy is a type of imaging that uses X-rays to obtain real-time moving images of the inside of your body. Nonetheless, this method is rarely used in operating rooms due to its practical difficulties and because it exposes both the patient and healthcare providers to radiation.
Who is needed to perform Caudal Anesthesia?
Getting caudal anesthesia, a type of pain relief, should be done by a trained expert. This could be an anesthesiologist (who is a doctor responsible for putting you to sleep during surgeries), a nurse trained in giving anesthesia, or a doctor specializing in chronic pain management. They could even be an anesthesiologist who’s still learning. They’ll be supervised by an experienced anesthesiologist to make sure everything goes safely. During the procedure, another person may be there to help position you correctly to ensure the treatment is effective and comfortable.
Preparing for Caudal Anesthesia
A caudal epidural block is a type of treatment where a healthcare professional injects anesthesia into the lower section of your spinal area. To prepare for this, they will review your health history, conduct an examination, and teach you about the procedure. Your safety is a top priority, so they’ll monitor your vital signs throughout the process. For the procedure, you may be lying on your side or stomach. You’ll be made comfortable and secure in this position.
For young patients, sleep-inducing medicine is usually given before the procedure begins. The healthcare provider will take a moment to check everything before starting the treatment and will clean the area with a special solution to prevent infection.
The type of medicine used for this procedure is usually either bupivacaine or ropivacaine. The dosage depends on the treatment area and your body weight. Some healthcare providers may prefer to use ropivacaine because it has less impact on motor ability.
Special additives can prolong the pain relief from the procedure. Epinephrine and clonidine are two examples that help extend the duration of the block. Options like morphine and fentanyl can be used as well, but these may cause side effects like itching, nausea, and difficulty breathing. It’s important to be observed for 24 hours if these are used in your procedure.
For patients suffering from chronic low back and radiating leg pain, injections of corticosteroids can even be administered into the lower spinal area. These types of medicines, such as dexamethasone, betamethasone, methylprednisolone, and triamcinolone, are often used for this purpose.
How is Caudal Anesthesia performed
A caudal block is a type of medical procedure that can be performed in different ways: blindly, using ultrasound guidance, or fluoroscopic guidance.
For a Blind Caudal Epidural Block, doctors identify a region called the sacral hiatus, using certain body landmarks as guides. After preparing the skin, they insert a specialized needle at an angle of 45 degrees. The doctor might feel a “pop” or “give” which tells them they’ve gone through a certain ligament and entered the epidural space (the area that surrounds your spinal cord). To ensure the needle is in the right place, they might perform what’s known as the “whoosh test.” This involves listening to the thoracolumbar region (the mid and lower back area) while injecting air into the epidural space.
For an Ultrasound-Guided Caudal Epidural Block, you would be lying on your stomach or on your side. A device called a transducer is placed in the middle of the sacrum (a triangular bone at the back of your pelvis). This device sends sound waves into your body and picks up the echoes, creating an image that the doctor uses to guide the needle to the correct spot. The needle is then inserted, but is carefully managed to avoid puncturing the dura (a layer around your spinal cord). The doctor will also use color doppler technology, which shows the movement of blood flow, to ensure the needle is successfully placed.
For a Fluoroscopy-Guided Caudal Epidural Block, you would also be lying on your stomach. The doctor uses a method called fluoroscopy, which gives a continuous X-ray image, to visualize the sacral hiatus. A needle is advanced into the sacral canal, and by injecting a contrast medium (a dye that improves the X-ray images), the doctor can confirm if the needle placement is accurate and safe.
In children who are under general anesthesia, the success of the caudal block can be checked by assessing the relaxation of the anal sphincter (a ring of muscle that keeps the opening of the anus closed). A study showed that checking the anal sphincter tone was a better predictor for a successful caudal block than other methods.
Possible Complications of Caudal Anesthesia
Caudal anesthesia, a type of anesthesia often used in surgeries, may have some common complications. These could include an injection accidentally placed in the wrong spot like a bone, blood vessel or between layers of tissues; an infection; low blood pressure; injury to the nerve roots located at the lower end of the spinal cord; accidental injection before reaching the sacrum with a chance of damaging the rectum; formation of a pool of blood called a hematoma; local anesthetic toxicity, meaning having too much anesthetic that becomes harmful; delayed difficulty in breathing; inability to urinate and infection of the sacrum bone.
A serious complication from a caudal block, a type of caudal anesthesia, could be total spinal anesthesia. This can happen when the outermost membrane covering the spinal cord is accidentally punctured, leading to the anesthesia being injected into the spinal canal. This complication is more common in infants as the termination of the spinal cord at the sacrum is further down than in adults.
Additionally, seizures related to the local anesthetic are more likely with caudal epidural blocks as compared to other anesthetic methods such as those applied to the brachial plexus, or lumbar or thoracic epidural blocks. There’s a documented 0.69% rate of seizures with caudal anesthesia in contrast to a 0.01% rate with lumbar or thoracic epidurals. Therefore, during these procedures, it’s crucial to administer a test dose with epinephrine to check if the anesthetic is being introduced into the bloodstream, which could prevent these side effects.
What Else Should I Know About Caudal Anesthesia?
Caudal anesthesia is an age-old method of providing pain relief that is still in use today. This technique was initially used in childbirth, but now it’s more commonly used in children for surgeries below the belly button, and also in adults managing persistent lower back pain and nerve root pain.
In surgeries for kids, it can many times be used by itself, helping avoid the risks that come with general anesthesia. Overall, caudal blocks are typically successful, considered pretty safe, and carry a small chance of complications.
