Overview of Epidural Blood Patch
An epidural blood patch (EBP) is a medical procedure that involves injecting a small amount of the patient’s own blood into a space near their spine called the epidural space. This is done to stop cerebrospinal fluid from leaking from a person’s brain and spinal cord. This leaked fluid can make it harder for the brain to maintain the right balance of blood flow, especially when a person is standing upright. These leaks can cause severe headaches, known as post-dural puncture headaches (PDPH), often referred to as a “spinal headache”.
PDPHs are usually triggered when the covering of the brain and spine, known as the dura, is punctured or torn. This can happen unintentionally when a patient is being given an epidural injection for pain relief, or if they are undergoing some diagnostic or therapeutic procedures like a lumbar puncture or certain types of spinal surgery. However, these headaches are very rare after spinal surgery and rarely treated with EBP.
Statistics show that the chances of PDPH occurring vary depending on the size of needles used for spinal procedures. A less than 1% risk exists when a small 25-gauge needle is used for subarachnoid block (a specific kind of spinal anaesthesia), but this risk increases to 36% when a larger 20 or 22-gauge needle is used in a lumbar puncture. If a 17-gauge needle is used in an epidural procedure and accidentally punctures the dura, the risk of PDPH can be as high as 80%. Younger people less than 60 years, and women are more at risk. Most people experience intense headaches within 24 to 48 hours of puncture, exacerbated by standing up and sometimes accompanied by problems with hearing or blurry vision. Luckily, with no treatment, more than 90% of these types of headaches disappear on their own within a week to ten days.
There are many temporary remedies, including bed rest, painkillers, drinking plenty of fluids, or even drinking caffeinated drinks or taking an IV dose of caffeine. However, for a more long-term solution, the EBP is quite successful, with an 85% success rate after one treatment, and 90% after a second treatment. If all else fails, there is the option of surgical intervention, but this is very rare.
Anatomy and Physiology of Epidural Blood Patch
The epidural space is an area within your spine located between the dural meninges (protective coverings of the brain and spinal cord) at the front, the ligamentum flavum (a type of ligament in your spine) at the back, and the walls of the individual bones of the spine at the sides. This space extends all the way from the foramen magnum (the large hole at the base of your skull where the spinal cord enters) down to the sacral hiatus (a small opening at the bottom of the spine).
Inside this space, there are tiny arteries and lymphatics (parts of the body’s circulatory system), some fat, and a network of small veins that don’t have valves (known as the Batson plexus). Despite being called a “space,” the epidural “space” is more like a series of small compartments that can be filled with liquid or air during certain types of medical procedures. These compartments are usually closed-off, but open up when something is injected into them.
Why do People Need Epidural Blood Patch
An Epidural Blood Patch (EBP) is a treatment used for severe headaches after a medical procedure that involves the spinal cord, like a spinal tap or epidural. These headaches happen if the protective layer around your spinal cord, called the dura, is accidentally punctured. Typically, these headaches get better on their own in about a week to ten days. During this time, doctors recommend resting, drinking plenty of fluids, taking pain relievers, and having caffeine, as these can help ease the discomfort.
However, for some people, these treatments aren’t enough, and the headache is too severe to wait for it to go away on its own. In these cases, an Epidural Blood Patch is used. This procedure can provide quick relief from the headache caused by the dural puncture.
When a Person Should Avoid Epidural Blood Patch
There are a few reasons why a person might not be able to have an Epidural Blood Patch (EBP). One reason is a condition called coagulopathy or if they are on anticoagulants, which means that their blood doesn’t clot normally. This could make the procedure too risky. Infection at the site where the injection is supposed to happen is another reason, as it could spread or become worse. Finally, if a patient does not want the procedure or is unable to cooperate with the doctors, the EBP could not be done.
Equipment used for Epidural Blood Patch
To do a procedure called an Epidural Blood Patch (EBP), your doctor will need a standard kit that usually contains the materials necessary for the epidural procedure. In addition, an 18 or 20-gauge angiocatheter, a small, flexible tube, is used to draw your own blood in a way that keeps everything clean and free of germs.
Your doctor may choose to place this tube and seal it off, then flush it with a saline solution. This is done to quickly draw your own blood once they have reached the epidural space, which is the area in your spine where they will inject the blood to perform the EBP procedure.
Who is needed to perform Epidural Blood Patch?
Evidence-based practice, or EBP for short, can be done by one person. But, usually, there is a need for another person who can take blood in a clean, safe way. Sometimes a third helper might be needed to help get the patient into the right position. This practice is basically about making the best healthcare decisions through careful consideration of current evidence and professional expertise.
Preparing for Epidural Blood Patch
Before starting the procedure, the doctor thoroughly explains what will happen. After the patient gives consent to proceed, they are positioned either on their side or in a seated position. The seated position, however, might make some patients feel more uncomfortable and they might not be able to remain in that position for very long. The doctor then cleans and preps the area on the back where the injection will be given. This might be a spot where a previous injection was made into the spine (the dura) or a different spot just above or below that area. The doctor also prepares the area on the arm or hand where they will draw blood.
How is Epidural Blood Patch performed
The epidural space, the area outside the membrane that covers your spinal cord, is usually located by a technique called loss-of-resistance. This method uses air or saline injected through a needle to determine when the needle has entered the right space. However, if this approach proves difficult, the doctor may use imaging techniques like C-arm radiography or ultrasound.
Once the needle is in the right place, about 20 milliliters of your own blood is drawn out in a very clean way to ensure no germs are introduced. This blood is then slowly injected back into the epidural space over a period of 30 to 60 seconds. This creates something called a “blood patch”, which is used to seal off the area that’s causing you headaches. The injection may cause some discomfort or cramping, which may limit how much blood can be used for the patch. However, smaller amounts can still be helpful and some blood patches have been successful with as little as 5 milliliters of blood. Most doctors prefer to use about 20 milliliters if possible.
Possible Complications of Epidural Blood Patch
The most common problems after an Epidural Blood Patch (EBP) — a procedure used to treat severe headaches after a patient has received an epidural — can include the treatment not working (15-20% chance), making the headache worse by accidentally puncturing the covering of the spinal cord more than once, back pain, and infection. Mild to moderate back pain is often reported, but usually resolves on its own in a few days and is typically less troublesome than the headache. Patients should also be aware of certain signs that could indicate an infection at the injection site, such as fever, feeling unwell, redness, or signs of pus. This is important as the injected blood may promote infection. Any of these signals require immediate medical care.
What Else Should I Know About Epidural Blood Patch?
Post-dural puncture headaches (PDPH’s) are headaches that occur after a certain medical procedure where a needle is inserted into the space around the spinal cord, such as a spinal tap or anesthesia applied directly to the nerves of the spine (epidural). Most of these headaches go away on their own in about a week or a bit longer.
Some people may choose non-surgical treatment instead of an epidural blood patch (EBP), a procedure where a small amount of your blood is injected into the area around your spinal cord to help relieve the headache. Non-surgical treatment could involve trying to stay lying down as much as possible, drinking plenty of fluids, using over-the-counter pain relievers, and taking caffeine either orally or through an IV. Although caffeine, which narrows blood vessels in the brain, may only provide short-term relief, staying hydrated and consuming caffeinated drinks and oral pain relievers at home can help.
However, not all people can reduce their activity levels enough for non-surgical treatment to be effective, such as new mothers with newborns or younger patients. Also, those with severe symptoms (like intense headaches even when lying flat, high sensitivity to light, and emotional distress) will probably choose to get an EBP, even if they are also using non-surgical methods.
Doctors should remember that not all headaches after spinal procedures are PDPH’s, and other causes should be ruled out before performing an EBP. Also, patients with mild symptoms, like mild headaches that come on after being on their feet for 15 to 20 minutes, might find that non-surgical treatment can help their symptoms without the need for another procedure. The EBP procedure, which involves another puncture of the spinal area with a large needle, carries a risk of back pain and infection, even though it’s generally a safe and effective treatment for some people with post-spinal procedure headaches.