An epidural blood patch (EBP) treats a post-dural puncture headache (PDPH), often called a spinal headache. This headache results from a leak of cerebrospinal fluid (CSF) following procedures like a spinal tap or epidural injection. While the EBP effectively stops the fluid leak and relieves the severe headache, localized back pain is a common side effect. This soreness is temporary, and understanding its cause and duration aids recovery.
What is an Epidural Blood Patch and Why is it Done
A spinal headache occurs when a continuous leak of cerebrospinal fluid causes pressure around the brain and spinal cord to drop. This low pressure allows gravity to pull the brain downward when standing, causing a severe headache that improves when lying flat. The epidural blood patch is the standard treatment when conservative measures like bed rest fail to resolve the headache.
The procedure involves injecting a small volume of the patient’s own blood into the epidural space near the spinal fluid leak. This blood clots immediately, forming a physical seal over the puncture site in the dura mater. The resulting clot stops the CSF from leaking and restores necessary pressure within the spinal canal.
The Source of Post-Procedure Back Pain
Back discomfort following an EBP is common, usually localized to the lumbar injection site. One primary mechanism for this pain is the “volume effect,” which is the temporary pressure created by injecting blood into the confined epidural space. This sudden volume increase irritates surrounding nerves and tissues, causing immediate, intense pressure or cramping.
Another factor is the mild trauma to muscles and ligaments from the epidural needle insertion. Passing a needle through tissue layers to reach the epidural space causes localized soreness. Furthermore, the injected blood triggers a localized inflammatory response as the body reacts to the substance. This natural healing process contributes to residual aching and stiffness in the days following the procedure.
Expected Timeline for Pain Resolution
Back pain resolution typically occurs in two distinct phases, with most patients improving quickly.
Acute Phase
The acute phase lasts for the first 24 hours after the procedure. Localized pain is often at its peak due to the mechanical pressure of the injected blood (the volume effect). This pressure-like pain subsides rapidly as the blood clot organizes and the body absorbs the fluid components.
Subacute Phase
In the subacute phase, the sharp, pressure-like pain is replaced by residual soreness, aching, or stiffness. This manageable discomfort results from localized inflammation and muscle irritation from the needle insertion. Most patients report significant improvement within 48 hours, manageable with rest and over-the-counter pain relievers.
Most patients experience full resolution of localized back pain within one week. To aid healing, patients should avoid strenuous activities, heavy lifting, and excessive bending or twisting for a period following the patch.
When to Contact Your Doctor
While temporary back pain is common, certain symptoms require immediate medical evaluation. Contact your healthcare provider if localized pain worsens significantly after the first 48 hours or does not respond to pain medication. The development of fever or chills is a serious warning sign, potentially indicating an infection at the injection site.
Any new onset of neurological symptoms must be reported promptly. These include:
- Numbness, tingling, or weakness radiating into the legs.
- Changes in bladder or bowel function, such as difficulty passing urine or new incontinence.
These rare symptoms could signal a serious issue like a hematoma or nerve irritation. Severe, throbbing pain disproportionate to expected recovery or accompanied by an extremely stiff neck also warrants immediate medical attention.