Overview of Fluoroscopy Lumbar Puncture Assessment, Protocols, and Interpretation
A lumbar puncture, also known as a spinal tap, is a method that doctors use to collect fluid from the spine. This technique was first developed by Heinrich Irenaeus Quincke and Walter Essex Wynter in the late nineteenth century (1888 and 1889). It is a common procedure, with over 90,000 spinal taps being carried out on people enrolled in Medicare in 2018. More and more, these procedures are being performed by radiologists.
These days, lumbar punctures are often done with the help of an imaging technique called ‘fluoroscopy’. This helps guide the doctor to the correct position in the spine. Alternatively, if more detailed guidance is needed, a technique involving computed tomography (CT) scans can be used. This is often necessary in cases where a patient’s spine has been altered due to surgeries, diseases like scoliosis, or severe age-related changes. It’s also used when there have been failed attempts at a spinal tap, or when it’s hard to find specific parts of the spine due to obesity.
Using fluoroscopy to guide a lumbar puncture has the potential to make the process safer and more successful. There’s only a 3.5% chance that any complications will occur with this method, such as accidentally drawing blood, which is significantly lower than the 10.1% chance associated with performing a lumbar puncture without any image guidance.
Anatomy and Physiology of Fluoroscopy Lumbar Puncture Assessment, Protocols, and Interpretation
When a lumbar puncture (LP) is performed, a needle has to go through many layers of the body. These layers include the skin and underlying fat, a tissue layer called the paraspinal fascia, muscles, another layer of fat called the epidural fat and finally, a thick membrane called the dura. The LP is performed to access what’s known as the thecal sac.
The thecal sac is connected to a part of the brain and is made up of two layers – the outer dura and inner arachnoid mater. It holds the cerebrospinal fluid (CSF), the spinal cord which is covered by a layer called the pia mater, and nerves. Different amounts of epidural fat can be found covering the thecal sac.
Encased by the lumbar vertebra, the backbone in your lower back, are the spinal cord, nerve roots, thecal sac, and epidural fat. The vertebra itself is covered by a layer called the periosteum. On top of this are the paraspinal muscles and their protective layer, the fascia. Lastly, you’ll find the subcutaneous fat and skin on the very outside.
Why do People Need Fluoroscopy Lumbar Puncture Assessment, Protocols, and Interpretation
A lumbar puncture, often known as a spinal tap, is a procedure where a needle is inserted into the lower part of the spine to remove a sample of cerebrospinal fluid (CSF). Doctors will often perform this procedure in the following cases:
1. To collect and examine CSF to check for signs of infection, cancer, or inflammatory conditions affecting the brain and spinal cord.
2. To measure the pressure of CSF, especially if there’s a chance the brain is under high pressure due to infection, cancer, or a condition known as idiopathic intracranial hypertension.
3. To directly administer chemotherapy drugs into the spine.
4. For myelography and cisternography, procedures that use special dyes and X-ray imaging to provide detailed images of the spinal cord and its surrounding structures.
5. To seal leaks in the CSF, a procedure known as a blood patch.
6. To test the effectiveness of the drug Baclofen in relieving severe muscle spasms. The drug is administered directly into the spine in a controlled dose and observed for effects.
7. To place a shunt (a flexible tube) in the lumbar spine, usually to alleviate high CSF pressure due to conditions like hydrocephalus or intracranial hypertension.
Additionally, sometimes a lumbar puncture needs to be done under fluoroscopy guidance, where real-time X-ray imaging is used. The circumstances where this method is preferable are:
1. When a standard lumbar puncture attempt did not succeed.
2. For individuals who have obesity, as it may be hard to locate the exact puncture site without imaging.
3. For those who have had prior surgeries or hardware installed in the lumbar spine.
4. For those with severe spinal degeneration or an abnormally curved spine (scoliosis).
5. If the health professional lacks the training to conduct a standard lumbar puncture.
6. At the patient’s request, particularly after a failed attempt at a standard lumbar puncture, to reduce the chances of further unsuccessful attempts.
When a Person Should Avoid Fluoroscopy Lumbar Puncture Assessment, Protocols, and Interpretation
Coagulopathy is a condition where the blood’s ability to clot is impaired. Anticoagulants are drugs that help prevent blood clots. When treating these conditions, doctors follow certain guidelines to ensure patient safety. For instance, uncorrected coagulopathy can lead to a spinal hematoma. This is a collection of blood outside of a blood vessel in the spine, which can compress the spinal cord or nerves, requiring urgent surgery. To avoid this, doctors will ensure that the patient’s INR (a measure of how long it takes for the blood to clot) is less than 1.5 and they have more than 50,000 platelets (blood cells that help in forming clots).
Patients are also given drugs with specific instructions, such as:
– Warfarin: It should be stopped for 5 days prior to the procedure and resumed 12-24 hours after the procedure.
– Heparin: It should be stopped at least 4 hours before the procedure and resumed 1 hour after.
– Lovenox: Either skip the last dose or pause for 24 hours before the procedure and then resume 6 hours after.
– Fondaparinux and Rivaroxaban: Stop these 48 hours before the procedure and resume after 6 hours and 48 hours respectively.
– Argatroban and Desirudin: Stop these 4 hours prior to the procedure and resume one hour after.
– Aspirin: It’s fine to continue with the 81 mg dose daily, but for the 325 mg daily dose, it should be stopped for 5 days.
– Clopidogrel, Ticlopidine, and Abciximab: These should all be stopped 5 days before the procedure.
In some circumstances, getting imaging like an MRI or a head CT scan is necessary when doctors suspect a CSF obstruction, which increases pressure inside the skull.
There are, however, some situations where performing these procedures may not be ideal. For instance:
– Weight: Newer imaging machines have a weight limit of 400 pounds. Exceeding this limit might damage the machine.
– Infection: If the lower back area where the procedure is to be done has a skin infection, there’s a risk of transferring that infection to the membranes that cover the brain and spinal cord (meningitis).
– Unsettled patients: Sedation helps keep a patient still during a procedure, but it also can reduce their ability to respond if there is an injury to the nerve or spinal cord.
– Pregnancy: Pregnant women are also advised caution due to the risk of radiation exposure for the developing baby.
Equipment used for Fluoroscopy Lumbar Puncture Assessment, Protocols, and Interpretation
When doing a procedure called a lumbar puncture, doctors use a special type of X-ray machine, which can have a two-directional camera or a C-arm for better viewing. They also need a standard lumbar puncture kit. This kit includes a very thin spinal needle (22 or 25 gauge), Lidocaine 1% (a medication to numb the skin), gauze strips, paper covers to keep the area clean, skin cleaning liquid, and another smaller needle (25 gauge) for giving the Lidocaine under the skin.
The main spinal needle in the kit often comes in two types – a Quincke needle, which has a sharp cutting edge, and either a Sprotte or Whitacre needle, which do not have sharp edges and are therefore considered ‘non-traumatic’. The choice between the two often depends on the doctor’s training and preference. Both needle types have their advantages and disadvantages. ‘Non-traumatic’ needles, for instance, lead to fewer cases of headaches after the procedure but can be harder to guide and judge how deep they go into the skin. That’s why the 22 or 25 gauge needles are often chosen.
The standard needle usually measures 3.5 inches, suitable for most cases. However, a longer 5.5 inches needle should be available, as some cases might require a longer needle.
Who is needed to perform Fluoroscopy Lumbar Puncture Assessment, Protocols, and Interpretation?
A doctor, a type of medical assistant called a physician assistant, a type of technician who uses a special x-ray machine called fluoroscopy, and a nurse are usually part of your medical team. The nurse keeps an eye on your blood pressure and breathing, makes sure an IV line (a small tube placed in your vein to give medicine or fluids) is secured, and if needed, can give you medicine to make you feel relaxed or sleepy.
Preparing for Fluoroscopy Lumbar Puncture Assessment, Protocols, and Interpretation
Before having a lumbar puncture (LP), a medical procedure that involves inserting a needle into the spine to examine the fluid surrounding the brain and spinal cord, it’s important for patients to understand what’s involved and give their consent. If the patient is unable to give their own consent, a person legally identified as a healthcare proxy can give it on their behalf. Sometimes, in an emergency, the doctor might decide the procedure is necessary and write this down in the patient’s medical record.
Before the procedure, the doctor will review some important things about the patient’s health, including any medical conditions and mental health issues, allergies, medications they’re taking, and if there are any implants in their back, like spinal hardware or past surgeries. The doctor will also take into account the patient’s weight, whether they have ever had this procedure before, whether they might be pregnant, and document these in a pre-procedure checklist.
The LP procedure also requires special equipment including a fluoroscopy table and imaging facility, which can help the doctor see the spine better during the procedure. If a patient is too heavy for the table, it might not be able to move or tilt properly, which could interfere with the procedure. In this case, alternatives may need to be considered.
Several precautions are taken to ensure the patient’s safety during an LP. Brain MRI or CT head scans are done beforehand to make sure there are no masses or fluid build-up in the brain that could become dangerous during the procedure. If a patient doesn’t have a recent scan, this might need to be done first. Lastly, any previous images of the patient’s lower spine are checked to determine the best point for the needle to enter.
The information from these earlier scans also helps in deciding the best site for the puncture. The doctors ensure to avoid areas where recent surgeries were carried out or where there are infections. Moreover, they avoid spinal areas that are tightly packed, as this can cause unnecessary pain. If it’s difficult to feel the bony bumps of the spine, a longer needle may be required. Lastly, to make the procedure easier, it might be helpful for someone to lightly press on the patient’s back during the procedure.
How is Fluoroscopy Lumbar Puncture Assessment, Protocols, and Interpretation performed
When a medical professional needs to perform a Fluoroscopy-Guided Lumbar Puncture (FGLP), it is critical to ensure that the patient is positioned correctly. This is not only important for the patient’s comfort but also so the procedure can be carried out safely. Many patients who need to have an FGLP will likely already be in the hospital and could be dealing with other health conditions. As a result, they may find it hard to stay still for a long time and might experience breathing difficulties or arm discomfort in certain positions.
There are several ways the patient can be positioned for this procedure. In the prone approach, the patient lies on their stomach. In this position, a pillow placed under the abdomen helps straighten the spine and increase the space between the spinal bones. In the prone oblique approach, the patient lies on their side at an angle. This can be more comfortable for patients with other health conditions but can make it harder for the practitioner to guide the needle. Finally, in the lateral approach, patients lie on their side. This position is preferred for patients that cannot lie on their stomach due to conditions such as obesity, back pain, or high blood pressure.
Once the patient is positioned correctly, a small area of skin is numbed with a local anesthetic so the spinal needle can be inserted. The needles used can vary in size, but most practitioners favor a 20 or 22 gauge needle. However, in patients with obesity, longer needles may be needed.
When the needle is ready to be inserted, the practitioner does so carefully, ensuring that the needle does not penetrate the protective layers around the spinal cord or nerves. The needle is inserted several centimeters at a time, with the position checked frequently under x-ray. If the needle meets resistance, it can be rotated slightly to help it continue on its path.
Once the needle has entered the soft protective covers of the spinal cord, the cerebrospinal fluid (CSF) should flow freely. The pressure of this fluid can be measured, and a certain amount is collected for analysis. If no fluid is obtained, the practitioner may have to try a different approach.
After the procedure, it’s crucial to monitor any sharp, shooting pain in the limbs as this could be a sign that the nerve root has been touched by the needle. If not resolved immediately after withdrawing the needle slightly, another technique may need to be considered.
Every effort is made to ensure the safety and comfort of the patient throughout this entire process, and the exact method used will depend on the individual circumstances of each patient.
Possible Complications of Fluoroscopy Lumbar Puncture Assessment, Protocols, and Interpretation
Feeling faint or sick during a procedure known as vasovagal syncope is not unusual. These symptoms can usually be managed by taking a short break. Although it’s pretty rare, a serious complication known as herniation can occur after the procedure. This involves the protrusion of the brain tissues and can be quite dangerous. That’s why before conducting a lumbar puncture, which is a procedure where a needle is inserted towards the lower part of the spine, a CT or MRI scan of the head is often done to ensure there’s no buildup of cerebrospinal fluid that can lead to pressure on the brain (obstructive hydrocephalus).
Injury to the nerves at the bottom of the spine (cauda equina) is another potential risk. Particularly in people with specific conditions, the procedure can also cause injury to the spinal cord. If these risks are present, it’s a good idea to have a specialist in neurology or neurosurgery consulted.
Improper disinfection process can lead to an infection called meningitis but following the right hygiene measures helps in avoiding it.
Some people may experience a headache after the procedure. The headache usually starts a day after, peaks on the second day, and then gradually fades. This happens more with certain types of needles and techniques. However, this issue can usually be managed without any treatment. Some people might feel better just by resting for a couple of hours or by having a caffeinated drink. In some cases, a procedure called an epidural blood patch can be done, which often helps with severe headaches that don’t respond to basic measures.
A complication like vascular injury – injury to a big blood vessel called aorta, although very rare, can occur if a long needle is used. If this happens, there can be a risk of a blood clot (hematoma) or a bulge in the blood vessel (pseudo-aneurysm). The best way to handle this is to consult with a vascular surgeon and closely monitor the patient’s heart rate and blood pressure. Certain scans might be conducted to check the hematoma and make sure it’s stable.
There is some exposure to radiation during this procedure, but on average, the radiation dose is on par with many common medical imaging tests. The procedure usually takes about 12 to 30 minutes. The specific radiation dose can vary, but overall it’s considered manageable and within safe limits.
What Else Should I Know About Fluoroscopy Lumbar Puncture Assessment, Protocols, and Interpretation?
Lumbar puncture (LP) is a commonly performed procedure in a doctor’s office, emergency department or hospital setting. This involves your doctor inserting a needle into your lower back to access the fluid that bathes your spinal cord and brain for testing. This procedure is very critical to diagnose conditions like infections, diseases involving the loss of insulation around nerve cells, cancer, and it’s also used for some kind of imaging procedures called myelography and cisternography.
Beyond its diagnostic uses, Lumbar puncture is also used for treatment purposes like lowering the pressure in the brain in people with a condition known as idiopathic intracranial hypertension.
Fluoroscopy-guided lumbar puncture (FGLP) is increasingly required because of the growing number of patients undergoing spine surgery, those with high body mass indexes (BMIs), or because of numerous failed attempts at standard lumbar punctures, or even the fear of failed attempts. In people with high BMI, prior spine surgery, or serious wear and tear-related disease, FGLP is linked with a lower chance of not being able to perform the lumbar puncture successfully. This method has several advantages, such as guiding the needle with real-time X-ray images which helps keep track of the needle’s path, lowering the number of attempts needed, decreasing the chance of drawing blood into the spinal fluid sample, and reducing the time required for the procedure.