Overview of Fluoroscopy Lumbar Puncture Assessment, Protocols, and Interpretation
In 1888 and 1889, two doctors named Heinrich Irenaeus Quincke and Walter Essex Wynter developed the method to perform what is now known as a lumbar puncture. A lumbar puncture is a common medical procedure, with over 90,000 performed on patients covered by Medicare in 2018 alone. Recently, there has been a shift towards radiologists, who are doctors trained in reading medical images, conducting these procedures.
Nowadays, we see a growing trend of using image guidance, or medical imaging technologies, to guide the lumbar puncture in a hospital setting. The most common method uses something called fluoroscopy, which allows doctors to see real-time, moving images of a patient’s internal structures.
Other times, doctors use a technique involving computed tomography (or CT) scans to guide the lumbar puncture, especially when the case is challenging. For instance, when a patient has spinal hardware, scoliosis (a sideways curvature of the spine), or severe changes related to age or disease, they might require this special approach. It’s also useful if previous attempts to perform the lumbar puncture have failed, or if the doctor can’t find the bony landmarks in the back (often due to obesity), which are necessary for standard lumbar punctures.
The fluoroscopy-guided method has significantly lowered the risk of a ‘traumatic tap’, a complication that can occur during a lumbar puncture – only 3.5% of cases experience this, compared to 10.1% when the procedure is done without images to guide the doctor.
Anatomy and Physiology of Fluoroscopy Lumbar Puncture Assessment, Protocols, and Interpretation
When a Lumbar Puncture (LP) or a ‘spinal tap’ is performed, the needle has to go through several layers of the body. It starts with the skin, followed by a layer of fat under the skin, then tough protective sheaths of tissue, and then muscles. After the muscle, it goes through another layer of fat and finally pierces through a tough layer called the dura.
After passing through the dura, the needle enters a space called the thecal sac. This sac is an extension of a cavity in the brain, which is filled with cerebrospinal fluid (CSF) – the liquid that cushions the brain and spinal cord. This sac also contains the spinal cord, which is wrapped in a delicate layer of tissue, as well as nerves.
The thecal sac is covered by varying amounts of fat and is enclosed within a structure called the lumbar vertebra – a part of your lower back bone. This vertebra also encloses the spinal cord, various nerve roots, the thecal sac, and layers of fat.
Furthermore, the vertebra is covered with a sheath called the periosteum and is then followed by muscles wrapped with their protective sheaths. Lastly, then comes a layer of fat and then the most outer layer, the skin. These layers must all be carefully penetrated to perform an LP procedure successfully and safely.
Why do People Need Fluoroscopy Lumbar Puncture Assessment, Protocols, and Interpretation
A lumbar puncture, also known as a spinal tap, is a medical procedure that can be used for a number of reasons. Here are some instances where a lumbar puncture might be necessary:
1. When a sample of spinal fluid needs to be analyzed in a laboratory. This may be done to check for signs of infections, cancer, or certain disorders affecting a particular type of tissue found in the nervous system.
2. If a doctor suspects that the pressure within a person’s skull is too high. This can be caused by an infection, cancer, or a condition where the pressure inside the skull increases for no obvious reason.
3. In some cases, cancer-fighting drugs are directly injected into a space surrounding the spinal cord. This space is known as the “thecal sac”.
4. During certain types of medical imaging procedures that require the injection of dye into the spinal canal.
5. To treat a leak of spinal fluid using a procedure called a “blood patch”.
6. To test if a particular drug, known as Baclofen, can help with certain conditions when delivered through a special pump placed under the skin.
7. During a procedure to place a tube, known as a shunt, in the lower part of the spine to drain fluid.
In some cases, a lumbar puncture is carried out with the help of a special type of X-ray machine called fluoroscopy. This might be necessary in the following situations:
1. If previous attempts to do a lumbar puncture without fluoroscopy did not succeed. This is the most common reason to use fluoroscopy.
2. If the patient is obese.
3. If the patient has had surgery on the lower part of their spine, or there are metal implants present.
4. When the patient has severe disease of the spine or abnormal curvature.
5. If the person performing the lumbar puncture lacks necessary skills or experience.
6. If the patient asks for the procedure to be done under fluoroscopic guidance to avoid a failed attempt, especially after an unsuccessful initial attempt without it.
When a Person Should Avoid Fluoroscopy Lumbar Puncture Assessment, Protocols, and Interpretation
If someone has a coagulation disorder (a health issue that causes their blood not to clot properly) or is taking blood thinners, certain guidelines need to be followed. Their disorder needs to be managed carefully because a spinal bleed could lead to pressure on the spinal cord or nerves and might require emergency surgery. It’s important for their INR (International Normalized Ratio – a test to monitor how quickly their blood clots) to be less than 1.5 and their platelet count (tiny blood cells that help the body form clots) to be more than 50,000. In addition, the aPTT (Activated Partial Thromboplastin Time – a test that measures how long it takes for blood to clot) of people taking a type of heparin (a blood thinner) should be 1.5 times normal.
Before someone gets a particular medical procedure, here’s how certain blood thinners should be managed:
– Warfarin: Stop taking it 5 days before, then start again between 12 to 24 hours after the procedure.
– Heparin: Wait at least 4 hours after the last dose and check the aPtt, then start again 1 hour after the procedure.
– Lovenox: Skip the last dose or wait 24 hours after the previous dose, then start again 6 hours after the procedure.
– Fondaparinux and Rivaroxaban: Stop taking it 48 hours before the procedure, then start again 6 hours (Fondaparinux) or 48 hours (Rivaroxaban) after the procedure.
– Argatroban and Desirudin: Wait 4 hours after the last dose before the procedure, then start again 1 hour after the procedure.
– Aspirin: If you take 81mg a day (“baby aspirin”), you can continue to take it. If you take 325mg a day, stop 5 days before the procedure.
– Clopidogrel, Ticlopidine, and Abciximab: Stop taking it 5 days before the procedure.
If someone has increased pressure in their brain due to an obstruction in their cerebrospinal fluid, an MRI or CT scan of the head may be needed if no recent imaging is available.
There are also some situations where performing the procedure may be risky, but not impossible:
– Weight: Some tables used for fluoroscopy (an imaging technique that uses X-rays to obtain real-time moving images) have a weight limit of 400 pounds. Going over this limit can potentially damage the hydraulic mechanism of the table.
– Infection: If there’s an infection on the skin of the lower back, the risk of developing meningitis (an infection of the membranes covering the brain and spinal cord) can increase.
– Uncooperative patient: If a patient is moving a lot or very anxious, giving them a sedative can help them stay still. However, it can also decrease their ability to tell if they’re experiencing a nerve or spinal cord injury.
– Pregnancy: Because X-rays can harm a developing baby, pregnancy is also a relative contraindication.
Equipment used for Fluoroscopy Lumbar Puncture Assessment, Protocols, and Interpretation
A Lumbar Puncture (LP) procedure needs various medical tools. One key instrument is the fluoroscopy machine, which gives doctors an x-ray-like view of the area they’re working on. This machine usually has either a biplane camera or a C-arm to provide the best images. The doctor also uses a standard LP kit, which includes a specific type of needle (either 22 or 25 gauge), a small amount of 1% Lidocaine (a local anesthetic that numbs the area), sterile gauze pads, paper drapes, skin cleaning solution, and a small needle to inject the Lidocaine under the skin.
The kit contains two different types of spinal needles. The Quincke needle is known as a “traumatic” needle because it has a cutting edge. The Sprotte or Whitacre needles are “non-traumatic” needles, meaning they don’t have a cutting edge. The doctor chooses the needle based on their preference and experience. Each needle has advantages and disadvantages, for instance, the non-traumatic needles cause fewer headaches after the procedure, but they are harder to handle and to determine how deep they’re going.
Most of the time, a 3.5 inch needle works fine. However, a longer needle of 5.5 inches should be on hand in case it’s needed.
Who is needed to perform Fluoroscopy Lumbar Puncture Assessment, Protocols, and Interpretation?
During a medical procedure, there’s usually a team of healthcare professionals that work together. This team usually includes a doctor, a physician assistant, a technician who handles a special type of X-Ray called fluoroscopy, and a nurse. The nurse has several important jobs during this process. They check your blood pressure and breathing, make sure you have an IV line (a tube that puts fluids or medicine directly into your body), and if needed, they can give you medicines to make you feel relaxed or even sleep.
Preparing for Fluoroscopy Lumbar Puncture Assessment, Protocols, and Interpretation
Before undergoing a lumbar puncture (LP), or a procedure where a needle is inserted into the lower part of your spine to test your spinal fluid, you’ll need to give doctors your written and informed consent. If you are not in a position to give consent yourself, then your designated healthcare proxy (someone you have chosen to make decisions for you) can do it on your behalf. Doctors will only do this without consent in emergency situations if they feel it is essential for your health.
Before the procedure, your doctor will conduct a thorough check, taking into account a number of important factors. This includes determining why you need the procedure, making sure there are no reasons not to perform it, and assessing your overall health and wellbeing. They will also check for any allergies you may have, current drugs you’re taking, and if there are any other conditions that might affect the procedure such as pregnancy, or if you have had previous surgeries or any metallic medical devices inserted in your spine.
For your comfort and safety, the doctor may also consider if you’ll need sedation during the procedure. The doctor will need to ensure the availability of a procedure room with a specialized imaging tool known as a fluoroscopy table. This table helps guide them to the exact place in your spine where they’ll insert the needle. In some cases, they need to confirm if you can physically fit on this table before scheduling the procedure, especially if you are heavier.
Before undergoing an LP, you would often have a brain MRI or head CT scan. These advanced imaging tests help doctors make sure that there’s no swelling or abnormality in your brain that can get worse with the procedure. Furthermore, doctors will also check any prior images of your spine to decide the best spot for the needle insertion. If you’ve had previous spine surgeries or if there are any infections close to your back, these could prevent doctors from performing the LP. Examining prior spinal images also helps the doctor anticipate if the procedure could cause more pain.
Lastly, your doctor will examine specific measures like the distance from your skin to the sack around your spinal cord, which can influence the length of the needle required for your LP. If your back’s bony processes can’t be felt, then they may need to use a longer needle. At times, another healthcare professional may help by gently pressing on your back to reduce this distance, making the procedure easier and more comfortable for you.
How is Fluoroscopy Lumbar Puncture Assessment, Protocols, and Interpretation performed
Making sure the patient is positioned correctly is crucial not just for the patient’s comfort, but so that the medical procedure can be done safely. Often, patients having a lumbar puncture (a test where a needle is used to take a sample of the fluid from around the spinal cord) are already in the hospital and might have other health issues. They might find it hard to stay still and could be uncomfortable in certain positions.
Prone Approach: This involves the patient lying face down on the table where the lumbar puncture will be done. Pillows under the stomach can help straighten the curve in their lower back, which can make the spaces between their backbone wider and easier for the doctor to work with. It also helps to target the fluid by a method of X-ray called fluoroscopy. Additionally, for patients who have changes to their backbone because of old age, it’s sometimes helpful to tilt the X-ray machine slightly.
Prone Oblique Approach: In this position, the patient is partly on their side and partly on their front. This can make the spaces between the bones in their back seem wider than the prone approach. Some doctors prefer this approach as it can be more comfortable for the patient. However, it can be harder for the doctor to work with.
Lateral Approach: If the patient can’t lie on their stomach because of discomfort or underlying health conditions such as obesity or heart disease, they can lie on their side. The disadvantage of this method is that it often requires a certain type of X-ray machine which isn’t available everywhere.
For the lumbar puncture, doctors will use a local anesthetic to numb the skin before using a long, thin needle to collect the fluid. Sometimes, doctors need longer needles for larger patients, but it can make the procedure more challenging. It’s important to insert the needle correctly to avoid damaging the spinal cord and nerves.
Once the needle is inserted, the doctor needs to take care to advance it slowly and carefully, checking its progress with the fluoroscopy X-ray. If the needle goes too far, it can touch a nerve and cause pain down the patient’s leg. If this happens, the doctor will pull the needle back slightly. The procedure is usually successful when cerebrospinal fluid (CSF), the fluid that surrounds the brain and spinal cord, starts to flow out of the needle.
Sometimes, the needle is correctly positioned, but no CSF comes out. This usually happens in elderly patients, and can be due to excess fat around the spinal cord, previous surgery, inflammation or narrowing of the spinal canal. If the fluid is not able to be collected, doctors have several options, including tilting the patient, using mild suction, or resorting to a CT-guided puncture, in which an imaging machine is used to exactly guide the needle.
Usually, doctors collect 8-15ml of fluid for a lumbar puncture, and this is usually enough to diagnose different conditions. Removing more fluid can help improve symptoms in some disorders like idiopathic intracranial hypertension, a condition where there is too much pressure around the brain.
Possible Complications of Fluoroscopy Lumbar Puncture Assessment, Protocols, and Interpretation
People may experience a hot feeling or nausea during a procedure known as a lumbar puncture, which is a test where a needle is inserted into your lower back to collect fluid from around your spine. If this happens, often times a short break can help ease these feelings.
Although it’s rare, there could be a serious complication called an uncal herniation after the procedure. In this case, part of the brain starts to press against other structures in the skull. If a doctor is worried about this, they may do a CT scan or an MRI before the lumbar puncture.
The lumbar puncture can potentially cause direct damage to the nerves at the base of your spine. It can also harm the spinal cord, particularly in people with a low-lying sac of nerves at the end of the spine or a type of dwarfism called achondroplasia. Because of this, it’s usually best to consult a neurologist or neurosurgeon in these cases.
Another risk is meningitis, which is an infection of the fluid and membranes around the brain and spinal cord. We can usually avoid this by cleaning the area properly before the procedure.
Some people can experience a headache after the lumbar puncture. This headache can come on a day after the test, peak a day later, and finally go away the day after that. The chance of getting a headache is more if larger needles are used. We can reduce the risk by using certain types of needles, only puncturing the membrane around the spine once, and replacing a protective cover on the needle before pulling it out. The direction the needle is inserted can also reduce this risk. Most people get better without any treatment, but lying down for a couple of hours after the procedure can help, and caffeine may also be beneficial. In rare cases, if the headache doesn’t get better, a special procedure can be done to treat it.
In very rare cases, a long needle could also potentially harm the large blood vessel at the back of the abdomen, causing internal bleeding or a bulge in the vessel. This might be suspected if fresh, pulsing blood comes out of the needle. If this happens, a doctor may get an x-ray to see how far the needle has gone and could also ask a vascular surgeon for help.
Lastly, the procedure takes an average of 12 minutes and there is a small amount of radiation exposure, similar to some other medical procedures. The estimated average radiation exposure is around the level you would naturally encounter in about one year.
What Else Should I Know About Fluoroscopy Lumbar Puncture Assessment, Protocols, and Interpretation?
A lumbar puncture (LP) is a common medical procedure done in different settings such as doctors’ offices, emergency departments, or inpatient facilities. This procedure is essential for diagnosing a variety of conditions, such as infections, certain types of cancer, or diseases affecting the nerves and brain. It can also be used for imaging tests like myelography and cisternography. Additionally, an LP can be done to relieve pressure on the brain in patients with a condition called idiopathic intracranial hypertension, which is characterized by high pressure in the fluid around the brain with no identifiable cause.
We’ve noticed a growing need for a variation of this procedure called fluoroscopy-guided lumbar puncture (FGLP). This need is primarily because more patients are having surgery on their spine, or due to an increase in higher body mass index (BMI) cases. There are also cases where the traditional LP procedure has failed repeatedly or where there’s anxiety about potential failures. FGLP is found to be very beneficial, especially in patients who have a high BMI or have had prior surgery or significant degenerative disease. It offers lower rates of failure when compared to the traditional LP.
FGLP comes with a few specific advantages. It uses real-time imaging to guide the needle, which helps to reduce the number of attempts to properly place the needle. It also helps prevent a complication known as a “blood tap,” where a blood vessel gets accidentally punctured. Moreover, FGLP generally reduces the time required to perform the procedure.