lumbar puncture

Lumbar puncture is one of the commonly used examination methods in neurology. It is of great value, simple and safe for the diagnosis and treatment of nervous system diseases. However, if the indications are not properly controlled, the light can aggravate the original condition and emphasize It even endangers the safety of patients. In order to perform this procedure safely and effectively, physicians need to understand contraindications for lumbar puncture, related anatomy, and methods to minimize the risk of complications. Although lumbar puncture is rarely dangerous, once it occurs, it can be very serious and may even endanger the patient's life. Understanding the indications, contraindications, and proper procedures for lumbar puncture can minimize the risk of injury. Indications Lumbar puncture is used to obtain samples of cerebrospinal fluid (CSF) to help diagnose infections, inflammation, tumors, and metabolic processes. Its therapeutic indications include the administration of chemotherapeutics, antibiotics and anesthetics. Lumbar puncture is suitable for: 1. Understand the nature of cerebrospinal fluid, diagnose central nervous system tumors, trauma, infection and cerebrovascular disease. 2. Perform cerebrospinal fluid dynamic test to understand whether there is obstruction in the subarachnoid space. 3. Inject air into the subarachnoid space and perform cerebral angiography. 4. Inject an anesthetic and perform anesthesia with subarachnoid nerve block. 5. Inject anticancer drugs or antibiotics into the subarachnoid space to play an anti-tumor and anti-infective role. 6. For craniotomy, spinal cord surgery or subarachnoid hemorrhage, appropriate amount of cerebrospinal fluid can be released through lumbar puncture to prevent adhesion and reduce the condition. 7. Determine intracranial pressure. Contraindications The position of the patient during lumbar puncture can affect the patient's cardiopulmonary function, so patients with a certain degree of cardiopulmonary dysfunction should avoid lumbar puncture. The following patients should also avoid this procedure, including patients with signs of cerebral palsy, patients with initial cerebral palsy due to elevated intracranial pressure, patients with increased intracranial pressure, and patients with focal neurological symptoms. . If the physician has concerns about the implementation of lumbar puncture, the patient should be examined by computed tomography (CT) before starting the procedure, but CT may not be able to determine whether the patient has signs of elevated intracranial pressure. Coagulopathy can increase the risk of spinal hematoma, but it is unclear to what extent the coagulopathy will increase the risk of spinal hematoma. For patients who have previously undergone lumbar surgery, if the interventional radiologist uses imaging techniques to perform lumbar puncture, it may increase the success rate of the operation. Operation of lumbar puncture instruments Commercialized lumbar puncture packages include the necessary components for lumbar puncture: a needle with a needle core, a skin disinfectant, a surgical towel, a collection tube, and a manometer. The 22-gauge puncture needle is preferred because the smaller the puncture hole reduces the risk of CSF leakage. In general, infants use 1.5-inch (3.8 cm) needles, children use 2.5-inch (6.3 cm) needles, and adults use 3.5-inch (8.9 cm) needles. Patients in position should take a lateral position or a sitting position. In order to obtain accurate open pressure and reduce the risk of headache after puncture, the lateral position is better. Not all patients can receive a lumbar puncture in any position, so the physician should learn to do this in the left, right, and upright positions of the patient. Once the patient's basic posture is determined, the physician should instruct the patient to take the fetal position or "like a cat" to bow the waist to increase the gap between the spinous processes. When the patient is in a sitting position, the lumbar spine should be perpendicular to the table top. When the patient is in the lateral position, the lumbar spine should be parallel to the table top. The landmarks draw a line between the upper edges of the ridges on both sides and intersect the midline through the L4 spines. The needle is inserted in the gap between L3 and L4 or L4 and L5 because these points are located below the terminal segment of the spinal cord. Physicians should find out the landmarks before disinfecting the skin and injecting local anesthetics, as these operations may obscure the landmarks. Use the skin marker to mark the correct location. Before the puncture, the physician prepares the disinfectant glove and disinfects the skin with a suitable disinfectant (povidone-iodine or chlorhexidine-containing solution), starting from the center and expanding outwards in a circle. Then cover the disinfecting towel. Analgesic and sedation lumbar puncture can cause pain and anxiety to the patient and is suitable for use with a minimum dose of local anesthetic. If time permits, the physician can use the anesthetic cream locally for the patient prior to skin disinfection. After the skin is sterilized and the disinfectant towel is applied, a local anesthetic can be injected subcutaneously, or a systemic sedative or an analgesic can be used. After the lumbar puncture doctor once again touched the landmark, a needle with a needle core was inserted at the midline position and the upper edge of the next spinous process. The needle was oriented toward the head at about 15 degrees, which appeared to be toward the umbilicus of the patient. CSF leaks can cause headaches after puncture, and the latest information suggests that the use of a "pencil-like" needle can reduce the risk of headaches because the needles can spread the fibers of the dural sac without cutting it. If a more commonly used beveled needle is used, the bevel of the needle should be in the sagittal plane so that the fibers parallel to the axis of the spine can be spread without cutting it. If the needle position is correct, the needle should pass through the skin, subcutaneous tissue, supraspinous ligament, interspinous ligament between the spinous processes, ligamentum flavum, epidural space (including internal vertebral venous plexus, dura mater and arachnoid) , enters the subarachnoid space and is located between the cauda equina nerve roots. When the needle passes through the ligamentum flavum, the physician can feel a sense of breakthrough. At this point, the needle should be pulled out 2mm to see if there is cerebrospinal fluid outflow. If the puncture is unsuccessful and hits the bone, retract the puncture needle to the subcutaneous tissue, but do not quit the skin, adjust the direction and then re-inject the needle. Once the needle enters the subarachnoid space, CSF flows out. If there is trauma during puncture, CSF may be slightly bloody. When collecting CSF, CSF should be clear and bloodless unless there is subarachnoid hemorrhage. If the cerebrospinal fluid is not flowing out, the needle can be rotated 90 degrees because the needle opening may be blocked by nerve roots. Open pressure only patients in the lateral position can measure the open pressure. Connect the pressure gauge to the needle holder of the needle with a hose. This should be done before collecting any samples. When the liquid column no longer rises, the measured value is read. You may see a liquid beat caused by your heart or breathing movements. Sample collection should allow the CSF to drip into the collection tube and should not be pumped, as even small negative pressures can easily cause bleeding. The amount of liquid collected should be limited to the minimum required amount, usually 3 to 4 ml. If the patient receives an open-pressure test, the physician should turn the rotary valve to the patient and let the CSF in the manometer flow into the collection tube for CSF sample collection. After collecting a sufficient amount of sample, insert the needle and pull out the needle. Follow-up should be performed on the puncture site and covered with gauze. Although it is widely believed that bed rest can reduce the incidence of headaches after lumbar puncture, this is not the case. Complications The landmarks of obese patients are difficult to determine, which is a challenge for physicians. Osteoarthritis, ankylosing spondylitis, posterior scoliosis, history of lumbar surgery, and degenerative disc disease may make lumbar puncture difficult to complete. For patients with such diseases, an anesthesiologist or an interventional radiologist may be required to improve the success rate of lumbar puncture. Complications of lumbar puncture include cerebral palsy, impaired cardiopulmonary function, local or involved pain, headache, bleeding, infection, arachnoid epithelial cyst, and CSF leakage. The most common complication is headache, which occurs as much as 36.5% within 48 hours of lumbar puncture. The cause of the headache is that the rate of leakage of CSF from the puncture site exceeds the rate of CSF formation. The increase in the incidence of headache is related to the thickness of the lumbar needle used. The most serious complication is cerebral palsy, which can lead to cerebral palsy if the pressure difference between the cranial cavity and the spinal canal is large. During lumbar puncture, this pressure difference can increase, leading to brain dryness. Physicians can find high-risk patients prone to cerebral palsy by asking about medical history and neurological examinations in detail. If the physician still has concerns about performing lumbar puncture, CT may be helpful, but elevated intracranial pressure may not be detected by imaging. However, not all patients need to undergo a CT scan because it can delay diagnosis and treatment. Patients with hemorrhagic qualities are prone to bleeding, which can cause compression of the spinal cord. There is no absolute standard for the relationship between the degree of coagulopathy and the risk of bleeding, so the doctor must judge according to the clinical situation. The arachnoid epithelial cyst is caused by the skin embolus entering the subarachnoid space. It can be avoided by using a needle with a needle core. Basic Information Specialist classification: growth and development check classification: biochemical examination Applicable gender: whether men and women apply fasting: not fasting Tips: Observe the patient's breathing, pulse, complexion, etc. during the puncture. Normal value The cerebrospinal fluid pressure in the normal lateral position is 0.69-1.764 kPa or 40-50 drops/min. Clinical significance Lumbar puncture is used to obtain samples of cerebrospinal fluid (CSF) to help diagnose infections, inflammation, tumors, and metabolic processes. Its therapeutic indications include the administration of chemotherapeutics, antibiotics and anesthetics. Precautions 1. Pay attention to the patient's breathing, pulse, complexion, etc. during the puncture. Once there is dilated pupil, unconsciousness, slow breathing or pathological respiration, it indicates the formation of cerebral palsy, should immediately stop the drainage, and inject 10 to 20 ml of air or saline into the spinal canal, or vein Quickly inject 20 ml of 20% mannitol and take other appropriate rescue measures. 2. After the needle is inserted into the subcutaneous tissue, the needle should be slowly inserted to avoid excessive damage to the cauda equina or blood vessels, resulting in pain in the lower limbs or the result of mixing the blood in the cerebrospinal fluid. 3. When intrathecal injection, the same amount of cerebrospinal fluid should be released first, and then the drug is injected. 4. The needle should be fine, and the amount of cerebrospinal fluid should be less than 10 ml to avoid pain after waist wear. 5. If cerebrospinal fluid is found to continue to flow out of bright red blood, it may be secondary hemorrhage in the subarachnoid space, and patients often have cerebrovascular disease. At this point, stop the operation and do the corresponding processing. 6. When the child has increased intracranial pressure, papilledema, if the condition requires, should first use a dehydrating agent, reduce the intracranial pressure and then puncture, and the child puts the cerebrospinal fluid when the partial core is plugged on the needle to slow down Drop the speed to prevent cerebral palsy. 7. Because the age of the child is different from that of the fat and thin, the depth of the spinal cord cavity is also different. For the thinner, the patient should be careful when puncture, and then slowly advance after the puncture, so as not to enter the deep and cause bleeding. 8. Newborns can use a common injection needle for lumbar puncture, which is easier than conventional lumbar puncture. 9. The child is at least 4 to 6 hours after surgery. In children with intracranial hypertension, the prone time after lumbar puncture can be extended. 10. Puncture site skin with suppurative infection, contraindications to avoid infection. 11. Piercing should be performed on a hard bed. 12. If the child's breathing, pulse, and complexion are abnormally abnormal during puncture, stop the operation and rescue. Inspection process 1. Position: The patient is lying on the hard bed on the side of the bed, rubbing his head to the chest as far as possible, and holding the knees against the chest with both hands, the purpose is to widen the gap between the spines to facilitate puncture. 2. Selection of puncture point: puncture can be performed in the 3rd to 4th lumbar vertebrae (about the intersection of the upper and lower iliac spine and the posterior median line on both sides). If necessary, you can choose 2 to 3 or 4 to 5 gaps in the lumbar spine. Children under the age of 4, because the lower end of the spinal cord ends at the level of 2, 3 lumbar vertebrae, so the lumbar vertebrae 4 to 5 spinous process gap should be selected as a puncture point to prevent injury to the spinal cord. 2. routine disinfection, use the thumb to fix the third lumbar spinous process, use 1% procaine local anesthesia along the spinous process, push the needle while pushing the needle, deep into the ligament, press with sterile gauze, wait a moment after pulling the needle . 3. Fix the finger on the skin of the puncture point with the index finger and thumb of the left hand, and pierce the puncture point with the right hand. During the puncture, the thumb and middle finger of the right hand hold the needle, and the index finger is held on the handle of the needle. The tip of the needle is cut upward, and the puncture direction is parallel to the bed surface (ie, perpendicular to the direction of the spine). 4. The adult needle depth is about 4 to 6 cm, and the child is 2 to 4 cm. In case of bone, you can withdraw a little, change direction and then stab. When the needle passes through the ligament and the dura mater, the resistance is suddenly reduced, and there is a "falling feeling", suggesting that the needle tip has entered the subarachnoid space. At this point, the needle core can be slowly withdrawn, and the cerebrospinal fluid can be seen to flow out. 5. Immediately after the cerebrospinal fluid outflow, connect the piezometer to measure the pressure and record the cerebrospinal fluid pressure, ie the initial pressure of the cerebrospinal fluid. Under normal circumstances, the cerebrospinal fluid pressure on the side is 70-180 mm water column or 40 to 50 drops per minute. 6. Remove the pressure tube, collect 2 to 5 ml of cerebrospinal fluid, and send it to routine, biochemical, and cytological examination sets, and send bacteriology and serological examination if necessary. Then connect the pressure tube and measure the final pressure of the cerebrospinal fluid. 7. To understand the degree of obstruction and obstruction in the subarachnoid space, a dynamic test can be performed. The method is: after measuring the initial pressure, the assistant presses the patient's jugular vein for 10 seconds. Under normal circumstances, the cerebrospinal fluid pressure immediately rises to about twice the original. After the pressure is relieved, the cerebrospinal fluid pressure drops to the original level within 20 seconds, which is called the positive test of the test force, suggesting that the subarachnoid space is unobstructed. If the cerebrospinal fluid pressure does not rise after compression of one of the jugular veins, it is called a negative dynamic test, suggesting that the subarachnoid space is completely blocked. If the pressure of the cerebrospinal fluid slowly rises after compression of the jugular vein and slowly declines or does not decrease after relaxation of the compression, the side dynamic test is negative, indicating that there is incomplete obstruction on the side (such as tumor in the cerebellar fossa or thrombosis in the transverse sinus). Patients with cerebral hemorrhage or patients with increased intracranial pressure do not perform this test. 8. Subarachnoid administration: The most commonly used drug is methotrexate (MTX), which is used for the prevention of central nervous system leukemia and chemotherapy for meningeal leukemia. (1) drug dosage and usage: generally MTX 0.25 ~ 0.5mg / kg / time or 12mg / m2 / time (extreme amount 20mg) intrathecal injection, twice a week, until the symptoms are relieved. Thereafter, intrathecal injection of the same drug at the same dose was performed between 6 and 8 weeks to prevent recurrence. (2) Specific operation method: release about 5 to 10 ml of cerebrospinal fluid (note that the amount of release is the same as the amount of injection), and slowly inject the methotrexate solution diluted with physiological saline (about 5 to 10 ml) into the sheath. Cavity. 9. At the end of the operation, re-insert the needle core, pull out the puncture needle together, cover the sterile gauze and fix it with tape. 10. 嘱 patients go to the pillow for 4 to 6 hours, so as to avoid headaches and other symptoms after the waist.

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