1 00:00:03,439 --> 00:00:07,419 This is a video in Clinical Medicine from the New England Journal of Medicine. 2 00:00:17,420 --> 00:00:22,699 This video will demonstrate safe and successful methods of performing lumbar puncture. 3 00:00:23,980 --> 00:00:28,440 Lumbar puncture is indicated for both diagnostic and therapeutic purposes. 4 00:00:29,260 --> 00:00:36,240 Also, the administration of spinal and epidural anesthesia involves the use, essentially, of this same technique. 5 00:00:36,240 --> 00:00:43,960 Analysis of cerebrospinal fluid may be helpful in the diagnosis of infectious processes such as meningitis, 6 00:00:44,399 --> 00:00:51,240 inflammatory diseases such as multiple sclerosis, cancers such as leukemia, and metabolic processes. 7 00:00:52,380 --> 00:00:59,859 Therapeutically, lumbar puncture allows for the intrathecal administration of chemotherapeutic agents and antibiotics. 8 00:01:00,259 --> 00:01:04,140 There are specific contraindications to lumbar puncture. 9 00:01:04,140 --> 00:01:10,260 The condition of patients with cardiorespiratory compromise may worsen as a consequence of the 10 00:01:10,260 --> 00:01:16,099 position they need to assume for lumbar puncture. The procedure should also be avoided in patients 11 00:01:16,099 --> 00:01:22,459 with signs of cerebral herniation, incipient herniation, or increased intracranial pressure 12 00:01:22,459 --> 00:01:28,920 and in those with focal neurologic signs. In such patients, cranial CT should be performed 13 00:01:28,920 --> 00:01:35,239 before lumbar puncture, although CT may not reveal signs of increased intracranial pressure. 14 00:01:36,500 --> 00:01:43,159 Finally, there is an increased risk of a spinal hematoma if a coagulopathy is present or if the 15 00:01:43,159 --> 00:01:49,260 patient is receiving anticoagulant therapy. Patients who have previously undergone lumbar 16 00:01:49,260 --> 00:01:56,719 surgery should be referred to an interventional radiologist. Before performing the lumbar puncture, 17 00:01:56,719 --> 00:02:02,299 you will need a commercially available tray containing the necessary supplies a spinal 18 00:02:02,299 --> 00:02:10,520 needle with a stylet equipment for skin preparation drapes collection tubes and in 19 00:02:10,520 --> 00:02:18,020 some cases a manometer typically a 20 to 22 gauge needle is used with the length ranging 20 00:02:18,020 --> 00:02:25,879 from 1.5 inches or 3.8 centimeters for infants to 2.5 inches or 6.3 centimeters for children 21 00:02:25,879 --> 00:02:30,560 and 3.5 inches or 8.9 centimeters for adults. 22 00:02:31,120 --> 00:02:33,080 You will also need sterile gloves. 23 00:02:34,680 --> 00:02:37,099 Before you begin, you should explain the procedure, 24 00:02:37,460 --> 00:02:40,419 along with potential risks and benefits, to the patient 25 00:02:40,419 --> 00:02:45,500 and obtain informed consent from the patient or his or her parent or guardian. 26 00:02:46,120 --> 00:02:50,159 After obtaining appropriate patient consent, the patient is positioned. 27 00:02:50,800 --> 00:02:55,000 Either the lateral recumbent position or a sitting position can be used. 28 00:02:55,000 --> 00:03:00,419 The lateral recumbent position is preferred to obtain an accurate opening pressure 29 00:03:00,419 --> 00:03:03,259 and to reduce the risk of post-puncture headache. 30 00:03:03,699 --> 00:03:10,080 Instruct the patient to assume a fetal position or to arch like a cat with the back flexed. 31 00:03:10,879 --> 00:03:14,539 This position widens the gap between the spinous processes. 32 00:03:15,439 --> 00:03:21,280 Ideally, the lumbar spine should be perpendicular to the table if the patient is in the sitting position 33 00:03:21,280 --> 00:03:25,979 and parallel to the table if he or she is in the lateral recumbent position. 34 00:03:26,460 --> 00:03:29,340 These positions help keep the needle at the midline. 35 00:03:30,479 --> 00:03:35,039 A line is visually drawn between the superior aspects of the iliac crest 36 00:03:35,039 --> 00:03:39,039 and intersects the midline at the L4 spinous process. 37 00:03:39,960 --> 00:03:45,800 Insert the needle in the interspace between L3 and L4 or L4 and L5 38 00:03:45,800 --> 00:03:49,659 since this location is below the termination of the spinal cord. 39 00:03:49,659 --> 00:03:56,620 Palpate the landmarks before preparing the skin and before administering local anesthesia since 40 00:03:56,620 --> 00:04:02,860 the anesthesia may make landmarks harder to identify. Use a skin marking pen to identify 41 00:04:02,860 --> 00:04:11,039 the site of needle insertion. While wearing sterile gloves, clean a sufficiently large 42 00:04:11,039 --> 00:04:17,759 area of the overlying skin with a disinfecting agent such as chlorhexidine or povidone iodine 43 00:04:17,759 --> 00:04:20,759 using a pattern of widening concentric circles. 44 00:04:21,399 --> 00:04:23,439 Drape the area with sterile drapes. 45 00:04:24,019 --> 00:04:26,660 Lay out the collection bottles in the order of priority 46 00:04:26,660 --> 00:04:28,639 for the diagnostic indications. 47 00:04:29,279 --> 00:04:30,740 Lumbar puncture is a painful 48 00:04:30,740 --> 00:04:33,600 and potentially anxiety-provoking procedure. 49 00:04:34,259 --> 00:04:37,300 At a minimum, the use of a local anesthetic is appropriate. 50 00:04:38,060 --> 00:04:41,240 Sedation or systemic anesthesia may be required 51 00:04:41,240 --> 00:04:42,800 under some circumstances. 52 00:04:43,939 --> 00:04:46,540 You can apply anesthetic cream topically 53 00:04:46,540 --> 00:04:52,420 before preparing the skin. After preparing the skin, you can inject local anesthetics 54 00:04:52,420 --> 00:05:05,800 subcutaneously. Identify the anatomical landmarks once again and insert the needle with stylet 55 00:05:05,800 --> 00:05:13,199 firmly in place in the midline at the superior aspect of the inferior spinous process, directing 56 00:05:13,199 --> 00:05:21,860 it at an angle of approximately 15 degrees as if aiming at the patient's umbilicus. Either use a 57 00:05:21,860 --> 00:05:27,019 pencil-tipped needle or ensure that the bevel of the needle is in the sagittal plane in order to 58 00:05:27,019 --> 00:05:33,720 spread rather than cut the fibers of the dural sac. These fibers run parallel to the spinal axis. 59 00:05:34,639 --> 00:05:40,120 The use of this needle position should theoretically decrease the leakage of cerebrospinal fluid. 60 00:05:43,389 --> 00:05:48,709 If properly positioned, the needle should pass through the skin, the subcutaneous tissue, 61 00:05:48,709 --> 00:05:53,769 the supraspinous ligament, the interspinous ligament between the spinous processes, 62 00:05:54,129 --> 00:05:59,870 the ligamentum flavum, the epidural space, including the internal vertebral venous plexus, 63 00:06:00,310 --> 00:06:07,029 the dura, the arachnoid, into the subarachnoid space, and between the nerve roots of the cauda 64 00:06:07,029 --> 00:06:17,339 equina. As the needle passes through the ligamentum flavum, you may feel a popping sensation. Once you 65 00:06:17,339 --> 00:06:22,240 have reached this point, the needle should be advanced in two millimeter increments and the 66 00:06:22,240 --> 00:06:28,740 stylet withdrawn after each increment to check for CSF flow. If no fluid is detected and bone 67 00:06:28,740 --> 00:06:35,000 is encountered, withdraw the needle to the level of subcutaneous tissue without exiting the skin 68 00:06:35,000 --> 00:06:41,620 and redirect the needle. Fluid will flow once the needle enters the subarachnoid space. 69 00:06:41,620 --> 00:06:46,920 If the lumbar puncture is traumatic, the cerebrospinal fluid may be tinged with blood. 70 00:06:46,920 --> 00:06:55,220 As additional fluid accumulates in the barrel, the fluid should become clear, unless the source of the blood is a subarachnoid hemorrhage. 71 00:06:56,079 --> 00:07:03,459 If the flow is poor, a nerve root may be obstructing the opening of the needle, and you should rotate the needle 90 degrees. 72 00:07:03,860 --> 00:07:06,920 If drops of blood enter the needle, it may become clogged. 73 00:07:07,800 --> 00:07:13,420 In this case, you should obtain a new needle and enter the site through a different interspace. 74 00:07:13,420 --> 00:07:22,790 For you to obtain an opening cerebrospinal pressure, the patient must be in the lateral recumbent position. 75 00:07:23,670 --> 00:07:28,269 Use a flexible connector and attach a manometer to the hub of the spinal needle. 76 00:07:29,170 --> 00:07:37,629 After waiting for the column of fluid to rise and possibly seeing pulsation from cardiac or respiratory motion, you may take a measurement. 77 00:07:37,629 --> 00:07:50,389 If the cerebral spinal fluid pressure exceeds 25 centimeters of water, you should closely monitor the patient for signs of herniation and determine the cause of the patient's elevated intracranial pressure. 78 00:07:52,970 --> 00:07:56,970 You must allow cerebral spinal fluid to drip into the collection tubes. 79 00:07:57,509 --> 00:07:59,689 Never aspirate cerebral spinal fluid. 80 00:08:00,050 --> 00:08:03,529 Even a small amount of negative pressure can precipitate a hemorrhage. 81 00:08:03,529 --> 00:08:08,810 The amount of fluid collected should be limited to the smallest volume necessary for testing. 82 00:08:09,329 --> 00:08:14,170 Typically, 3 to 4 milliliters of fluid is sufficient for routine indications. 83 00:08:14,730 --> 00:08:19,829 By turning the stopcock toward the patient, fluid in the manometer may be collected. 84 00:08:20,709 --> 00:08:25,990 After collecting an adequate specimen, replace the stylet and remove the needle. 85 00:08:26,449 --> 00:08:32,649 Although, traditionally, patients have been told to lie flat for several hours after a lumbar puncture, 86 00:08:32,950 --> 00:08:38,169 there is no evidence that this precaution decreases the risk of a cerebrospinal fluid leak, 87 00:08:38,169 --> 00:08:41,429 post-puncture headache, or other complications. 88 00:08:42,129 --> 00:08:46,169 All sharps should be properly disposed of in appropriate sharps containers 89 00:08:46,169 --> 00:08:51,149 or needle-lock devices to help minimize the risk of needle-stick injury. 90 00:08:54,200 --> 00:08:59,759 Obese patients may represent a challenge due to difficulty in identifying landmarks. 91 00:09:00,320 --> 00:09:06,220 Other conditions such as osteoarthritis, ankylosing spondylitis, kyphoscoliosis, 92 00:09:07,100 --> 00:09:09,879 previous surgery that has altered landmarks or spaces, 93 00:09:10,220 --> 00:09:14,639 and degenerative disc disease also may make the procedure more difficult. 94 00:09:14,639 --> 00:09:21,940 If faced with these challenges, consider consultation with an anesthesiologist or perhaps a radiologist 95 00:09:21,940 --> 00:09:26,220 if fluoroscopy-guided lumbar puncture seems to be a better approach. 96 00:09:29,240 --> 00:09:34,460 Lumbar puncture has numerous possible complications, including cerebellar herniation, 97 00:09:34,460 --> 00:09:41,899 referred pain, headache, bleeding, infection, the formation of a subarachnoid epidermal cyst, 98 00:09:42,279 --> 00:09:48,720 and leakage of spinal fluid. You can avoid many of these complications by conducting a careful 99 00:09:48,720 --> 00:09:54,279 assessment of the patient before the procedure, including a thorough neurologic examination 100 00:09:54,279 --> 00:10:00,419 and retinoscopy, and monitoring the patient throughout the procedure. A subarachnoid 101 00:10:00,419 --> 00:10:05,559 epidermal cyst occurs when a skin plug is introduced into the subarachnoid space. 102 00:10:06,240 --> 00:10:09,960 The standard use of a needle with a stylet will avoid this complication. 103 00:10:10,759 --> 00:10:17,259 Leakage of spinal fluid can occur at the puncture site. A large-bore spinal needle is more likely 104 00:10:17,259 --> 00:10:23,080 than a smaller-bore needle to produce a leak, so the latter should be used whenever possible. 105 00:10:23,679 --> 00:10:29,419 In the case of persistent leakage of spinal fluid, an anesthesiologist should be consulted 106 00:10:29,419 --> 00:10:33,340 to determine whether a blood patch is needed to occlude the leak. 107 00:10:35,559 --> 00:10:38,419 Lumbar puncture is a commonly performed procedure 108 00:10:38,419 --> 00:10:42,919 that can be a very useful aid in clinical diagnosis and treatment.