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Punción lumbar

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Subido el 8 de marzo de 2018 por Mercedes C.

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This is a video in Clinical Medicine from the New England Journal of Medicine. 00:00:03
This video will demonstrate safe and successful methods of performing lumbar puncture. 00:00:17
Lumbar puncture is indicated for both diagnostic and therapeutic purposes. 00:00:23
Also, the administration of spinal and epidural anesthesia involves the use, essentially, of this same technique. 00:00:29
Analysis of cerebrospinal fluid may be helpful in the diagnosis of infectious processes such as meningitis, 00:00:36
inflammatory diseases such as multiple sclerosis, cancers such as leukemia, and metabolic processes. 00:00:44
Therapeutically, lumbar puncture allows for the intrathecal administration of chemotherapeutic agents and antibiotics. 00:00:52
There are specific contraindications to lumbar puncture. 00:01:00
The condition of patients with cardiorespiratory compromise may worsen as a consequence of the 00:01:04
position they need to assume for lumbar puncture. The procedure should also be avoided in patients 00:01:10
with signs of cerebral herniation, incipient herniation, or increased intracranial pressure 00:01:16
and in those with focal neurologic signs. In such patients, cranial CT should be performed 00:01:22
before lumbar puncture, although CT may not reveal signs of increased intracranial pressure. 00:01:28
Finally, there is an increased risk of a spinal hematoma if a coagulopathy is present or if the 00:01:36
patient is receiving anticoagulant therapy. Patients who have previously undergone lumbar 00:01:43
surgery should be referred to an interventional radiologist. Before performing the lumbar puncture, 00:01:49
you will need a commercially available tray containing the necessary supplies a spinal 00:01:56
needle with a stylet equipment for skin preparation drapes collection tubes and in 00:02:02
some cases a manometer typically a 20 to 22 gauge needle is used with the length ranging 00:02:10
from 1.5 inches or 3.8 centimeters for infants to 2.5 inches or 6.3 centimeters for children 00:02:18
and 3.5 inches or 8.9 centimeters for adults. 00:02:25
You will also need sterile gloves. 00:02:31
Before you begin, you should explain the procedure, 00:02:34
along with potential risks and benefits, to the patient 00:02:37
and obtain informed consent from the patient or his or her parent or guardian. 00:02:40
After obtaining appropriate patient consent, the patient is positioned. 00:02:46
Either the lateral recumbent position or a sitting position can be used. 00:02:50
The lateral recumbent position is preferred to obtain an accurate opening pressure 00:02:55
and to reduce the risk of post-puncture headache. 00:03:00
Instruct the patient to assume a fetal position or to arch like a cat with the back flexed. 00:03:03
This position widens the gap between the spinous processes. 00:03:10
Ideally, the lumbar spine should be perpendicular to the table if the patient is in the sitting position 00:03:15
and parallel to the table if he or she is in the lateral recumbent position. 00:03:21
These positions help keep the needle at the midline. 00:03:26
A line is visually drawn between the superior aspects of the iliac crest 00:03:30
and intersects the midline at the L4 spinous process. 00:03:35
Insert the needle in the interspace between L3 and L4 or L4 and L5 00:03:39
since this location is below the termination of the spinal cord. 00:03:45
Palpate the landmarks before preparing the skin and before administering local anesthesia since 00:03:49
the anesthesia may make landmarks harder to identify. Use a skin marking pen to identify 00:03:56
the site of needle insertion. While wearing sterile gloves, clean a sufficiently large 00:04:02
area of the overlying skin with a disinfecting agent such as chlorhexidine or povidone iodine 00:04:11
using a pattern of widening concentric circles. 00:04:17
Drape the area with sterile drapes. 00:04:21
Lay out the collection bottles in the order of priority 00:04:24
for the diagnostic indications. 00:04:26
Lumbar puncture is a painful 00:04:29
and potentially anxiety-provoking procedure. 00:04:30
At a minimum, the use of a local anesthetic is appropriate. 00:04:34
Sedation or systemic anesthesia may be required 00:04:38
under some circumstances. 00:04:41
You can apply anesthetic cream topically 00:04:43
before preparing the skin. After preparing the skin, you can inject local anesthetics 00:04:46
subcutaneously. Identify the anatomical landmarks once again and insert the needle with stylet 00:04:52
firmly in place in the midline at the superior aspect of the inferior spinous process, directing 00:05:05
it at an angle of approximately 15 degrees as if aiming at the patient's umbilicus. Either use a 00:05:13
pencil-tipped needle or ensure that the bevel of the needle is in the sagittal plane in order to 00:05:21
spread rather than cut the fibers of the dural sac. These fibers run parallel to the spinal axis. 00:05:27
The use of this needle position should theoretically decrease the leakage of cerebrospinal fluid. 00:05:34
If properly positioned, the needle should pass through the skin, the subcutaneous tissue, 00:05:43
the supraspinous ligament, the interspinous ligament between the spinous processes, 00:05:48
the ligamentum flavum, the epidural space, including the internal vertebral venous plexus, 00:05:54
the dura, the arachnoid, into the subarachnoid space, and between the nerve roots of the cauda 00:06:00
equina. As the needle passes through the ligamentum flavum, you may feel a popping sensation. Once you 00:06:07
have reached this point, the needle should be advanced in two millimeter increments and the 00:06:17
stylet withdrawn after each increment to check for CSF flow. If no fluid is detected and bone 00:06:22
is encountered, withdraw the needle to the level of subcutaneous tissue without exiting the skin 00:06:28
and redirect the needle. Fluid will flow once the needle enters the subarachnoid space. 00:06:35
If the lumbar puncture is traumatic, the cerebrospinal fluid may be tinged with blood. 00:06:41
As additional fluid accumulates in the barrel, the fluid should become clear, unless the source of the blood is a subarachnoid hemorrhage. 00:06:46
If the flow is poor, a nerve root may be obstructing the opening of the needle, and you should rotate the needle 90 degrees. 00:06:56
If drops of blood enter the needle, it may become clogged. 00:07:03
In this case, you should obtain a new needle and enter the site through a different interspace. 00:07:07
For you to obtain an opening cerebrospinal pressure, the patient must be in the lateral recumbent position. 00:07:13
Use a flexible connector and attach a manometer to the hub of the spinal needle. 00:07:23
After waiting for the column of fluid to rise and possibly seeing pulsation from cardiac or respiratory motion, you may take a measurement. 00:07:29
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. 00:07:37
You must allow cerebral spinal fluid to drip into the collection tubes. 00:07:52
Never aspirate cerebral spinal fluid. 00:07:57
Even a small amount of negative pressure can precipitate a hemorrhage. 00:08:00
The amount of fluid collected should be limited to the smallest volume necessary for testing. 00:08:03
Typically, 3 to 4 milliliters of fluid is sufficient for routine indications. 00:08:09
By turning the stopcock toward the patient, fluid in the manometer may be collected. 00:08:14
After collecting an adequate specimen, replace the stylet and remove the needle. 00:08:20
Although, traditionally, patients have been told to lie flat for several hours after a lumbar puncture, 00:08:26
there is no evidence that this precaution decreases the risk of a cerebrospinal fluid leak, 00:08:32
post-puncture headache, or other complications. 00:08:38
All sharps should be properly disposed of in appropriate sharps containers 00:08:42
or needle-lock devices to help minimize the risk of needle-stick injury. 00:08:46
Obese patients may represent a challenge due to difficulty in identifying landmarks. 00:08:54
Other conditions such as osteoarthritis, ankylosing spondylitis, kyphoscoliosis, 00:09:00
previous surgery that has altered landmarks or spaces, 00:09:07
and degenerative disc disease also may make the procedure more difficult. 00:09:10
If faced with these challenges, consider consultation with an anesthesiologist or perhaps a radiologist 00:09:14
if fluoroscopy-guided lumbar puncture seems to be a better approach. 00:09:21
Lumbar puncture has numerous possible complications, including cerebellar herniation, 00:09:29
referred pain, headache, bleeding, infection, the formation of a subarachnoid epidermal cyst, 00:09:34
and leakage of spinal fluid. You can avoid many of these complications by conducting a careful 00:09:42
assessment of the patient before the procedure, including a thorough neurologic examination 00:09:48
and retinoscopy, and monitoring the patient throughout the procedure. A subarachnoid 00:09:54
epidermal cyst occurs when a skin plug is introduced into the subarachnoid space. 00:10:00
The standard use of a needle with a stylet will avoid this complication. 00:10:06
Leakage of spinal fluid can occur at the puncture site. A large-bore spinal needle is more likely 00:10:10
than a smaller-bore needle to produce a leak, so the latter should be used whenever possible. 00:10:17
In the case of persistent leakage of spinal fluid, an anesthesiologist should be consulted 00:10:23
to determine whether a blood patch is needed to occlude the leak. 00:10:29
Lumbar puncture is a commonly performed procedure 00:10:35
that can be a very useful aid in clinical diagnosis and treatment. 00:10:38
Subido por:
Mercedes C.
Licencia:
Dominio público
Visualizaciones:
142
Fecha:
8 de marzo de 2018 - 13:26
Visibilidad:
Público
Centro:
IES BENJAMIN RUA
Duración:
11′
Relación de aspecto:
4:3 Hasta 2009 fue el estándar utilizado en la televisión PAL; muchas pantallas de ordenador y televisores usan este estándar, erróneamente llamado cuadrado, cuando en la realidad es rectangular o wide.
Resolución:
320x240 píxeles
Tamaño:
27.57 MBytes

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