LUMBAR PUNCTURE || SPINAL TAP|| LUMBER PUNCTURE PROCEDURE || CSF STUDY|| EPIDURAL||#shorts -Dr Raj

Lumbar puncture:

INDICATIONS
LP is essential or extremely useful in the diagnosis of bacterial, fungal, mycobacterial, and viral central nervous system (CNS) infections and, in certain settings, for help in the diagnosis of subarachnoid hemorrhage (SAH), CNS malignancies, demyelinating diseases, and Guillain-Barré syndrome.

●Suspected CNS infection (with the exception of brain abscess or a parameningeal process).
●Suspected SAH in a patient with a negative CT scan [3]. The use of cerebrospinal fluid (CSF) examination in the evaluation of a patient with suspected SAH is discussed in detail separately. (See "Aneurysmal subarachnoid hemorrhage: Clinical manifestations and diagnosis", section on 'Lumbar puncture'.)
The most common use of the LP is to diagnose or exclude meningitis in patients presenting with some combination of fever, altered mental status, headache, or meningeal signs. Examination of the CSF has a high sensitivity and specificity for determining the presence of bacterial and fungal meningitis.

●Idiopathic intracranial hypertension (pseudotumor cerebri)
●Carcinomatous meningitis
●Normal pressure hydrocephalus
●CNS syphilis
●CNS lymphoma
●Autoimmune encephalitis
Conditions in which LP is rarely diagnostic but still useful include:

●Multiple sclerosis
●Guillain-Barré syndrome and chronic inflammatory demyelinating polyneuropathy
●Paraneoplastic syndromes
●Neurosarcoidosis
●CNS vasculitis
LP is also required as a therapeutic or diagnostic maneuver in the following situations [1,2,4,5]:

●Spinal anesthesia
●Intrathecal administration of chemotherapy
●Intrathecal administration of antibiotics
●Injection of contrast media for myelography or for cisternography
CONTRAINDICATIONS
Although there are no absolute contraindications to performing the procedure, caution should be used in patients with:

When the LP is delayed or deferred in the setting of suspected bacterial meningitis, it is important to obtain blood cultures (which reveal the pathogen in more than half of patients) and promptly institute antibiotic therapy. Urgent evaluation and treatment of increased ICP, along with the administration of antibiotics and steroids, should be instituted promptly when this is suspected. Specific treatments are discussed separately. (See "Initial therapy and prognosis of bacterial meningitis in adults", section on 'Avoidance of delay'.)

TECHNIQUE
The choice of needle type (cutting versus atraumatic) and bore size can influence the risk of a post-LP headache, but also may increase the technical difficulty of the procedure. This is discussed in detail separately. (See "Post dural puncture headache", section on 'Prevention of PDPH after dural puncture'.)

Positioning — An LP can be performed with the patient in the lateral recumbent or prone positions or sitting upright. The lateral recumbent or prone positions are preferred over the upright position because they allow more accurate measurement of the opening pressure. The prone position is generally used for LPs performed under fluoroscopic guidance. (See 'Imaging guidance' below.)

The correct level of entry of the spinal needle is most easily determined with the patient sitting upright or standing. The highest points of the iliac crests should be identified visually and confirmed by palpation; a direct line joining these is a guide to the fourth lumbar vertebral body. However, this line may intersect the spine at points ranging from L1-L2 to L4-L5 [6], and tends to point to a higher spinal level in females and in patients with obesity [7]. The lumbar spinous processes of L3, L4, and L5, and the interspaces between, can usually be directly identified by palpation. The spinal needle can be safely inserted into the subarachnoid space at the L3-4 or L4-5 interspace, since this is well below the termination of the spinal cord in most patients. Spinal cord imaging is not considered necessary prior to LP, but, if performed, images should be reviewed to confirm the position of the conus prior to LP.

An alternate approach to obtaining cerebrospinal fluid (CSF) with a paramedian needle insertion through the L5-S1 space (Taylor approach) (figure 1) has been successfully used in a patient with advanced ankylosing spondylitis [8].

Correct patient positioning is an important determinant of success in obtaining CSF. The patient is instructed to remain in the fetal position with the neck, back, and limbs held in flexion. The lower lumbar spine should be flexed with the back perfectly perpendicular to the edge of a bed or examining table. The hips and legs should be parallel to each other and perpendicular to the table. Pillows placed under the head and between the knees may improve patient comfort.#shorts #medical #neet #doctor #viral #mbbs #nurse #emergency #life #trending #raj #india #motivational #biology #scince