lumbar puncture (redirected from Lumber puncture)

puncture /punc·ture/ (-cher) the act of piercing or penetrating with a pointed object or instrument; a wound so made.

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cisternal puncture  puncture of the cisterna cerebellomedullaris through the posterior atlanto-occipital membrane to obtain cerebrospinal fluid.

lumbar puncture , spinal puncture the withdrawal of fluid from the subarachnoid space in the lumbar region, usually between the third and fourth lumbar vertebrae.

sternal puncture  removal of bone marrow from the manubrium of the sternum through an appropriate needle.

ventricular puncture  puncture of a cerebral ventricle for the withdrawal of fluid.

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lumbar puncture

n. Abbr. LP

Puncture into the subarachnoid space of the lumbar region for diagnostic or therapeutic purposes. Also called rachicentesis, rachiocentesis, spinal puncture, spinal tap.

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Lumbar puncture

A procedure in which the doctor inserts a small needle into the spinal cavity in the lower back to withdraw some spinal fluid for testing. Also known as a "spinal tap."

Mentioned in: Arteriovenous Malformations, Botulism, Central Nervous System Infections, Cryptococcosis, Leukemias, Chronic, Rabies, Subarachnoid Hemorrhage

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lumbar puncture (LP),

a diagnostic or therapeutic procedure in which a hollow needle and stylet are introduced into the subarachnoid space of the lumbar part of the spinal canal to obtain cerebrospinal fluid (CSF). Strict aseptic technique is used. Diagnostic indications include measuring of CSF pressure; obtaining CSF for laboratory analysis; and injecting oxygen or a radiopaque substance for radiographic visualization of the structures of the nervous system of the spinal canal and meninges and brain. Therapeutic indications for lumbar puncture include removing blood or pus from the subarachnoid space, injecting sera or drugs, withdrawing CSF to reduce intracranial pressure, introducing a local anesthetic to induce spinal anesthesia, and placing a small amount of the patient's blood in the subarachnoid space to form a clot to patch a hole in the dura to prevent leak of CSF into the epidural space.

method The skin over the interspace of the third and fourth lumbar vertebrae is cleansed. A fenestrated sterile drape is placed over the back, the window over the puncture site. The needle is inserted through the interspace to the subarachnoid space, and the stylet is withdrawn. If the needle is in the proper place, clear, straw-colored CSF will begin to drip out through the needle. Depending on the indication for the procedure, various techniques follow. The pressure of the CSF may be measured with a manometer attached to a catheter and stopcock, or fluid may be withdrawn, visually examined, and sent to the laboratory for chemical or bacteriologic analysis.

interventions The nurse may be responsible for obtaining the patient's written permission for the physician to perform a lumbar puncture. If the patient is apprehensive, he or she may be given a sedative one-half hour before the procedure. The techniques to be used and the treatments to be given or the information to be obtained are explained. The patient is placed in a lateral recumbent position, the back as near the edge of the bed as possible. The legs are flexed on the thighs, the thighs are flexed on the abdomen, and the head and shoulders are bent down, curving the spine convexly to afford the greatest space between the vertebrae. If the patient is excessively hairy, a dry shave of the lumbar area is performed before draping the area. After the procedure, significant signs to be observed by the nurse include pain, change in mentation or alertness, leakage of CSF from the puncture site, fever, and urinary retention. The patient is usually kept flat in bed, often in a prone position, for 1 hour after the procedure.

outcome criteria Lumbar puncture is contraindicated if intracranial tumor is suspected and there is evidence of greatly increased intracranial pressure, if there are signs of infection at the site of puncture, or (to avoid a second puncture) if encephalography or myelography is planned in the near future. Infection, leakage of CSF, headache, nausea, vomiting, dysuria, or signs of meningeal irritation occur in approximately 25% of patients.

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lumbar

pertaining to the loins.

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lumbar epidural analgesia

see epidural anesthesia.

lumbar paralysis

paraplegia generally and specifically that due to cerebrospinal nematodiasis.

lumbar plexus

one formed by the ventral branches of the last four or five lumbar nerves in the psoas major muscle.

lumbar puncture

insertion of a needle and stylet into the subarachnoid space between the seventh lumbar vertebra and sacrum in most species except the dog, where the space between the sixth and seventh lumbar vertebrae is usually used; called also spinal puncture. A lumbar puncture may be done to measure the pressure of cerebrospinal fluid and obtain a specimen for examination, and to inject a contrast medium for special radiographic examinations such as myelography. As a therapeutic measure it is sometimes done to relieve intracranial pressure or to remove blood or pus from the subarachnoid space. A lumbar puncture also is necessary for injection of a spinal anesthetic.

lumbar spinal stenosis

see lumbosacral stenosis.

lumbar tap

see lumbar puncture (above).

lumbar vertebrae

the vertebrae between the thoracic vertebrae and the sacrum, numbering seven in dogs and cats, six in horses and cattle, and six or seven in sheep and pigs.

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lumbar puncture

Spinal tap Neurology A diagnostic procedure in which a very long needle is inserted into the subarachnoid space between the 3^rd and 4^th lumbar vertebrae in order to obtain CSF; an LP is used to measure intracranial pressure, which may be ↑ 2º to hemorrhage, tumors, or edema, measure CSF chemistries–eg, glucose, proteins, diagnose inflammation of the CNS, especially infections–eg, meningitis, and stroke, spinal cord tumors and metastases to the CNS, or inject a dye into the spine before myelography Complications Uncommon; meningitis, bleeding into spinal canal; if intracranial pressure is ↑, removal of CSF from spinal canal may cause fatal herniation of cerebellar tonsils. See Cerebrospinal fluid.