Lesson 18. Lumbar Puncture
2-18. LUMBAR PUNCTURE
a. Lumbar puncture is the insertion of a sterile needle into the subarachnoid space of the spinal canal, usually between the third and fourth vertebra, to reach the cerebral spinal fluid. This test requires sterile technique and careful patient positioning. It is performed therapeutically to administer drugs or anesthetics and to relieve intracranial pressure.
b. Diagnostic uses for lumbar puncture:
- (1) To determine the pressure of the cerebral spinal fluid.
- (2) To detect increased intracranial pressure.
- (3) To detect presence of blood in the cerebral spinal fluid which indicates cerebral hemorrhage.
- (4) To obtain cerebral spinal fluid specimens for laboratory analysis.
c. Nursing implications.
- (1) Review the patient's clinical record to determine the reason for the patient's scheduled lumbar puncture procedure and what the patient has been told about the procedure.
- ( 2) Assemble the necessary equipment. Sterile disposable lumbar tray. Overbed table.
- Sterile gloves.
- Betaine solution.
- Local anesthetic.
- Laboratory request slips.
- (3) Approach and identify the patient.
- (4) Interview the patient to determine his/her knowledge of the purpose of the lumbar puncture procedure.
- (5) As indicated, explain to the patient the specific purpose of the lumbar puncture procedure. Explain purpose in a manner consistent with that offered by the physician to avoid confusing the patient.
- (6) Explain the procedure to the patient.
- (1) Ask the patient to empty his/her bladder.
- (2) Position the patient.
- (a) Lateral recumbent, at the edge of the bed, knees drawn up to abdomen, and chin tucked to chest.
- (b) To help the patient maintain this position, the nursing paraprofessional places one hand behind the patient's neck and the other behind patient's knees to help support the patient's position throughout the procedure.
- (3) The physician will clean the puncture site area with sterile applicators from the lumbar puncture tray.
- (4) The physician will drape the area with a fenestrated drape to provide a sterile field.
- (5) The physician will inject local anesthetic into the planned needle puncture site.
- (6) The physician will insert the spinal needle. The patient will feel some pressure at this time.
- (7) If the procedure is being performed to administer contrast media for radiologic studies or spinal anesthetic, the physician will inject the dye or anesthetic.
- (8) When the needle is in place, the physician will attach a manometer with stopcock to the needle hub to read CSF pressure. (The patient may need to extend his legs to provide a more accurate pressure reading.)
- (9) The physician will detach the manometer and allow the fluid to drain from the needle hub into four collection tubes.
- (10) When there is approximately 2 or 3 ml of fluid in each tube, the physician will hand them to the assistant, who will mark the tubes in sequence, stopper them securely, and label them properly, as such:
- (a) Gram stain.
- (b) Culture, sensitivity.
- (c) Cell count.
- (d) Protein and glucose.
- (11) The physician will remove the spinal needle, apply pressure to the area briefly, and apply a band-aid or small dressing.
- (12) The entire procedure will last approximately 15 minutes.
- (1) Send the CSF specimens to the laboratory immediately.
- (2) Instruct the patient to lie flat for several hours to reduce chance of headache.
- (3) Monitor the patient carefully following the procedure. Adverse reactions including headache, vertigo, syncope, nausea, tinnitus, respiratory distress, change in vital signs, meningitis, and fever should be reported to the professional nurse.
- (4) Give the patient increased fluids for at least 24 hours after the procedure.
- (5) Inform the patient that the physician will report the results of the lumbar puncture as soon as they are available.
- Ensure the comfort and safety of the patient.
- Remove equipment from bedside and dispose of properly.
- Record the procedure in the patient's chart.