Lumbar Puncture objectives To know the indication and

Lumbar Puncture

objectives To know the indication and contraindication for lumber puncture. To know the technique of insertion of the lumber puncture. Too know the complication of lumber puncture.

CSF Formation 140 ml spinal and cranial CSF 30 ml in the spinal cord Production is approx. 0. 35 ml/min Net flow out of ventricles 50 – 100 ml/day Reduces brain weight from 1400 to 50 g.

Indications for Lumbar Puncture 1 - diagnosis of CNS infection 2 -suspection of spontaneous subarachnoid hemorrhage 3 - evaluation and diagnosis of demyelinating or inflammatory CNS process.

4 - infusion of anathesia, chemotherapy, or contrast dye into spinal canal 5 - treatment of idiopathic intracranial hypertension

Infectious Indications Fever of unknown origin Children 1 mo to 3 yrs: fever, irritability, and vomiting. Cannot comfort child Over age 3 yrs: nuchal rigidity, Kernig’s sign, and Brudzinski’s sign Petechial rash in a febrile child Partially treated children are less likely to be febrile or exhibit an altered mental status

Subarachnoid Hemorrhage Diagnosis usually made by CT scan or by blood in CSF. Initial presentation: CT 92 -98% accurate Later than 24 hr presentation: 76% accurate After initial leak, CT is usually negative

Contraindications for LP 1 -Absolutely contraindicated in the presence of infection in the tissues near the puncture site. 2 -suspesion of increase intracranial pressure due to cerebral mass. Caution advised when lateralizing signs or signs of uncal herniation.

3 - uncorrected coagulopathy 4 -acute spinal cord trauma

Technique of insertion

Equipment Spinal needle l l l Less than 1 yr: 1. 5 in 1 yr to middle childhood: 2. 5 in Older children and adults: 3. 5 in Three-way stopcock Manometer 4 specimen tubes Local anesthesia Drapes Betadine

Procedure Almost all patients are afraid of an LP. Explaining the procedure in advance and discussing each step aids in reducing anxiety. Inquire about allergies to anesthetics. Informed consent.

positioning Performed with the patient in the lateral recumbent position. Or sitting upright A line connecting the posterior superior iliac crest will intersect the midline at approx. the L 4 spinous process. Spinal needles entering the subarachnoid space at this point are well below the termination of the spinal cord.

Site of injection In the adult, the spinal cord extends to the lower level of L 1 or the body of L 2. LP in adults and in older children may be performed from L 2 to L 3 interspace to the L 5 to S 1 interspace. At birth, the cord ends at the level of L 3. LP in infant may be performed at the L 4 to L 5 or L 5 to S 1 interspace.

steps Position the patient: l Generally performed in the lateral decubitus position. l A pillow is placed under the head to keep it in the same plane as the spine. l Shoulders and hips are positioned. perpendicular with the table. l Lower back should be arched toward practitioner.

Insertion 1. Sterile gloves MUST be used. 2. Wash back with antiseptic solution. 3. Sterile towel under hips. 4. The skin and deeper subcutaneous tissue are infiltrated with local anesthetic. 5. Warn patient of transient discomfort of anesthetic.

6 -Anesthetizing the deeper subcutaneous tissue significantly reduces the procedure discomfort. -Some operators not only anesthetize the interspinous ligament but also apply local anesthesia in a vertical fanning distribution on both sides of the spinous processes near the lamina.

7 -The patient should be told to report any pain and should be informed that he or she will feel some pressure. 8 -The needle is placed into the skin in the midline parallel to the bed. 9 -The needle is held with both thumbs and index fingers.

10 -After the subcutaneous tissue has been penetrated, the needle is angled toward the umbilicus. 11 -The bevel of the needle should be facing laterally (toward patients side).

The ligaments offer resistance to the needle, and a “pop” is often felt as they are penetrated. Clear fluid will flow from the needle when the subarachnoid space has been penetrated.

11 -If bone is encountered, withdrawal into subcutaneous tissue and redirect. 12 -Attach a manometer and record opening pressure. 13 -Turn stopcock and collect fluid. Withdrawal needle and place a dressing.

Tube 1 is used for determining protein and glucose Tube 2 is used for microbiologic and cytologic studies Tube 3 is for cell counts and serologic tests for syphilis

a. b. c. Ligament flavum is a strong, elastic, yellow membrane covering the interlaminar space between the vertebrae. Interspinal ligaments join the inferior and superior borders of adjacent spinous processes. Supraspinal ligament connects the spinous processes

Interpretations Pressure Opening pressure is taken promptly, avoiding falsely low values due to leakage through and around the needle l Normal pressure is between 70 and 180 mm H 20 l

Interpretation Appearance If CSF is not crystal clear, a pathologic condition of the CNS should be suspected l Compare fluid to water l Fluid may be clear with as many as 400 RBCs/mm 3 and 200 WBCs/mm 3 l

Interpretation Cells l l l WBC counts over 5 cells/mm 3 should be taken to indicate the presence of pathologic condition Polymorphonuclear leukocytes are never seen in normal adults Neutrophilic pleocytosis is commonly associated with bacterial infections or early stages of viral infections, tuberculosis, meningitis, hematogenous meningitis, and chemical meningitis due to foreign bodies.

Interpretation Cells l l Eosinophils are always abnormal and most commonly represent a parasite infestation. Eosinophils have also been reported in cases of subarachnoid hemorrhage, lymphoma, Hodgkin’s disease, brucellosis, fungal meningitis, mycoplasma pneumonia infection, measles, lymphocytic choriomeningitis, rickettsial infections, leukemia, demyelinating disease, sarcoiodosis, acute inflammatory demyelinating polyneuropathy, allergic reactions, and idiopathic eosinophilic meningitis.

Interpretation Cells Normal CSF RBCs are less than 10/mm 3. l Counts that are otherwise unexplained may be due to a traumatic tap. l Herpes simplex virus encephalitis may elevate the CSF RBC count in many patients. l

Interpretation Glucose Low CSF glucose concentration indicates increased glucose use in the brain and the spinal cord. l The normal range of CSF glucose is between 50 and 80 mg/dl l 60 -70% of serum glucose concentration l Only low concentrations of glucose are significance l

Interpretation Low CSF Glucose Syndromes Bacterial meningitis Syphilis Tuberculous meningitis Chemical meningitis Fungal meningitis Subarachnoid meningitis Sarcoidosis Mumps meningitis Meningeal carcinomatosis Herpes simplex encephalitis Amebic meningitis Hypoglycemia Cysticercosis Trichinosis

Interpretation Protein Increase in CSF total protein levels are a nonspecific abnormality associated with many disease states. l Levels > 500 mg/dl are uncommon and are seen mainly in meningitis, in subarachnoid bleeding, and with spinal tumors. l

The Traumatic Tap It should not be difficult to distinguish between subarachnoid hemorrhage and a traumatic tap. In traumatic taps, the fluid generally clears between 1 st and 3 rd tubes.

CSF Analysis with Infections Bacterial Infections l l l The Gram stain is of great importance, because this often dictates the initial choice of antibiotic. Gram-negative intracellular or extracellular diplococci are indicative of Neisseria meningitidis Small Gram-negative bacilli may include Haemophilus influenza, especially in children. Gram-positive cocci indicates Streptococcus pneumoniae, other Streptococcus species, or Staphylococcus. 20% of Gram stains may be falsely negative.

CSF Analysis with Infections Bacterial Infections l l l While the culture is pending, one may suspect a bacterial infection in the presence of an elevated opening pressure and a marked pleocytosis ranging between 500 and 20, 000 WBCs/mm 3. The differential count is usually chiefly neutrophils. A count above 1000 cells/mm 3 seldom occurs in viral infections.

CSF Analysis with Infections Bacterial Infections CSF glucose levels less than 40 mg/dl or less than 50% of a simultaneous blood glucose level should raise the question of bacterial meningitis. l The CSF protein content in bacterial meningitis ranges from 500 to 1500 mg/dl. l

CSF Analysis with Infections Viral Studies l The organisms most commonly isolated in viral meningitis are enteroviruses and mumps. Enteroviruses: summer and fall l Mumps: winter and spring l

CSF Analysis with Infections Viral Studies WBC count in viral meningitis and encephalitis usually: 10 to 1000 cells/mm 3. l The differential count is predominantly lymphocytic and mononuclear in type. l Protein levels are usually mildly elevated l Antibiotic coverage pending culture results may be reasonably initiated pending culture results if in doubt. l

Complications Headache After Lumbar Puncture l l Most common complication Occurs 5 -30% of all spinal taps Usually starts up to 48 hours after to procedure. Usually lasts 1 -2 days (occas 14 days)

Complications Headache After Lumbar Puncture Usually begins within minutes after arising and resolves with recumbent position. l Pain is mild to incapacitating and is usually cervical and sub-occipital, but may involve the shoulders and the entire cranium. l

Etiology of headache after LP 1 - leakage of fluid through dural puncture site. 2 - low CSF pressure. 3 - some contributing factors as : The diameter of the needel, the shape of the needel, the use of spinal anesthesia

How to minimize the headache? 1 -choice of needle standerd Quinck versus atraumatic. 2 - decrease the number of attempts 3 -reinsersion of the stylet 4 - bed rest after the proceedures

Headache After Lumbar Puncture Incidence is higher in younger patients and females, and those with headache history. Treatment: barbiturates, fluids, caffeine (500 mg in 2 ml NS IV push) more common 500 mg in 2 L over 1 hr.

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