Instructions for users

1. Instructions for users • This slide presentation provides an overview of performing a lumbar puncture. • Below many of the slides, there are notes to explain the information in the slide. • You should adapt the presentation for your own use.

2. Diagnosing Encephalitis:Review of Lumbar Puncture (LP)

3. Learning Objectives Participants will: • Know how to prepare a patient for LP. • Revise the steps for safely performing an LP. • Know what tests can be performed on CSF that is collected.

4. Relative contraindications to lumbar puncture • Evidence of a space-occupying lesion such as tumor or brain abscess. • Signs of increased intracranial pressure. • Unequal pupils, elevated blood pressure, slow heart rate, irregular breathing, posturing • Cardiopulmonary instability. • Soft tissue infection at puncture site. • Significant, uncontrolled bleeding disorder. *See note

5. Steps in performing a lumbar puncture • Obtain informed consent. • Gather materials. • Position patient. • Administer local anesthetic. • Insert needle with sterile technique. • Measure opening pressure. • Collect cerebrospinal fluid (CSF).

6. Informing the patient • Reason for the lumbar puncture: • Collection and testing of spinal fluid are standard management for encephalitis patients to direct treatment (e.g., if CSF profile suggests bacterial infection). • Potential complications: • The most common side effect is a headache which occurs in 10-30% of adult patients. It is managed with bed rest and analgesics and usually disappears in a few days. • Soreness of the lower back may also occur. • Other risks, including infection, bleeding, leakage of spinal fluid or damage to the spinal cord, are extremely rare. • Children tolerate lumbar punctures really well.

7. Materials to prepare • Materials for sterile technique (gloves, mask) • Spinal needle • Manometer (typically used in patients > 2 years of age) • Three-way stop-cock • Sterile drapes • Anesthetic • Solutions for skin sterilization • Adhesive dressing • Sponges • Get assistant (to help position patient and handle equipment)

8. 1. Place the patient in the left lateral position • The lower back should be as close to the edge of the bed as possible. • Ask the patient to curl up and hug his knees as close to the chest as possible (“fetal position”). • The neck should be flexed forward. • If physician is left-handed, the right lateral position should be used. • The patient may also be positioned sitting upright. However, the lateral position is preferred for accurate measurement of opening pressure. Note: The most important part of performing a successful lumbar puncture is good position! Be sure you give feedback to your assistant to ensure the patient is in proper fetal position.

9. 2. Locate the site • Find and palpate the posterior iliac crest. • Move your finger down and palpate the L4 spinous process. • Mark the puncture site at L4-5 or L3-4 (e.g. put a slight indent in the skin with your finger nail). The diagrams on the following slides provide illustrations

10. Site for Lumbar Puncture in a Child posterior iliaccrest Note: Having the patient curl around a pillow can help ensure proper position. Source: Harriett lane - 16th edition

11. Site for Lumbar puncture in an Adult Source: http://www.postgradmed.com

12. Indicating site of posterior iliac crest and puncture site Source: http://www.emedicinehealth.com

13. 3. Prepare sterile area • Use iodine to swab in a circle from the L4-5 area outwards. • Cover an area of 20cm diameter. • Once dried, remove the iodine with alcohol (to avoid introduction of iodine into the subarachnoid space). • Put on sterile gloves. • Drape the patient.

14. 4. Anesthetize the area • Anesthetize the skin. • Anesthetize between the spinous processes. • Insert the needle. • Draw back to ensure it has not reached the subarachnoid space. • Gradually withdraw the syringe while slowly injecting anesthetic into the interspace. Note: For infants local anesthetic is not needed. Instead, may give sugar water solution orally to help soothe.

15. 5. Insert the lumbar puncture needle • Insert the LP needle, with stylet, in the midline. • Direct the point of the needle to the umbilicus. • Keep the needle parallel to the ground. • Continue to insert until a slight pop is felt. • Withdraw the stylet slightly to be sure the needle is in the subarachnoid space. • If there is no CSF return, advance the needle about 2-3mm, and withdraw the stylet again. • When CSF begins to flow, attach a three-way stop-cock. Note: Only remove the spinal needle when the stylet is inserted.

16. Notes on LP needle insertion • If the needle strikes bone, withdraw it to just below the skin, then reinsert. • If blood slowly drips from the needle when the stylet is removed, discard the needle and start again. • Never aspirate CSF with a syringe, as a nerve root may be trapped against the needle and injured. • If you are unsuccessful in reaching subarachnoid space check: • Is the needle aimed towards the umbilicus? • Is the needle in the midline? • Is the needle parallel to the ground?

17. 6. Measure the pressure • Attach a manometer to the hub of the needle (via three-way stop-cock). • Have your assistant gently extend the patient’s leg and return his neck to a neutral position. • Ensure the patient is relaxed and watch for good respiratory variation of the fluid level as the patient breathes normally. • Check the CSF pressure. • Remove the manometer. Note: Typically used in patients older than 2 years of age.

18. Measuring opening pressure Source: http://www.emedicinehealth.com

19. 7. Collect cerebrospinal fluid (CSF) • Allow CSF to flow into sterile tubes. • Rubbing the fontanel of an infant may help increase flow of CSF. • CSF can be collected for • Chemistry • Microbiology • Antibody testing (in particular Japanese Encephalitis IgM) • Collect extra tube of CSF to hold in lab for possible later testing.

20. Collecting CSF into sterile tubes Source: http://www.emedicinehealth.com

21. 8. Final steps • Replace stylet and withdraw the needle. • Massage the puncture point with a sterile sponge. • Cover with a Band-Aid. • Advise adult patients to lie flat in bed for 3 hours and limit activity for 24 hours to minimize headache. Note: Children may resume their usual activity.

22. 9. Recording • Label tubes with patient information and date of collection. • Record immediate results. • Appearance of CSF • ?clear ?turbid • Pressure of CSF Note: pressures over 200mm H2O are probably abnormal

23. Laboratory tests on CSF • Cell count, differential • Glucose • Protein • Gram stain • India ink preparation • Stain for acid-fast bacilli • Viral, bacterial, and fungal cultures • Anti-JEV IgM ELISA • JEV RT-PCR (If available)

24. Normal Bacterial Viral TB Cells 0-5 WBC/mm3 >1000/mm3 <1000/mm3 25-500/mm3 Polymorphs 0 predominate early +/- increased Lymphocytes 5 late predominate increased Glucose 40-80 mg/dl decreased normal decreased 66% < 40% Normal < 30% Protein 5-40 mg/dl increased +/-increased increased Culture negative positive negative +TB Gram stain negative positive negative positive Summary of typical CSF findings CSF plasma : glucose ratio

25. Acknowledgements Please include the following acknowledgement if you use this slide set: This slide set was adapted from a slide set prepared by PATH’s Japanese Encephalitis Project. For information: www.JEproject.org