Collection, transport and processing of clinical specimens: CSF

Cerebrospinal fluid

1. PRESENTED BY:- S. Raghavigneshwari Faizan Raza .M. Pathan Gautami .A. Digavkar COLLECTION, TRANSPORT AND PROCESSING OF CLINICAL SPECIMENS: CSF

2. WHAT IS CSF? Cerebrospinal fluid is the liquid (colourless) around your brain & spinal cord. The fluid is made by a group of cells, called the choroid plexus , that are deep inside your brain. CSF is a product of plasma filtration and membrane secretion, and so its composition is different from that of plasma. CSF, in general, is clear ,  colourless , nearly acellular , and has a low protein concentration. Various ions, enzymes, and other substances are also found in normal CSF.

3.  It cushions those organs, picks up needed supplies from your blood, & gets rid of waste products from brain cells & provides lubrication between surrounding bones and the brain and spinal cord. CSF is slightly alkaline and is about 99 percent water.  There are about 100 to 150 ml of CSF in the normal adult human body.

4. Collection of CSF Examination of the CSF may diagnose a number of diseases. A fluid sample is obtained by inserting a needle into the  lumbar region of the lower back below the termination of the spinal cord; this procedure is called a  lumbar puncture  or spinal tap . The needle is inserted in the lower back, usually between the third and fourth lumbar vertebrae , into the subarachnoid space of the spinal cord, where the CSF is located.

5. The kit for collection of CSF should contain: Skin disinfectant: 70% alcohol swab and povidone -iodine Alcohol with concentrations greater than 70% should not be used because the increased concentrations result in decreased bactericidal activity. Do not use alcohol with glycerol added to it. Sterile gloves Be sure to check the expiration date. Sterile gauze Surgical mask Adhesive bandage Lumbar puncture needle 22 gauge/89 mm for adults 23 gauge/64 mm for children

6. Sterile screw-cap tubes Syringe and needle Transport container T-I medium (if CSF cannot be analyzed in a microbiological laboratory immediately) T-I should be refrigerated at 4°C and added to the kit immediately before use in the field. Venting needle (only if T-I is being used) Instructions for lumbar puncture and use of T-I medium

7. Lumbar puncture procedure Gather all materials from the CSF collection kit and a puncture-resistant autoclavable container for used needles. Wear surgical mask and sterile latex or nitrile gloves that are impermeable to liquids and change gloves between every patient. Label the collection tubes with appropriate information: patient’s name, date and time of specimen collection, and Unique Identification Number. Be sure this number matches the number on both the request and report forms. Ensure that the patient is kept motionless during the lumbar puncture procedure, either sitting up or lying on the side, with his or her back arched forward so that the head almost touches the knees in order to separate the lumbar vertebrae during the procedure.

8. Disinfect the skin along a line drawn between the crests of the two ilia with 70% alcohol and povidone -iodine to clean the surface and remove debris and oils. Allow to dry completely. Position the spinal needle between the 2 vertebral spines at the L4-L5 level and introduce into the skin with the bevel of the needle facing up. Accurate placement of the needle is rewarded by a flow of fluid, which normally is clear and colourless. Remove CSF (1 ml minimum, 3-4 ml if possible) and collect into sterile screw-cap tubes. If 3-4 ml CSF is available, use 3 separate tubes and place approximately 1ml into each tube. Withdraw the needle and cover the insertion site with an adhesive bandage. Discard the needle in a puncture-resistant, autoclavable discard container.

9. Remove mask and gloves and discard in an autoclavable container. Wash hands with antibacterial soap and water immediately after removing gloves. Transport the CSF to a microbiology laboratory within 1 hour for culture and analysis. If that is not possible, inoculate CSF into T-I medium (see Section I.C. below). If T-I is not available, incubate CSF at 35-37°C with ~5% CO 2  (see Section I.D. below) and store in an approved location if the laboratory is closed. In the event of a needle-stick injury or other skin puncture or wound, wash the wound liberally with soap and water. Encourage bleeding. Report a needle-stick injury, any other skin puncture, or any contamination of the hands or body with CSF to the supervisor and appropriate health officials immediately as prophylactic treatment of the personnel performing the procedure may be indicated.

10. CSF analysis: What is it used for? A CSF analysis may include tests to diagnose: Infectious diseases of the brain and spinal cord , including  meningitis  and  encephalitis . CSF tests for infections look at white blood cells , bacteria , and other substances in the CSF. Autoimmune disorders , such as  Guillain-Barré Syndrome  and  multiple sclerosis . CSF tests for these disorders look for high levels of certain proteins in the cerebrospinal fluid. These tests are called albumin protein and igG /albumin . Bleeding  in the brain . Brain tumors.

11. You may need a CSF analysis if you have symptoms of an infection of the brain or spinal cord, or of an autoimmune disorder, such as multiple sclerosis (MS ). Symptoms of a brain or spinal cord infection include: Fever Severe headache Seizures Stiff neck Nausea and vomiting Sensitivity to light Double vision Changes in behaviour Confusion

12. Symptoms of MS include : Blurred or double vision Tingling in the arms, legs, or face Muscle spasms Weak muscles Dizziness Bladder control problems You may also need a CSF analysis if you've had an injury to your brain or spinal cord , or have been diagnosed with cancer that has spread to the brain or spinal cord.

13. Tests: Leucocyte Count It is done within first half an hour after withdrawal, because, on longer standing, cells begin to disintegrate. Normally, 0-10 cells/mm 3 , all of which are lymphocytes , which are present. In children , a normal count is slightly high, about 20 cells / mm 3 . Polymorphs are found only in pathological conditions . Cell count should be done soon after collection of the fluid.

14. Differential Count Centrifuge a little CSF and make 3 smears from deposit: First smear stain by Leishman stain, to observe leucocytes . Second smear with Grams stain and look for meningococci . Third smear with Ziehl-Neelsen stain and look for acid fast bacilli .

15. Total count It is done as follows: CSF Diluting Fluid: Composition 1.Crystal violet - 0.2 gms 2. Glacial acetic acid - 10 ml 3. Distilled water - 90 ml Filter if cloudy, add a race of potassium oxalate The Fuchs- Rosenthal counting chamber is specially meant for CSF cell count in entire ruled area & divide the no. of cells by 3 or multiply by 0.35 to get no. of cells per mm 3

16. Tumor cells, when suspected, should be searched for after staining the smear of the centrifuged deposit with pan - cytokeratin stain . Count is between 10 to 100 cells/mm 3 : In syphilits disease of CNS , encephalitis , anterior poliomyelitis , in chronic degenerative diseases of CNS. Count is between 100 to 500 cells/mm 3 : In lymphocytic choriomeningitis , syphilitic meningitis , TB meningitis , aseptic meningitis , acute poliomyelitis , brain tumors . Count is over 500 cells/mm 3 : Count of 1000 or more with predominance of lymphocytes found in late TB meningitis , poliomyelitis , pyogenic meningitis , influenzal meningitis , brain abscess , etc.

17. TRANSPORT OF CSF CSF specimens should be transported to a microbiology laboratory as soon as possible. Specimens for culture should not be refrigerated or exposed to extreme cold , excessive heat , or sunlight . They should be transported at temperatures between 20°C and 35°C . For proper culture results, CSF specimens must be plated within 1 hour.

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