Cerebrospinal Fluid Interpretation
This document contains information about cerebrospinal fluid (CSF) characteristics, including normal values for components such as volume, color, transparency, pH, and electrolyte levels. It also describes abnormal CSF appearances such as being bright red, xanthochromic, or turbid that can indicate conditions like recent hemorrhage or bacterial infection. Common CSF analytes that are measured are discussed, such as total protein, glucose, and cell counts, and how their levels may be altered in different pathological states including infection, inflammation, and tumors. Overall, the document provides a review of typical CSF findings and how they can help to distinguish between normal, bacterial, viral, tuberculosis, and other neurological conditions.
Cerebrospinal Fluid Interpretation
- 1. 05/08/13 1E. S. MOKGWANE; 4TH YR MED
- 2. CHARECTERISTICS OF NORMAL CSF Total Volume: 150ml Colour: colourless, like water Transparency: clear, like water Osmolality at 37o C: 281mOsm/L Specific Gravity: 1.006 to 1.008 Presure: 80-100 mm H2O 05/08/13 2E. S. MOKGWANE; 4TH YR MED
- 3. ACID-BASE BALANCE pH 7.31 pCO2 47g mmHg HCO3 22g mEq/L Sodium 138 – 150 mEq/L Potassium 2.7 to 3g mEq/L Chloride 116 to 127 mEq/L Calcium 2.0 to 2.5 mEq/L Magnesium 2.0 to 2.5 mEq/L Lactic Acid 1.1 to 2.8 mmol/L 05/08/13 3E. S. MOKGWANE; 4TH YR MED
- 4. APPEARANCE 1. BRIGHT RED •Recent haemorrhage involving the subarachnoid •Damage to a blood vessel during puncture 05/08/13 4E. S. MOKGWANE; 4TH YR MED
- 5. APPERANCE 2. XANTHOCROMIA •Suggests subarachnoid haemorrhage in recent past (days). Rarely Xanthochromia may be due to: • Severe Jaundice • Carotenaemia • Rifampicin 05/08/13 5E. S. MOKGWANE; 4TH YR MED
- 6. APPERANCE 3. TURBID white cells present suggest bacterial infection. 05/08/13 6E. S. MOKGWANE; 4TH YR MED
- 7. APPERANCE 4. PIGMENTS • Oxyhaemoglobin – Released with lysis of red cells detected in the supernatant fluid within 2h after SAH. • Bilirubin – maximum at 48hrs after SAH. 05/08/13 7E. S. MOKGWANE; 4TH YR MED
- 8. TOTAL PROTEIN 0.5% or 1/200 that of plasma Typical reference values for a lumbar tap: Age g/L <1 month <1.9 1-3 months <0.95 3-12 months <0.5 1-10 years <0.4 >10 years <0.7 05/08/13 8E. S. MOKGWANE; 4TH YR MED
- 9. TOTAL PROTEIN IS RAISED IN: 1. Infection (white cells, pus) e.g. bacterial meningitis 2. Blood Contamination 3. Chronic inflammatory diseases of the CNS. 4. Froin’s syndrome 5.Lysis of contaminated blood from traumatic tap 6.Increased permeability of the epithelial membrane 7.Increased production by CNS tissue 05/08/13 9E. S. MOKGWANE; 4TH YR MED
- 10. DECREASED CSF GLUCOSE • Disorder in carrier –mediated transport of glucose into CSF • Active metabolism of glucose by cells or organisms • Increased metabolism by CNS eg Brain tumor, diffuse, meningeal neoplasia. 05/08/13 10E. S. MOKGWANE; 4TH YR MED
- 11. SUMMARY OF A TYPICAL CSF FINDINGS NORMAL BACTERIA VIRAL TB Cells 0-5 >1000 <1000 <500 Polymorphs 0 Predominate Early +/- Increased Lymphocytes 5 Late Predominate Increased Glucose 60-80 Decreased Normal Decreased CSF Plasma: Glucose ratio 66% <40% Normal <30% Protein 5-40 Increased +/- Increased Increased Culture Negative Positive Negative +TB 05/08/13 11E. S. MOKGWANE; 4TH YR MED
- 12. END 05/08/13 12E. S. MOKGWANE; 4TH YR MED