Reference range (CSF)

Concentration of sodium, potassium and urea are similar to those found in the plasma.

The normal ranges for some of the other CSF components are:

• glucose - 3.3 to 4.4 mmol/l; normally at least two thirds of the blood glucose levels
• chloride, 122 to 128 mmol/l
• lactate less than 2.8 mmol/l
• pressure less than 200 mm CSF
• protein less than 430 mg/l, with an albumin:globulin ratio of aproximately 8:1
• lymphocytes less than 4 per cubic millimetre. In the neonatal period this figure can be up to 25, and in a bloody tap one extra white cell can be allowed for every 500 red cells.
• polymorphs - none
• pH 7.31

The normal adult CSF volume is about 130 ml.