Lactate:pyruvate ratio in CSF and plasma
Measurement of plasma lactate may be indicated in children presenting with myopathy or neurological signs. A child with a persistently elevated lactate level, not explained by causes such as hypoxia, poor perfusion/shock, fits or liver disease, should be investigated for inborn metabolic disorders. In neurological disorders, lactic acidosis may be confined to the CNS without systemic acidosis and the measurement of CSF lactate is useful. A relatively low pyruvate with a raised lactate (lactate:pyruvate ratio >25) is suggestive of pyruvate carboxylase deficiency or respiratory chain defects.
A child with a persistently elevated lactate level not explained by causes such as hypoxia, poor perfusion/shock, fits or liver disease.
|Sample & container required
|Pyruvate is an unstable intermediate. Samples for lactate:pyruvate ratio must be deproteinised on collection according to the protocol of the referral laboratory.
|Up to 6 weeks
Not currently performed in house; this is a referred test.