Blood lactate is useful in ruling out mitochondrial diseases. Blood gases Patients with urea cycle disorders may be alkalotic due to stimulation of the respiratory drive by ammonia. Patients with urea cycle disorders are rarely acidotic. Severe refractory acidosis suggests organic acid disorder or mitochondrial disorder. Initial management should consist of cessation of protein intake with provision of as many nonprotein calories as practical, by intravenous or oral routes, or both if possible.
More specific therapy depends on the etiology of the hyperammonemia.
The role of the biochemical geneticist is to assist in interpretation of available laboratory tests toward a diagnosis of a specific genetic entity. Treatment must be guided by a professional experienced in the treatment of urea cycle disorders. This may be a biochemical geneticist, clinical geneticist, endocrinologist, or pediatrician depending on the expertise available at a specific institution. The role of the neurologist is to provide a basic status evaluation for later reference during follow-up care. This is especially useful in the primary genetic entities, where recurrence is a virtual certainty together with the risk of additional nervous system compromise.