Plasma amino acid patterns in respiratory encephalopathy.

Serum amino acid determinations were made in 23 patients with chronic bronchitis presenting with acute respiratory insufficiency both during and after regression of signs of encephalopathy. The ratio of branched chain amino acids to aromatic amino acids was initially significantly lower than normal but returned to normal range when the signs of encephalopathy had disappeared. The modifications observed in amino acid concentrations were similar to those seen in hepatic encephalopathy. The role of the liver in the observed modifications of amino acid levels in respiratory failure is discussed.