Organic aciduria in hypoxic premature newborns simulating an inborn error of metabolism

A very unusual pattern of organic acid excretion was established in the urine of two premature newborns with severe respiratory distress and cerebral haemorrhages. By combined gas chromatography/mass spectrometry the following acids were identified: lactic acid, alpha-hydroxy-butyric acid, beta-hydroxy-butyric acid, alpha-hydroxy-isovaleric acid, and p-hydroxy-phenyllactic acid. Calculation of the concentration revealed an excessive excretion of lactic acid and also very high excretion of the other acids. A postmortem blood sample from one of the patients revealed a comparable pattern. The abnormal urinary organic acid excretion pattern was most probably caused by severe tissue hypoxia.