Paradoxical metabolic acidosis after vomiting in children with spinal muscular atrophy: A report of 9 patients.

Background: Spinal muscular atrophy (SMA) is a hereditary neuromuscular disease that progresses toward restrictive respiratory failure due to muscle paralysis. We observed that SMA patients presented with a specific clinical and laboratory profile, consisting of severe metabolic acidosis following an episode of mild vomiting. This is an unusual, little-known, and life-threatening situation for these patients, as hyperventilation induced by metabolic acidosis can lead to exhaustion and to death by mixed acidosis.