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Approach to the child with metabolic acidosis

Kanwal Kher, MD, MBA
Matthew Sharron, MD
Section Editor
Tej K Mattoo, MD, DCH, FRCP
Deputy Editor
Melanie S Kim, MD


Infants and children with metabolic acidosis can present with varying degrees of acute and chronic illness that range from a seemingly healthy child to one in a catastrophic clinical state. Metabolic acidosis results from an underlying primary disease or a disorder. Consequently, a careful history and physical examination is required to diagnosis the underlying condition and direct appropriate evaluation and treatment of the pathophysiologic events that result in metabolic acidosis.

An approach to the physiology, diagnosis, and treatment of metabolic acidosis in children will be reviewed in this topic. Metabolic acidosis in adults is discussed separately. (See "Approach to the adult with metabolic acidosis".)


Acidosis is defined as an arterial pH below the normal range (<7.36). Acidosis is a manifestation of an underlying disease state. Acidosis can result from a clinical state that lowers the extracellular fluid pH (increase in hydrogen ion concentration) by one of two mechanisms:

Metabolic acidosis due to a fall in serum bicarbonate (HCO3-) concentration

Respiratory acidosis due to an elevation in arterial partial pressure of carbon dioxide (PaCO2) concentration

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Literature review current through: Sep 2017. | This topic last updated: Jul 05, 2016.
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