Metabolic Acidosis Clinical Presentation

Updated: Sep 13, 2022
  • Author: Christie P Thomas, MBBS, FRCP, FASN, FAHA; Chief Editor: Vecihi Batuman, MD, FASN  more...
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Symptoms of metabolic acidosis are not specific. The respiratory center in the brainstem is stimulated, and hyperventilation develops in an effort to compensate for the acidosis. As a result, patients may report varying degrees of dyspnea. Patients may also report chest pain, palpitations, headache, confusion, generalized weakness, and bone pain. Patients, especially children, also may present with nausea, vomiting, and decreased appetite.

The clinical history in metabolic acidosis is helpful in establishing the etiology when symptoms relate to the underlying disorder. The age of onset and a family history of acidosis may point to inherited disorders, which usually start during childhood. Important points in the history include the following:

  • Diarrhea - Gastrointestinal (GI) losses of HCO 3 -
  • History of diabetes mellitus, alcoholism, or prolonged starvation - Accumulation of ketoacids
  • Polyuria, increased thirst, epigastric pain, vomiting - Diabetic ketoacidosis (DKA)
  • Nocturia, polyuria, pruritus, and anorexia - Kidney failure [14]
  • Ingestion of drugs or toxins - Salicylates, acetazolamide, cyclosporine, ethylene glycol, methanol, metformin, topiramate
  • Visual symptoms, including dimming, photophobia, scotomata - Methanol ingestion
  • Renal stones - Renal tubular acidosis (RTA) or chronic diarrhea
  • Tinnitus, blurred vision, and vertigo - Salicylate overdose

Physical Examination

The best recognized sign of metabolic acidosis is Kussmaul respirations, a form of hyperventilation that serves to increase minute ventilatory volume. This is characterized by an increase in tidal volume rather than respiratory rate and is appreciated as deliberate, slow, deep breathing.

Chronic metabolic acidosis in children may be associated with stunted growth and rickets.

Coma and hypotension have been reported with acute severe metabolic acidosis.

Other physical signs of metabolic acidosis are not specific and depend on the underlying cause. Some examples include xerosis, scratch marks on the skin, pallor, drowsiness, fetor, asterixis, and pericardial rub for kidney failure, as well as reduced skin turgor, dry mucous membranes, and fruity breath odor for DKA.