Lactic Acidosis Clinical Presentation

Updated: Sep 11, 2020
  • Author: Kyle J Gunnerson, MD; Chief Editor: Michael R Pinsky, MD, CM, Dr(HC), FCCP, FAPS, MCCM  more...
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The onset of acidosis may be rapid (ie, within minutes to hours) or progressive (ie, over a period of several days).

Lactic acidosis frequently occurs during strenuous exercise in healthy people, bearing no consequence. However, development of lactic acidosis in disease states is ominous, often indicating a critical illness of recent onset. Therefore, a careful history should be obtained to evaluate the underlying pathophysiologic cause of shock that contributed to lactic acidosis. Furthermore, a detailed history of ingestion of various prescription drugs or toxins from the patient or a collateral history from the patient's family should be obtained.

The clinical signs and symptoms associated with lactic acidosis are highly dependent on the underlying etiology. No distinctive features are specific for hyperlactatemia.

Lactate acidosis is present in patients who are critically ill from hypovolemic, septic, or cardiogenic shock.

Lactate acidosis always should be suspected in the presence of elevated anion gap metabolic acidosis.

Lactic acidosis is a serious complication of antiretroviral therapy. A history of antiretroviral treatment should be obtained.

Children who have a relatively mild form of congenital lactic acidosis may develop firmament metabolic acidosis during an acute illness such as respiratory infection. These patients have a deficiency in the activity of pyruvate dehydrogenase, and the stress-induced increases in the glycolytic rate may result in severe metabolic acidosis.

D-lactic acidosis, a unique form of lactic acidosis, can occur in patients with jejunoileal bypass or small bowel resection causing short bowel syndrome. In these settings, the glucose and carbohydrates are metabolized in the colon into D-lactic acid, which is absorbed into systemic circulation. The overgrowth of gram-positive anaerobes such as lactobacilli is able to produce lactate from carbohydrates. These patients develop confusion, ataxia, slurred speech, and altered mental status.


Physical Examination

The clinical signs usually indicate tissue hypoperfusion. Severe hypotension, oliguria or aneuria, deteriorating mental status, and tachypnea always are present when the cause of lactic acidosis is tissue hypoxemia.

Clinical signs of impaired tissue perfusion include the following:

  • Hypotension

  • Alteration in sensorium

  • Peripheral vasoconstriction

  • Oliguria

Findings that may be late manifestations of shock and that are relatively insensitive indicators of hypoperfusion are as follows:

  • Tachypnea

  • Hypotension

  • Deteriorating mental status

Kussmaul hyperventilation (deep sighing respiration) may be observed if the severity of the acidosis is sufficient to elicit a degree of respiratory compensation.

Because sepsis accounts for most cases of lactic acidosis, fever (>38.5°C) or hypothermia (35°C) commonly is present in addition to symptoms and signs indicating the organ where the sepsis originated.