From the Guidelines
Nausea, vomiting, and diarrhea commonly result in metabolic acidosis with a non-anion gap, specifically due to bicarbonate loss, as evidenced by the loss of bicarbonate-rich fluids from the gastrointestinal tract 1. When a person experiences prolonged vomiting, they lose gastric acid but also develop paradoxical acidosis due to volume depletion and subsequent kidney bicarbonate wasting.
- Diarrhea directly causes bicarbonate loss from the gastrointestinal tract, leading to non-anion gap metabolic acidosis.
- Severe dehydration from these symptoms can cause hypoperfusion, leading to lactic acidosis as tissues switch to anaerobic metabolism. The study by the espen expert group 1 highlights the importance of maintaining fluid and electrolyte balance, and the potential consequences of fluid overload or deficit, including the development of hyperchloremic acidosis.
- Treatment focuses on fluid resuscitation with isotonic solutions containing bicarbonate precursors, addressing the underlying cause, and monitoring electrolytes.
- In severe cases, direct bicarbonate supplementation may be necessary, as the body's compensatory mechanisms, such as increased respiratory rate and renal retention of bicarbonate, can be overwhelmed in severe or prolonged cases of gastrointestinal fluid loss. It is essential to note that the management of metabolic acidosis resulting from nausea, vomiting, and diarrhea should prioritize the correction of fluid and electrolyte imbalances, as well as the treatment of the underlying cause, to prevent further complications and improve patient outcomes 1.
From the Research
Metabolic Acidosis Resulting from Nausea, Vomiting, and Diarrhea
- Nausea, vomiting, and diarrhea can lead to metabolic acidosis, but the type of acidosis resulting from these conditions is not always straightforward.
- According to 2, diarrhea can cause loss of large quantities of base, leading to acute non-anion gap metabolic acidosis, also known as hyperchloremic acidosis.
- However, 3 describes a case where a patient presented with severe vomiting, which would typically be expected to cause metabolic alkalosis, but instead had metabolic acidosis.
- The type of metabolic acidosis resulting from nausea, vomiting, and diarrhea can be classified into two main subtypes: high anion gap metabolic acidosis and normal anion gap (or hyperchloremic) metabolic acidosis, as mentioned in 4.
- Hyperchloremic normal gap metabolic acidosis can occur due to extrarenal processes, such as increased endogenous acid production and accelerated loss of bicarbonate from the body, as described in 5.
- In the context of nausea, vomiting, and diarrhea, the loss of bicarbonate-rich fluids can lead to a hyperchloremic normal gap metabolic acidosis, as the body tries to compensate for the loss of bicarbonate by increasing chloride reabsorption, resulting in an increased chloride concentration in the blood, as mentioned in 2 and 5.