Differential Diagnosis for Metabolic Acidosis with Intestinal Fistula
- Single most likely diagnosis
- Hyperchloraemic metabolic acidosis: This condition is characterized by a low bicarbonate (HCO3) level and a high chloride level, often seen in patients with intestinal fistulas. The loss of bicarbonate-rich intestinal secretions can lead to a hyperchloraemic metabolic acidosis.
- Other Likely diagnoses
- Intestinal fistula: While the intestinal fistula itself is not a diagnosis but rather a given condition in the scenario, its presence can lead to various complications, including metabolic acidosis due to the loss of bicarbonate and other electrolytes.
- Hypovolaemic shock: This can occur due to fluid loss from the intestinal fistula, leading to decreased perfusion of tissues and potentially contributing to lactic acidosis, a form of metabolic acidosis.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
- Diabetic ketoacidosis (DKA): Although less directly related to intestinal fistulas, DKA is a critical cause of metabolic acidosis that must be considered, especially if the patient has diabetes or is at risk for developing diabetes.
- Lactic acidosis due to sepsis: Sepsis can arise from the intestinal fistula, especially if there is an infection. Lactic acidosis is a serious condition that requires prompt recognition and treatment.
- Rare diagnoses
- Renal tubular acidosis (RTA): While less common, certain types of RTA can present with metabolic acidosis and hypokalemia. The presence of an intestinal fistula might complicate the diagnosis, but RTA should be considered if other causes are ruled out.
- Inborn errors of metabolism: In rare cases, especially if the patient is younger, inborn errors of metabolism can cause metabolic acidosis. These conditions are less likely but critical to diagnose due to their potential for severe outcomes if not properly managed.