Causes and Clinical Features of Metabolic Acidosis

Renal Causes: Role of the Kidneys in Acid-Base Balance

Metabolic acidosis occurs when there is an excess accumulation of acid in the body or inadequate removal of acid by the kidneys. This condition can significantly impact homeostasis and lead to various clinical manifestations.

Renal Contributions to Acid-Base Balance

The kidneys play a vital role in maintaining acid-base balance by excreting hydrogen ions (H+) and reabsorbing bicarbonate (HCO3-). Dysfunction in renal mechanisms can result in metabolic acidosis.

Causes of Renal-Related Metabolic Acidosis

• Loss of bicarbonate due to proximal tubule dysfunction (e.g., renal tubular acidosis type 2)
• Failure to excrete hydrogen ions in distal tubules (e.g., renal tubular acidosis type 1)
• Impaired ammonium excretion due to chronic kidney disease (CKD)

Clinical Features of Metabolic Acidosis

Patients with metabolic acidosis may exhibit several symptoms and compensatory mechanisms, including:

• Respiratory compensation: Kussmaul breathing (deep, rapid respiration)
• Neurological symptoms: Confusion, lethargy
• Cardiovascular effects: Arrhythmias, hypotension
• Electrolyte imbalances: Hyperkalemia

Diagnosis and Management

Diagnosis involves arterial blood gas analysis, serum electrolytes, and anion gap calculation. Management includes addressing the underlying cause, bicarbonate therapy, and renal support in severe cases.