Causes and Clinical Features of Metabolic Acidosis

Definition and Pathophysiology

Metabolic acidosis is a condition characterized by a decrease in blood pH due to increased acidity or loss of bicarbonate. It occurs due to either excessive acid production or insufficient acid excretion by the kidneys.

Causes of Metabolic Acidosis

• Lactic Acidosis: Caused by tissue hypoxia, sepsis, or prolonged strenuous exercise.
• Ketoacidosis: Common in diabetes mellitus due to uncontrolled glucose metabolism.
• Renal Failure: Leads to accumulation of metabolic acids due to impaired excretion.
• Toxin Ingestion: Methanol, ethylene glycol, and salicylate poisoning can induce metabolic acidosis.
• Diarrhea: Leads to excessive bicarbonate loss from the gastrointestinal tract.

Clinical Features

• Increased respiratory rate (Kussmaul respiration) as a compensatory mechanism.
• Confusion, lethargy, and headache due to acidic disturbance.
• Cardiovascular instability, including hypotension and arrhythmias.
• Electrolyte imbalances such as hyperkalemia.

Diagnosis and Management

Diagnosis involves arterial blood gas analysis, serum electrolyte tests, and identifying underlying causes. Management includes addressing the primary disorder, bicarbonate therapy when necessary, and supportive treatment for symptoms.