acidoseihin

Acidosis is a medical condition in which the body's pH falls below the normal range (pH < 7.35). It results from an excess of hydrogen ions or a loss of bicarbonate and can arise from disturbances in respiratory function, metabolic processes, or both. Diagnosis typically relies on arterial blood gas measurements that report pH, PaCO2, and bicarbonate (HCO3−).

Two principal categories are respiratory acidosis and metabolic acidosis. Respiratory acidosis occurs when ventilation is insufficient to eliminate CO2, leading to elevated PaCO2 and increased hydrogen ion concentration. Metabolic acidosis results from bicarbonate loss or accumulation of non-volatile acids, lowering bicarbonate and pH. Mixed forms are possible.

Common causes of respiratory acidosis include airway obstruction, central nervous system depression, neuromuscular disorders, pneumonia, COPD, and severe asthma. Metabolic acidosis can follow lactic acidosis from shock or sepsis, diabetic or alcoholic ketoacidosis, renal failure, diarrhea, toxins such as methanol or ethylene glycol, and loss of bicarbonate via the gut or kidneys.

Diagnosis uses arterial blood gas and chemistry, including calculation of the anion gap: AG = Na − (Cl + HCO3−). A normal anion gap is typically 8–12 mEq/L. High-AG acidosis points to lactate, ketoacids, or renal failure; normal-AG acidosis suggests bicarbonate loss or renal tubular acidosis.

Treatment targets the underlying cause and stabilization. For respiratory acidosis, improving ventilation through airway support or oxygen therapy is key. For metabolic acidosis, therapy focuses on treating the precipitating condition, correcting electrolyte disturbances, and, in selected cases, bicarbonate administration with careful monitoring. Potassium balance is closely monitored since acidosis affects potassium distribution.

Prognosis depends on the underlying disorder, the severity of acidosis, and the timeliness of treatment. Early recognition and management of the trigger are essential for favorable outcomes.