23/10/2025
Acidosis
Definition:
Acidosis is a condition characterized by an abnormal increase in the acidity (decrease in pH) of blood and other body tissues. It is categorized as:
• Metabolic acidosis: Decreased bicarbonate (HCO₃⁻) and low pH.
• Respiratory acidosis: Increased CO₂ (carbon dioxide) due to hypoventilation.
Symptoms:
• Nausea, vomiting
• Fatigue, lethargy
• Rapid breathing (especially in metabolic acidosis)
• Confusion or altered mental status
• Headache
• Cardiac arrhythmias (in severe cases)
Diagnosis:
• Arterial blood gas (ABG):
• pH < 7.35
• Metabolic acidosis: ↓ HCO₃⁻
• Respiratory acidosis: ↑ PaCO₂
• Serum electrolytes: Anion gap calculation
• Urinalysis: May show acid-base abnormalities (especially in renal causes)
Differential Diagnosis:
• For metabolic acidosis:
• Diabetic ketoacidosis (DKA)
• Lactic acidosis
• Renal failure
• Toxin ingestion (e.g., methanol, ethylene glycol)
• Diarrhea (loss of bicarbonate)
• For respiratory acidosis:
• Chronic obstructive pulmonary disease (COPD)
• Respiratory depression (e.g., opioids, neuromuscular disease)
• Obstructive sleep apnea
Treatment:
• Identify and treat the underlying cause
• DKA → insulin and fluids
• Sepsis/lactic acidosis → antibiotics, fluid resuscitation
• COPD exacerbation → bronchodilators, steroids, oxygen
• Sodium bicarbonate may be considered in severe metabolic acidosis (controversial)
• Ventilatory support for respiratory acidosis
Follow-Up:
• Monitor ABGs, serum electrolytes, and clinical status
• Address chronic causes (e.g., dialysis in chronic renal failure)
• Educate patient on triggers (e.g., medication adherence in COPD, glycemic control in diabetes)
