Compensated respiratory acidosis

In a compensated respiratory acidosis, although the PCO₂ is high, the pH is within normal range. The kidneys compensate for a respiratory acidosis by tubular cells reabsorbing more HCO₃ from the tubular fluid, collecting duct cells secreting more H+ and generating more HCO₃, and ammoniagenesis leading to increased formation of the NH3 buffer. Compensated respiratory acidosis is typically the result of a chronic condition, the slow nature of onset giving the kidneys time to compensate.

• Common causes of respiratory acidosis include hypoventilation due to:
• Respiratory depression (sedatives, narcotics, CVA, etc.) Respiratory muscle paralysis (spinal cord injury, Guillan-Barre, residual paralytics).
• Chest wall disorders (flail chest, pneumothorax) Lung parenchyma disorders (ARDS, pneumonia, COPD, CHF, aspiration)
• Abdominal distension (laporoscopic surgery, ascites, obesity, etc.).