Respiratory Acidosis

Causes

• Decreased respiratory drive
  • CNS:
    • CVA, tumour, infection (encephalitis), haemorrhage
  • Drugs
    • Narcotics and sedatives
• Decreased chest wall movement
  • Neurological
    • NM disorders, Guillain-Barre
    • Myasthenia gravis, demyelinating disorders
    • Tetanus
  • Toxicity
    • Muscle relaxants, Organophosphates, fentanyl
  • Respiratory (Acute)
    • Trauma, surgery, chest wall deformity
    • Tension pneumothorax, pleural effusion
    • Upper airway obstruction
  • Equipment
    • Increased dead space, improper connection
• Obstructive pulmonary disease (chronic)
  • COPD, asthma, pneumonia

Clinical

• Vasodilation, sweaty, tachycardic, mydriasis, asterixis
• Confusion
• Drowsy and ALOC

Correction

• Renal compensation is slow and requires ventilatory changes for treatment
• Increase alveolar minute ventilation

NOTE:

• Usually the rise in pCO2 will stimulate the respiratory centre to increase minute volume.
• If this fails then rapid rise in pCO2 with sedation and failure of respiratory drive and death