Cause of CO2 flap

Introduction

• • Brief, arrhythmic interruptions of sustained voluntary muscle contraction causing brief lapses of posture, with a frequency of 3–5 Hz

  • It is bilateral but may be asymmetric

Causes

• • Can be a sign of hepatic encephalopathy

    • Damage to brain cells due to the inability of the liver to metabolize ammonia to urea

    • Thought to be related to abnormal ammonia metabolism.

  • Seen most often in drowsy or stuporous patients with metabolic encephalopathies

    • Especially in decompensated cirrhosis or acute hepatic failure.

  • Also seen in some patients with renal failure and azotemia

  • Also seen in carbon dioxide toxicity

  • Can also be a feature of Wilson's disease

Pathophysiology