When your patient turns blue after you’ve infiltrated lignocaine around their wound…think Methaemoglobinaemia

EMKF #FOAMed
MetHb level (%)   Signs and symptoms
 1-3% (normal)
  • None
 3-15%
  • Low pulse oximetry (<90%)
  • Gray cutaneous coloration
 15-20%
  • Chocolate brown blood
  • Cyanosis
 20-50%
  • Dizziness, syncope
  • Dyspnea
  • Weakness
  • Headache
 50-70%
  • CNS depression, coma, seizure
  • Dysrhythmias
  • Tachypnea
  • Metabolic acidosis
 >70%
  • Death
  • Hypoxic injury

EMKF

Emergency Medicine Kenya Foundation (EMKF) is a not-for-profit (NGO) public benefit organisation registered in Kenya