Hydrofluoric acid (HF)



Background

  • Hydrofluoric acid (HF) is found in industrial cleaning agent for metals / glass or in household rust removing agents.
  • HF is an extremely caustic inorganic acid.

Pathophysiology

  • Fluoride ion penetrates skin and permeates deep tissues (incl. bone).
  • Fluoride binds calcium forming insoluble salts.
  • ↓↓Ca++ in local tissues → cell necrosis.
  • Local tissue death → local K+release irritating nerve endings = pain ++.

Clinical

  • HF burns may present early (severe pain, HF conc. usually >20%) or late.
  • Typically, very intense (± delayed) pain.
  • Systemic toxicity due to ↓Ca++, ↓Mg++, ↑K+ → arrhythmia.

Management

Diphoterine
  1. Manage systemic toxicity.
  2. Local pain control.
  3. Prevention of progressive tissue damage.

Systemic toxicity

  • IV calcium gluconate

Local toxicity / burn

  • Wash (repeatedly) with Diphoterine (cylinder in decontamination room in CUH ED).
  • Topical calcium gluconate.
  • Local Ca++ gluconate infiltration.
  • "Biers block"
    • 10-20 ml Ca++ gluconate diluted to 40ml.
    • Leave cuff inflated for 15 minutes.
    • Early release of cuff may cause flushing, headache, and
      arrhythmia.
  • Intra-arterial Ca++ gluconate.

Content by Dr √ćomhar O' Sullivan 27/04/2011. Last review Dr IOS 18/09/14.