II. Background
- Hydrofluoric Acid Industrial Uses
- Electroplating
- Glass Etching
- Rust Removal
- Brick Cleaning
- Semiconductor Manufacturing
- Mechanism of Injury
- Skin contact injury results in both local Burn Injury from Hydrogen Ions
- Systemic effects occur due to fluoride ion movement from weak surface acids to deep spaces (subcutaneous fat, vessels, nerves)
- Results in liquefaction necrosis
- Myocardial toxicity via increased cAMP (risk of refractory Ventricular Fibrillation)
- Fluoride chelates Calcium and Magnesium
- Results in Hypocalcemia and Hypomagnesemia
- Other Electrolyte abnormalities
III. Symptoms
- Onset of symptoms within hours to 24 hours after exposure
- Local vasospasm (pallor)
- Pain out of proportion
IV. Signs
- Cardiovascular
- Neurologic
V. Grading: Indications of Significant Hydrofluoric Acid Exposure
- Hydrofluoric Acid concentration >50% and burn of any size
- Hydrofluoric Acid burn affecting >5% Body Surface Area (BSA)
- Hydrofluoric Acid injury to the eyes, face, genitalia or mucosa
- Ingestion of Hydrofluoric Acid
- Inhalation Injury associated with Hydrofluoric Acid
VI. Labs
- Basic Metabolic Panel
- Serum Magnesium and Serum Phosphorus
- Suspected myocardial injury
- Serum Troponin
- N-Terminal BNP
VII. Diagnostics
-
Electrocardiogram (EKG) Findings of HFA-related Myocardial Effects (esp. Electrolyte abnormalities)
- Prolonged QRS interval
- Prolonged PR Interval (first degree AV Block)
- QTc Prolongation
- T Wave Inversion or Peaked T Waves
- ST Segment Elevation or depression
VIII. Management
-
General
- Personal Protective Equipment for all with patient contact
- ABC Management and evaluate for hemodynamic stability
- Early Consultation with poison control
- Burn Center coordination for any significant Burn Injury
-
Decontamination
- Remove all clothing
- Copious Irrigation of contaminated regions
- Use saline or water for continuous 20 minute flush of burn area
- Saline and water have equivalent efficacy to chelating agents
- Antidote
- Topical Calcium Gluconate 2.5% gel
- Preprepared or mix 1 gram of 10% Calcium Gluconate IV solution in lubricant jelly
- Apply to all areas of Burn Injury to neutralize acid
- Calcium Gluconate in contact with Hydrofluoric Acid will form white Calcium fluoride crystals
- Replace the topical solution or gel every 15-30 minutes (after it has turned to a white color)
- Hand burns may be inserted into a Calcium Gluconate filled HFA-resistant glove
- Expect pain relief after serial applications of Calcium Gluconate (except in severe deep burns)
- Advanced measures for severe refractory cases
- Parenteral Calcium Gluconate (controversial)
- Subcutaneous into affected region
- Intravenously via regional block at affected area
- Distal arterial injection (e.g. radial artery, dorsalis pedis artery)
- Burn Center or Surgical Interventions
- Vasodilator infusion (e.g. alprostadil)
- Escharotomy
- Parenteral Calcium Gluconate (controversial)
- Topical Calcium Gluconate 2.5% gel
- Monitoring of severe exposure
- Vital Signs for hemodynamic instability
- Telemetry and serial EKG as needed
- Electrolyte abnormalities
- Renal dysfunction
- Hemodialysis may be needed in severe Poisonings for Renal Failure (not for HFA removal)
IX. Complications
- Congestive Heart Failure
- Chronic Kidney Disease
- Fluoride-induced osteolysis
X. References
- Kinker and Glauser (2021) Crit Dec Emerg Med 35(9): 19-27