1. Hydrofluoric Acid Intensive Review Course in Clinical Toxicology 2007 Rama B. Rao

2. Hydrofluoric Acid (HF) Household Glass etching Cleaning bricks and porcelain Rust removal Industrial Leather tanning Electroplating Etching microchips

3. Hydrofluoric Acid pK a 3.5 Weak Acid Permeability coefficient 1.4 x 10 24 cm/sec Concentrations of HF Household (aqueous) 3-40% Industrial (aqueous) >70% Anhydrous HF 100%

4. Pathophysiology Deep penetration of tissues Fluoride binding of divalent cations Calcium Magnesium Alters Calcium dependent Potassium channels

5. Routes of Exposure Dermal Inhalational Oral Ocular

6. HF Clinical Presentation: Local Systemic

7. Systemic HF Hypocalcemia Hypomagnesemia Hyperkalemia Prolonged QT Bleeding Prolonged QT Torsades ECG changes

8. Assessment: Systemic HF Vital signs Mental status ECG Hyperkalemia Peaked T waves Progression to sine waves QT prolongation Ventricular dysrhythmias, ectopy

9. Laboratory Indicators Systemic HF Acidemia Prolonged PT (or bleeding) Electrolytes:  iCa 2+,  Mg 2+,  K +

10. Management Systemic HF Continuous ECG Monitoring 2 + large bore IVs, foley Laboratory: Ca 2+, Mg 2+, electrolytes, CBC Type and Screen PT/PTT ABG or VBG

11. Therapy Systemic HF Restore electrolyte homeostasis Decontamination Enhancement of urinary excretion F - Treatment of dysrhythmias

12. Calcium Cardioprotective, restorative Dosing: 1 gm IV over 5 minutes Titrate to ECG effect May require grams Pediatrics: 20-60 mg/Kg Monitor concentrations

13. Calcium Preparations (10%) Calcium gluconate 0.465 mEq/mL Peripheral lines 60 mg/kg pediatric Calcium chloride 1.36 mEq/mL Central line 20 mg/kg pediatric

14. Magnesium sulfate 20% Adults 20 ml (4 gm) over 20 minutes* Cautious/avoid in renal failure Observe vascular, neurological effects Pediatrics 25-50 mg/kg/dose over 20 minutes

15. NaHCO 3 Urinary alkalinization/Ion trapping F - 1-2 mEq/kg bolus Isotonic drip at 1.5 –2 x maintenance Serum pH 7.5-7.55 No potassium supplementation without absolute indication

16. Dysrhythmias Correct underlying derangements In refractory cases: Amiodarone In vitro Animal models with HF induced hyperkalemia Human data lacking

17. HF Ingestions

18. Readily absorbed High fatality rate Assume all ingestions are systemic exposures

19. HF Ingestions: Clinical Presentation Vomiting Dysrhythmias Rapid deterioration Caustic injury minor

20. HF Decontamination Removal of gastric contents* Careful NGT suction Use caution as provider Delivery cations to GI tract Calcium carbonate Magnesium citrate

21. Inhalational HF Assume exposure with any dermal exposure to the face Burning, stridor Dyspnea Bronchospasm Presume associated systemic and ocular toxicity

22. Inhalational HF Airway management prn Screen for systemic, ocular toxicity Nebulization therapy 2.5 - 5 % Calcium gluconate (Dilution of a 10% solution) Limited data

23. Ocular HF Assume in inhalational exposures Screen for additional facial/systemic exposures Irrigation 1L LR Avoid calcium or magnesium application*

24. Dermal HF Most common presentation Evaluate for systemic toxicity if: Vital sign abnormalities Facial/neck exposures Alteration mental status High concentration solution Large body surface area any concentration

25. Dermal HF Severe pain with few findings Onset pain often related to concentration Concentration of HF (%) Symptoms onset <20May not occur for 12-18 hours 20-50Within 1-8 hours >50Immediate

26. Dermal HF

27. Irrigation with soap and water Topical calcium Sterile water soluble lubricant 3.5 gm CaGluconate powder in 150 mL 25 mL of 10% CaGluconate in 75 mL Can consider calcium carbonate Calcium chloride Consider filling glove if hand exposure

28. Dermal HF Local intradermal injection calcium 0.5 mL/cm 3 of 5% calcium gluconate Distal to injury Limited utility esp in digits

29. Dermal HF Intra-arterial Calcium Hand injuries Careful placement arterial line on AFFECTED side

32. Intra-Arterial Calcium 10 mL of 10% Calcium gluconate in 40 mL D 5 W or NS Infuse over 4 hours Repeat prn Huisman LC, et al. Lancet. 2001;358:1510.

33. Dermal HF Digital blocks useful Single digit/tip Delayed presentations No systemic toxicity “Bier” blocks 25 mL of 2.5% CaGlu Limited utility: tourniquet

34. HF Summary Rapid screening for systemic toxicity Intravascular Calcium administration: Gluconate unless central venous line Adjunctive pain control

35. Acknowledgements Lewis Nelson Susi Vassallo NYCPCC