see also: see: [RCH Hydrofluoric acid exposure](x-devonthink-item://A2B8F577-C7EB-40C1-B33D-53B615CB5EC2), [Murray Hydrofluoric acid](x-devonthink-item://DA1896AC-D57C-4A67-B2C7-65B1D27BB53E?page=269), [Austin Hydrofluoric acid](x-devonthink-item://46CF0796-3A4D-4AE6-B04D-E0FDAD72B4EA) > [!important] Key Points > - **risk_dose**:: >5% BSA (>1% if >50% concentration) > - *update:* 2.5% BSA risk if 100% HF > - **Antidote**:: [[Calcium Gluconate#Hydrofluroic acid injury|Calcium Gluconate]], magnesium, treat hyperkalemia > - **key_points**:: > - [mnemonic::] # Sources - wheel cleaners - rust removers - glass etching # Risk assessment - ==50% HF conc. - risk of systemic fluorosis with BSA >1%== - Any HF concentration with >5% BSA -- risk of [[#Fluorosis (systemic effects)|systemic fluorosis]] > 100 % HF → 2.5% BSA > 70% HF → 8% BSA > 23% HF → 11% BSA > ingestion ≥ 100mL of 6% HF or any volume of higher concentration # Toxic Mechanism Fluoride ions bind directly with calcium and magnesium, and interfere with cellular potassium channels → leads to cell dysfunction and death systemic toxicity and ventricular dysrhythmias 2/2 [[Hypocalcemia|hypo-Ca]], [[hyperkalemia|hyper-K]], [[Hypomagnesemia|hypo-mg]], and acidosis. it is readily absorbed after ingestion or dermal contact; penetrates deeply into tissues to release fluoride ions. # Clinical features ## Dermal exposure - may not be immediately painful if HF concentration <50% → unnoticed for several hours - gradual onset of severe deep unremitting pain at contact site over hours **without obvious erythema or blistering** - pain usually lasts <36 hours - **very large exposures result in systemic fluorosis** ![[Pasted image 20240915225922.png]] ## Inhalation exposure - immediate onset of mucosal irritation followed by delayed dysponea, cough, wheeze - non-cardiac pulm oedema in severe cases ## Ingestion - low concentrations are minimally corrosive to GI tract - ==cardiac arrest from systemic fluorosis may occur without warning 30 min to 6 hours post ingestion== # Fluorosis (systemic effects) - [[Hypocalcemia]] and [[Hypomagnesemia]] manifest as tetany and [[Long QT|prolonged QT]] - risk of [[Torsades de Pointes]] - Ventricular dysrhythmias and cardiac arrest # Treatment **intraarterial calcium gluconate injection** - in severe burns/systemic fluorosis - 10 mL of 10% *calcium gluconate* is diluted in 50 mL of a 5% dextrose and water solution. The dilute solution is administered by slow infusion into an arterial catheter. - Advantages: elimination of the need for painful SQ injections and avoidance of the volume limitations of the SQ route while providing substantially more calcium to neutralize the fluoride. - Disadvantages: possibility of local arterial spasm (which can be treated with vasodilators such as phentolamine or removal of the catheter), local arterial injury or thrombus, and the long duration of treatment required. **bier's block of IV calcium gluconate** - could only do in upper-extremity burns - not very well studied > [!warning] > - Do not give *CALCIUM CHLORIDE* by SC injection, regional IV infusion or arterial infusion as it will cause tissue damage. # Disposition # Mnemonic