odhydroflouricacid
Table of Contents
hydroflouric acid poisoning or burns
see also:
introduction
- hydrofluoric acid exposure can occur through oral, inhalation, ocular or dermal exposure.
- Industrial HF preparations may have concentrations of up to 100%.
- Domestic solutions contain generally less than 15% HF.
- Dermal exposure to any concentration of HF can cause severe, delayed pain and liquefactive necrosis.
- Ingestion can cause local corrosive effects to the GIT, and systemic fluorosis can manifest suddenly with refractory ventricular dysrhythmias and cardiac arrest.
- Life threatening fluorosis occurs with dermal exposure of 100% HF to 2.5% BSA, 70% HF to 8% BSA, 23% HF to 11% BSA and ingestion of 100ml or more of 6% HF or any quantity of higher concentrations.
- Children who ingest any quantity of HF are at risk of lethal toxicity.
mechanism of toxicity
- local corrosive activity (liquefactive necrosis)
- dissociated fluoride ions
- fluoride ions will bind with calcium and magnesium ions causing profound hypocalcaemia and hypomagnesaemia with subsequent tetany and QT prolongation.
- potassium channels are also affected causing potassium efflux out of cells leading to hyperkalaemia.
- in conjunction, there may be cell lysis and release of intracellular potassium from the exposure site, contributing to existing metabolic acidosis and hyperkalaemia.
- hydrofluoric acid (HF) does not appear to have a direct effect on sodium channels.
Mx
- staff must don chemical protective PPE
- rapid assessment
- assessment and management life-threating conditions such as airway compromise or cardiac arrythmias
- burns larger than 160 square cm may result in serious systemic toxicity
- inhalational injuries or those with burns greater than 25 square cm should be admitted to an intensive care unit and carefully monitored for 24 to 48 hours
- in some cases, haemodialysis is necessary for fluoride removal and correction of hyperkalemia and recurrent hypocalcemi
- high inhaled concentrations may cause glossitis (obstruction of the airway) and acute pulmonary edema
- may need supplmental oxyufen, NIV, nebulised calcium gluconate and/or intubation or surgical airway
- cardiac monitoring and ECGs
- QT prolongation from hypocalcemia
- peaked T waves/arrhythmias from hyperkalemia
- polymorphic ventricular tachycardia (specifically Torsades de Pointes) from hypomagnesia
- regularly check U&Es, Ca, Po4, flouride levels
- removal of contaminated clothing
- as well as jewellery that could trap HF, should be immediately removed and double-bagged to prevent secondary exposure
- decontamination
- copious amounts of water, saline or solution of soap and water
- using a soft brush, moving in a downward motion (from head to toe) with household dish soaps (Dawn, Palmolive) and water, with a pH value of at least 8 and should not exceed a pH value of 10.5
- thorough rinsing
- initial treatment for eye exposure includes irrigation with large amount of gently flowing cool plain water or sterile 0.9 % saline solution for 15-30 minutes
- topical ophthalmic anesthetic solution can be used
- neutralization
- calcium gluconate
- topical use of calcium gluconate gel (2.5%)
- applied and rubbed into the affected area for 15 - 30 minutes and should be reapplied every 10 - 15 minutes
- will turn white as the calcium binds to the fluoride ions creating calcium fluoride (CaF2)
- if used as a definitive treatment, should be applied 4 to 6 times daily, for 3 to 4 days.
- if pain persists after 30 minutes of treatment, subcutaneous infiltration of calcium gluconate is generally recommended at a dose of 0.5 mL of a 5% solution per square centimeter of surface burn extending 0.5 cm beyond the margin of involved tissue
- to minimise compartment syndrome issues, injections into the hand should be limited to 0.5 ml per phalanx with repeat injections as needed
- ocular use
- ofter initial decontamination of the eye, intermittent irrigation using a sterile 1% calcium gluconate solution via a Morgan lens for 20 minutes
- consider also hexaflourine
- 2.5% to 3% calcium gluconate nebulized solution
- consider for those with inhalational injury
- additional possible topical agents:
- benzalkonium chloride
- iced solution of benzalkonium chloride (Zephiran Chloride) concentration of (0.13%)
- side effects include stinging pain or allergic reaction (urticaria, pruritus, dyspnea, chest tightness, swelling of the face, lips or tongue)
- polyethelene glycol
- magnesium oxide
- Hexafluorine
- developed by PREVOR laboratories was designed for active washing of hydrofluoric acid splashes
- triple effect in that it has the same rinsing and diluting properties as water, can neutralize the hydrogen ions and chelate the fluoride ions
odhydroflouricacid.txt · Last modified: 2023/03/23 00:41 by wh