Ver el código de «Hydrofluoric acid»

==Background==
*Used in both commercial and home setting<ref>Cheong H, Kim J. Fatal hydrofluoric acid poisoning: histologic findings and review of the literature. Forensic Sci Med Pathol. 2023 Mar;19(1):67-71. PMID 36334175</ref>
**Rust remover (most common home use)
**Glass etching, chrome and other metal cleaning, petroleum processing
*Oral ingestion has very high mortality rate
*Onset and severity of symptoms correlated with concentration
**Dilute solutions (<20%) may have delayed onset up to 24hr post-exposure
**Moderate solutions (20-50%) develop symptoms within 1-8hr
**Concentrated solutions (>50%) develop symptoms immediately
***These patients are at highest risk for systemic toxicity/death
***Pain immediately (even if wound appears minor) implies severe injury
*Burn itself may appear relatively minor
*Toxicity caused by binding of calcium and magnesium leading to electrolyte derangement and myocardial dysfunction<ref>McKee D, et al. A review of hydrofluoric acid burn management. Plast Surg (Oakv). 2014 Summer;22(2):95-8. PMID 25114621</ref>

==Clinical Features==
[[File:HF burned hands.jpg|thumb|Hydrofluoric acid (HF) burns, which were not evident until a day after exposure.]]
[[File:Hydrofluoric_acid_burn.png|thumb|Hydrofluoric acid burn]]
*Skin exposure
**[[Burns]]
**Pain out of proportion to extent of burn
*Ophthalmic exposure
**[[Eye pain]]
**Erythema
*Ingestion
**[[Nausea and vomiting]]
**[[Abdominal pain]]
*Inhalation
**[[Shortness of breath]]
**[[Throat pain]]/burning
*Signs/symptoms of [[hypocalcemia]] and  [[hypomagnesemia]]
**Can lead to QTc interval prolongation and cardiac arrhythmias, the primary cause of death in HF burns

==Differential Diagnosis==
{{Caustic burn types}}

==Evaluation==
*Clinical diagnosis
*Trend calcium, magnesium, and potassium levels
**Hydrofluoric acid chelates calcium and poisons the Na+/K+ pump
**Expect [[hypocalcemia]], [[hypomagnesemia]], and [[hyperkalemia]]
*Monitor EKG for signs of electrolyte abnormality
**[[QTc prolongation]]
**[[Ventricular tachycardia]]

==Management==
*Decontamination: remove soiled clothing and irrigate thoroughly. 
*Mainstay of treatment is application of calcium to affected area.

===Cutaneous Burns===
====Minor injuries (<50 cm2 from dilute solutions <20%)====
*Application of gel paste of Ca gluconate or benzalkonium Cl
**Rub into affected area for 10-15min with pain relief being used as end-point of treatment
**Calcium gel is commercially available (found in industrial first-aid kits)
**Calcium gel can be made:
***Mix calcium gluconate powder 3.5gm with 150mL water-soluble lubricant (KY-Jelly) '''OR'''
***Mix 25mL 10% calcium gluconate solution with 75mL water-soluble lubricant (KY-Jelly)
**Benzalkonium Cl is commercially available
**If calcium gluconate is not available calcium chloride can be used

====Severe injuries====
*Treat with intradermal injections of 5% calcium gluconate
**Prepare by diluting conventional 10% Ca gluconate with sterile NS in 1:1 ratio
**Inject in and around the burned area in amount not to exceed 0.5mL per cm2

====Refractory injuries====
*Treat with intravenous infusion of calcium gluconate using Bier block
**Place tourniquet proximal to exposure site on affected extremity and inject though IV distal to tourniquet
**Inject 10 mL of 10% Ca gluconate diluted in 40 mL of saline and remove tourniquet after 20 min of dwell time
*In severe refractory cases may also infuse intra-arterial calcium gluconate
**Deliver via arterial line placed proximal to injury in the same limb
**Infuse 10 mL of 10% Ca gluconate diluted in 40mL of saline over 4 hr

===Ocular burns===
*Irrigate with saline for at least 5 min
*If persistent pain administer 1% calcium gluconate to eye (dilute 10% calcium gluconate with normal saline)
**Consult ophthalmology due to irritation effect of calcium salts to eye

===Ingestion===
*If <1hr of ingestion, may consider NG tube for suction and gastric lavage
**Follow lavage by 300mL 10% Ca gluconate down NGT
*Consider intubation for airway protection

===Inhalation===
*Consider in any patient with facial burns or exposure to HF in confined space
*Oxygen via NRB
*Nebulized 2.5% calcium gluconate
*Intubation may be required in severe cases

===Systemic toxicity===
*Administer [[calcium gluconate]] 100mg IV (10 mL of a 10% solution) over 2-3 minutes 
*May also need to replete [[magnesium]] (4g IV over 20 minutes)
*May see [[QTc prolongation]], [[cardiac arrhythmia]], or obvious systemic illness
*Treat [[hyperkalemia]] as needed


==Medication Dosing==
{{MedicationDose
| drug = Calcium gluconate
| dose = Topical gel (3.5g powder in 150mL lubricant or 25mL 10% soln in 75mL lubricant)
| route = Topical
| context = Minor cutaneous burns (<50 cm2 from <20% solutions)
| indication = Hydrofluoric acid
| population = Adult
| notes = Rub into affected area 10-15min; pain relief is treatment endpoint
}}
{{MedicationDose
| drug = Calcium gluconate
| dose = 5% intradermal injection (max 0.5mL/cm2)
| route = Intradermal
| context = Severe cutaneous burns
| indication = Hydrofluoric acid
| population = Adult
| notes = Dilute 10% calcium gluconate 1:1 with sterile NS
}}
{{MedicationDose
| drug = Calcium gluconate
| dose = 10mL of 10% in 40mL NS via Bier block (20min dwell time)
| route = IV regional (Bier block)
| context = Refractory cutaneous burns
| indication = Hydrofluoric acid
| population = Adult
}}

==Disposition==
*Consultation with poison center and burn center transfer per [[Burn center criteria]]
*Admission for all patients with arrhythmia on ECG or severe electrolyte disturbance

==See Also==
*[[Caustics]]
*[[Burn]]

==References==
<references/>

[[Category:Toxicology]]