Hydrofluoric acid: Difference between revisions
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**Glass etching, chrome and other metal cleaning, petroleum processing | **Glass etching, chrome and other metal cleaning, petroleum processing | ||
*Oral ingestion has very high mortality rate | *Oral ingestion has very high mortality rate | ||
*Onset and severity of symptoms correlated with concentration | *Onset and severity of symptoms correlated with concentration | ||
**Dilute solutions (<20%) may have delayed onset up to 24hr post-exposure | **Dilute solutions (<20%) may have delayed onset up to 24hr post-exposure | ||
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***These patients are at highest risk for systemic toxicity/death | ***These patients are at highest risk for systemic toxicity/death | ||
***Pain immediately (even if wound appears minor) implies severe injury | ***Pain immediately (even if wound appears minor) implies severe injury | ||
*Burn itself | *Burn itself may appear relatively minor | ||
*Toxicity caused by binding of calcium | *Toxicity caused by binding of calcium and magnesium leading to electrolyte derangement and myocardial dysfunction | ||
==Clinical Features== | |||
[[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== | ==Differential Diagnosis== | ||
{{Caustic burn types}} | {{Caustic burn types}} | ||
== | ==Evaluation== | ||
*Trend calcium and potassium levels | *Clinical diagnosis | ||
** | *Trend calcium, magnesium, and potassium levels | ||
**Hydrofluoric acid chelates calcium and poisons the Na+/K+ pump | |||
**Expect [[hypocalcemia]] and [[hyperkalemia]] | **Expect [[hypocalcemia]], [[hypomagnesemia]], and [[hyperkalemia]] | ||
* | *Monitor EKG for signs of electrolyte abnormality | ||
** | **[[QTc prolongation]] | ||
**[[Ventricular tachycardia]] | |||
==Management== | ==Management== | ||
* | *Decontamination: remove soiled clothing and irrigate thoroughly. | ||
*Mainstay of treatment is application of calcium to affected area. | |||
===Cutaneous Burns=== | ===Cutaneous Burns=== | ||
====Minor injuries (<50 cm2 from dilute solutions <20%)==== | ====Minor injuries (<50 cm2 from dilute solutions <20%)==== | ||
*Application of gel paste of Ca gluconate or benzalkonium Cl | *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 | **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 is commercially available (found in industrial first-aid kits) | ||
**Calcium gel can be made: | **Calcium gel can be made: | ||
***Mix calcium gluconate powder 3.5gm with 150mL water-soluble lubricant OR | ***Mix calcium gluconate powder 3.5gm with 150mL water-soluble lubricant '''OR''' | ||
***Mix 25mL 10% calcium gluconate solution with 75mL water-soluble lubricant | ***Mix 25mL 10% calcium gluconate solution with 75mL water-soluble lubricant | ||
**Benzalkonium Cl is commercially available | **Benzalkonium Cl is commercially available | ||
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====Refractory injuries==== | ====Refractory injuries==== | ||
*Treat with intra-arterial | *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 | **Deliver via arterial line placed proximal to injury in the same limb | ||
**Infuse | **Infuse 10 mL of 10% Ca gluconate diluted in 40mL of saline over 4 hr | ||
===Ocular burns=== | ===Ocular burns=== | ||
*Irrigate with saline for at least 5 min | *Irrigate with saline for at least 5 min | ||
*If persistent pain administer 1% calcium gluconate to eye (dilute 10% calcium gluconate with normal saline) | |||
*If persistent pain administer 1% calcium gluconate to eye | |||
**Consult ophthalmology due to irritation effect of calcium salts to eye | **Consult ophthalmology due to irritation effect of calcium salts to eye | ||
===Ingestion=== | ===Ingestion=== | ||
*If <1hr of ingestion | *If <1hr of ingestion, may consider NG tube for suction and gastric lavage | ||
**Follow lavage by 300mL 10% Ca gluconate down NGT | **Follow lavage by 300mL 10% Ca gluconate down NGT | ||
*Consider intubation for airway protection | |||
===Inhalation=== | ===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=== | ||
*Treat | *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 | |||
==Disposition== | ==Disposition== | ||
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==References== | ==References== | ||
<references/> | <references/> | ||
[[Category:Toxicology]] | [[Category:Toxicology]] |
Revision as of 15:54, 24 March 2020
Background
- Used in both commercial and home setting
- 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
Clinical Features
- Skin exposure
- Burns
- Pain out of proportion to extent of burn
- Ophthalmic exposure
- Eye pain
- Erythema
- Ingestion
- 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 Burns
- Caustic ingestion
- Caustic eye exposure (Caustic keratoconjunctivitis)
- Caustic dermal burn
- Airbag-related burns
- Hydrofluoric acid
- Tar burn
- Cement burn
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
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 OR
- Mix 25mL 10% calcium gluconate solution with 75mL water-soluble lubricant
- 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
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