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
**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==
==Clinical Features==
*Skin
**Burns
[[File:Hydrofluoric_acid_burn.png|thumb|Hydrofluoric acid burn]]
[[File:Hydrofluoric_acid_burn.png|thumb|Hydrofluoric acid burn]]
*Ophthalmic
*Skin exposure
**Eye pain
**[[Burns]]
**Pain out of proportion to extent of burn
*Ophthalmic exposure
**[[Eye pain]]
**Erythema
**Erythema
*Ingestion
*Ingestion
**N/V
**[[Nausea and vomiting]]
**Abdominal pain
**[[Abdominal pain]]
*Inhalation
*Inhalation
**Shortness of breath
**[[Shortness of breath]]
**Throat pain/burning
**[[Throat pain]]/burning
*Signs/symptoms of [[hypocalcemia]]
*Signs/symptoms of [[hypocalcemia]] and [[hypomagnesemia]]
*Onset and severity of symptoms correlated w/ concentration
**Can lead to QTc interval prolongation and cardiac arrhythmias, the primary cause of death in HF burns
**Dilute solutions (<20%) may have delayed onset up to 24hr post-exposure
**Moderate solutions (20-50%) develop symptoms w/in 1-8hr
**Concentrated solutions (>50%) develop symptoms immediately
***These pts are at highest risk for systemic toxicity/death
***Pain immediately (even if wound appears minor) implies severe injury
*Burn itself is usually relatively minor
*Toxicity caused by binding of calcium


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


==Diagnosis==
==Evaluation==
*Trend calcium and potassium levels
*Clinical diagnosis
**HF acid chelates calcium and poisons the Na+/K+ pump
*Trend calcium, magnesium, and potassium levels
**Order serial chemistries, EKGs
**Hydrofluoric acid chelates calcium and poisons the Na+/K+ pump
**Expect [[hypocalcemia]] and [[hyperkalemia]]
**Expect [[hypocalcemia]], [[hypomagnesemia]], and [[hyperkalemia]]
*Obtain other electrolytes including magnesium
*Monitor EKG for signs of electrolyte abnormality
**Can get [[hypomagnesemia]]
**[[QTc prolongation]]
**[[Ventricular tachycardia]]


==Management==
==Management==
===Minor injuries (<50 cm2 from dilute solutions <20%)===
*Decontamination: remove soiled clothing and irrigate thoroughly.
*Copious irrigation
*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
*Application of gel paste of Ca gluconate or benzalkonium Cl
**Rub into affected area for 10-15min w/ pain relief being used as end-point of tx
**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 w/ 150mL water-soluble lubricant OR
***Mix calcium gluconate powder 3.5gm with 150mL water-soluble lubricant '''OR'''
***Mix 25mL 10% calcium gluconate solution w/ 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
**If calcium gluconate is not available calcium chloride can be used
**If calcium gluconate is not available calcium chloride can be used


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


===Refractory injuries===
====Refractory injuries====
*Treat w/ intra-arterial infusion of calcium gluconate
*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 10mL of 10% Ca gluconate dilued in 40mL of NS or D5water over 4 hr
**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===
===Ingestion===
*If <1hr of ingestion place NG tube, suction, gastric lavage
*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
**Provide aggressive IV supplementation if ECG signs of hypoCa or hyperK
*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


===[[Hyperkalemia]] and [[Hypocalcemia]]===
==Disposition==
*Treat medically as needed
*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==
==See Also==
*[[Caustics]]
*[[Caustics]]
*[[Burn]]


==References==
==References==
<references/>
<references/>


[[Category:Tox]]
[[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

Hydrofluoric acid burn

Differential Diagnosis

Caustic Burns

Evaluation

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

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

References

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