Hydrogen fluoride toxicity: Difference between revisions
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==Background== | ==Background== | ||
*Hydrogen fluoride (HF) is a byproduct of standard fire suppression systems.<ref>JOINT TRAUMA SYSTEM CLINICAL PRACTICE GUIDELINE (CPG ID: 12)</ref> | *Hydrogen fluoride (HF) is a byproduct of standard fire suppression systems.<ref>JOINT TRAUMA SYSTEM CLINICAL PRACTICE GUIDELINE (CPG ID: 12)</ref> It is also used as rust remover and in glass etching, metal cleaning, and 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== | ==Clinical Features== | ||
*Exposure to HF may result in rapidly progressive or fatal respiratory failure despite minimal external evidence of injury. <ref>JOINT TRAUMA SYSTEM CLINICAL PRACTICE GUIDELINE (CPG ID: 12)</ref> | *Exposure to HF may result in rapidly progressive or fatal [[respiratory failure]] despite minimal external evidence of injury. <ref>JOINT TRAUMA SYSTEM CLINICAL PRACTICE GUIDELINE (CPG ID: 12)</ref> | ||
*Symptoms include shortness of breath, cough, or hypoxia; there must be a high level of suspicion for HF inhalation.<ref>JOINT TRAUMA SYSTEM CLINICAL PRACTICE GUIDELINE (CPG ID: 12)</ref> | *Symptoms include [[shortness of breath]], [[cough]], or [[hypoxia]]; there must be a high level of suspicion for HF inhalation.<ref>JOINT TRAUMA SYSTEM CLINICAL PRACTICE GUIDELINE (CPG ID: 12)</ref> | ||
==Differential Diagnosis== | ==Differential Diagnosis== | ||
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==Evaluation== | ==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== | ==Management== | ||
* | *Decontamination: remove soiled clothing and irrigate thoroughly. | ||
**If | *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== | ==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 | |||
==Complications== | ==Complications== | ||
* | *Broncho[[pneumonia]] can develop within a week.<ref>JOINT TRAUMA SYSTEM CLINICAL PRACTICE GUIDELINE (CPG ID: 12)</ref> | ||
==See Also== | ==See Also== | ||
*[[Burns]] | *[[Burns]] | ||
*[[Caustics]] | |||
==External Links== | ==External Links== | ||
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==References== | ==References== | ||
<references/> | <references/> | ||
[[Category:Toxicology]] | |||
Latest revision as of 17:19, 25 October 2020
Background
- Hydrogen fluoride (HF) is a byproduct of standard fire suppression systems.[1] It is also used as rust remover and in glass etching, metal cleaning, and 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
- Exposure to HF may result in rapidly progressive or fatal respiratory failure despite minimal external evidence of injury. [2]
- Symptoms include shortness of breath, cough, or hypoxia; there must be a high level of suspicion for HF inhalation.[3]
Differential Diagnosis
Burns
- Smoke inhalation injury (airway compromise)
- Chemical injury
- Acrolein
- Hydrochloric acid
- Tuolene diisocyanate
- Nitrogen dioxide
- Systemic chemical injury
- Specific types of burns
- Associated toxicities
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