View source for Hydrochloric acid

==Background==
[[File:Hydrochloric acid 30 percent.jpg|thumb|Hydrochloric acid]]
[[File:Hydrochloric acid dissociated.svg|thumb|Hydrochloric acid]]
*Strong acid, causes coagulation necrosis due to denaturation of proteins
*Patients may have occupational exposures if working in steel picking, chemical manufacturing, oil/gas-well acidizing, and food processing
*HCl is combustion product of polyvinyl chloride (PVC), can cause chemical [[Smoke inhalation injury|inhalation injury]], can persist in air for up to an hour after fire extinguished

==Clinical Features==
*Can be systemically absorbed and → [[metabolic acidosis]], hemolysis, [[AKI]]
*Dermal [[caustic burns]]
*Ingestion
**All patients with serious esophageal injuries have ''some'' initial sign/symptom
**[[Dysphagia]], odynophagia, [[epigastric pain]], [[vomiting]]
**Laryngotracheal injury: [[dysphonia]], [[stridor]], [[respiratory distress]]
***Occurs via aspiration of caustic or vomitus or inhalation of acidic fumes
*[[Smoke inhalation injury|inhalation injury]]
**PVCs and other [[arrhythmias]]
**Delayed onset (2-12 hours) [[pulmonary edema]]
**[[Dyspnea]], [[chest pain]]
*[[Caustic keratoconjunctivitis]]
**Severe [[eye pain]], blepharospasm, [[vision loss|reduced visual acuity]]
**Altered ocular pH (normal = 7.0-7.2)
**Conjunctival injection '''OR''' blanching, chemosis, hemorrhage, epithelial defects, corneal loss '''OR''' edema, perilimbal ischemia (white ring around iris)

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

==Evaluation==
*Clinical diagnosis
===Work-up===
*Only necessary in patients with significant injury or volume of ingestion
*CBC, metabolic panel, [[lactate]], serum calcium (if concern for [[hydrofluoric acid]] exposure
*[[ECG]]
*Tylenol/ASA levels if concerned about coingestion (suicidal patients)
*Ingestion, consider:
**3-View [[CXR]]: look for free air under diaphragm or mediastinal free air
**CT: if suspect perforation but CXR negative

==Management==
*'''Decontaminate''' first: use appropriate personal protective equipment, remove all patient's clothing, decontaminate patient
*Irrigate areas of dermal or ocular exposure, early and copiously!
*'''Airway management'''
**Monitor closely for [[stridor]], airway edema, hoarseness, or other signs of airway injury
**[[Intubate]] early if signs of airway injury exist, before airway becomes more difficult to manage.
**Consider awake fiberoptic or video laryngoscopy if concern for difficult airway
**Blind nasotracheal intubation is contraindicated in caustic ingestion due to the potential for perforations and false passages
**[[Bronchodilators]] for bronchospasm if concern for inhalational injury
===Systemic Exposure===
*[[Metabolic acidosis]]: consider [[bicarbonate]] for severe acidosis
*Severe hemolysis may require [[exchange transfusion]]
===[[Caustic ingestion|Ingestion]]===
*'''Airway management''' especially important!
*Endoscopy 
**Indications:
***''All'' intentional ingestions (higher likelihood of high volume ingestion)
***Any ingestion with [[stridor]], drooling, significant oropharyngeal burns, [[vomiting]], food refusal
**Perform within 12-24 hours of ingestion (too early can underestimate extent of injury, too late increases risk of wound softening and perforation)
*Esophageal stricture mitigation<ref>High Doses of Methylprednisolone in the Management of Caustic Esophageal Burns. Pediatrics 2014;133:e1518–e1524</ref>
**Discuss with GI or toxicologist
**Grade IIb or higher esophageal burns: [[Methylprednisolone]] (1 g/1.73 m2 per day for 3 days), [[ranitidine]], [[ceftriaxone]], total parenteral nutrition
*Surgical intervention: indicated if perforation or peritoneal signs
*''Contraindicated'' (or controversial) therapies:
**[[Antibiotics]] (unless giving steroids]]
**[[Activated charcoal]] (may consider when coingestants pose a risk for severe systemic toxicity)
**[[Gastric lavage]]: contraindicated due to potential to cause reflux of caustic agent into esophagus, creating more damage
**Dilution with water or milk: causes vomiting, elevating risk for perforation
**Neutralization (e.g. with milk or mag citrate): generates excess heat

{{Caustic ocular exposure managment}}

==Disposition==
*Dependant on severity of exposure and complications

==See Also==
*[[Caustic burns]], [[Caustic ingestion]], [[Caustic keratoconjunctivitis]], [[Inhalation exposure]]

==External Links==

==References==
<references/>

[[Category:Misc/General]]
[[Category:Toxicology]]
[[Category:Trauma]]