Ver el código de «Alkali ingestion»

==Background==
*Alkali (caustic/corrosive) ingestion refers to oral exposure to substances with a pH ≥ 12, which cause '''liquefactive necrosis''' — saponification of fats, protein denaturation, and cell membrane destruction that penetrates deeply into tissue<ref name="hoffman">Hoffman RS, Burns MM, Gosselin S. Ingestion of caustic substances. ''N Engl J Med''. 2020;382(18):1739-1748. PMID 32348644.</ref>
*Unlike acids (which cause coagulative necrosis with a protective eschar), alkalis penetrate through tissue layers and can cause '''transmural injury and perforation'''<ref name="hoffman"/>
*Alkali ingestions are more common than acid ingestions in the US and are the most frequent cause of serious caustic GI injury<ref name="statpearls">Alkali Toxicity. In: ''StatPearls''. Treasure Island (FL): StatPearls Publishing; 2023. PMID 31082166.</ref>
*Common alkali substances:
**Drain cleaners / oven cleaners: Sodium hydroxide (NaOH) or potassium hydroxide (KOH) — "lye"; most common cause of severe injury
**Hair relaxers/straighteners: Sodium hydroxide or calcium hydroxide
**Laundry/dishwasher detergent pods (LDPs): Concentrated alkaline surfactants; increasingly common pediatric exposure
**Household bleach (NaOCl): Low concentration (3–8%) rarely causes serious injury; industrial-strength bleach or international formulations may have higher concentration
**Ammonia: Household cleaners
**Disc/button batteries: Generate alkali via electrolysis at the anode; cause focal liquefactive necrosis on contact with mucosa
*Epidemiology:
**Children < 5 years: Accidental ingestion; usually small volumes → less severe injury
**Adolescents / Adults: Intentional ingestion (suicidal); typically larger volumes → more severe injury and higher mortality<ref name="statpearls"/>
*Severity of injury depends on: pH, titratable alkali reserve (TAR), volume ingested, concentration, physical form (liquid vs. solid vs. gel), and duration of tissue contact<ref name="chirica">Chirica M, Bonavina L, Kelly MD, Sarfati E, Cattan P. Caustic ingestion. ''Lancet''. 2017;389(10083):2041-2052. PMID 28045663.</ref>
*Liquid alkalis tend to cause more extensive injury (spread distally to esophagus and stomach); solid/granular alkalis tend to adhere to oropharynx and proximal esophagus
*Long-term complications: Esophageal stricture (most common long-term sequela), gastric outlet obstruction, and a '''1,000-fold increased risk of esophageal carcinoma''' decades after injury<ref name="hoffman"/>

==Clinical Features==
*Presentation ranges from '''asymptomatic''' to '''cardiac arrest''' depending on severity
*Absence of oropharyngeal burns does NOT exclude significant esophageal or gastric injury — up to 10–30% of patients without visible oral burns have esophageal injury on endoscopy<ref name="hoffman"/>

===Oropharyngeal===
*Oral pain, drooling, dysphagia, odynophagia
*Erythema, edema, ulceration, or white/gray pseudomembranes of the lips, tongue, palate, and posterior pharynx
*Refusal to swallow (children)

===Airway===
*Stridor, hoarseness, dysphonia — '''signs of laryngeal/epiglottic edema; may progress rapidly to complete obstruction'''
*Cough, tachypnea, respiratory distress
*Aspiration → chemical pneumonitis

===Esophageal / Gastric===
*Chest pain, epigastric pain, back pain
*Hematemesis
*Signs of perforation: severe chest/abdominal pain, rigidity, subcutaneous emphysema

===Systemic (Severe Ingestions)===
*Hypotension, tachycardia (hemorrhage, third-spacing, sepsis)
*Metabolic acidosis (lactic acidosis from tissue necrosis and hypoperfusion)
*Fever, leukocytosis
*Disseminated intravascular coagulation
*Multiorgan failure

===Delayed Complications===
*Esophageal/gastric stricture (weeks to months)
*Esophageal perforation (greatest risk in first 5–14 days post-ingestion when tissue is weakest during granulation)
*Esophageal carcinoma (years to decades)

==Differential Diagnosis==
*[[Caustic ingestion]]
*[[Boron toxicity|Boric acid ingestion]]
*Foreign body ingestion (especially [[Button battery ingestion|button battery]])
*[[Esophageal Perforation]] (Boerhaave syndrome)
*Infectious esophagitis (candidal, herpetic, CMV — in immunocompromised)
*Pill esophagitis
*[[Epiglottitis]] / supraglottitis (if airway symptoms predominate)
*[[Anaphylaxis]] (airway edema without history of ingestion)
*Other toxic ingestions (paraquat, formaldehyde)
*Thermal burn to the oropharynx

==Evaluation==
===Workup===
*Airway assessment is the first priority — examine for stridor, drooling, voice changes, respiratory distress
*'''Do NOT delay airway management''' — early intubation if any concern for progressive airway edema; airway can deteriorate rapidly<ref name="rumpf">Rumpf JJ, Settmacher U, Rauchfuss F. Acute emergency care and airway management of caustic ingestion in adults. ''Scand J Trauma Resusc Emerg Med''. 2016;24:45. PMID 27068117.</ref>
*Labs:
**CBC (leukocytosis may indicate severe injury/necrosis)
**BMP/CMP (electrolytes, renal function, bicarbonate)
**VBG/ABG with lactate (metabolic acidosis and elevated lactate are predictive of transmural necrosis)<ref name="chirica"/>
**LFTs (hepatic injury in severe cases)
**Coagulation studies (PT/INR) — coagulopathy may develop
**Type and screen/crossmatch (anticipate hemorrhage)
**Lipase (if concern for pancreatic injury)
**Serum β-hCG in women of reproductive age
*Imaging:
**CXR and upright abdominal XR: Evaluate for pneumomediastinum, pneumoperitoneum, pleural effusion, aspiration
**Contrast-enhanced CT (neck/chest/abdomen): Increasingly used as first-line imaging in adults; can identify transmural necrosis (absence of post-contrast wall enhancement), perforation, and extent of injury<ref name="chirica"/>
***CT should be performed 3–6 hours post-ingestion per WSES guidelines
***High specificity for severe injury; may reduce need for emergent endoscopy in some centers
*Endoscopy (EGD):
**Standard for grading injury severity using the '''Zargar classification'''<ref name="zargar">Zargar SA, Kochhar R, Mehta S, et al. The role of fiberoptic endoscopy in the management of corrosive ingestion and modified endoscopic classification of burns. ''Gastrointest Endosc''. 1991;37(2):165-169. PMID 2032601.</ref>
**Should be performed '''within 12–24 hours''' (do not delay beyond 48 hours — perforation risk increases after this point)
**Typically performed by GI or surgery; not an ED procedure

===Diagnosis===
*Diagnosis is '''clinical''' — based on history of alkali exposure and consistent symptoms
*Zargar Endoscopic Classification:<ref name="zargar"/>
{| class="wikitable"
|-
! Grade !! Findings !! Prognosis
|-
| '''0''' || Normal || No injury
|-
| '''1''' || Mucosal edema, hyperemia || Excellent; heals without sequelae
|-
| '''2a''' || Superficial ulceration, exudates, friability || Good; low stricture risk
|-
| '''2b''' || Deep or circumferential ulceration || Moderate; '''significant stricture risk (~70%)'''
|-
| '''3a''' || Focal/scattered necrosis || Poor; high perforation and stricture risk
|-
| '''3b''' || Extensive necrosis || '''Surgical emergency; high mortality'''
|}
*Abnormal labs (severe acidosis, elevated lactate, leukocytosis, thrombocytopenia, elevated CRP, renal injury) are predictive of transmural necrosis and poor outcomes<ref name="chirica"/>
*'''Initial normal labs do NOT exclude transmural necrosis''' — serial monitoring is essential

==Management==
===Airway (First Priority)===
*Early intubation if any evidence of airway compromise (stridor, voice changes, drooling, respiratory distress, significant oropharyngeal edema)<ref name="rumpf"/>
*Have a '''difficult airway plan''' ready — consider early involvement of anesthesia; awake fiberoptic intubation or surgical airway may be needed if severe laryngeal edema
*50% of patients with intentional alkali ingestion in one series required intubation<ref name="rumpf"/>

===Resuscitation===
*IV access (two large-bore) and crystalloid resuscitation
*NPO — nothing by mouth until injury is graded
*Correct coagulopathy and acidosis as needed
*Blood products if hemorrhaging

===What NOT To Do===
*'''Do NOT induce emesis''' — re-exposes esophagus to caustic agent; risk of aspiration and perforation<ref name="hoffman"/>
*'''Do NOT attempt neutralization''' (i.e. do not give a weak acid) — exothermic reaction causes thermal injury on top of chemical injury<ref name="statpearls"/>
*'''Do NOT place a nasogastric tube blindly''' — risk of esophageal perforation
*'''Do NOT give activated charcoal''' — does not adsorb alkalis; obscures endoscopy; aspiration risk<ref name="hoffman"/>
*'''Do NOT perform gastric lavage''' — contraindicated due to perforation risk<ref name="statpearls"/>

===Dilution (Controversial / Limited Role)===
*Small volumes of water or milk (120–240 mL) may be offered '''within 30 minutes''' of ingestion of '''solid/granular''' alkali only — goal is to dislodge particles adhering to mucosa<ref name="statpearls"/>
*Do NOT use for liquid alkali ingestions (risk of inducing emesis outweighs benefit)
*Do NOT delay other management for dilution

===Supportive Care===
*Pain management: IV opioid analgesia as needed
*PPI therapy: IV proton pump inhibitor (reduces acid exposure to injured tissue); routinely initiated though evidence is limited
*Antibiotics: Not routinely indicated; give if perforation suspected or documented, or if the patient develops signs of sepsis
*Corticosteroids:
**Role is '''controversial'''
**Some evidence supports high-dose methylprednisolone (starting within 48 hours) for '''grade 2b''' injuries to reduce stricture formation<ref name="usta">Usta M, Erkan T, Cokugras FC, et al. High doses of methylprednisolone in the management of caustic esophageal burns. ''Pediatrics''. 2014;133(6):e1518-e1524. PMID 24864180.</ref>
**Steroids are NOT indicated for grade 1, 2a (unnecessary) or grade 3 (may mask perforation signs and impair healing)
**Decision should be made in consultation with GI/surgery after endoscopic grading

===Surgical Consultation===
*'''Emergent surgery''' is indicated for:<ref name="chirica"/>
**Evidence of perforation (pneumomediastinum, pneumoperitoneum)
**Zargar grade 3b on endoscopy (extensive necrosis)
**Absence of post-contrast wall enhancement on CT (transmural necrosis)
**Clinical deterioration despite supportive care (peritonitis, hemodynamic instability, worsening acidosis)
*Surgical options include esophagogastrectomy with delayed reconstruction

==Disposition==
*Discharge after 4–6 hour observation:
**Asymptomatic patients with '''accidental''' ingestion of '''small volume''' of '''low-concentration''' alkali (e.g. small taste of dilute household bleach, household ammonia cleaner)
**Must tolerate PO challenge without difficulty prior to discharge
**Ensure close follow-up; consider outpatient GI referral for delayed EGD
*Admit:
**All symptomatic patients
**All '''intentional''' ingestions regardless of symptoms
**All pediatric patients with suspected significant ingestion
**Any patient requiring endoscopy or CT for injury grading
**Patients with abnormal labs (acidosis, elevated lactate, leukocytosis)
*ICU admission:
**Airway compromise or intubation
**Hemodynamic instability
**Zargar grade 2b or higher on endoscopy
**Evidence of perforation
**Multiorgan dysfunction, DIC, or severe metabolic acidosis
*Surgical consultation: Early for all significant ingestions; emergent for perforation or grade 3b injury
*Psychiatric evaluation: '''Mandatory''' for all intentional ingestions prior to hospital discharge<ref name="chirica"/>
*Poison Control: '''1-800-222-1222'''

==See Also==
*[[Acid ingestion]]
*[[Caustic ingestion]]
*[[Button battery ingestion]]
*[[Esophageal perforation]]
*[[Boron toxicity]]
*[[Toxicology (Main)]]

==External Links==
*[https://pubmed.ncbi.nlm.nih.gov/32348644/ Ingestion of caustic substances - N Engl J Med 2020]
*[https://pubmed.ncbi.nlm.nih.gov/28045663/ Caustic ingestion - Lancet 2017]
*[https://www.ncbi.nlm.nih.gov/books/NBK544235/ Alkali Toxicity - StatPearls]
*[https://pubmed.ncbi.nlm.nih.gov/2032601/ Modified endoscopic classification of caustic burns (Zargar) - Gastrointest Endosc 1991]
*[https://pubmed.ncbi.nlm.nih.gov/27068117/ Acute emergency care of caustic ingestion in adults - Scand J Trauma Resusc Emerg Med 2016]
*[https://www.emdocs.net/toxcard-caustic-ingestions-dos-and-donts-of-diagnosis-and-management/ ToxCard: Caustic Ingestions Do's and Don'ts - emDOCs]

==References==
<references/>

[[Category:Toxicology]] [[Category:GI]]