What is the management approach for a patient with a history of acid ingestion, where a gastric fluid lavage sample is available instead of a tissue biopsy?

Management of Acid Ingestion with Gastric Fluid Lavage Sample

In patients with acid ingestion where gastric fluid lavage is available instead of tissue biopsy, proceed immediately with contrast-enhanced CT imaging of the neck, thorax, and abdomen 3-6 hours post-ingestion to assess for transmural necrosis, as CT has superior diagnostic accuracy (90-100% sensitivity) compared to endoscopy and should guide all subsequent management decisions. 1, 2

Initial Diagnostic Approach

Laboratory Evaluation

• Obtain comprehensive laboratory workup including CBC, serum electrolytes (sodium, potassium, chlorine, magnesium, calcium), renal function (urea, creatinine), liver function tests (bilirubin, ALT, AST), arterial blood gas with pH and serum lactate, and β-HCG in women of childbearing age 1
• Monitor laboratory kinetics serially, as initial normal values do not exclude transmural necrosis 1
• Severe acidosis (low pH, elevated lactate), deranged liver function, leukocytosis, elevated CRP, renal failure, and thrombocytopenia predict transmural necrosis and poor outcomes 1

Imaging Strategy

• Perform contrast-enhanced CT of neck, thorax, and abdomen 3-6 hours after ingestion using nonionic contrast agent (2-3 mL/kg) with 18-25 second acquisition time and 90-second scan delay 1, 2
• CT outperforms endoscopy in detecting transmural injuries and predicting stricture formation 1, 2
• The absence of post-contrast wall enhancement at any level (esophagus, stomach, duodenum) indicates transmural necrosis and mandates emergency surgery 1, 2
• Obtain plain radiographs of neck, chest, and abdomen to evaluate for free air indicating perforation 1

CT-Based Injury Grading and Management

Grade I Injuries

• Homogenous esophageal wall enhancement without edema or mediastinal fat stranding 1
• Patients can be fed immediately and discharged within 24-48 hours as stricture risk is nil 2

Grade IIa Injuries

• Internal mucosal enhancement with hypodense, thickened esophageal wall showing "target" appearance 1
• Mediastinal fat stranding present 1
• Moderate stricture risk requiring close follow-up 2

Grade IIb Injuries

• Fine rim of external wall enhancement with non-enhancing necrotic mucosa filling the lumen 1
• High stricture risk (>80%) requiring nutritional support via feeding tube or jejunostomy 2

Grade III Injuries

• Complete absence of post-contrast wall enhancement indicating transmural necrosis 1, 2
• Emergency surgery is mandatory and should be performed as soon as possible to prevent death 2

Role of Endoscopy

When CT is Preferred Over Endoscopy

• CT-based algorithms have replaced endoscopy as the primary diagnostic modality in adults due to superior detection of transmural necrosis 2
• CT accurately identifies patients requiring emergency surgery, significantly improving outcomes 2

Limited Indications for Emergency Endoscopy

• Perform emergency endoscopy within 12-48 hours only when: CT is unavailable or logistically impossible, CT with IV contrast is contraindicated (renal failure, iodine allergy), or in pediatric patients where severe injuries are rare and radiation exposure is a concern 2
• Endoscopy remains useful for stricture management in symptomatic patients presenting later with dysphagia 2

Surgical Management

Emergency Surgery Indications

• Transmural necrosis (Grade III injury) on CT imaging 1, 2
• Clinical signs of perforation with free air on imaging 1
• Clinical deterioration despite conservative management 3

Surgical Principles

• Resect all obvious transmural necrotic tissue during initial operation 2
• Place feeding jejunostomy at operation end for nutritional support 2
• Acid ingestions more commonly cause gastric injury and may require gastrectomy, while alkali causes esophageal injury 4, 5

Specific Considerations for Acid Ingestion

Injury Pattern

• Liquids transit rapidly causing burns of esophagus and stomach 1
• Acid ingestions (particularly hydrochloric and sulfuric acid) cause more severe gastric injuries compared to esophageal injuries 4, 5
• Suicidal acid ingestion causes more severe injuries than accidental ingestion 4

Systemic Effects

• Monitor for hypocalcemia (phosphoric, hydrofluoric acids), hyponatremia, hypokalemia, and acidosis 1
• Severe acidosis with elevated lactate predicts transmural necrosis 1

Nutritional Support

• Reintroduce oral feeding as soon as patients can swallow normally in mild injuries 2
• Provide enteral feeding via nasogastric tube or feeding jejunostomy in patients unable to eat due to severe injury 2
• Consider total parenteral nutrition in cases of extensive injury or complications 6

Follow-Up and Complications

Stricture Management

• Most strictures develop within 4-6 months post-ingestion 2
• Schedule follow-up at 4-6 months for Grade II injuries 2
• Begin endoscopic dilation 3-6 weeks after ingestion for patients with few (<3) short (<5 cm) strictures 2
• Avoid dilation within first 3 weeks due to increased perforation risk 2

Long-Term Outcomes

• Pyloric stenosis may develop requiring surgical intervention 4
• Mortality rate ranges from 5.6% to 11% depending on severity and timing of intervention 4, 6
• Psychiatric evaluation is mandatory prior to discharge in intentional ingestions to prevent recurrence 2

Critical Pitfall to Avoid

Do not rely on clinical symptoms or absence of oral lesions to exclude life-threatening gastrointestinal injuries, as these do not correlate reliably with extent of damage 1, 4. The gastric lavage fluid sample alone cannot replace CT imaging for determining transmural necrosis, which is the key determinant for emergency surgical intervention 1, 2.