Caustic Ingestions Workup

Updated: Oct 21, 2022
  • Author: Derrick Lung, MD, MPH, FACEP, FACMT; Chief Editor: David Vearrier, MD, MPH  more...
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Laboratory Studies

Laboratory studies may include the following:

  • pH testing of product: A pH less than 2 or greater than 12.5 indicates greater potential for severe tissue damage, [9] but a pH outside of this range does not preclude significant injury.

  • pH testing of saliva: Unexpected high or low values may confirm ingestion in questionable cases; however, a neutral pH cannot rule out a caustic ingestion.

  • Complete blood count (CBC) and electrolyte, blood urea nitrogen (BUN), creatinine, and arterial blood gas (ABG) levels may all be helpful as baseline values and as indications of systemic toxicity.

  • Liver function tests and a disseminated intravascular coagulation (DIC) panel may also be helpful to establish baselines or, if abnormal, confirm severe injury following acid ingestions.

  • Urinalysis and urine output may help guide fluid replacement.

  • Blood type and crossmatch are indicated for any potential surgical candidates or those with the potential for gastrointestinal bleeding.

  • Obtain aspirin and acetaminophen levels as well as an electrocardiogram (ECG) in any patient whose intent may have been suicidal.

  • In cases of hydrofluoric acid (HF) ingestion, precipitous falls in calcium level may lead to sudden cardiac arrest. Although ionized calcium levels are likely to have too long a turnaround to be clinically useful, cardiac monitoring and serial ECGs may help anticipate this event


Imaging Studies

Obtain an upright chest radiograph in all cases of caustic ingestion. Findings may include pneumomediastinum or other findings suggestive of mediastinitis, pleural effusions, pneumoperitoneum, aspiration pneumonitis, or a button battery (metallic foreign body). However, the absence of such findings does not preclude perforation or other significant injury.

Abdominal radiographic findings may include pneumoperitoneum, ascites, or an ingested button battery (metallic foreign body). If contrast studies are obtained, water-soluble contrast agents are recommended because they are less irritating to the tissues in cases of perforation.

Computed tomography (CT) scans will often be able to delineate small amounts of extraluminal air, not seen on plain radiographs.

Chirica et al cite CT as superior to traditional endoscopy for helping to decide whether patients require emergency resection or observation. [1]  Similarly, Bruzzi et al reported that emergency CT outperforms endoscopy in predicting esophageal stricture formation after caustic ingestion. [10]

On the other hand, Lurie et al evaluated the role of chest and abdominal CT in assessing the severity of acute corrosive ingestion and concluded that CT should not be the only basis for surgical decisions during the initial phase of acute corrosive ingestions. They noted that CT can underestimate the severity of corrosive ingestion as compared with endoscopy. In their retrospective study of 23 patients, endoscopy findings were graded as 0, 1, 2a, 2b, 3a, and 3b (Zargar criteria); and CT findings were graded as 0, 1, 2, and 3. Endoscopy grading was found to be higher than CT grading in 14 patients (66%). [11]



Airway protection is critical following caustic ingestion if there is any indication of airway compromise. This can develop rapidly and be complicated by multiple factors. See Emergency Department Care. Cardiac monitoring is indicated for any patient with a caustic ingestion.

Endoscopy is generally indicated for the following patients:

  • Small children who are not tolerating liquids or with complaints of pain
  • Patients with a disk battery ingestion identified in the esophagus or stomach
  • Symptomatic older children and adults
  • Patients with abnormal mental status
  • Patients with intentional ingestions
  • Patients in whom injury is suspected for other reasons (eg, ingestion of large volumes or concentrated products)

However, because of the risk of increased injury, esophagoscopy should not be performed in patients with evidence of esophageal or gastrointestinal perforation, significant airway edema, or necrosis and in those who are hemodynamically unstable. Endoscopy is typically avoided when more than 24 hours have elapsed after the ingestion due to decreased wound strength and an increased risk of iatrogenic perforation. 

Obtaining meaningful information from endoscopy after treatment with activated charcoal is very difficult. Routine use of activated charcoal is not recommended in caustic ingestions.

Endoscopic ultrasonography has been shown to more accurately show the depth of lesions than endoscopy alone. [12] Further studies will be necessary to determine the utility of this procedure in aiding in diagnosis and treatment.



Endoscopy findings are commonly graded as described in the table below. [13]

Classification of caustic mucosal damage [14]   (Open Table in a new window)

Grade Findings Complication risk
0 None None
1 Swelling and redness of mucosa Low risk for development of outlet obstruction of strictures
2A Superficial ulcers, bleeding, friability Low risk for development of outlet obstruction of strictures
2B Deep ulcers, bleeding, friability High risk for strictures, low risk for perforation
3A Focal necrosis High risk for strictures, moderate risk for perforation
3B Extensive necrosis High risk for strictures and perforation, moderate risk for fatality
4 Perforation High risk of fatality