GI Emergencies: Foreign Body and Caustic Ingestion

0:00Welcome to Board Pearls. This is episode three of four of the GI Emergencies chapter, in the Special Populations and Acute or Supportive Care module. In this episode we cover two of the mechanical and structural GI emergencies: foreign body and food bolus impaction with EGD timing driven by object type, and caustic ingestion graded by the Zargar endoscopic scale.

0:21Each of these emergencies hands you a recognition cue and a defined intervention, and each has a clock embedded in it. The clock starts when the object enters the lumen or when the caustic touches the mucosa. The teaching is the same shape both times: name the cue, reason from the mechanism to the threshold, then act.

0:41Start with foreign body and food bolus impaction. The unifying principle is that the urgency of removal follows the mechanism of injury, not the politeness of the object. Objects whose injury escalates over hours come out within hours. Objects that sit safely until they reach the duodenum come out within a day. Objects beyond the duodenum that are blunt and asymptomatic do not come out at all.

1:05That principle organizes the three timing tiers. Emergent removal within six hours covers three scenarios: esophageal obstruction with inability to manage secretions, a disc battery in the esophagus, and a sharp pointed object in the esophagus. The mechanism of urgency is different in each, and the difference is the teaching.

1:26Secretion overflow risks aspiration pneumonia and acute respiratory failure within hours. The patient drooling at the bedside cannot protect the airway during the next hour the way they did during the last one.

1:39A disc battery in the esophageal lumen is its own emergency. The two poles in contact with mucosa establish an electrolytic circuit that hydrolyzes water and produces hydroxide ions. Hydroxide drives alkaline liquefactive necrosis at the negative pole within two hours and can perforate within hours. The catastrophic late event is aortoesophageal fistula reported up to weeks after a missed esophageal disc battery. So the threshold is removal within two hours of impaction, not six. Honey or sucralfate slurry may reduce mucosal injury in pediatric ingestion before transport, but neither delays endoscopic removal.

2:20Sharp pointed objects in the esophagus include chicken or fish bones, open safety pins, dental partials with hooks, and glass fragments. They can lacerate the wall and cut adjacent vascular structures including the aorta if allowed to migrate or apply sustained pressure. That risk is what places them in the same emergent tier as the disc battery.

2:43Urgent removal within twenty-four hours covers the rest of the high-injury list. Food bolus impaction without complete obstruction. Non-sharp esophageal foreign bodies. Sharp objects in the stomach or duodenum, because they can perforate the small bowel beyond endoscopic reach. Objects longer than six centimeters at or above the proximal duodenum, because they cannot negotiate the duodenal C-loop. High-power magnets within endoscopic reach, because two or more magnets in different bowel loops attract across intervening tissue and produce pressure necrosis with fistula.

3:18Non-urgent management beyond twenty-four hours applies to coins and similar blunt asymptomatic objects beyond the duodenum, which can be followed with serial radiographs until they clear. Objects larger than two point five centimeters in diameter are unlikely to pass the pylorus and should be removed while still in the stomach.

3:36Drug-containing packets sit outside this algorithm. Body packers conceal large quantities of cocaine, heroin, or methamphetamine; body stuffers impulsively swallow smaller quantities. Neither group is endoscoped, because rupture during retrieval risks systemic toxic dose absorption with potentially fatal consequences. The surgical option is laparotomy when symptoms of leak develop, and otherwise the patient is observed while the packets traverse the GI tract under monitoring.

4:05Food bolus impaction is the most common adult foreign body presentation and the eosinophilic esophagitis gateway. Complete esophageal food bolus impaction with inability to manage oral secretions is an endoscopic emergency requiring removal within six hours, to prevent mucosal ischemia, deep ulceration, and perforation from sustained mural pressure. Food bolus without complete obstruction is removed within twenty-four hours.

4:33Glucagon one milligram intravenously has historically been used as a temporizing measure to relax the lower esophageal sphincter, but the success rate is under twenty percent. It should never delay endoscopy, and its main side effect is nausea and vomiting. In a patient with an obstructing bolus already pressuring the wall, emetogenic glucagon can produce a Boerhaave-pattern perforation. Blind nasogastric or bougie pushing of an impacted bolus is contraindicated because of perforation risk, particularly in eosinophilic esophagitis where the mucosa is friable and the entire esophagus may be narrow.

5:08At endoscopy the bolus is extracted en bloc with a retrieval net, snare, or specialized devices, or carefully advanced into the stomach when the distal esophagus is unobstructed on visualization. The high-yield teaching is what happens next. Approximately half of adult food bolus impactions are attributable to undiagnosed eosinophilic esophagitis. Biopsies of the proximal and distal esophagus at the same procedure are mandatory when no prior diagnosis exists. Take at least four biopsies from each level. The histologic threshold of fifteen eosinophils per high-power field requires adequate sampling, and the diagnostic window may not reopen if the patient does not return for elective EGD.

5:49Move to caustic ingestion. The teaching here is that substance category drives the injury pattern, the airway is the first priority, the Zargar grade at endoscopy drives short-term management, and late-stricture and squamous cell carcinoma risks drive long-term surveillance.

6:07Alkali ingestion, drain cleaner, lye, sodium hydroxide, oven cleaner, household ammonia, and impacted disc batteries, produces liquefactive necrosis with deep transmural injury. Hydroxide-mediated saponification of cellular fats and protein hydrolysis dissolves the architecture and allows continued penetration without an eschar to limit it. The alkali penetrates rapidly through mucosa toward the muscularis and on toward the mediastinum until tissue fluids buffer it.

6:37The esophagus is damaged more than the stomach in alkali ingestion, because gastric acid partially neutralizes the alkali in the gastric lumen. Acid ingestion, battery acid, toilet bowl cleaner, pool acid, hydrochloric and sulfuric acids, does the opposite. It produces coagulative necrosis with a superficial eschar that limits but does not prevent transmural injury at high volumes. The stomach is damaged more than the esophagus in acid ingestion, because the esophageal eschar deflects further contact while the stomach receives the bulk of the exposure. Liquid household bleach at typical exposure volumes rarely causes severe esophageal injury and is the lowest-risk caustic in the adult differential.

7:21Initial management is airway, intravenous access and resuscitation, analgesia, and nothing by mouth. Alkali ingestion can cause supraglottic edema requiring intubation, and airway compromise is the first priority because the upper airway can swell catastrophically over the first several hours.

7:40Several historical interventions are contraindicated, each through a specific mechanism. Induced emesis with syrup of ipecac aggravates injury through repeated mucosal contact during retching. Activated charcoal does not bind caustics and obscures endoscopy. Neutralization with weakly acidic or basic agents releases heat through the exothermic reaction and causes thermal injury on top of chemical injury. Nasogastric intubation in the acute window induces retching and risks perforation through an already weakened wall. Delayed endoscopy beyond forty-eight hours misses the diagnostic window because the mucosa softens and tears more easily as edema and inflammation peak.

8:22Upper endoscopy within twelve to twenty-four hours of ingestion grades the mucosal injury and guides management. A normal-appearing oropharynx does not preclude esophageal injury. The absence of visible oral burns is not a reason to skip endoscopy, because the esophagus and stomach can be heavily injured even when the mouth and pharynx are spared. Endoscopy is contraindicated in hemodynamic instability, evidence of perforation on imaging, severe respiratory distress, or severe oropharyngeal or glottic edema requiring airway management first.

8:53The Zargar grading system maps endoscopic findings to management, because depth of injury maps directly to perforation risk and to the safety of enteral feeding. Grade zero is normal mucosa. Grade one is mucosal edema and hyperemia. Grade two-A is superficial ulcers, bleeding, or whitish exudates. Grade two-B is deep focal or circumferential ulcers. Grade three-A is focal necrosis. Grade three-B is extensive necrosis. Grade four is perforation.

9:25Grades zero through two-A represent epithelial injury with intact submucosa and low perforation risk. Enteral feeding is safe and stimulates mucosal recovery, with a liquid diet advanced as tolerated. Grades two-B and three represent transmural muscle injury with high near-term perforation risk. Feeding is delayed until the wall is structurally sound. ICU monitoring is initiated because hemodynamic instability and hidden perforation can develop over the first forty-eight hours. Surgical consultation is obtained because perforation or transmural necrosis can require emergent esophagectomy or gastrectomy.

10:01Steroids are not routinely given for stricture prevention, because the trial evidence is mixed and the immunosuppression risks outweigh the inconsistent benefit. PPI is given for acid suppression to reduce ongoing acid-mediated mucosal injury.

10:14Late strictures from grade two-B and grade three injury are managed with serial endoscopic dilation. The dilation discipline matters. One to two millimeter increments per session toward a target diameter of fourteen to fifteen millimeters reached over multiple sessions, often with intralesional triamcinolone. Aggressive single-session dilation is avoided because caustic strictures are densely fibrotic and ischemic. Tearing through ischemic tissue in a single pass exceeds its mechanical tolerance and produces perforation.

10:45Intralesional triamcinolone reduces fibroblast activity and remodels collagen, which slows the rate of restenosis between sessions and reduces the total number of dilations required. Grade three-B carries a seventy to one hundred percent late stricture risk and frequently requires staged surgical reconstruction, gastric pull-up or colonic interposition, when dilation fails.

11:06Squamous cell carcinoma risk is elevated decades after caustic injury, with a latency period typically thirty to forty years. Chronic mucosal regeneration over scarred tissue accumulates DNA damage. Surveillance endoscopy every two to three years beginning ten to twenty years after severe caustic injury is appropriate in long-term survivors, with biopsy of any suspicious lesion.

11:29So pull these two threads together. For foreign body and food bolus impaction, the timing tiers follow the rate of injury escalation. Disc batteries within two hours because hydroxide is already burning. Sharp esophageal objects within six hours because the wall is already at risk. Food bolus with complete obstruction within six hours because the airway is at risk. Everything else within twenty-four hours, or expectantly beyond the duodenum if blunt and asymptomatic. And the food bolus is the eosinophilic esophagitis biopsy opportunity that closes if you do not take it at the same procedure. For caustic ingestion, the Zargar grade drives everything. Grades zero through two-A feed and observe, grades two-B and three monitor and stage, grade four operate. The substance category, alkali burning the esophagus through liquefactive necrosis, acid burning the stomach through coagulative necrosis with an eschar that deflects, predicts which compartment carries the disease.

12:30The next episode takes the other two mechanical emergencies: esophageal perforation and Boerhaave syndrome, where the twenty-four hour window separates clean primary closure from sealed stent and drainage, and acute colonic pseudo-obstruction, the Ogilvie syndrome, with its cecal-diameter threshold and neostigmine-with-cardiac-monitoring decision.

12:49For the full chapter, the practice vignettes, and the topic-tagged question bank, head to board pearls dot com. You'll find the rest of the series on Apple Podcasts, Spotify, or wherever you listen to podcasts. That brings us to the end of episode three of four of chapter thirty one, and I'll see you in the next one.