Caustic Ingestion (Acid & Alkali): An ICU Nurse's Guide

Part of the ICU Emergencies Hub — browse every related guide in one place.

Updated July 2026  |  More ICU nursing guides →

Caustic ingestions — drain cleaners, oven cleaners, industrial descalers, concentrated bleach, button batteries, dishwasher pods in children — are among the exposures where reflexive "first aid" does real harm. A strong acid or alkali burns tissue on contact, and the injury keeps evolving for hours to days. The ICU nurse's role is to protect the airway, avoid the interventions that make things worse, and monitor for the perforation and shock that can arrive after the patient initially looks stable.

Acid vs. alkali: two different burns

The chemistry drives the clinical picture. Alkalis (lye, sodium/potassium hydroxide, many drain and oven cleaners) cause liquefactive necrosis: they dissolve into tissue, penetrate deeply, and are classically worst in the esophagus, where they can burn through the full thickness of the wall. Acids (toilet-bowl and pool cleaners, rust removers, battery acid) cause coagulative necrosis: they form a firm eschar that can limit depth of penetration, and they tend to injure the stomach preferentially because the pylorus holds the acid there. Both can be devastating; the old teaching that "acids spare the esophagus" is unreliable, and either agent can injure the airway if aspirated or if fumes are inhaled.

What you never do

Three interventions that feel intuitive are contraindicated. Do not induce vomiting — re-exposing the esophagus and airway to the caustic on the way back up doubles the injury and risks aspiration. Do not attempt to neutralize the agent (no acid for an alkali, no baking soda for an acid) — the neutralization reaction is exothermic and adds a thermal burn to a chemical one. And do not give activated charcoal — it does not bind caustics, obscures the endoscopic view, and increases aspiration and perforation risk. Blind nasogastric tube placement is also avoided early; any gastric tube is placed under direct visualization by the team when indicated.

The airway is the first priority

Drooling, stridor, hoarseness, and a muffled voice signal laryngeal or supraglottic edema, and that edema can progress fast. Early airway control — ideally before swelling makes intubation impossible — is often the single most important decision. Because the anatomy may be burned and distorted, these are frequently anticipated difficult airways, and the team plans for a double setup. Keep the head of bed up, have suction ready, and escalate any change in voice or work of breathing immediately.

Monitoring for perforation and systemic injury

After the initial contact, the nurse watches for the signs that a burn has become a hole. Severe chest or abdominal pain, back pain, subcutaneous emphysema, rigid abdomen, fever, and rising heart rate with falling blood pressure point toward esophageal or gastric perforation and mediastinitis or peritonitis — a surgical emergency. Serial abdominal exams, keeping the patient NPO, large-bore IV access, and readiness for fluid resuscitation are the bedside priorities. High-grade burns can also cause a systemic inflammatory response and metabolic acidosis.

Endoscopy grades the injury and drives the plan

Upper endoscopy, usually within the first 12–24 hours (but not through a perforated or unstable patient), grades the burn depth much like a skin burn. Superficial injury generally heals; deep circumferential burns carry a high risk of stricture that shows up weeks later as difficulty swallowing, and a much higher perforation risk acutely. The grade determines whether the patient can advance to feeding, needs prolonged NPO and nutrition support, or heads to surgery. Nurses reinforce the long tail of this injury: strictures and, decades later, an elevated esophageal cancer risk mean these patients need follow-up.

The button battery and pediatric angle

A swallowed button battery lodged in the esophagus generates a local alkaline current that burns through tissue in as little as two hours — a true "clock is running" emergency requiring urgent removal, and honey may be advised pre-hospital in specific pediatric scenarios per current guidance. Many pediatric caustic ingestions are unintentional and small, but intentional adult ingestions tend to be large-volume and severe. Either way, the monitoring principles are the same: airway first, no harmful first aid, watch for perforation.

For the airway pieces, see the nurse's role in RSI and the difficult airway. Related toxic-exposure guides: hydrofluoric acid exposure and amatoxin mushroom poisoning.