Caustic ingestion represents a significant problem due to both acute and chronic damage, involving patients of all age groups. In the pediatric population, it is usually associated with accidental ingestion, mainly of cleaning products stored incorrectly and the reuse of packaging. In other age groups, suicide attempts through the intentional ingestion of caustics are a significant cause, if not the most frequent and severe.
Caustic agents can be acids (muriatic acid, sulfuric acid, formic acid – “formaldehyde”) or alkalis (bases), of which the main representatives in our environment are sodium hypochlorite (bleach) and sodium hydroxide (caustic soda). The potential for significant damage is associated with two main factors, the pH of the product (higher risk with pH<2 or >11) and the ingested volume.
The ingestion of alkaline caustics is associated with damage by liquefaction necrosis where there is saponification of lipids, denaturation of proteins, and capillary thrombosis with the potential for deeper damage and perforation. The secondary damage to acid ingestion is associated with coagulation necrosis. There is a natural evolution in the process of damage and healing of the mucosa that can be divided into three main phases:
- Acute phase (up to 10 days) – acute necrosis (liquefaction or coagulation), thrombosis, and activation of the inflammatory cascade; beginning of collagen deposition and re-epithelialization.
- Subacute phase (10 days – 6 to 8 weeks) – increased activity of repair mechanisms, increased collagen, and re-epithelialization which can confer initial symptomatic improvement, with the potential to return to oral diet. Considered a “treacherous” phase because symptoms improve while the esophagus re-epithelializes and forms possible strictures.
- Chronic phase (>6 to 8 weeks) – phase of scarring and strictures. There is a resurgence of symptoms of odynophagia, dysphagia, and vomiting due to the establishment of cicatricial strictures in the esophagus.
Initial Management
The initial management aims to provide support, with an assessment of possible damage to the airways, hydration, nil per os (NPO), and the performance of complementary exams. Laboratory tests include complete blood count, urea, creatinine, liver enzymes, while imaging exams may include plain radiography (to assess pneumoperitoneum, pneumothorax, or pneumomediastinum) and endoscopy. Computed tomography has the ability to assess the depth of damage to the digestive tract (not assessed by endoscopy) and is used in various centers, but is not routinely used in our environment.
Endoscopy
Upper gastrointestinal endoscopy plays an important role in the treatment of patients with caustic ingestion through the classification of lesions and the consequent identification of the group of patients at higher risk for the development of strictures, who should be included in a dilation program. The classification used is the Zargar Classification, which is quite simple:
– Grade 1 – edema and erythema;
– Grade 2a – Friability, erosions, erythema, diffuse inflammatory exudate;
– Grade 2b – superficial or deep ulcers, confluent or not;
– Grade 3a – areas of necrosis;
– Grade 3b – extensive necrosis.
Endoscopy should be performed as soon as possible, preferably within the first 24 hours of ingestion and at most up to 48 hours after. After this period, the risk of worsening lesions is greater, and endoscopy should be suspended, being able to be performed after 3 weeks from ingestion, when dilation sessions can be started in patients at risk for the development of strictures (Zargar 2b or 3). Some studies suggest performing a contrast study to confirm the presence of stricture before dilation, which can also be performed in patients who were unable to undergo endoscopy within the first 48 hours. The presence of esophageal necrosis may be associated with perforation, making it important to assess the depth of the lesion with computed tomography. Cases of extensive necrosis are usually surgical.
It is important to consider that caustic ingestion can trigger a series of systemic changes such as metabolic acidosis, electrolyte disturbances, renal failure, and also damage (or hyperactivity) of the airways (especially the more volatile ones) requiring additional care in the sedation of these patients.
Main Messages:
- Endoscopy should be performed early (maximum 48 hours);
- Do not induce vomiting due to the risk of reflux to the esophagus and worsening of damage;
- Zargar 1 and 2a – low risk of developing strictures;
- Zargar 3a and 3b – risk of perforation;
- Increased risk of stricture and perforation – pH <2 or >11;
- Damage to the airways with volatile caustics.
It is important to assess that on many occasions we do not have reliable information related to the ingested product for various reasons:
- Children or caregivers may not know the ingested product or may not provide true information for fear of possible repercussions;
- Patients with suicide attempts are going through a moment of great sorrow and emotional instability, unknown to the emergency physician, and may maximize or minimize relevant data;
- Formulated, manipulated, diluted products may contain unknown substances or cause uncertain chemical reactions;
- Ingestion of caustic products in work environments, schools, nurseries, farms, third-party homes, etc. – the fear of negative repercussions and liability for damages can influence employees and family members.
References
- Methasate A, Lohsiriwat V. Role of endoscopy in caustic injury of the esophagus. World J Gastrointest Endosc. 2018 Oct 16;10(10):274-282. doi: 10.4253/wjge.v10.i10.274. PMID: 30364838; PMCID: PMC6198306.
- ASGE Standards of Practice Committee, Lightdale JR, Acosta R, Shergill AK, Chandrasekhara V, Chathadi K, Early D, Evans JA, Fanelli RD, Fisher DA, Fonkalsrud L, Hwang JH, Kashab M, Muthusamy VR, Pasha S, Saltzman JR, Cash BD; American Society for Gastrointestinal Endoscopy. Modifications in endoscopic practice for pediatric patients. Gastrointest Endosc. 2014
- Chirica M, Kelly MD, Siboni S, Aiolfi A, Riva CG, Asti E, Ferrari D, Leppäniemi A, Ten Broek RPG, Brichon PY, Kluger Y, Fraga GP, Frey G, Andreollo NA, Coccolini F, Frattini C, Moore EE, Chiara O, Di Saverio S, Sartelli M, Weber D, Ansaloni L, Biffl W, Corte H, Wani I, Baiocchi G, Cattan P, Catena F, Bonavina L. Esophageal emergencies: WSES guidelines. World J Emerg Surg. 2019
- Tosca J, Villagrasa R, Sanahuja A, Sanchez A, Trejo GA, Herreros B, Pascual I, Mas P, Peña A, Minguez M. Caustic ingestion: development and validation of a prognostic score. Endoscopy. 2021 Aug;53(8):784-791. doi: 10.1055/a-1297-0333. Epub 2021 Jan 18. PMID: 33096569.
How to cite this article
Ferreira F. Caustic ingestion and endoscopy – when can we really help in the acute setting? Endoscopia Terapêutica 2022. Available at: https://endoscopy.news/general-topics/caustic-ingestion-and-endoscopy-when-can-we-truly-help-in-the-acute-setting/
Membro Titular da Sociedade Brasileira de Endoscopia Digestiva (SOBED);
Especialização em Endoscopia Digestiva na Universidade de São Paulo (USP);
Mestrado em Cirurgia na Universidade Federal de Pernambuco (UFPE);
Médico endoscopista da NeoGastro (PE);
Coordenador do Serviço de Endoscopia Digestiva do Hospital Otávio de Freitas (PE)