Acid ingestion: toxicology and treatment

Accidental aspiration of a solid tablet of sodium hydroxide

Sodium hypochlorite is a corrosive, highly alkaline (pka=7.52) household product. Ingestion of sodium hypochlorite liquid is common, showing toxicity on the oesophagus and stomach. Nevertheless, cases of sodium hypochlorite ingestions in pellet are rare and the management of them is unknown. We report the case of a 65-year-old man who accidentally swallowed a bleach tablet of 3.5 g. Six hours later, the patient developed an aphonia associated with dysponea stage IV, motivating a nasofibroscopy showing glottis and supraglottic necrosis and oedema for which the patient received intravenous steroids, was intubated and then underwent a tracheotomy. After 2 weeks under tracheotomy, local evolution was favourable allowing a removal of the cannula and a return back home.

[Caustic injury of upper gastrointestinal tract: 20 year experience at a tertiary referral center]

BACKGROUND/AIMS

Caustic ingestion can cause severe injury to upper gastrointestinal tract. There were few studies about clinical characteristics and treatments of caustic injury in Korea. We investigated the changes in clinical features of caustic injury over the past 20 years including pattern of endoscopic mucosal injury and treatment modality.

METHODS

This study was a retrospective review of medical records from patients with caustic injury from September 1993 through December 2012. Patients were classified into two groups based on the year when caustic ingestion occurred: patients who visited the hospital from 1993 to 2002 (early group) and patients who visited the hospital from 2003 to 2012 (late group).

RESULTS

A total 140 patients were included (early group [n=50] vs. late group [n=90]). Annual number of caustic ingestions did not show decreasing tendency over the past 20 years. Alkali ingestion increased (20.0% vs. 65.6%, p<0.001) and cases with more than grade 2b of esophageal mucosal injury decreased (41.3% vs. 20.7%, p=0.012) in late group. There were no differences between two groups in sex, age, proportion of accidental ingestion, and systemic/gastrointestinal complications. Use of gastric lavage (p<0.01) and broad spectrum antibiotics (p=0.03) decreased in late group. However, there was no difference in use of steroid between two groups.

CONCLUSIONS

In this study, overall caustic ingestion did not decrease and ingestion of alkali agents increased over the past 20 years. Tighter legislation on caustic agents is required and we need to be alert to the best management of caustic injury.

Management of extravasation injuries: a focused evaluation of noncytotoxic medications

Extravasations are common manifestations of iatrogenic injury that occur in patients requiring intravenous delivery of known vesicants. These injuries can contribute substantially to patient morbidity, cost of therapy, and length of stay. Many different mechanisms are behind the tissue damage during extravasation injuries. In general, extravasations consist of four different subtypes of tissue injury: vasoconstriction, osmotic, pH related, and cytotoxic. Recognition of high-risk patients, appropriate cannulation technique, and monitoring of higher risk materials remain the standard of care for the prevention of extravasation injury. Prompt interdisciplinary action is often necessary for the treatment of extravasation injuries. Knowledge of the mechanism of extravasation-induced tissue injury, agents for reversal, and appropriate nonpharmacologic treatment methods is essential. The best therapeutic agent for treatment of vasopressor extravasation is intradermal phentolamine. Topical vasodilators and intradermal terbutaline may provide relief. Intradermal hyaluronidase has been effective for hyperosmotic extravasations, although its use largely depends on the risk of tissue injury and the severity of extravasation. Among the hyperosmotic agents, calcium extravasation is distinctive because it may present as an acute tissue injury or may possess delayed clinical manifestations. Extravasation of acidic or basic materials can produce significant tissue damage. Phenytoin is the prototypical basic drug that causes a clinical manifestation known as purple glove syndrome (PGS). This syndrome is largely managed through preventive and conservative treatment measures. Promethazine is acidic and can cause a devastating extravasation, particularly if administered inadvertently through the arteriolar route. Systemic heparin therapy remains the accepted treatment option for intraarteriolar administration of promethazine. Overall, the evidence for managing extravasations due to noncytotoxic medications is nonexistent or limited to case reports. More research is needed to improve knowledge of patient risk, prompt recognition of the extravasation, and time course for tissue injury, and to develop prevention and treatment strategies for extravasation injuries.

Severe metabolic acidosis following assault chemical burn

Assault chemical burns are uncommon in northern Europe. Besides local toxicity, systemic manifestations are possible after strong acid exposure. A 40-year-old woman was admitted 1 h after a criminal assault with sulfuric acid. The total burned surface area was 35%, third degree. Injury was due to sulfuric acid (measured pH 0.9) obtained from a car battery. Immediate complications were obstructive dyspnea and metabolic acidosis. The admission arterial pH was 6.92, with total bicarbonate 8.6 mEq/l and base deficit 23.4 mEq/l. The correction of metabolic acidosis was achieved after several hours by the administration of bicarbonate and lactate buffers. The patient developed several burns-related complications (sepsis and acute renal failure). Cutaneous projections of strong acids may cause severe metabolic acidosis, particularly when copious irrigation and clothes removal cannot be immediately performed at the scene.

[Upper gastrointestinal tract injury caused by ingestion of caustic substances]

BACKGROUND

To determine the distribution, extension and severity of injuries produced by the ingestion of caustic substances in the upper gastrointestinal tract, and to assess the relationship of these factors with the type of caustic substance ingested, whether intake was accidental or deliberate and the appearance of strictures or death.

PATIENTS AND METHOD

Between 1993 and 1999, 138 patients (74 males and 84 females) who underwent upper gastrointestinal endoscopy in our unit within the first 24 hours after ingestion of caustic substances were included in the study. Mean age was 47 years (14-97 years). The severity of caustic injury was evaluated using the classification of Showkat et al.

RESULTS

The type of caustic substance ingested was as follows: lye in 84 patients (53%), nitric acid in 21 (13%), different caustic mixtures in 43 (27%) and unknown in 10 patients (6%). Lesions were grade I in 51 patients(32%), grade II in 33 (21%) and grade III in 20 (13%). No lesions were seen in 54 patients (34%). Of the 158 patients, gastric injury was found in 91 (57.5%), esophageal burn in 72 (45.5%) and duodenal injury in 28 (18%). Ingestion was accidental in 80 patients (51%) and voluntary in 62 (39%); the reasons for ingestion were unclear in 16 patients (10%). Voluntary ingestion and acid use were associated with greater severity of lesions (p < 0.0005). Eight patients (5.0%) died, 10 patients (6.3%) required emergency surgery, and 7 (4.4%) developed esophageal-gastric strictures that required surgery or endoscopic treatment.

CONCLUSIONS

The most common type of caustic substance ingested was lye. In 66% of the patients, lesions were absent or superficial. The more severe injuries, producing strictures and higher mortality, were related to voluntary and nitric acid ingestion. The part of the digestive tract most frequently affected after lye and acid ingestion was the stomach.

Clinical impact of upper gastrointestinal tract injuries in glyphosate-surfactant oral intoxication

Fifty patients with glyphosate-surfactant oral ingestion were studied with upper gastrointestinal (UGI) endoscopic grading using Zargar's modified grading system for mucosal corrosive injury. Esophageal injury was seen in 68% of the patients, gastric injury in 72%, and duodenal injury in 16%. There were no grade 3 injuries. The upper gastrointestinal tract injuries caused by glyphosate-surfactant were minor in comparison with those by other strong acids. The WBC count, amount of glyphosate-surfactant ingested, length of hospital stay and the occurrence of serious complications increased markedly in the group which had grade 2 esophageal injuries. Thus, the severity of the esophageal injuries may be a prognostic factor for the patient with glyphosate-surfactant ingestion. The UGI endoscopy may be indicated for grading esophageal injury in patients who have ingested glyphosate-surfactant in amounts greater than 100 ml. Physicians should pay more attention to the patients with grade 2 or 3 esophageal injuries to prevent serious complications and to provide aggressive supportive care.

Histopathologic evaluation of the therapeutic efficacy of water and milk dilution for esophageal acid injury

OBJECTIVE

To determine whether acid-induced injury to the esophagus is decreased by early dilutional therapy with water or milk.

METHODS

A controlled in-vitro animal model for acid injury to the esophagus was carried out using esophagi harvested from 70 Sprague-Dawley rats of both sexes and weighing 250-350 g. One control and six experimental groups each containing ten esophagi were instilled with 1 mL of 0.5 normal solution of hydrogen chloride (N HCl). Dilution with water or milk was performed at 0, 5, or 30 minutes postinjury in the experimental groups. No dilution was performed with the control group. Specimens were maintained in an oxygenated saline bath for a 60-minute experimental period and then fixed in 10% formalin for histologic evaluation. Injury severity was rated by blinded histopathologic examination using scores of 0 (no injury), 1 (minor), 2 (moderate), and 3 (severe) for the histopathologic categories: cornified epithelial cells (CEs), granular cells (GCs), granular cell nuclei (GNs), and basal cells (BCs). Red blood cells were scored as positive or negative for lysis.

RESULTS

The controls showed the most severe outcomes. Significant differences in injury occurred for all time periods and histopathologic categories, except for the GN/water and BC/milk histopathologic category/treatment groups. However, a linear trend analysis was significant for all histopathologic categories except BC. These analyses support decreased injury in the earlier treated groups. Injury severity was highest in the most superficial cell layer (CE).

CONCLUSIONS

Emergency therapy with water or milk reduces acute acid injury to the esophagus. Earlier treatment is associated with decreased injury severity. This research supports the use of dilutional therapy with water or milk for acute acid injury to the esophagus.

Battery acid burns of the upper gastro-intestinal tract

Strong acid ingestion produces distinctly different injuries from alkali burns. Alkali burns are well described but the lack of literature on the diagnosis and management of acid burns is apparent. This retrospective review of 18 patients with battery acid (30% sulphuric acid) ingestion showed no correlation between the severity of the symptomatology and the degree of injury. The quantity of acid needed to cause a significant upper GIT burn was more than 200 ml. Previous reports that acid spared the oesophagus due to rapid transit were disproved, since oesophageal involvement was found in 55% (10/18). Deep burns rather than circumferential burns resulted in stricture formation. The major injury site was the gastric antrum with 4 patients (23%) requiring surgical intervention to restore function.

The effect of milk on ipecac-induced emesis

A prospective study at two regional poison centers was undertaken in 500 children under six years of age (mean age 2.3 y) to resolve the question of whether milk has an effect on ipecac-induced emesis. When home administration of ipecac was recommended, parents were asked to select either milk or clear fluids. The mean volume of fluid +/- standard deviation administered was 159 +/- 72 mL in the milk group and 161 +/- 77 mL in the clear fluid group (p = 0.79). There was no difference in the onset of vomiting (23.4 +/- 18.5 vs. 23.3 +/- 12.9 min, p = 0.92), number of vomiting episodes (3.5 +/- 1.9 vs. 3.4 +/- 1.8, p = 0.65), or duration of vomiting (45 +/- 73 vs. 39 +/- 54 min, p = 0.31) for the milk group compared with the clear fluid group. Side effects including lethargy and diarrhea occurred with similar frequency in both groups. The substance ingested had no effect on onset of vomiting, vomiting duration or number of vomiting episodes. These findings again demonstrate that milk does not interfere with ipecac-induced emesis.

Tracheoesophageal fistula secondary to muriatic acid ingestion

Acid ingestion may result in a variety of early and late complications. A patient is presented with severe sequelae from muriatic acid ingestion, including a tracheoesophageal fistula which is a previously unreported complication of acid ingestion injury. Recommendations are made for diagnosis and prevention of this potentially lethal complication.

Metabolic abnormalities associated with phosphoric acid ingestion

A 64-year-old man ingested a phosphoric acid solution in a suicide attempt. He subsequently developed hyperphosphatemia, hypocalcemia, and systemic metabolic acidosis. Local caustic effects of the acid were mild. The patient recovered and was lost to follow-up.

Caustic injuries to the esophagus in children

The ingestion of caustic chemical agents, usually accidentally by children, produces a wide range of injuries from minor mouth burns to necrosis of the esophagus and stomach. The type of agent, amount, concentration, and duration of exposure are the determining factors. The treatment for the average burn is fairly well standardized, but the serious injuries require prompt recognition of complications and appropriate therapy to prevent more serious complications.

Gastric lavage

Gastric lavage has been used to manage toxic ingestions since the early 1800s. The entire realm of gastrointestinal decontamination has been extensively studied for the past 30 years. Recommendations are still evolving and remain controversial. The current indications for lavage are obtundation, unprotected airway, seizures, the need for urgent removal, and the tendency to form concretions. Hydrocarbon management depends on specific toxicity and viscosity. Contraindications for this procedure are insignificant ingestions, prolonged time since ingestion, and caustic poisoning. Proper technique minimizes complications and maximizes toxin removal. Activated charcoal and a cathartic are given after lavage. Complications include nasal trauma, esophageal perforation, tracheal intubation, aspiration, electrolyte imbalance, and hypothermia.

Liquid caustic ingestions: an in vitro study of the effects of buffer, neutralization, and dilution

Changes in pH and temperature of solutions of common commercial liquid caustics were determined in vitro following the addition of neutralizing agent, buffer, and diluent. Neutralization of strong base was complete following the addition of less than twice the volume of weak acid with only a minimal release of heat. Buffer added to a strong acid caused an immediate temperature elevation without changing the pH; a gradual rise in pH followed. Large volumes of diluent caused little change in temperature or pH of either strong base or strong acid. We conclude that dilution as a first-aid measure is ineffective, whereas buffer is ineffective and possibly harmful. Neutralization is effective in reversing pH change, but in vivo studies are needed to confirm the relative roles of pH extremes and heat in the genesis of tissue injury.

Gastric damage from ingested acid in children

Acid ingestion occurs relatively rarely and produces a spectrum of injury that is markedly different from the more commonly encountered alkaline burns of the oropharynx and esophagus. Gastric damage results from pylorospasm with pooling of the ingested caustic in a dependent location. Symptoms may be delayed for days or weeks. Perforation and/or strictures may require extensive gastric surgery. Early fiberoptic endoscopy is essential.

Nasogastric Intubation as Sole Treatment of Caustic Esophageal Lesions

In this partly retrospective and partly prospective study, we examined 200 patients with suspected caustic ingestion. No steroids were administered to the patients involved. Lesions in the esophagus were found in 93 patients. Thirty-two patients with deep circular burns had nasogastric tubes inserted immediately. Of these patients, two developed esophageal strictures, but subsequent dilatation was successful. No stricture formation was observed in the group of patients with noncircular lesions. We feel that this low percentage of stricture formation is due to the use of nasogastric tubes. Since neither the presence nor the severity of esophageal burns is predictable, an endoscopy should be performed in all suspected cases. In the absence of severe pharyngeal lesions, the use of a flexible fiberoptic endoscope is preferable because it also allows examination of the stomach and proximal part of the duodenum.

Chemical burns of the upper gastrointestinal tract

Burns of the upper gastrointestinal tract, caused by acids, alkalis, drugs or heat may lead to stenoses, some of them severe, to perforations, to inanition and to the patient's death. The type of damage differs among the various groups of noxious agents. First aid at home is almost non existent. On admission every effort must be made to identify the ingested material. Parenteral fluids and antibiotics are used and in some patients nutritional support will be required. The extent of the damage must be evaluated endoscopically. Strictures, caused by intramuscular collagen formation, could possibly be prevented by steroid therapy. If stenoses occur, these must be cautiously dilated. A late complication of oesophageal burns is carcinoma. There appears to be a relation between this grave complication and the use of very hot beverages in certain countries where oesophageal cancer is common. Upper gastrointestinal burns are similar to skin burns, however, their dangers may be greater as they occur in a pipe-like structure and very close to vital viscera.