Emergency management and sequelae of acid ingestion

Successful Treatment of Potentially Fatal Heavy Metal Poisonings

Pure inorganic heavy metal ingestions for suicidal intent are a rare occurrence. Most case reports on this subject focus on the serious neurological, hepatic, or renal side effects. We describe two cases of significant heavy metal poisonings (arsenic trioxide and mercuric chloride) that were successfully managed with aggressive decontamination and combined chelation therapy. Both chemicals were obtained in pure powder form through the Internet.

[Endoscopic dilatation of caustic esophageal strictures]

OBJECTIVE

To evaluate the results of endoscopic dilatation in caustic esophageal strictures and to analyze the factors associated with a favorable response.

PATIENTS AND METHOD

We performed a retrospective study of 33 patients who underwent dilatation with Savary bougie between 1989 and 2001. Response to initial dilatation and outcome during follow-up were analyzed.

RESULTS

The mean age was 50 years (8-83) and 58% were women. Intake was accidental in 29 (88%). In all patients, the caustic substance ingested was alkali. Dilatation was started in the acute phase in 12 patients (36%) and 13 presented inflammatory phenomena adjacent to the stenosis. During initial dilatation, 2 1.6 sessions (2-18) were performed and a favorable response was obtained in 18 patients (54%). At the end of follow-up, 68% of the patients presented satisfactory health status. The comparative study revealed that statistically significant variables for a favorable response to treatment were: accidental alkali intake, instauration of treatment in the chronic phase, absence of inflammatory phenomena, and a small number of initial dilatation sessions.

CONCLUSIONS

In our series, more than half the patients with esophageal stenosis due to intake of corrosive alkalis showed a favorable initial response. In these patients with acute-phase stenosis who required a greater number of initial dilatation sessions, endoscopic therapy was less effective.

Thermal characteristics of neutralization therapy and water dilution for strong acid ingestion: an in-vivo canine model

OBJECTIVE

To determine whether in-vivo neutralization therapy for acid ingestions will superimpose a thermal injury upon tissue already damaged by acid.

METHODS

An in-vivo canine model was used with repeated measures of tissue and luminal temperatures. All dogs were placed under halothane general anesthesia. The stomach was exteriorized and temperature probes were placed in the lumen and mucosa. 25 mL of 0.5 N HCl (25 degrees C) was placed in the gastric lumen followed 5 minutes later by 75 mL of either 8% NaHCO3 neutralization (25 degrees C, n = 10) or water dilution (25 degrees C, n = 10). Temperature measurements were recorded at specified intervals for 5 minutes post HCl acid exposure and for 30 minutes post treatment. Temperature profiles were analyzed by repeated-measures ANOVA. Post-treatment changes were evaluated using signed-rank tests.

RESULTS

In both treatment groups, treatment resulted in significant decreases in initial mucosa and intraluminal temperatures. Both the mucosa and intraluminal temperatures decreased immediately after treatment with HCO3 by an average of 1.6 degrees C (p = 0.05). In the water dilution treatment group, both temperatures decreased by 1.1 degrees C (p = 0.05). Ensuing post-treatment temperatures increased but did not reach baseline temperatures at any time up to 30 minutes post treatment.

CONCLUSIONS

In the in-vivo setting, there is no evidence of hazardous temperature elevation when a weak alkali or dilution therapy is used to neutralize strong acid-induced injury. Contraindication of this form of emergency treatment should not be based on the preconceived idea that a resultant exothermic reaction will cause a superimposed thermal injury. Further clinical study is needed to determine the clinical utility of this emergency therapeutic modality.

Effective treatment of acute alkali injury of the rat esophagus with early saline dilution therapy

BACKGROUND

Controversy persists regarding the appropriate treatment of acute alkali injury to the esophagus. The current study establishes a controlled model of alkali esophageal injury and examines the efficacy of saline dilution therapy.

STUDY HYPOTHESIS

Early saline dilution therapy effectively reduces esophageal injury resulting from acute alkali exposure.

METHODS

The esophagi were harvested from 60 Sprague-Dawley rats. Each end was cannulated with a 20-gauge catheter. Specimens were maintained in an oxygen-perfused saline bath (37 C) during a 60-minute experimental period and then fixed immediately in 10% formalin solution for histologic examination. Three experimental groups (A, B, and C) were perfused with 50% NaOH solution at time zero. Treatment with saline perfusion was performed immediately in group A, five minutes after injury in group B, and 30 minutes after injury in group C. The positive control group D was perfused with saline at time zero. A negative control, group E, was perfused with 50% NaOH at time zero. This group did not receive subsequent treatment with saline. Pathologic examination was performed in a blinded fashion using a score of 0 to 3 (0, no injury; 1, minimal; 2, moderate; 3, severe) for seven histologic criteria: epithelial viability, extent of injury, cornified epithelial cell differentiation, granular cell differentiation, epithelial cell nuclei, muscle cells, and muscle cell nuclei.

RESULTS

The positive control group demonstrated scores of zero. Nonparametric analysis showed a significant difference among treatment groups for each injury category. Trend analysis revealed a significant progression of injury for each category associated with time to treatment. Discriminant analysis indicated that the muscle cells category was the most useful category with which to distinguish injury among groups.

CONCLUSION

In our model, saline lavage decreased objective evidence of esophageal injury after a severe alkaline exposure, and early therapy enhanced this beneficial effect.

Extensive multi-organ necrosis secondary to sulfuric acid ingestion

This is a report of a case in which a significant quantity of sulfuric acid was ingested, causing life threatening respiratory distress, secondary to glottic injury and edema, and cardiovascular collapse. Vigorous resuscitive efforts allowed survival through the first 48 hours and two major operations. Persistent and complex surgical management eventually restored oropharyngeal competence and gastrointestinal integrity. Survival of a child from such an overwhelming injury has not been previously reported.

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.

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.

Acid ingestion: toxicology and treatment

The effects of strong acid ingestion are distinctly different from those of alkali. Strong acids produce superficial injuries to the esophagus and deep injuries to various portions of the stomach. Prevailing early treatment recommendations of simple dilution or weak-base neutralization are inappropriate because of their extraordinary thermal results. Dilution of concentrated sulfuric acid with an equivalent volume of water results in a temperature elevation of approximately 80 C. Neutralization results in even greater heat production. Vigorous gastric aspiration prior to cold fluid lavage is the management of choice in cases treated immediately following acid ingestion.

Caustic esophageal and gastric erosion without evidence of oral burns following detergent ingestion

The effects of accidental ingestion of a caustic detergent are studied in the report of 14 patients seen in the Hennepin County Medical Center. Since the history of amount ingested was unclear, all patients underwent endoscopy. Four patients had esophageal injury serious enough to warrant hospitalization. None of the patients had evidence of oropharyngeal burns, thus challenging the validity of the widely held notion that oral lesions nearly always accompany esophageal injury following caustic ingestion. The importance of analyzing the ingested substance is emphasized, as is the need for emergency departments to have wide range pH paper available to help determine the necessity for endoscopy.