EFFECTIVE TREATMENT FOR ACUTE ALKALI INJURY TO THE ESOPHAGUS USING WEAK-ACID NEUTRALIZATION THERAPY - AN EX-VIVO STUDY

Objective: 1) To evaluate whether neutralization therapy with weak aci d is effective in reducing observed histopathologic esophageal tissue injury secondary to liquid alkali, 2) to quantify the temperature chan ge of the neutralizing agent, and 3) to determine the effect of interv al to therapy on injury severity. Methods: Harvested Sprague-Dawley ra t esophagi were catheterized and placed in an oxygenated saline bath ( 37 degrees C) for 60 minutes and then fixed in 10% formalin. Nine grou ps (n = 10) were perfused with 50% sodium hydroxide (NaOH). Six of the groups were treated by neutralization with cooled orange juice (OJ) o r cola that was maintained between 2 degrees C and 4 degrees C. This w as performed at 0, 5, or 30 minutes after injury. In addition, two pos itive control groups were exposed to OJ or cola at time 0 and were not exposed to strong alkali. a third control group was exposed to strong alkali but was not administered any subsequent treatment. The tempera ture of the neutralizing agent was recorded prior to instillation and after exiting the esophagus. Blinded pathologic scoring of 0 (no injur y) to 3 (severe) was performed for six histopathologic categories: epi thelial cell viability, cornified epithelial cell differentiation, gra nular cell differentiation, epithelial cell nuclei, muscle cells, and muscle cell nuclei. Comparisons were made among treatment times using the Kruskal-Wallis test and linear trend analysis. Results: For each h istopathologic category and each treatment mode. the Kruskal-Wallis te st showed significant differences between the groups (p < 0.002) over time. Trend analyses showed more severe injury with delayed neutraliza tion therapy (p < 0.05) for each treatment mode and histopathologic ca tegory. Conclusion: Early neutralization therapy with OJ or cola reduc es acute esophageal alkali injury. Additional in-vivo study is needed before neutralization therapy is adopted for clinical use.