Thermal effects of neutralization therapy and water dilution for acute alkali exposure in canines

Objective: To evaluate the change in temperature of the gastric mucosa and lumen contents when a weak acid or water is used to manage acute alkali exposure. Methods: A prospective in-vivo canine model was used in a university-based animal laboratory setting. Eighteen adult canines weighing 20-25 kg were placed under a surgical plane of anesthesia and a laparotomy was performed. A gastrotomy was then made after ligation of the distal esophagus and proximal duodenum. Separate mucosa and lumen temperature probes were placed. Then 25 mL of room-temperature (24-26°C) 50% sodium hydroxide (NaOH) was instilled in the gastric lumen. After 5 minutes, each canine was given treatment. Group 1 (n = 10) was treated with 75 mL of room-temperature orange juice. Group 2 (n = 8) was treated with 75 mL of room-temperature water. Continuous mucosa and lumen temperatures were observed and recorded at baseline and at specified intervals for 35 minutes after the alkali insult. Repeated-measures analysis of variance was used to evaluate the overall temperature profile. Signed-rank tests were used to compare the changes in temperature immediately following neutralization treatment. Results: Significant temperature decreases of 1.1°C and 2.1°C were observed for both mucosa (p = 0.002) and lumen (p < 0.001) temperatures, respectively, following neutralization therapy with room-temperature orange juice. In the group treated with room-temperature water, significant temperature decreases of 2.1°C for mucosa (p = 0.01) and 2.4°C for lumen (p = 0.01) were observed. Posttreatment temperatures did not exceed baseline for the entire observation period. Conclusion: Neutralization therapy with room-temperature orange juice or water dilution for acute gastric injuries by liquid alkali does not cause a rise in mucosal or intraluminal temperatures in an in-vivo canine model.