Study objective: To gather preliminary data on the safety and efficacy of IV magnesium in a rat model of hydrofluoric acid burns.
Model: Forty-seven anesthetized male rats (200 to 300 g) received a standardized burn with 52% hydrofluoric acid.
Interventions: Animals were anesthetized with 30 to 50 mg/kg ketamine IM and 1 to 3 mg/kg xylazine IM. A standardized chemical burn was created by topical application of 52% hydrofluoric acid. The rats were divided into four treatment groups: group 1 received no treatment; group 2 received intradermal injection of 10% calcium gluconate; group 3 received 80 mg/kg MgSO4 IV; and group 4 received 160 mg/kg MgSO4 IV. After the rats were killed, the burn lesions were excised and examined by a pathologist to determine the grade of burn (which was equal to the clinical degree of burn).
Measurements and main results: Microscopic examination of the burns revealed differences among the four groups. Five of 13 group 1 rats (37%) died within 24 hours of burn initiation. Of group 1 survivors, 50% had grade 2 burns, and the other 50% had grade 3 burns. In group 2, eight of 11 rats (73%) had grade 3 burns. Twenty-five percent of group 3 rats (three of 12) had grade 3 burns, and only 9% of group 4 rats (one of 11) had grade 3 burns. Only the difference in the rates of grade 3 burns for groups 2 and 4 was statistically significant. Although not statistically significant, burns in groups 3 and 4 tended to be smaller in diameter than burns in groups 1 and 2.
Conclusion: High-dose IV magnesium sulfate reduces the severity of hydrofluoric acid burn compared with conventional intradermal calcium gluconate therapy. Early deaths appeared to be prevented by both calcium and magnesium therapies.