Establishment and evaluation of severe head injury model for treatment with mild hypothermia / 中华创伤杂志

ABSTRACT

Objective To set up an animal model with severe head injury that is similar to clinical condition and treated with mild hypothermia. Methods A total of 120 SD rats were randomly divided into eight groups (n=15 in each group), ie, before cooling, cooling 6, 12, 24, 48, 72, 96 and 120 hours groups. The model was induced by dropping a object of 60 g from a height of 50 cm onto the epidura and treated with mild hypothermia (32-34℃). Blood pressure and ECG were observed and serum K+, Na+ and Mg 2+levels measured. The change of neuron microstructure in rat cerebral traumatic tissue of every group was observed by transmission electron microscope (TEM). Results Animal mortality increased but serum K+ and Mg 2+levels gradually decreased with the treating time lasting. Serum Na+ showed insignificant change. Bradytachycardia occurred in one rat of 72 hours group, two of 96 hours group and two of 120 hours group. TEM showed that the rat’s encephaledema presented gradual relief trend during mild hypothermia treatment. There was one rat in 96 hours group and one in 120 hours group with diffuse tubuli renales necrosis. Conclusion The established model is in conformity with the characteristics of vital sign, serum electrolyte and cerebral microstructure of clinical severe head injury treated with mild hypothermia.