Effects of behavior and pathological indexes of rat model suffered from spinal cord trauma under hypoxia and hypobaropathy

SHANG Yong; YANG Liqian; XU Yuxin; MEN Pengxiang; YU Panfeng

Abstract：Objective To investigate the effects of hypobaropathy and hypoxia to the model of rat with spinal cord injury, and discuss the security and protection of the patients in aero medical evacuation. Methods The experiment used 90 rats of female Sprague Dawley that weighed 200~250 g, divided them into 6 groups. We exposed spinal cord of T10 by surgery after anesthesia and made the model of spinal cord injury with NYU (impact height was 25 mm, impact weight was 10 g, contact area was 2 mm2). The control group’s background was of normal environment, not hypobaropathy and hypoxia. In contrast, the experimental group model of rat was put into low pressure oxygen cabin and reducing pressure at a constant speed to the air pressure of 2 500 m. The two groups were kept for 1 h, 2 h and 4 h respectively. Then we could measure the PaCO2 and PaO2 with arterial blood. After 24 h, we could measure hind limbs motor function of the rat (Points-scoring system use Basso-Beattie-Bresnahan and Rivlin Slope method) and the area of spinal cord hematoma. Results The PaCO2 of the groups under hypoxia and hypobaropathy was significantly higher than that in normal environment(P<0.05), while the PaO2 of the groups under hypoxia and hypobaropathy was lower (P<0.05). In the same environment, both PaCO2 and PaO2 were statistically different between the group of 4 h and the group of 1 h (P<0.05). There were no significant differences with regard to BBB method, Rivlin Slope method and the area of spinal cord hematoma (P>0.05). Conclusion The effects of PaCO2 and PaO2 of the model of rat with spinal cord injury are obvious under hypobaropathy and hypoxia with short distance (1 h), medium range (2 h), long distance (4 h) respectively. So we should take care of breath monitor and use oxygen therapy. But the effects of body function early after injury and spinal cord hematoma under hypobaropathy and hypoxia are not obvious.