Analysis of risk factors for autonomic reflex dysfunction hypotension of acute spinal cord injury / 中华创伤杂志

ABSTRACT

Objective:To investigate the incidence and risk factors of autonomic reflex dysfunction hypotension in patients with acute spinal cord injury.Methods:A retrospective case control study was made on the data of 191 patients with acute spinal cord injury admitted to Seventh Medical Center of PLA General Hospital from January 2011 to December 2016, including 164 males and 27 females, aged 18-60 years with an average age of 46.4 years. The injury mechanisms of injuries were traffic accidents in 97 patients, high falling injury in 55, heavy pound injury in 30 and fall injury in 9. The injured segments included 98 patients with cervical spinal cord injury, 52 with thoracic spinal cord injury, 19 with lumbar spinal cord injury and 22 with cone injury. According to the American Spinal Injury Association (ASIA), 61 patients were classified as grade A, 52 as grade B, 38 as grade C and 40 as grade D. Autonomic reflex dysfunction hypotension was defined as a systolic blood pressure below 90 mmHg and heart rate below 60 beat/min. There were 35 patients in hypotension group and 156 patients in non-hypotension group. Incidence of autonomic reflex dysfunction hypotension was observed. The data of sex, age, body mass index, injury mechanism, fracture type, spinal cord injury segment, spinal cord injury grade, blood pressure, heart rate, combined injury and length of hospital stay were collected. Univariate analysis was used to observe the correlation between each factor and the occurrence of autonomic reflex dysfunction hypotension, to screen the suspected related factors, and then Logistic regression analysis was used to identify the independent correlation factors related to autonomic reflex dysfunction hypotension.Results:Autonomic reflex dysfunction hypotension was found in patients with acute spinal cord injury at the cervical and thoracic regions. In 98 patients with cervical spinal cord injury, 26 patients (27%) had autonomic reflex dysfunction hypotension; in 54 patients with thoracic spinal cord injury, 9 patients (17%) had autonomic reflex dysfunction hypotension. All of them showed T 5 segment or above injury. Univariate analysis showed significant differences in spinal cord injury segment and spinal cord injury grading between the two groups( P<0.01), but not in gender, age, body mass index, injury mechanism, fracture type, combined injury or not, and length of hospital stay ( P>0.05). Logistic regression analysis showed that spinal cord injury segment( OR=0.185, 95% CI 0.081-0.424) and spinal cord injury grade ( OR=0.108, 95% CI 0.048-0.244) were independent factors related to autonomic reflex dysfunction hypotension ( P<0.01). Conclusions:Spinal cord injury segment and spinal cord injury grading are independently correlated to autonomic reflex dysfunction hypotension. The higher the injury segment is and the severer the injury is, the more likely autonomic reflex dysfunction hypotension is to occur.