Abstract
Blood volume is influenced by physical activity. Physical activity in patients with spinal cord injury is lower than able-bodied individuals and associated with the level of lesion. We hypothesized that blood volume in patients with cervical spinal cord injury might be lower than able-bodied individuals and influenced by the level of lesion. To eliminate the effect of the lesion level, we determined blood volume by Evans blue dilution technique in 9 male patients with cervical spinal cord injury (age; 25.9 ± 1.9 years, mean ± SEM) whose level of lesions were C6 and compared them with 5 male able-bodied individuals (age; 27.6 ± 1.9). Plasma volume and blood volume in patients with cervical spinal cord injury were similar to those in able-bodied individuals. Despite the lower activity level of patients with cervical spinal cord injury in a wheelchair, blood volume did not change. Maintenance of blood volume in patients with cervical spinal cord injury is probably due to a reduction of central blood volume. The mechanism underlying reduced central blood volume appears to be lower vessel tension caused by autonomic nervous system dysfunction and/or lack of the muscle pump below the level of spinal cord lesion.
