Increases of peripheral blood pressure in men with cervical spinal cord injuries

Patients with cervical spinal cord injuries (CSCI) experience hypotension mainly caused by attenuated total peripheral resistance. Some physicians and nurses believe that this peripheral blood pressure (PBP) decrease in patients with CSCI results in the formation of pressure injuries. We hypothesized that the measurement of PBP, such as arteriole and capillary pressure, could be a simple and efficient means of detecting skin and deep tissue damage in patients with CSCI. However, PBP in the skin has not been measured in patients with CSCI. The purpose of this study was to investigate PBP in patients with CSCI. Eleven men patients with CSCI with a lesion between C6 and C7 (American Spinal Injury Association score A, average age 32.5 years) and 13 healthy participants (average age 40.1 years) participated in the study. To measure PBP, laser Doppler blood flowmetry with a fixed pressure transducer was gently applied to the pretibial skin, and the pressure when skin blood velocity was zero was determined as the PBP. The mean blood pressure (MBP) was measured simultaneously. There was a significant correlation between MBP and PBP in patients with CSCI, but not in healthy individuals. A significantly lower MBP was observed in patients with CSCI (means ± SE; 76.7 ± 3.9 mm Hg) than in healthy individuals (means ± SE; 91.0 ± 4.0 mm Hg). PBP in patients with CSCI (means ± SE; 55.7 ± 2.0 mm Hg) was significantly greater than in healthy individuals (means ± SE; 45.9 ± 2.3 mm Hg). Transection of the sympathetic nervous system from the medulla to the peripheral nerves in patients with CSCI results in decreased MBP and increased PBP. We suggest that cervical spine transection diminishes the tonic impulses of sympathetic nerves to resistant vessels in patients with CSCI.