Orthostatic Hypotension for People with Spinal Cord Injuries

Orthostatic (postural) hypotension (OH) is a clinical feature commonly seen in spinal cord injury (SCI) subjects with cervical and high thoracic lesions. It usually gets worse during head-up tilt postural change and is relieved by lying flat. The mechanisms of regulating the arterial blood pressure (BP) are complex. Normally, BP is maintained through a rapid and effective reflex adjustment of the autonomic nervous system, and with slower humoral compensatory changes to counteract the gravitational forces on blood. The leg muscle pumping mechanism also helps to facilitate venous return and improves BP. Failure of these mechanisms may lead to OH and orthostatic intolerance symptoms. The occurrence of OH may limit active participation in intense physical rehabilitation programmes by people with SCI, and facilitate the deterioration effects of immobilization and development of undesirable secondary medical complications. Advances in understanding the pathophysiology of OH are crucial for success in combating OH. Treatment usually includes both non-pharmacological and pharmacological measures. This article provides a review of the mechanisms of normal regulation of arterial BP, the pathophysiology of OH in SCI, and the common clinical management of OH.