Hypotension, Orthostatic clinical trials

Controlling Orthostatic Hypotension in People With Cervical Spinal Cord Injury

A common therapeutic intervention after spinal cord injury (SCI) is prolonged standing in a standing frame. For people with SCI, standing for 40 minutes or more, three to four times weekly improves several health-related issues including well-being, circulation, skin integrity, reflex activity, bowel and bladder function, digestion, sleep, pain, and fatigue. However, a person who experiences orthostatic hypotension (OH)-defined as a decrease of 20mm hg in systolic blood pressure or a decrease of 10mm hg in diastolic pressure within 3 minutes of standing from a sitting or supine position-secondary to SCI may not tolerate positioning in a standing frame, thus resulting in a loss of access to these health benefits. OH is common for people with SCI. It results from central nervous system dysregulation causing pooling of blood in the lower extremities that can lead to dizziness, light-headedness, blurred vision, weakness, fatigue, nausea, palpitations, headache, and/or syncope. Although an array of physical and pharmacologic interventions are available to people in the general population for managing OH, few such interventions have been evaluated for use by people with SCI, especially when the level of injury is C5 or above. One possible intervention that may be effective for people with OH secondary to SCI is functional electrical stimulation (FES) because its application results in a dose-dependent increase in blood pressure. An unanswered question is whether the placement of FES electrodes on various parts of the body has differential effects. Therefore, the purpose of this study is to evaluate blood pressure responses among people with OH secondary to cervical SCI when receiving FES intervention involving the placement of electrodes in three different positions as well as when receiving no FES intervention during tilt table sessions. The selected positions for electrode placement are: (a) the calves, (b) the quads and abdominals, and (c) the quads, abdominals, and calves. The researchers hypothesize that FES intervention, regardless of placement, will result in better control of OH than no FES intervention and that no significant blood pressure difference will occur across the three FES placements.