Division of Physical Medicine and Rehabilitation (Krassioukov)

Abstract

Objective: To review systematically the evidence for the management of orthostatic hypotension (OH) in patients with spinal cord injuries (SCIs). Data Sources: A key word literature search was conducted of original and review articles as well as practice guidelines using Medline, CINAHL, EMBASE, and PsycInfo, and manual searches of retrieved articles from 1950 to July 2008, to identify literature evaluating the effectiveness of currently used treatments for OH. Study Selection: Included randomized controlled trials (RCTs), prospective cohort studies, case-control studies, prepost studies, and case reports that assessed pharmacologic and nonpharmacologic intervention for the management of OH in patients with SCI. Data Extraction: Two independent reviewers evaluated the quality of each study, using the Physiotherapy Evidence Database score for RCTs and the Downs and Black scale for all other studies. Study results were tabulated and levels of evidence assigned. Data Synthesis: A total of 8 pharmacologic and 21 nonpharmacologic studies were identified that met the criteria. Of these 26 studies (some include both pharmacologic and nonpharmacologic interventions), only 1 pharmacologic RCT was identified (low-quality RCT producing level 2 evidence), in which midodrine was found to be effective in the management of OH after SCI. Functional electrical stimulation was one of the only nonpharmacologic interventions with some evidence (level 2) to support its utility. Conclusions: Although a wide array of physical and pharmacologic measures are recommended for the management of OH in the general population, very few have been evaluated for use in SCI. Further research needs to quantify the efficacy of treatment for OH in subjects with SCI, especially of the many other pharmacologic interventions that have been shown to be effective in non-SCI conditions. Key Words: Hypotension; orthostatic; Rehabilitation; Review [publication type]; Spinal cord injuries. © by the American Congress of Rehabilitation Medicine T HE DEFINITION OF orthostatic hypotension is typically accepted as a decrease in systolic blood pressure of 20mmHg or more, or a reduction in diastolic blood pressure of 10mmHg or more, on changing body position from a supine position to an upright posture, regardless of the presence of symptoms. 1 Numerous studies have documented the presence of OH after SCI. 2-5 OH is more common in tetraplegia than paraplegia, with prevalence rates as high as 82% for tetraplegia versus 50% for those with paraplegia immediately post-SCI. 5 This condition not only is evident in the acute period postinjury but also has persisted in a significant number of persons for many years. 6-8 Standard mobilization during physiotherapy (eg, sitting or standing) is reported to induce blood pressure decreases that are diagnostic of OH in 74% of patients with SCI, and which are accompanied by OH symptoms (like lightheadedness or dizziness) (appendix 1) in 59% of patients with SCI. 5 This in turn may have a negative impact on the ability of subjects with SCI to participate in rehabilitation. Current management approaches for the treatment of OH consist of pharmacologic and nonpharmacologic interventions. The low level of efferent sympathetic nervous activity and the loss of reflex vasoconstriction after SCI are among the major causes of OH. The decrease in arterial blood pressure after a change to an upright position in subjects with SCI appears to be related to excessive pooling of blood in the abdominal viscera and lower extremities. 10 A subsequent reduction in cardiac output and arterial pressure may lead to tachycardia. However, this reflex tachycardia is often insufficient to compensate for the lowered output and pressure. Consequently, the pooling of blood in the lower extremities and the decrease in blood pressure may resul