The incidence of OH during acute SCI has only been evaluated by two observational studies to date. Illman et al. (2000) observed patients who were undergoing initial physiotherapy treatments. BP was monitored during the baseline rest period, mobilisation treatment period, and upon resumption of the resting period. OH occurred during 73.6% of treatment sessions, and was present for all patients on at least one treatment occasion. Additionally, the incidence of OH was higher among tetraplegic patients compared to paraplegic patients. Sidorov et al. (2008) performed a retrospective review of patients admitted to an acute SCI unit, beginning from the time of hospital admission and continuing for the duration of the first month following injury. The observed incidence of OH in this population was 60%, with a significantly higher occurrence among patients with cervical and upper thoracic SCI than among those with lower thoracic and lumbar SCI (p<0.01).
The incidence of orthostatic hypotension ranges from 60% to 74% in acute SCI patients, and is more common in higher versus lower injuries and patients with tetraplegia versus paraplegia (based on two observational studies; Sidorov et al. 2008; Illman et al. 2000).
Orthostatic hypotension is a commonly occurring complication during the acute phase post SCI; Patients with higher levels of injury are more susceptible to the development of orthostatic hypotension.