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Non-pharmacological Interventions for Orthostatic Hypotension

To date, studies addressing the non-pharmacological management of OH in acute SCI are limited and have only investigated the effect of electrical stimulation. However, the effectiveness of inflatable external leg compression for acute OH has been studied in case report format (Helmi et al. 2013). There have been several more non-pharmacological modalities of treatment studied in the chronic SCI population, including fluid intake and salt loading, use of elastic stockings and abdominal binders, harness application, whole-body vibration, exercise, and stand training (refer to SCIRE Orthostatic Hypotension rehabilitation evidence chapter).

Non-pharmacological Management of Orthostatic Hypotension during Acute SCI

Discussion

Three studies have examined the non-pharmacological management of OH during acute SCI with electrical stimulation. In a RCT by Elokda et al. (2000), five patients who were, on average, 3 weeks post SCI were examined during a tilting procedure with or without functional neuromuscular stimulation (FNS) of the knee extensors and foot plantar flexors. The effect of FNS on postural-related orthostatic stress was measured at 0°, 15°, 30°, 45°, 60° tilt angles. Measures of systolic BP at 15° (p=0.05), 30° (p<0.001), 45° (p=0.04), and 60° (p=0.07) positions without FNS were significantly lower than with stimulation, while measures of diastolic BP at 30° (p=0.02) and 45° (p=0.01) without stimulation were lower than with FNS. Sampson et al. (2000) studied six patients in a RCT who underwent a tilting procedure at four functional electrical stimulation (FES) intensities (0, 48, 96, and 160 mA). Half of the participating subjects recruited for this study had an acute SCI as they were studied at 8-10 weeks post injury, while the other half were 10-14 years post injury (chronic phase of SCI). Patients were tilted by 10° increments from 0° to 90° during separate stimulation of the quadriceps and pretibial muscles, and at the patellae and malleoli. The authors observed a dose-dependent increase in BP, regardless of stimulation site. The mean systolic (p=0.001) and diastolic BP (p=0.0019) increased significantly with increasing stimulation intensities. Lastly, Tesini et al. (2013) recruited nine patients who were a median of 34 days after injury. Participants were positioned on a tilt-table at increasing angles (0°, 15°, 30°, 45°, 60°, and 70°) with varying electrical stimulation intensities being used according to each patient. The tilting procedure was conducted for three sites of stimulation, which included the abdominal muscles, lower limb muscles, and a combination of abdominal and lower limb muscles, as well as a baseline measure without stimulation. Although a tendency towards the beneficial use of ES for OH was seen, BP was not observed to differ significantly between the interventions at any degree of incline (p>0.05 for all).

Conclusion

There is level 2 evidence (from three RCTs; Tesini et al. 2013; Elokda et al. 2000; Sampson et al. 2000) that functional electrical stimulation leads to improvement of symptoms of orthostatic hypotension in acute SCI patients.

  • The use of functional electrical stimulation may be effective for the management of orthostatic hypotension during the acute phase post SCI.