Pharmacological Interventions
Studies addressing the pharmacological management of neurogenic shock in acute SCI are limited. One study investigated the effect of pseudoephedrine as an adjuvant therapy in acute SCI patients (Wood et al. 2014). Pseudoephedrine is a stimulant and amphetamine.
Discussion
A case series conducted by Wood et al. (2014) investigated the effectiveness of pseudoephedrine as an adjunctive therapy option to the use of vasopressors and atropine in acute SCI. Patients who were administered pseudoephedrine for more than one day during their hospital stay or who received vasopressor support and/or atropine were retrospectively reviewed. Treatment with pseudoephedrine was considered successful based on discontinued vasopressor and atropine use, or a reduction in bradycardic episodes following pseudoephedrine administration; effectiveness was observed in 31 of 38 (82%) of patients. The mean duration of pseudoephedrine therapy was 32 days on average. A cohort study by Readdy et al. (2015) found that patients over the age of 55 had higher rates of complications. Cardiac complications occurred in 26% of patients. Complications regardless of severity of injury and vasopressor use.
Phillips et al. (2014) conducted a prospective controlled study to examine the association between baroreflex sensitivity (BRS) and common carotid artery (CCA) stiffness, as well as the influence of midodrine on BRS and arterial stiffness. The majority of SCI participants included in this study were within 6.5-11 weeks of injury, although 1 participant had chronic SCI and was 144 weeks after injury at the time of the study. Arterial stiffness was elevated in SCI patients compared to able-bodied controls when in the upright position (p<0.05). BRS and arterial stiffness were found to be negatively associated in the upright position in SCI patients (p=0.03), indicating that reduced BRS is related to increased arterial stiffness following SCI. Midodrine administration led to increased BP and reduced HR in SCI patients; however, it had no effect on BRS or CCA parameters.
Conclusion
There is level 4 evidence (from one case series study: Wood et al. 2014) that pseudoephedrine may be an effective adjuvant for the treatment of neurogenic shock in acute SCI patients; however, this pharmacological agent may require up to one month for effectiveness.
There is level 2 evidence (from one PCT: Phillips et al. 2014a) that midodrine may lead to increased blood pressure and reduced heart rate in SCI populations compared to health controls.
