A systematic review of the evidence supporting a role for vasopressor support in acute SCI

Abstract

Study design: A systematic review of clinical and preclinical literature. Objective: To critically evaluate the evidence supporting a role for vasopressor support in the management of acute spinal cord injury and to provide updated recommendations regarding the appropriate clinical application of this therapeutic modality. Background: Only few clinical studies exist examining the role of arterial pressure and vasopressors in the context of spinal cord trauma. Methods: Medical literature was searched from the earlier available date to July 2009 and 32 articles (animal and human literature) answering the following four questions were studied: what patient groups benefit from vasopressor support, which is the optimal hypertensive drug regimen, which is the optimal duration of the treatment and which is the optimal arterial blood pressure. Outcome measures used were the incidence of patients needing vasopressors, the increase of arterial blood pressure and neurologic improvement. Results: Patients with complete cervical cord injuries required vasopressors more frequently than either incomplete injuries or thoracic/lumbar cord injuries (Po0.001). There was no statististical difference in neurologic improvement between patients on vasopressor support with a mean arterial pressure (MAP) of less than 85 mm Hg and those with MAP less than 90 mm Hg. Duration of treatment is often recommended between 5 and 7 days although this is not supported by high-level evidence and no single vasopressor appeared superior over the variety used in clinical treatment. Conclusion: There is currently no gold standard on vasopressor support. Based on non-randomized human studies, complete cervical cord injuries require vasopressors more frequently than other spinal cord injuries.

Effect of norepinephrine on spinal cord blood flow and parenchymal hemorrhage size in acute-phase experimental spinal cord injury

“…To maintain MABP above 85 mmHg after SCI, norepinephrine (NE) is considered a vasopressor of choice [10,11]. However, we are aware of no experimental studies assessing the effect of NE on SCBF or hemorrhage size.…”

“…A widely recommended method for increasing SCBF consists in maintaining the mean arterial blood pressure (MABP) above 85 mmHg for 1 week after the injury. However, published evidence supporting this recommendation is scant [9][10][11][12]. All the clinical studies were level III or IV and, for ethical reasons, none included a control group.…”

A prospective evaluation of hemodynamic management in acute spinal cord injury patients

“…It is one thing, however, to appreciate and acknowledge 'practice guidelines' and 'recommendations' , and quite another to actually translate and implement these effectively in patients. Despite the fact that numerous reviews have been conducted on the topic of MAP support in acute SCI, [10][11][12] to our knowledge, there are no published reports that specifically evaluate how successfully target MAPs were maintained in acute SCI patients. Therefore, the purpose of this study was to evaluate the observed MAP in a cohort of prospectively evaluated acute SCI patients, in order to determine how closely the intended MAP was actually achieved in these individuals.…”

Importance of checking prehospital neurological findings to reveal incidence of spinal cord concussion

“…In patients with cervical cord injury, bradycardia and hypotension may occur due to suppression of the sympathetic tone following predominance of the vagus. 10,11 The autonomic nervous system regulates many different target tissues in the somatic and visceral domains of the body in a differentiated manner, indicating that there apparently exist separate sympathetic pathways that are functionally defined by their target cells. 12 Most of the actions of the autonomic nervous system are involuntary, whereas some activities, such as breathing, can also be controlled by conscious patients.…”

“…14,15 Neurogenic shock tended to occur more frequently in patients with complete cervical cord injury in comparison with those with incomplete or spinal cord injury without a cervical lesion. 11 The spinal cord concussion is different from complete spinal cord injury, so patients with a spinal cord concussion do not generally demonstrate neurogenic shock. However, animal studies have shown that severe concussion can cause death via profound autonomic dysfunction, without leaving anatomical evidence of injury, and there was a rare clinical case who may have died due to a vasovagal stimulus after blunt trauma.…”