Higher Mean Arterial Pressure Values Correlate with Neurologic Improvement in Patients with Initially Complete Spinal Cord Injuries

Abstract

Background: Traumatic spinal cord injury (SCI) guidelines recommend to maintain mean arterial pressures (MAPs) above 85 mm Hg for 7 days following SCI to minimize spinal cord ischemia. Some physicians doubt that patients with initially complete injuries benefit.

Objective: To assess the relationship between MAP augmentation and neurologic improvement in SCI patients stratified by initial American Spinal Injury Association Impairment Scale (AIS) score.

Methods: High-frequency MAP values of acute SCI patients admitted over a 6-year period were recorded, and values were correlated with degree of neurologic recovery in an analysis stratified by postresuscitation AIS score.

Results: Sixty-two patients with SCI were analyzed. Thirty-three patients were determined to have complete injuries, and of those 11 improved at least 1 AIS grade by discharge. The average MAP of initially AIS A patients who improved versus those who did not was significantly higher (96.6 ± 0.07 mm Hg vs. 94.4 ± 0.06 mm Hg, respectively; P < 0.001), and the proportion of MAP values <85 mm Hg was significantly lower (13.5% vs. 25.6%, respectively; P < 0.001). A positive correlation between MAP values and outcome was also observed in AIS B and C patients but was not observed in patients who were initially AIS D.

Conclusion: A positive correlation was observed between MAP values and neurologic recovery in AIS A, B, and C patients but not AIS D patients. These data raise the possibility that patients with an initially complete SCI may derive greater benefit from MAP augmentation than patients with initial AIS D injuries.

Keywords: Blood pressure; Complete; Outcome; Spinal cord injury; Trauma.