Introduction: Guidelines for the care of patients with acute spinal cord injuries (SCIs) recommend maintaining MAP values of 85-90 mmHg for 7d following an acute SCI, however little evidence supports this recommendation(1). We sought to better characterize the relationship between MAP values and neurological recovery.

Methods: Arterial line MAP values were collected every minute from 100 spinal cord injured patients over a 6y period. 73 patients also had AIS grades determined on admission and at time of hospital discharge. The proportion of MAP values below thresholds were explored for values from 120 mmHg to 40 mmHg in 1 mmHg increments; these thresholds were analyzed within 1d, 3d, 5d, and 7d of ICU admission for a relationship with outcome.

Results: A total of 994,875 q1 minute MAP values were recorded. Within 7d of injury 28.2% of measures were below 85 mmHg. Higher MAP values were consistently seen throughout the first 7d in patients achieving greater degrees of neurological recovery. A MAP threshold of 85 mmHg robustly distinguished patients achieving a 1-point AIS grade improvement from those achieving 2 or 3 points of improvement. Patients achieving a 1-point AIS grade improvement had greater proportion of MAP recordings below 100 mmHg than those who did not improve neurologically.

Conclusions: This study provides strong evidence supporting a correlation between MAP values and neurological recovery but does not provide evidence of a causal relationship. It provides support for the notion of MAP thresholds in SCI recovery and the highest MAP values correlated with the greatest degree of neurological recovery. The results are concordant with current guidelines in suggesting that MAP thresholds >85 mmHg may be appropriate following acute SCI.

Patient Care: This data provides strong evidence demonstrating that blood pressure correlates with outcome following SCI. This is an important finding, however further research to determine if blood pressure augmentation leads to improved outcomes is needed.

Learning Objectives: 1. Understand that the data supporting blood pressure recommendation for acute spinal cord injury is limited. 2. Understand the relationship between MAP values and neurological recovery following acute human spinal cord injury as seen in our study. 3. Understand that the presented data does not provide evidence that blood pressure augmentation improves outcome.

References: 1. Ryken TC, Hurlbert RJ, Hadley MN, Aarabi B, Dhall SS, Gelb DE, Rozzelle CJ, Theodore N, Walters BC. The acute cardiopulmonary management of patients with cervical spinal cord injuries. Neurosurgery. 2013 Mar;72 Suppl 2:84-92.