Mean arterial pressure maintenance following spinal cord injury: Does meeting the target matter?

Abstract

INTRODUCTION Neurosurgical guidelines recommend maintaining mean arterial pressure (MAP) between 85 and 90 mm Hg following acute spinal cord injury (SCI). In our hospital, SCI patients receive orders for MAP targeting for 72 hours following admission, but it is unclear how often the patient’s MAP meets the target and whether or not this affects outcome. We hypothesized that the proportion of MAP measurements ≥85 mm Hg would be associated with neurologic recovery. METHODS Spinal cord injury patients with blunt mechanism of injury admitted between 2014 and 2019 were identified from the registry of a level 1 trauma center. Proportion of MAP values ≥85 mm Hg was calculated for each patient. Neurologic improvement, as measured by positive change in American Spinal Injury Association (ASIA) impairment scale by ≥1 level from admission to discharge was evaluated with respect to proportion of elevated MAP values. RESULTS A total of 136 SCI patients were evaluated. Average proportion of elevated MAP values was 75%. Admission ASIA grades were as follows: A, 30 (22.1%); B, 20 (14.7%); C, 28 (20.6%); and D, 58 (42.6%). One hundred six patients (77.9%) required vasopressors to elevate MAP (ASIA A, 86.7%; B, 95.0%; C, 92.9%; D, 60.3%). Forty patients (29.4%) were observed to have improvement in ASIA grade by discharge (admission ASIA A, 15%; B, 33%; C, 40%; D, 13%). The proportion of elevated MAP values was higher for patients with neurologic improvement (0.81 ± 0.15 vs. 0.72 ± 0.25, p = 0.014). Multivariate modeling demonstrated a significant association between proportion of elevated MAP values and neurologic improvement (p = 0.028). An interaction revealed this association to be moderated by vasopressor dose (p = 0.032). CONCLUSION The proportion of MAP measurements ≥85 mm Hg was determined to be an independent predictor of neurologic improvement. Increased vigilance regarding MAP maintenance above 85 mm Hg is warranted to optimize neurologic recovery following SCI. LEVEL OF EVIDENCE Therapeutic/care management, level IV.

Developing a National Trauma Research Action Plan: Results from the Neurotrauma Research Panel Delphi Survey

“…Additional specific high-priority questions for further study include the role of prehospital BP management, the role of spinal perfusion pressure management (rather than systemic pressure), and the role of BP management in pediatric patients. Although blood pressure augmentation has been commonly performed for years, there is remarkably little high-quality data to support its use 43–46 . This topic has been debated for years and is sorely in need of high-quality studies.…”

“…Although blood pressure augmentation has been commonly performed for years, there is remarkably little high-quality data to support its use. [43][44][45][46] This topic has been debated for years and is sorely in need of high-quality studies. One ongoing study of augmented systemic blood pressure in patients with acute SCI has had significant problems with recruitment.…”

Delayed, transient quadriplegia; the importance of spinal cord perfusion

“…The unusual course, however, strongly emphasises the importance of spinal cord perfusion in the postinjury management of acute spinal cord injury. The favourable impact on spinal recovery of maintenance of cord perfusion is now well established2 3 although the evidence is mostly derived from human cohort and observational studies. Nevertheless, systematic reviews over the years4 5 have consistently reported a beneficial effect of blood pressure maintenance in spite of the absence of high-level studies.…”

Autonomic Dysfunction and Management after Spinal Cord Injury: A Narrative Review

“…Mean arterial pressure (MAP) is determined as systolic blood pressure (SBP) + [2 × Diastolic Blood Pressure (DBP)]/3. During the acute stage of SCI, it is recommended to maintain mean arterial pressure (MAP) of 85–90 mm hg for seven days by IV fluid resuscitation, inotropes and chronotropes as needed [ 2 , 5 , 7 ] Chronically, persons with high thoracic and cervical SCI may stabilize with baseline sitting SBP in the 90–110 mmHg range.…”