Blood Pressure Variability Associates with Six-Month Outcomes in Acute Cervical Spinal Cord Injury: An Analysis of 105 Patients

Abstract

Blood pressure variability (BPV) has been shown to correlate with poor outcomes in patients with intracerebral hemorrhage (ICH) and traumatic brain injury. However, this association has not been elucidated in patients with traumatic cervical spinal cord injury (cSCI). We hypothesized that 24-hour BPV from time of admission is associated with worse outcomes in patients with cSCI. We performed a retrospective chart review analysis of adult patients at Huashan Hospital Fudan University between January 2006 and September 2022. We included isolated patients with traumatic cSCI within 6 hours of injury. Outcomes of patients with cSCI were assessed using 6-month American Spinal Injury Association (ASIA) impairment scale grade, and were dichotomized into poor (ASIA grade A-C, or decreasing ASIA grade compared with baseline) and good (ASIA grade D and E, or increasing ASIA grade compared with baseline) outcome groups. Blood pressures (BPs) were recorded during the first 24 hours of hospital course. BP was analyzed in the hyperacute period, from 0 to 4-5 hours; and in the acute period, from 4-5 to 24-25 hours after admission. BPV was analyzed by standard deviation (SD), coefficient of variation (CV), and successive variation (SV) of systolic BP (SBP). We analyzed 105 patients' charts. The first BP assessment, on emergency department arrival, at median 267 minutes (interquartile range, 152-312 minutes) after onset of injury was mean 152.2 mm Hg (SD, 51.8 mm Hg). The second BP assessment, on neurosurgical intensive care unit arrival, was mean 148.1 mm Hg (53.2 mm Hg). Poor outcomes occurred in 63 patients (60%). In univariate analysis, univariate quintile analysis or multivariate analysis, SBPSD, SBPCV, and SBPSV were associated with poor outcomes in both the hyperacute and the acute period. BPV during the first 24 hours after injury in patients with traumatic cSCI was independently associated with poor functional outcome at 3 months. Stabilization of BPV during the hyperacute and acute period may be a therapeutic target to improve functional outcomes of these patients.