Comparing Continuous versus Intermittent-Threshold Drainage Strategies for Spinal Perfusion Pressure Optimization in Patients with Acute Traumatic Spinal Cord Injuries

ABSTRACT Study Design A cross-sectional study. Objective The primary objective of this study is to compare the efficacy of continuous versus threshold drainage strategies for maintaining spinal cord perfusion pressure (SCPP) in patients with new traumatic spinal cord injuries (SCI). Setting Level 1 trauma center. Methods A retrospective study of 19 patients with traumatic SCIs. SCPP was optimized at the discretion of the managing clinician using either vasopressors to increase mean arterial pressure or cerebral spinal fluid (CSF) drainage to decrease intrathecal pressure. Six patients were managed with continuous drainage (CSF drained at regular intervals regardless of SCPP) and 13 had CSF drained only when SCPP fell below 65mmHg (i.e. threshold drainage). Intrathecal pressure, SCPP, mean arterial pressure, and vasopressor utilization were compared using univariate T-test statistical analysis. Results The cohort included over 1500 time points from 19 patients. While there was no difference in rates of sub-optimal SCPP (< 65mmHg; p = 0.257), patients managed with threshold drainage were more likely to exhibit critically-low SCPP (< 50 mmHg; p = 0.003) despite also having lower average intrathecal pressures (p < 0.001). There were no differences in average SCPP, MAP, or vasopressor utilization between the two groups (p > 0.05). Conclusions Acute SCI patients managed with continuous CSF drainage were less likely to exhibit critically-low SCPPs, previously shown to be associated with worse clinical recovery. A larger, prospective cohort is needed to validate the impact of CSF drainage strategies on long-term SCI outcomes.