SRS40 - Are out-of-hours transfers for MRI in suspected cauda equina syndrome justified?

Abstract Cauda equina syndrome (CES) is a neurological emergency requiring timely surgical decompression within 24 h of MRI confirmation. Limited out-of-hours (OOH) MRI access often necessitates emergency patient transfers to acute spinal centres. This study assesses the justification for such transfers. This retrospective cohort study analysis from April 2019 to March 2025, utilised electronic health records and referral data to UCLH (NHNN) which totalled 5525 OOH referrals for suspected CES. 706 patients were accepted for transfer. 285 were referred with local MRIs before referral, leading to 135 surgeries for CES. 116 were transferred after awaiting a local MRI, leading to 61 surgeries for CES. 305 patients were transferred for an urgent MRI with 37 requiring surgeries for CES. There was a significant difference in time from MRI to surgery for patients who awaited a local MRI (21.74 ± 1.67 h) versus those transferred for an MRI (9.25 ± 2.11 h) although both groups met the guideline target of undergoing surgery within 24 h of a scan (MWUT = 309.0, P = 2.76e-9). OOH MRI sensitivity was 9.8%. Patients with a negative scan result remained hospitalised for a mean of 69.76 ± 8.37 h until discharge, with an average admission cost of £3014.55. OOH referrals predominantly originated from doctors below ST4, with diagnostic accuracy of 4.2% compared to 5.2% for those above ST4 (χ² = 0.031, P = 0.86). OOH MRI transfers yield limited surgical benefit, accrue significant costs, and align poorly with GIRFT guidelines advocating for local MRIs to reduce unnecessary referrals. These findings support minimising OOH transfers for suspected CES.