Does a new MRI on-call service improve the timely imaging for suspected cauda equina syndrome?

Cauda equina syndrome (CES) develops due to compression of cauda equina nerve roots and requires urgent diagnosis, preferably using MRI. This will allow timely intervention to prevent irreversible neurological problems. On-call services can potentially reduce time taken to diagnose CES outside of standard operational hours. Most acute hospitals in the UK do not have on-call provisions for CES. This study therefore assessed whether introducing a short period of on-call service at an acute hospital significantly reduced the time in diagnosing CES. This can form the decision for future operational changes with possible replication in similar settings.

The study was retrospective, comparing MRI exam time between the 12 months prior to the introduction of the on-call service and the 12 months post-introduction. One hundred sixteen patients with suspected CES during each timepoint were randomly sampled and data were analysed using Mann Whitney U, Kruskal-Wallis and chi-squared tests.

Average MRI examination time (from request to report) was reduced by 0.7 h in the post-on-call timepoint compared to the pre-on-call timepoint, but this was not statistically significant (U = 6558.0, p = 0.739). However, for patients referred during the on-call period (19.30 to 22.00), examination time was reduced by 14.2 h (over 70%) in the post on-call timepoint compared to the corresponding period in the pre on-call timepoint. Also, grouping data by referral periods, there was a statistically significant difference between the two timepoints (H = 74.5, d. f = 5, p < 0.001). All the requests received during the on-call hours of the post on-call timepoint were completed within 24 h which was above the 95% target while only 85% completion was achieved in the corresponding period of the pre on-call timepoint. However, this difference was not statistically significant (χ2 (5) =8.4, p = 0.137) CONCLUSION: This study demonstrated that though the short period of on-call reduced the overall MRI examination time for CES slightly, the reduction was not statistically significant.