Re: Evaluation and management of cauda equina syndrome in the emergency department. Am J Emerg Med. 2020 38: 143–148

Long et al [1] refer to a paper of Domen et al [2] which said that a bladder U/S of >500 ml had an odds ratio of 4.0 for diagnosing CES, increasing to 15.5 if there was 1000 ml or more retention and to 48 if there was urinary retention of ≥500 ml with 2 or 3 of the following symptoms: bilateral sciatica, urinary retention or rectal incontinence. Patients who had normal perianal sensation and voluntary anal contraction with a PVR of 200 ml.