Dr Kola Tytler MBBS CertHE MBA MRCGPClinical Lead • iatroX
To differentiate between obstructive and non-obstructive causes of acute urinary retention (AUR) in a primary care setting, consider the following clinical approach:
- History and Symptoms: Obstructive causes often present with a history of lower urinary tract symptoms (LUTS) such as hesitancy, weak stream, intermittency, and incomplete emptying, commonly due to benign prostatic hyperplasia (BPH) in men. Non-obstructive causes may be related to neurological conditions or medications affecting bladder contractility and sensation NICE CG97.
- Physical Examination: Abdominal examination may reveal a palpable bladder in retention. Digital rectal examination (DRE) can assess prostate size and consistency to suggest obstruction. Neurological examination may identify signs of neurogenic bladder contributing to non-obstructive retention NICE CG148.
- Urinary Catheterisation: Immediate catheterisation is recommended to relieve retention regardless of cause NICE CG97. The ease of catheter insertion may provide clues; difficult catheterisation may suggest anatomical obstruction.
- Response to Alpha-Blockers: In men with suspected obstructive retention, alpha-blockers can be offered before catheter removal to improve bladder outflow by relaxing smooth muscle at the bladder neck and prostate NICE CG97. Alpha-blockers are not recommended for bladder emptying problems caused by neurological disease NICE CG148.
- Referral and Further Investigation: If non-obstructive causes are suspected (e.g., neurological disease), or if initial management fails, referral for specialist assessment including urodynamic studies may be necessary to differentiate causes definitively NICE CG148,NICE CG97.