urinary retention
| >300ml residual volume - treat as retention | |
|---|---|
| History | - PMH: prostate issues (if present), constipation, recent surgery - DHx: any precipitating drugs? - e.g. anticholinergic burden (Tricyclic antidepressants) - Red flags: - younger patients - think spinal cord - Trauma/signs of malignancy (cauda equina syndrome?) |
| Examination | - Neuro exam (is this retention part of a spinal cord lesion?) - |
| Diagnostic investigations | Bladder scan - 300ml is the cutoff US KUB if any Acute kidney injury |
| Differentials | |
| Immediate management | Catheterise! Relieve the backward pressure |
| Ongoing management | - Post-obstructive diuresis - conventionally defined as >200ml/h for 2 consecutive hours, or 3L over 24h - TWOC - address constipation, underlying causes |
mechanisms
- resistance to flow - due to mechanical or anatomical obstruction
- bladder stone
- BPH, prostate Ca
- iatrogenic
- gravid uterus
- inappropriate detrusor muscle innervation
- stroke
- spinal cord lesions
- neurogenic bladder
- over-distension
- drugs - alpha-adrenergic, antimuscarinic