The residual volume drained at catheterisation for acute urinary retention is not administrative detail. It predicts whether a trial without catheter will succeed — success falls markedly above about a litre — and it identifies the patient at risk of post-obstructive diuresis and of decompression haematuria.
So record it, and act on it. Above roughly a litre, keep the catheter in, check renal function and electrolytes, and monitor urine output for the next 24 hours; a diuresis of more than 200 mL an hour needs measured replacement rather than a fluid regimen chosen in advance. Drain steadily rather than clamping intermittently — the evidence does not support clamping, and it delays the decompression the patient needs.
Then start the alpha-blocker before the trial without catheter, not after it fails; a few days of tamsulosin before the catheter comes out measurably improves the chance of voiding. And tell the man what the volume was, because it is the single most useful piece of information the next clinician will want.
- Record the drained volume in the notes and tell the patient the number.
- Above about a litre, keep the catheter, check renal function, and monitor output for 24 hours.
- Watch for post-obstructive diuresis; replace measured losses rather than following a fixed regimen.
- Drain steadily — clamping is not supported and delays decompression.
- Start an alpha-blocker a few days before the trial without catheter, not after it fails.
Read the rest in the app
You have read your two free briefings this month. The app carries all 27 specialties, every morning, free — and this finding is waiting in it.
Scan to keep reading on your phone. No account needed to start.
Tomorrow morning, before your first patient
One edition a day for urology, written by the desk, every claim tied to its paper. Six minutes.
Get the app — free