Urinary retention

Theory

Acute urinary retention is the painful distension of the bladder with the inability to void.

It is commonly secondary to underlying bladder outlet obstruction and may occur associated with pre-existing symptoms (decreased urine flow, hesitancy, nocturia, etc.)

Acute urinary retention may be triggered in patients with or without bladder neck obstruction by other factors common in the hospital inpatient.

In the surgical patient, immobility, pain, analgesics, sedatives, regional anaesthetic, constipation.

In the medical patient, drugs e.g. diuretice, ant-cholinergics, bed confinement, stroke, confusion, constipation.

Chronic urinary retention is painless and usually detected after presentation with overflow incontinence and a large volume palpable bladder. These patients often have distension also of the upper urinary tract and associated renal impairment.

Immediate intern management

1. Acute retention

Insert a Foley catheter

Give parenteral narcotic if there is delay in arranging a catheter setup or if the patient is restless with severe pain (otherwise the fastest pain relief is achieved by catheterisation).

Explain clearly the procedure to the patient.

Sterile procedure i.e. gown, gloves, mask, prep and sterile drape.

Urethral lignocaine gel instill slowly and gently.

Use a size 14 or 16 Fr Foley catheter (5–15cc balloon). Insert while putting the penile urethra on gentle stretch. Advance the catheter gently without force. There may be a temporary holdup at the level of the pelvic floor (external sphincter). If so, stop and ask the patient to slowly breathe in and out through the mouth. Advance the catheter again as the patient is exhaling. If the catheter has passed up to the hilt and there is urine flow, then inflate the Foley balloon. Sometimes suction using the lignocaine gel syringe and nozzle is needed to initiate urine flow. Attach the catheter to the sterile catheter bag. Ensure that the bag is emptied after 5 minutes and the volume is recorded on the fluid balance chart. It is very important that this volume (i.e. volume of urine in the bladder obtained by catheterisation) is known to help with deciding the appropriate further management.

If catheterisation is unsuccessful:

Give parenteral narcotic (if not already given). Try a smaller size 12Fr catheter. If still unsuccessful, call the surgical registrar (or if available, Urology registrar).

The likely causes of catheter failure include urethral stricture and bladder neck contracture (following previous transurethral surgery). Success may be achieved after urethral dilatation. Otherwise a suprapubic catheter is the best solution but this and urethral dilatation should only be attempted by an experienced registrar.

2. Chronic retention:

Catheterise as with acute retention.

In the presence of significant renal impairment, watch for post-obstructive diuresis. Measure urine output hourly. Usually in an alert and co-operative patient, excess fluid loss can be replaced with oral fluids, otherwise intravenous fluids may be necessary. Rate of IV fluids is determined by the hourly urine output. Usually replace ½ urine output with IV fluid. The commonest mistake is to over-replace with IV fluids.

NEVER clamp and release a urinary catheter.

3. Clot retention:

Retention may occur due to heavy haematuria of whatever cause. Clot formation in the bladder obstructs the passage of urine or blocks an indwelling catheter.

First evacuate the clots from the bladder with a large catheter and a Toomey syringe. This is best done with the catheter balloon deflated. The catheter is flushed aspirated with normal saline using the Toomey syringe until ALL the clots are out. This step can be done using a large 2-way catheter (at least 18Fr) or 3-way catheter (at least 22Fr).

Remember that the size (French) relates to the outside diameter not he size of the drainage channel. Because a 3-way catheter also incorporates an irrigation channel, the drainage channel of a 18Fr 2-way is similar to a 22Fr 3-way catheter.

Next commence continuous bladder irrigation via a 3-way catheter with the aim of washing out the bloodstained urine to PREVENT further clot formation. The irrigation will not wash out clot so DO NOT irrigate unless the clots have been first evacuated manually with a Toomey syringe.

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