96 CHAPTER 3 Bladder outlet obstruction

Indications for and technique of urethral catheterization

Indications

For relief of urinary retention and prevention of urinary retention, a period of postoperative catheterization is commonly employed after many operations where limited mobility makes normal voiding difficult.

Other indications for catheterization include monitoring of urine output (e.g., postoperatively); prevention of damage to the bladder during cesarean section; bladder drainage following surgery to the bladder, prostate, or urethra (e.g., TURP, TURBT, open bladder stone removal, radical prostatectomy); and bladder drainage following injuries to the bladder.

Technique

Explain the need for and method of catheterization to the patient. Use the smallest catheter—in practical terms, usually a 12 Fr., with a 10 mL balloon. For longer catheterization periods (weeks) use a silastic catheter to limit tissue reaction, thereby reducing the risk of a catheter-induced urethral stricture. If there is clot retention, use a three-way catheter (20 Fr. or greater) to allow evacuation of clots and bladder irrigation to prevent subsequent catheter blockage.

The technique is aseptic. One gloved hand is sterile; the other is “dirty.” The dirty hand holds the penis or separates the labia to allow cleansing of urethral meatus; this hand should not touch the catheter. Use sterile water or sterile cleaning solution to prep skin around meatus.

Apply lubricant jelly to the urethra. Traditionally, this contains local anesthetic (e.g., 2% lidocaine), which takes 3–5 minutes to work. However, a randomized, placebo-controlled trial showed that 2% lidocaine was no more effective for pain relief than anesthetic-free lubricant,1 suggesting that it is lubricant action that prevents urethral pain.

If using local anesthetic lubricant, warn the patient that it may STING. Local anesthetic lubricant is contraindicated in patients with allergies to local anesthetics and in those with urethral trauma, where there is a (theoretical) risk of complications arising from systemic absorption of lidocaine.

When instilling jelly, do so gently—a sudden, forceful depression of the plunger of the syringe can rupture the urethra! In males, milk the gel toward the posterior urethra, while squeezing the meatus to prevent it from coming back out of the meatus.

Insert the catheter using a sterile hand, until flow of urine confirms it is in the bladder. Failure of urine flow may indicate that the catheter balloon is in the urethra. Intraurethral inflation of the balloon can rupture the urethra. If no urine flows, attempt aspiration of urine using a 50 mL bladder syringe (lubricant gel can occlude eyeholes of the catheter).

98 CHAPTER 3 Bladder outlet obstruction

Indications for and technique of suprapubic catheterization

Indications

Suprapubic catheterization is indicated if there is failed urethral catheterization in urinary retention; it is the preferred site for long-term catheters.

Long-term urethral catheters commonly lead to acquired hypospadias in males (ventral splitting of glans penis) and patulous urethra in females (leading to frequent balloon expulsion and bypassing of urine around the catheter). Hence, a suprapubic site is preferred for long-term catheters.

Contraindications

Suprapubic catheterization is best avoided in the following:

•Patients with clot retention, the cause of which may be an underlying bladder cancer (the cancer could be spread along the catheter track to involve the skin)

•Patients with lower midline incisions (bowel may be stuck to the deep aspect of the scar, leading to the potential for bowel perforation)

•Pelvic fractures, where the catheter may inadvertently enter the large pelvic hematoma that always accompanies severe pelvic fracture. This can lead to infection of the hematoma, and the resulting sepsis can be fatal. Failure to pass a urethral catheter in a patient with a pelvic fracture usually indicates a urethral rupture (confirmed by urethrography) and is an indication for formal open, suprapubic cystotomy.

Technique

Prior to insertion of the trocar, be sure to confirm the diagnosis by

•Abdominal examination (palpate and percuss the lower abdomen to confirm bladder is distended),

•Ultrasound (in practice, usually not available), and

•Aspiration of urine (using a green needle).

Patients with lower abdominal scars may have bowel interposed between the abdominal wall and bladder and this can be perforated if the trocar is inserted near the scar and without prior aspiration of urine. In such cases, ultrasound-guided catheterization may be sensible.

Use a wide-bore trocar if you anticipate that the catheter will be in place for more than 24 hours (small-bore catheters will block within a few days). Aim to place the catheter about 2–3 fingerbreadths above the pubis symphysis. Placement too close to the symphysis will result in a difficult trocar insertion (the trocar will hit the symphysis).

Instill a few mL of local anesthetic into the skin of the intended puncture site and down to the rectus sheath. Confirm location of the bladder by drawing back on the needle to aspirate urine from the bladder. This helps guide the angle of trocar insertion.

SUPRAPUBIC CATHETERIZATION 99

Make a 1 cm incision with a sharp blade through the skin. Hold the trocar handle in your right hand, and steady the needle end with your left hand (this hand helps prevent insertion too deeply). Push the trocar in the same direction as that in which you previously aspirated urine.

As soon as urine passes from the trocar, withdraw the latter, holding the attached sheath in place. Push the catheter in as far as it will go. Inflate the balloon.

Peel away the side of the sheath and remove it.