26: Bladder Catheterization

I. INDICATIONS

1. To collect a urine specimen when a clean-catch specimen cannot be obtained or is unsatisfactory or a suprapubic aspiration cannot be performed. Bladder catheterization is an alternative to suprapubic aspiration but is not the method of first choice. It has a higher false-positive rate than suprapubic aspiration and it can also introduce bacteria and cause a urinary tract infection (UTI).

2. To monitor urinary output, relieve urinary retention, or to instill contrast to obtain a cystogram or voiding cystourethrogram.

3. To determine a bladder residual urine volume.

II. EQUIPMENT

Sterile gloves, cotton balls, povidone-iodine solution, sterile drapes, lubricant, a sterile collection bottle (often packaged together as a commercial set), and choice of catheter (balloon retention [Foley] catheters are not used in newborns).

1. Use the smallest catheter possible. Recommendations vary widely; it is best to follow your institution's guidelines if available.

2. Urethral catheters. Commercially available sizes: 3.5, 5.0, 6.5, and 8F.

   1. 3.5F for weight <1000 g.

   2. 5F for weight 1000–1800 g.

   3. 6.5F for weight 1800–4000 g.

   4. 8F for weight >4000 g.

3. National Association of Neonatal Nurses (NANN) recommendations. 3.5F for weight <1000 g; 5F for weight 1000–1800 g; 8F for weight >1800 g.

4. Feeding tubes. When used as an alternative, they may increase the risk of trauma or knotting (tubes are softer). 5F feeding tube is sometimes used (not preferred).

5. 3.5F or 5F umbilical catheter. May be used as an alternative: 3.5F for weight <1000 g; 5F for weight >1000 g.

III. PROCEDURE

1. When performing catheterization to obtain a specimen, it is best to wait until 1–2 hours after voiding. Ultrasound the bladder to determine the urinary bladder index measurement (product of anteroposterior and transverse diameters, expressed in centimeters squared), which will identify whether there is sufficient urine in the bladder. A urinary bladder index <2.4 cm² means there is lack of urine volume and the catheterization may be unsuccessful. A urinary bladder index >2.4 cm² suggests an adequate urine volume.

2. Pain management. Consider the use of topical and intraurethral lidocaine-enhanced lubricant. Nonpharmacologic pain-reducing methods are also recommended.

3. Male catheterization. See Figure 26–1.

   1. Place the infant supine, with the thighs abducted (frog-leg position).

   2. The newborn male infant has a physiologic phimosis, and the penis cannot be retracted fully. Gently retract the foreskin just enough to expose the meatus; do not force retraction of the foreskin. The meatus can usually be aligned with the opening in the prepuce.

   3. Put on sterile gloves, and drape the area with sterile towels.

   4. Cleanse the penis with povidone-iodine solution. Begin with the meatus and move in a proximal direction. Infant smegma (white discharge from cell shedding) can be gently wiped away.

   5. Place the tip of the catheter in sterile lubricant.

   6. Hold the penis approximately perpendicular to the body to straighten the penile urethra and help prevent false passage. Use a small amount of pressure at the base of the penis to avoid reflex urination.

   7. Advance the catheter until urine appears. Length of insertion in males is generally as follows: ...