Atlas of Procedures in Neonatology, 4th Edition

Miscellaneous Sampling


Bladder Catheterization

S Lee Fragneto

  1. Indications (1,2,3,4,5,6 and 7)
  2. To obtain urine for culture, particularly when suprapubic collection is contraindicated and when clean-catch specimen is unsatisfactory

While suprapubic bladder aspiration is considered the most reliable method of obtaining urine for culture in infants and young children (see Chapter 18), bladder catheterization is an acceptable alternative method (5). Bladder catheterization has a higher success rate than suprapubic aspiration, especially if the practitioner is inexperienced in bladder aspiration. However, urine samples collected by catheterization have a higher false-positive rate than suprapubic aspiration (3,5,8,9 and 10), and catheterization can introduce bacteria colonizing the distal urethra into the bladder, causing a urinary tract infection (see F, “Complications”). The diagnosis of urinary tract infection cannot be made reliably by culturing urine collected in a bag (5,11).

  1. To monitor precisely the urinary output of a critically ill patient
  2. To quantify bladder residual
  3. To relieve urinary retention (e.g., in neurogenic bladder) (12,13 and 14)
  4. To instill contrast agent to perform cystourethrography (15)
  5. Contraindications

In the presence of uncorrected bleeding diathesis, potential risks and benefits must be considered.

  1. Equipment

All equipment must be sterile. Commercial prepackaged urinary drainage kits, with or without collection burettes for closed drainage, are available.

  1. Gloves
  2. Gauze sponges and cup with iodophor antiseptic solution (not containing alcohol), or
  3. Prepared antiseptic-impregnated swabs
  4. Towels for draping
  5. Surgical lubricant
  6. Cotton-tipped applicators
  7. Urinary catheter

Silicone urinary drainage catheters are available in 3.5, 5.0, 6.5, and 8.0 French (Fr) sizes. A 5-Fr infant feeding tube or a 3.5- or 5.0-Fr umbilical catheter may be substituted for a urinary catheter.

  1. Sterile container for specimen collection or collection burette for continuous closed drainage
  2. Precautions
  3. Use strict aseptic technique.
  4. Use adequate lighting.
  5. Try to time the procedure for when the infant has not recently voided (1 to 2 hours after the last wet diaper). Portable ultrasound can be helpful in determining when there is sufficient urine present in the bladder, reducing the chance of an unsuccessful attempt (16,17).
  6. Avoid vigorous irrigation of the perineum in preparation for catheterization. This may increase the risk of introducing bacteria into the urinary tract.
  7. Avoid separating the labia minora too widely, to prevent tearing of the fourchette.
  8. Use the smallest-diameter catheter to avoid traumatic complications. A 3.5-Fr catheter is recommended for infants weighing less than 1,000 g and a 5-Fr catheter is recommended for larger infants.
  9. If the catheter does not pass easily, do not use force. Suspect obstruction and abandon the procedure.
  10. To avoid coiling and knotting, insert the catheter only as far as necessary to obtain urine.
  11. If urine is not obtained in a female infant, recheck the location of the catheter by visual inspection or by radiographic examination. It may have passed through the introitus into the vagina.
  12. Remove the catheter as soon as possible to avoid infectious complications.


  1. If the catheter cannot be removed easily, do not use force. Consult urology, as it may be knotted.
  2. Technique

Male Infant (2,4,18,19)

  1. Set up equipment and squeeze a small amount of lubricant onto a sterile field.
  2. Restrain the infant supine in the frog-leg position.
  3. Wash hands thoroughly and put on gloves.
  4. Stabilize the shaft of the penis with the nondominant hand. This hand is now considered contaminated.
  5. If the infant is uncircumcised, gently retract the foreskin just enough to expose the meatus. Do not attempt to lyse adhesions. The young male infant has physiologic phimosis, and the foreskin cannot be fully retracted (19,20). If the foreskin is tightly adherent, attempt to line up the preputial ring and the meatus.
  6. Apply gentle pressure at the base of the penis to avoid reflex urination.
  7. Using the free hand for the rest of the procedure, clean the glans three times with antiseptic solution. Begin at the meatus and work outward and down the shaft of the penis. Blot dry with sterile gauze.
  8. Drape sterile towels across the lower abdomen and across the infant's legs.
  9. Place the wide end of the catheter or feeding tube into the specimen container.
  10. Lubricate the tip of the catheter copiously.
  11. Move the specimen container and catheter onto the sterile drape between the infant's legs.
  12. Gently insert the catheter through the meatus just until urine is seen in the tube (Fig. 19.1).
  13. During insertion, apply gentle upward traction on the penile shaft to prevent kinking of the urethra (Fig. 19.1).
  14. If the meatus cannot be visualized, insert the catheter through the preputial ring in a slightly inferior direction. If there is any question about catheter position, abandon the procedure.
  15. If resistance is met at the external sphincter, hold the catheter in place, applying minimal pressure. Generally, spasm will relax after a brief period, allowing easy passage of catheter. If not, suspect obstruction and abandon the procedure.
  16. Do not move the catheter in and out. This will increase the risk of urethral trauma.
  17. Do not insert extra tubing length in an attempt to stabilize a catheter to be left indwelling. This will increase the risk of trauma and knotting.
  18. Collect specimen for culture.
  19. If the catheter is to remain indwelling, connect the catheter immediately to a closed sterile system for urine collection. Tape the tube securely to the inner thigh.
  20. If the catheter is to be removed, gently withdraw it when urine flow ceases.

FIG. 19.1. Anatomic drawing demonstrating bladder catheterization in the male.



Female Infant (7,19,21)

  1. Follow Steps 1 through 3 of technique for male infant.
  2. Retract the labia minora.
  3. Use sterile gauze sponges with nondominant hand, or
  4. Have an assistant retract the labia with two cotton-tipped applicators (Fig. 19.2).
  5. Using the free hand for the rest of the procedure, cleanse the area between the labia minora three times with antiseptic solution.
  6. Swab in an anterior-to-posterior direction to avoid drawing fecal material into the field.
  7. Blot dry with sterile gauze.
  8. Follow Steps 8 through 11 of the technique for the male infant.
  9. Visualize the meatus (Fig. 19.2).
  10. The most prominent structure is the vaginal introitus. The urethral meatus lies immediately anterior (between the clitoris and the introitus).
  11. The meatus may be obscured by the introital fold. Gently push the fold down with a cotton-tipped applicator.
  12. If the meatus is not visible, the infant may have female hypospadias (the meatus is on the roof of the vagina, just inside the introitus) (19). The urethra must then be catheterized blindly, which may require a curved-tip catheter or urologic assistance.
  13. Gently insert the catheter only until urine appears in the tube. Do not insert extra tubing.
  14. Follow Steps 13 through 15 of technique for the male infant.

Female Infant in Prone Position (22)

This technique is useful in an infant who cannot be placed supine (e.g., one with a large meningomyelocele).

  1. Position the infant prone on folded blankets so the head and trunk are elevated about 3 in above the knees and lower legs. The hips should be flexed with knees abducted (Fig. 19.3A).
  2. Place a gauze pad over the anus and secure with tape across the buttocks, to avoid contamination of the perineum from reflex bowel evacuation (Fig. 19.3B).
  3. Place sterile drapes as shown in Fig. 19.3C. Follow the procedure for female catheterization above.

FIG. 19.2. External genitalia in the female. Retraction of labia majora and minora with cotton-tipped applicators. An arrow indicates urethral meatus.

  1. Complications
  2. Infection (23,24,25,26 and 27)
  3. Urethritis
  4. Epididymitis
  5. Cystitis
  6. Pyelonephritis
  7. Sepsis

The most common complication of bladder catheterization is the introduction of bacteria into the urinary tract and potentially into the bloodstream. Catheterization is the leading cause of nosocomial urinary tract infection and gram-negative sepsis in adult patients (24). The risk of bacteriuria from straight (“in-and-out”) catheterization is 1% to 5% in this population (23,24 and 25). The risk of infection is related directly to


the duration of catheterization. In infants and children, approximately 50% to 75% of hospital-acquired urinary tract infections occur in catheterized patients, the highest rate being in neonates (26,27). Urinary tract infection developed in 10.8% of catheterized pediatric patients (26), and secondary bacteremia in 2.9% (27). Risk of infection is decreased by adhering to strict aseptic technique during catheter placement, maintaining a closed sterile collection system, and removing the catheter as soon as possible.


FIG. 19.3. A: Position of infant for prone catheterization. B: Placement of gauze pad over anus. C: Placement of drapes. (Adapted from 

Campbell J. Catheterizing prone female infants: how can you see what you're doing? Am J Matern Child Nurs. 1979;4:376

, based on drawing by N. L. Gahan, with permission.)

  1. Trauma
  2. Hematuria
  3. Urethral erosion or tear (28)
  4. Urethral false passage (28,29)
  5. Perforation of the urethra or bladder (Fig. 19.4) (28,30,31)
  6. Tear of the fourchette (28)
  7. Meatal stenosis (20)
  8. Urethral stricture (32)
  9. Urinary retention secondary to urethral edema (28)

The risk of trauma is reduced by using the smallest-diameter catheter with ample lubrication, advancing the catheter only as far as necessary to obtain urine, and never forcing a catheter through an obstruction. Erosion and perforation are associated with long-indwelling catheters. This risk is reduced by removing the catheter as soon as possible.

  1. Mechanical
  2. Catheter malposition (19,28)
  3. Catheter knot (33,34,35,36 and 37)

The risk of knotting is reduced by using the minimal length of catheter insertion. Standard insertion lengths of 6 cm for male and 5 cm for female term newborns have been suggested (37). Shorter lengths would be appropriate for preterm infants. A more general standard is to insert the catheter only as far as needed to obtain urine. Using a feeding tube as a urinary catheter may also increase the risk of knotting, because these tubes are softer and more likely to coil.




FIG. 19.4. A: Cystogram shows dilated posterior urethra (arrows) secondary to posterior urethral valves. B: Subsequent film shows perforation of the bladder, with free contrast material in the peritoneal cavity.


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