Catheterization of the Urethra in Girls
Urethral catheterization permits direct drainage of the urinary bladder and is often performed in pediatric practice.
Diagnostic indications include collection of a sterile urine specimen for culture and urinalysis (especially in a young child who cannot void on command but from whom it is important to obtain a urine sample), the performance of voiding cystourethrography, and the monitoring of urine output in certain postoperative patients or in critically ill patients. Urethral catheterization may also be used for therapeutic indications, such as the decompression of acute urinary retention, intermittent catheterization of neurogenic bladder, and continuous bladder irrigation for the removal of blood and clots, or for drug administration. However, urethral catheterization for therapeutic indications is not the focus of this video.
The only absolute contraindication to urethral catheterization is suspected traumatic injury to the lower urinary tract. This type of injury should be suspected in patients with a pelvic or straddle-type injury. Physical findings such as perineal hematoma, blood at the meatus, or gross hematuria increase the suspicion that such injury might be present. When any of these findings are present in patients for whom there is a possibility of trauma, a retrograde urethrogram should be obtained to rule out a urethral tear before a catheter is inserted into the bladder. This procedure requires referral to a specialist.
Relative contraindications include known major anatomical malformations of the lower urinary tract and recent reconstruction of the urethra or bladder neck. In addition, be certain that there is no history of latex allergy, since many gloves and catheters are manufactured from latex.1 If the child has an allergy to latex, nonlatex materials should be obtained if catheterization is essential.
Many medical centers have packaged catheterization kits that contain most of the materials required to perform the procedure. The equipment required for urethral catheterization includes sterile water or saline, soap, sterile gauze pads and towels, an absorbent underpad, sterile and nonsterile gloves, sterile lubricant gel with or without 2% lidocaine,2 antiseptic solution (containing chlorhexidine or povidone–iodine), an appropriately sized urethral catheter, and a sterile urethral catheterization kit. The kit should contain at least one sterile fenestrated drape, swabs for cleansing, and a specimen-collection cup. You will also need appropriate containers for transporting the specimen to a laboratory for urinalysis or culture.
There are many types of catheters, varying in construction material, design, and size
(Figure 1FIGURE 1Appropriate Catheter Sizes for Use in Girls.). The choice of catheter depends on the size of the urethra and on the age of the child. The correct catheter sizes range from 4 to 6 French in newborns, 6 to 8 French in infants, 10 to 12 French in prepubertal girls, and up to 14 French in adolescents. Care should be taken with the use of long 4.0 French catheters, which can become knotted in the bladder. Although appropriately sized feeding tubes may be used for urethral catheterization in infants, they should be used with caution because intravesical knotting of the tube may occur if the length of the tube is excessive3; this complication impedes catheter removal.
The two types of urinary catheters that are most frequently used are straight catheters and balloon (or Foley) catheters. This video shows the use of a straight catheter for diagnostic urethral catheterization.
Straight catheters are soft, single-lumen catheters that are usually made of polyvinyl chloride. They are used for the collection of uncontaminated urine for diagnostic purposes and in patients with neurogenic bladder who need intermittent catheterization.
Before you begin, explain the relevant anatomy and the benefits, risks, and complications of the procedure to the patient’s parents or caregivers and to patients old enough to understand. Prepare every child for the procedure in a developmentally appropriate manner. A child life specialist (a pediatric health care professional who helps children cope with medical procedures and hospitalization) can be helpful in distracting the child during the procedure. Determine whether the patient has a history of latex or iodine allergies and has undergone previous attempts at catheterization.
After placing the patient in the supine frog-leg position, ask an assistant to hold the legs firmly, which will permit adequate stabilization of the pelvis and complete visualization of the external genitalia. Use gauze pads to wash the external genitalia with soap and water, rinse the area with clean water, and dry the skin. Wash and disinfect your hands. Place the sterile urethral catheterization kit on a tray and open it. Disinfect your hands and put on sterile gloves. Lubricate the distal end of the catheter with sterile gel.
The anatomy of the female infant or child is similar to that of the female adult, except for the obvious differences in size and the lack of secondary sexual characteristics. The urethra is short and straight and thus easy to catheterize. The meatus is found between the clitoris and the vagina (Figure 2FIGURE 2Location of the Meatus.). It can be difficult to locate, since the mucosa of the vaginal introitus may cover it. Visualization can be even more complicated if labial adhesion is present; this condition may also impede catheterization.
Prepare the entire genital area by cleansing three times, from the center to the periphery, using an antiseptic agent. Place the sterile fenestrated drape over the patient so that the vulva is accessible through the opening. Remove your gloves and put on another pair of sterile gloves. With the thumb and index finger of your nondominant hand, separate the labia, which are considered to be nonsterile. With your dominant hand, use antiseptic-soaked sterile swabs or povidone–iodine swabsticks to wash the urethral meatus three times, in the anterior-to-posterior direction.
At many medical centers, lubricant gel is placed on the catheter before the procedure is performed. At some centers, clinicians also use 2% lidocaine gel, squeezed out above the vagina, before the catheterization. If lidocaine gel has been used for analgesia, wait 2 minutes before proceeding with the catheterization.
If the mucosal covering of the vagina makes it difficult to localize the meatus, gently pull the cephalad fold of the vaginal introitus downward. Once you have located the urethra, hold the lubricated catheter with the fingers of your dominant hand and slowly and gently insert the tip of the catheter into the meatus and advance it into the bladder (Figure 3FIGURE 3Insertion of the Catheter.). The other end of the catheter should remain in the container. You should not encounter any resistance. If you encounter resistance, do not force the catheter, since this may cause trauma or even perforation. If the catheter slips into the vagina, leave it there as a landmark and make a second attempt to insert another catheter into the urethral meatus.
After the catheter has entered the bladder, urine should drain through it into the container. When urine flow ceases, remove the catheter (or both catheters, if there is also one in the vagina) and submit the urine for culture and urinalysis.
If it is impossible to perform catheterization through the urethral meatus because of anatomical variation or severe labial adhesion, and if it is essential to obtain a urine sample, you may consider the use of suprapubic aspiration. However, this procedure should be performed only if the bladder is palpable or if the presence of urine has been confirmed by means of ultrasonography and if you have experience in performing the procedure.
If the urine drainage is minimal, use gentle pressure to massage the suprapubic region to increase urine flow. If there is no flow of urine, the catheter should be removed and properly discarded. Consider whether the procedure should be attempted with another catheter that is different in size or stiffness. If the catheterization was performed to verify that a child is anuric, consider how much hydration should be provided before reattempting the procedure.
Although complications of urethral catheterization are rare, they may occur. Immediate complications may include gross or microscopic hematuria and the creation of a false passage. Long-term complications, such as urethral strictures, may also occur. In addition, iatrogenic infection may occur if conditions are not aseptic.4
The accompanying video explains the risks and benefits of catheterization of the urethra in girls and demonstrates how to prepare the patient, locate the urethra, and insert the catheter.
From the Pediatric Emergency Medicine Service, Child and Adolescent Department, Geneva University Hospitals, University of Geneva, Geneva.
Address reprint requests to Dr. Manzano at the Pediatric Emergency Medicine Service, Child and Adolescent Department, Geneva University Hospitals, 6 rue Willy-Donzé, CH-1211 Geneva, Switzerland, or at email@example.com.