Bladder catheterization is used to do the following:
Obtain urine for examination
Measure residual urine volume
Relieve urinary retention or incontinence
Deliver radiopaque contrast agents or medications directly to the bladder
Irrigate the bladder
Catheterization may be urethral or suprapubic.
Catheters
Catheters vary by caliber, tip configuration, number of ports, balloon size, type of material, and length.
Caliber is standardized in French (F) units—also known as Charrière (Ch) units. Each unit is 0.33 mm, so a 14-F catheter is 4.6 mm in diameter. Sizes range from 12 to 24 F for adults and 8 to 12 F for children. Smaller catheters are usually sufficient for uncomplicated urinary drainage and useful for urethral strictures and bladder neck obstruction; bigger catheters are indicated for bladder irrigation and some cases of hemorrhage (eg, postoperatively or in hemorrhagic cystitis) and pyuria because clots could obstruct smaller caliber catheters.
Tips are straight in most catheters (eg, Robinson, whistle-tip) and are used for intermittent urethral catheterization (ie, catheter is removed immediately after bladder drainage). Foley (double-lumen latex) catheters have a straight tip and an inflatable balloon for self-retention. Other self-retaining catheters may have an expanded tip, shaped like a mushroom (de Pezzer catheter) or a 4-winged perforated mushroom (Malecot catheter); they are used in suprapubic catheterization or nephrostomy. Elbowed (coudé) catheters, which may have balloons for self-retention, have a bent tip to ease catheterization through strictures or obstructions (eg, prostatic obstruction).
Ports are present in all catheters used for continuous urinary drainage. Many catheters have ports for balloon inflation, irrigation, or both (eg, 3-way Foley).
Balloons on self-retaining catheters have different volumes, from 2.5 to 5 mL in balloons intended for use in children and from 10 to 30 mL in balloons used in adults. Larger balloons and catheters are generally used to manage bleeding; traction on the catheter pulls the balloon against the base of the bladder and puts pressure on vessels, decreasing bleeding but potentially causing ischemia. It is recommended that the balloon be filled with plain water only.
Stylets are flexible metal guides inserted through the catheter to give stiffness and to facilitate insertion through strictures or obstructions and should only be used by physicians experienced with the technique.
Catheter material chosen depends on the intended use. Plastic, latex, or polyvinyl chloride catheters are for intermittent use. Latex with silicone, hydrogel, or silver alloy–coated polymer (to diminish bacterial colonization) catheters are for continuous use. Silicone catheters are used in patients with latex allergy.
Urethral catheterization
A urethral catheter can be inserted by any health care practitioner and sometimes by patients themselves. The bladder is catheterized through the urethra unless the urethral route is contraindicated.
Relative contraindications are the following:
Current urinary tract infection (UTI)
Urethral reconstruction, prostate surgery, or bladder surgery
How To Catheterize the Urethra in Women and How To Do Urethral Catheterization in Males.)
Complications of bladder catheterization include all of the following:
Urethral or bladder trauma with bleeding or microscopic hematuria (common)
UTI (common)
Creation of false passages
Scarring and strictures
Bladder perforation (rare)
Paraphimosis in uncircumcised males if the foreskin is not repositioned
Catheter-associated UTIs tend to increase morbidity, mortality, health care costs, and hospital length of stay. They are the most common health care–associated infections reported to the national Healthcare Safety Network and have been a focus of improvement for the Centers for Disease Control and Prevention (CDC) (1). Recommendations for how to minimize the rates of these UTIs include the following:
Restricting the use of urethral catheterization to indications that are clearly medically necessary (eg, not solely to minimize the number of bedside visits by health care providers made to empty urinals)
Removing catheters as soon as possible
Using strictly aseptic technique during catheter insertion
Maintaining sterility and closure of the drainage system
Urethral catheterization reference
1. Centers for Disease Control and Prevention: Catheter-associated urinary tract infections. Accessed November 3, 2023.
Suprapubic catheterization
Suprapubic catheterization via percutaneous cystostomy is done by a urologist or another experienced physician. General indications include need for long-term bladder drainage and inability to pass a catheter through the urethra or contraindication to catheter use when bladder catheterization is necessary.
Contraindications include the following:
Inability to define bladder location clinically or ultrasonographically
An empty bladder
Suspected pelvic or lower abdominal adhesions (eg, after pelvic or lower abdominal surgery or radiation therapy)
After the abdomen above the pubic area is numbed with a local anesthetic, a spinal needle is inserted into the bladder; ultrasound guidance is used if available. A catheter is then placed through a special trocar or over a guide wire threaded through the spinal needle. Prior lower abdominal surgery and previous radiation therapy contraindicate blind insertion. Complications include UTI, intestinal injury, and bleeding.
