Merck Manual

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Bladder Catheterization


Paul H. Chung

, MD, Sidney Kimmel Medical College, Thomas Jefferson University

Reviewed/Revised Jan 2024
Topic Resources

Bladder catheterization is used to do the following:

Catheterization may be urethral or suprapubic.


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 Urethral Stricture Urethral stricture is scarring that obstructs the anterior urethral lumen. Urethral stricture can be Congenital Acquired Anything that damages the urethral epithelium or corpus spongiosum can... read more and bladder neck obstruction Obstructive Uropathy Obstructive uropathy is structural or functional hindrance of normal urine flow, sometimes leading to renal dysfunction (obstructive nephropathy). Symptoms, less likely in chronic obstruction... read more ; 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:

How To Catheterize the Urethra in Women
How To Do Urethral Catheterization in Males

Complications of bladder catheterization include all of the following:

Catheter-associated UTIs Catheter-Associated Urinary Tract Infections A catheter-associated urinary tract infection (CAUTI) is a urinary tract infection (UTI) in which the positive culture was taken when an indwelling urinary catheter had been in place for >... read more 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 Urethral catheterization reference 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... read more ). 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

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.

Drugs Mentioned In This Article

Drug Name Select Trade
7T Lido, Akten , ALOCANE, ANASTIA, AneCream, Anestacon, Aspercreme with Lidocaine, AsperFlex, Astero , BenGay, Blue Tube, Blue-Emu, CidalEaze, DermacinRx Lidocan III, DermacinRx Lidogel, DermacinRx Lidorex, DERMALID, Dologesic, Ela-Max, GEN7T, Glydo, Gold Bond, LidaFlex, LidaMantle, Lido King Maximum Strength, Lidocan, Lidocare, Lidoderm, LidoDose, LidoDose Pediatric, Lidofore, LidoHeal-90, LIDO-K , LidoLite, Lidomar , Lidomark, LidoPure, LidoReal-30, LidoRx, Lidosense 4 , Lidosense 5, Lidosol, Lidosol-50, LIDO-SORB, Lidotral, Lidovix L, LIDOZION, Lidozo, LMX 4, LMX 4 with Tegaderm, LMX 5, LTA, Lubricaine For Her, Lydexa, Moxicaine, Numbonex, ReadySharp Lidocaine, RectaSmoothe, RectiCare, Salonpas Lidocaine, Senatec, Solarcaine, SUN BURNT PLUS, Tranzarel, Xyliderm, Xylocaine, Xylocaine Dental, Xylocaine in Dextrose, Xylocaine MPF, Xylocaine Topical, Xylocaine Topical Jelly, Xylocaine Topical Solution, Xylocaine Viscous, Zilactin-L, Zingo, Zionodi, ZTlido
NOTE: This is the Professional Version. CONSUMERS: View Consumer Version
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