Hi-R-Ed Online

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Size and Length:

The external diameter is the measure of catheter size. The sizes are stated in “French” and one French is equal to 0.33 millimeters. In the catalog page to the right you can see quite a few different sizes and lengths are available.

Sizes range between 5 French to 30 French or 1.65 mm to 9.9 mm in external diameter. The smallest bore catheter that can accomplish the task is recommended to reduce the risk of trauma and irritation.

The size of a catheter is considered for age, gender, body size, the presence of anomalies or resistance, the history of catheterization, urinary output character, and planned duration. A 5-12 French size may be suitable for children while a 16-18 French catheter can be used in adults. For instance, a larger 20-24 French catheter or a three-way catheter (with an added port) may be chosen when hematuria and clots require continuous bladder irrigation.

graphic courtesy of Byram Healthcare

For children, catheters are usually intermittent and used to pull a sterile urine sample to check for infections. For women, a 12-16 French catheter is most commonly used and a 3-way is indicated in cases of gross hematuria. For men, it is typical to use a 16-18 French catheter, which can be used with lidocaine jelly to reduce insertion discomfort. In cases of gross hematuria in men, 3-way Foleys are used with the largest French size that can be tolerated, usually a 22-24 French. Catheter lengths include 6-12 inches for pediatric use, 6-8 inches for women (though a male-length catheter may be preferred in some cases), and 16 inches for men. The longer length of catheters may also be used for obese females.

Tips:
Different tips are available according to the patient’s needs. The tips have openings to facilitate the drainage of urine, blood clots, and sediment. Catheters may have a straight tip without a balloon, and there is also a curved, or “coude”, tip catheter that has a rounded curved tip for use in cases of blockage or stricture, such as elderly men with enlarged prostate glands.

photo courtesy of Byram Healthcare

There are three types of coude tip catheters, some with or without balloons, including:

-the tapered tip, which has a short and strong tip to bypass enlarged prostate glands and urethral traumas,

-the olive tip, which has a small ball shaped bead for smoother passage in cases of obstruction and false passages, and

-the Tiemann tip, which has an elongated and tapered tip that is more pliable to more comfortably place through narrow passages in cases of BPH, distended bladders, enlarged prostate glands.

Balloon:
Indwelling catheters (urethral and supra-pubic) have balloons at the tips that are inflated with sterile water after insertion to prevent the catheter from migrating out during urinary drainage.

photo courtesy of Byram Healthcare

Balloons are present in both urethral and supra-pubic catheter placements. Balloon size varies, as well. Generally 10 milliliter balloons are a standard for adults and smaller 2.5 to 5 milliliter balloon sizes may be used for children, although the use of the smallest balloon possible can help to reduce the risk for development of residual urine in the bladder and bladder neck irritation. While the balloon is generally filled with sterile water, this could be a problem in silicone catheters, which may lose water over time and cause the catheter to fall out. Recommendations have included filling the balloon with a full 10 ml of sterile water knowing that up to half of that amount may be lost, or using a 10% aqueous glycerine solution.