What is French size?
The French size is three times the diameter in millimeters.
- Fr scale = Circumference in mm
- Fr scale = 2πr
- Fr scale = 2r * π
- 2r = Fr scale/π
- Diameter = Fr/3 or Fr = Diameter * 3
The French size is a measure of the outer diameter of a catheter (not inner diameter). So, for example, if a two-way catheter of 20 Fr is compared to a 20 Fr three-way catheter, they both have the same external diameter but the two-way catheter will have a larger drainage channel than the three-way.
Pediatric catheter size?
1-12 month - 5,6 F
1-2 yrs - 8F
2-6 yrs - 10
7-12 yrs - 12
> 12 yrs - 14
Pediatric foley catheter of 5,6,8,10 are available
[@ till 1 yr - 6, till 2 yrs - 8, till 6 yrs - 10, till 12 yrs - 12]
The average normal male meatus should accommodate a 24-Fr instrument or catheter. The prostatic urethra should accommodate a 32-Fr instrument and the bladder neck a 28-Fr catheter or instrument.
Foleys size and color coding?
[@ Black and White GORY, Pinky Babe, 6 and 16, 8 and 18 have same color code]
Contributions of Foley apart from foley catheter?
- 1. Foleys completely rotatable resectoscope.
- 2. A hydraulic cystolithotomy table.
- 3. pressurized fluid delivery system.
- 4. A canister which would inflate any balloon catheter.
- 5. A urethral sphincter device.
Types of Foley catheters (based on type of material used)?
- 1. Simple latex Foley catheter.
- 2. Siliconized latex Foley catheters (Silicolatex).
- 3. Silicone Foley catheters.
Infant feeding tubes are plastic catheters
Siliconized Latex Foley Catheters?
- Have a silicon coating over latex.
- Latex is supposed to be irritant to the urothelium of the urinary tract leading to microulcerations and stricture. Some patients have allergy to latex too. To overcome above drawbacks silicon coating was done over latex as former is considered to be urothelium friendly. With time silicone layer may be damaged exposing underlying latex, restricting their use for 2–3 weeks only, needing removal or replacement after that.
Silicone Foley catheters:
- Completely made of silicone and are costlier compared to siliconized latex catheter
- These catheters are often transparent but they also come in white, blue, green and other colors.
- The balloon when empty forms a slight thickening leading to slight increase in external diameter by French or two which may sometimes make passage difficult through stricture.
- Silicone catheters are believed to be superior to latex catheters, as silicone is
- - more biocompatible and less irritant
- - causes less cell death
- - less likely to become encrusted
- - more resistant to bacterial colonization
- - more rigid than siliconized latex catheters (easy passage in obstructive prostate gland)
- - Because of inert nature they can be placed in bladder for 6–8 weeks.
Indications for Lower Urinary Tract Drainage
- Diagnostic -
- - Patients, especially children or females, may require catheterization of the urinary bladder for sterile acquisition of urine for culture.
- - urine output monitoring
- - When lower urinary tract trauma is expected, atheterization may be required for diagnosis of a urethral or bladder injury.
- - cystogram requires the insertion of a catheter into the bladder, whereas a retrograde urethrogram requires insertion of the catheter into the fossa navicularis
- - performance of urodynamics studies
- - urinary retention including benign prostatic hyperplasia (BPH), clot retention, and urethral strictures can be temporarily treated with catheterization. In these situations, catheterization allows the urologist to temporize the emergent situation and permits the clinician to offer
- definitive therapy in a planned and controlled environment.
- - long-term urethral catheterization is used for selected patients with urinary retention and urinary incontinence when other definitive treatment options are not possible.
- - It may also be indicated in the setting of hematuria if continuous bladder irrigation is required
Contraindications of urethral catherization?
- - absolute contraindication - suspected or confirmed urethral injury or a history of bladder neck closure or repair.
- - Relative contraindications - recent urethral surgery or urethral stricture
- - Urethral catheterization should not be placed in a patient with an artificial urinary sphincter (AUS) without the consultation of a urologist
What is Hematuria Catheter?
- Three lumens to initiate continuous bladder irrigation
- They are also made with PVC, which does not compress. Alternatively they are made of latex along with a metal spring, which prevents the catheter from compressing.
- This allows the clinician to irrigate without the lumen of the catheter narrowing as negative pressure from a syringe
- is used to remove clots.
- These catheters also usually have a large drainage eye at the tip, which aids the extraction of thick material.
Rigidity from least to greatest: latex, silicone, PVC.
What are Diagnostic Catheters?
- The Lapides Diagnostic Foley catheter has five radiopaque rings, each 1 cm apart for calibration of female urethra length.
- The Davis and Trattner Diagnostic Foley catheters were used to diagnose urethral diverticula in females. These catheters have two balloons, one for the bladder neck and one to seal the meatus so that contrast can be instilled in the urethra. Currently, MRI technology has likely replaced the diagnostic method using these specialty catheters
Prostatic Obstruction - If BPH is suspected, ideally the clinician should use at least an 18-Fr catheter with a coudé tip. The coudé tip was developed to follow the angle of the male urethra. There is a small raised marker on the end of the coudé catheter that shows the orientation of the tip. The clinician should ensure this mark is always anterior, which will point the coudé tip anteriorly. If a false passage has been created, cystoscopy is indicated to not exacerbate the extent of the false passage. If blood is noticed in the catheter port or at the tip of the catheter once removed after difficulty with passage, a false passage should be suspected.
Urethral Stricture - If a stricture is suspected, the clinician may attempt to pass an atraumatic guidewire, which is usually a hydrophilic wire, past the stricture and into the bladder. Most efficiently, a cystoscope is used to pass the wire under direct vision.
Urethral Trauma - In posterior urethral injuries, one gentle passage of a catheter may be attempted. If resistance is noticed, the clinician should immediately remove the catheter.
Obesity - Obese patients, especially with a large amount of infrapubic adipose, can present a challenge in catheter placement. In a female, exposure can be attained with the help of others to provide adequate retraction. The bed can be placed in Trendelenburg as well.
Artificial Urinary Sphincter - Clinicians should avoid urethral catheterization in these patients if at all possible. If catheterization is required, the sphincter should be completely deactivated before placement. After deactivation, a 12-Fr catheter should be placed.
Chronic catheterization can lead to bladder inflammation and increase (1%) the risk of bladder cancer
Can you use vaseline as jelly during catherization?
Vaseline is petrolium, dissolves latex of Foleys
Counciling with 16 G Needle
Jelly - new edition 10-15 ml
What is KY jelly?
KY jelly is a water-based, personal lubricant that is usually used as a lubricant for sexual intercourse or masturbation.
Unlike petroleum or oil-based lubricants, it does not react with latex condoms, diaphragms, or sex toys