Catheterization
In urology, catheterisation is the use of a urinary catheter . (Catheterization can be used synonymously, but also generally stands for the insertion of a medical catheter.) A distinction is made between external and self-catheterization.
Indications
Transurethral indwelling catheters
- In case of urination disorders with high residual urine or urinary retention
- For temporary urinary diversion during operations and / or intensive care measures
- If it is necessary to balance urine excretion and monitor kidney function
- For irrigation of the bladder in cases of gross hematuria and after transurethral operations on the urinary bladder and prostate
- For clearing out a bladder packing
- For severe upper urinary tract infections such as kidney pelvic infections for temporary urinary drainage
- As a permanent drainage for urinary incontinence that cannot be controlled with other means (strict indication)
Suprapubic urinary catheters
- For voiding problems with high residual urine
- In case of urinary retention when transurethral catheterisation is not possible
- For infections of the prostate ( prostatitis ) and epididymis ( epididymitis )
- For temporary urinary diversion during operations and / or intensive care measures
- For permanent urinary diversion
Single-use transurethral catheters
- For collecting urine for bacteriological examinations. Especially with women, because the collection of midstream urine is not meaningful due to the anatomical features (germs of the vaginal flora get into the urine)
- As part of the diagnostics of the lower urinary tract for the application of contrast media into the urinary bladder, for bladder pressure measurements with special measuring catheters
- For instillation treatment with chemotherapeutic agents for the follow-up treatment of bladder cancer
- As intermittent self-catheterization or external catheterization, especially in the case of neurogenic bladder emptying disorders that cannot be treated otherwise
Technique of catheterization
In principle, sterility must be observed for all techniques. Every urinary catheter must be placed under sterile conditions in order to avoid the spread of germs into the urinary bladder. For this purpose, the urethral orifice and the surrounding tissue are disinfected , in the case of suprapubic urinary catheters the puncture site and its surroundings.
Single-use catheterization
Single-use catheterization is the one-time, short-term introduction of a transurethral catheter into the urinary bladder. This procedure is used to collect urine , to empty the bladder once in case of urinary behavior, to introduce ( instillation ) medication or contrast media into the urinary bladder and to measure and fill the urinary bladder in special urological examinations such as bladder pressure measurement .
For this purpose, after disinfection, a lubricant gel is first injected into the urethra and then the catheter is inserted sterile. This type of catheter cannot be blocked and is removed immediately after use.
Intermittent self-catheterization (ISC)
Intermittent self-catheterization is primarily used to treat neurogenic voiding disorders. For this purpose, the patient learns self-catheterization under professional guidance. Conventional disposable catheters are unsuitable for this, as they can lead to trauma to the urethra if used regularly . Special, largely atraumatic, single-use catheters are available for this purpose. These catheters are equipped with a special rounded tip and rounded drainage eyes. In addition, they have increased sliding properties thanks to a special coating . With some coatings, instead of a lubricant gel, it is also possible to wet them with a sterile saline solution , in which case the coating develops a gel-like consistency . Special sets are available for mobile use in which the lubricant and, in some cases, a collection bag are integrated into the sterile packaging.
These catheters can be aseptically inserted out of their packaging without being touched , so that sterile gloves are not necessary.
Indwelling transurethral catheterization
The application is similar to a single-use catheter. In addition, the balloon in the front part of the catheter is filled (also: blocked). It should be noted here that blocking fluid can gradually escape through diffusion , even if the blocking valve is intact . This fluid loss depends primarily on the temperature and on hydrostatic and osmotic pressure gradients . Sterile distilled water or an isotonic saline solution are not suitable blocking fluids. For filling for long-term use, the use of a 5 percent saline solution or a 10 percent glycerine solution is suitable, since the block channel does not have to be clogged by crystallization and a catheter material-independent sealing of the balloon pores with the comparatively lowest loss of fluid is guaranteed. Sterile glucose solutions or high-percentage saline solutions can block the block channel through crystallization . When using a saline solution of 10 percent and more, there is an increase in volume in the balloon.
When the catheter is removed, it is first unblocked. As the length of time a transurethral indwelling catheter is in place, the material of the balloon loses its elasticity . The resulting wrinkles and bulges after the blocking fluid has been completely removed can lead to micro-injuries of the urethra if removed. This risk is increased by incrustations on the catheter due to the crystallization of urine components. To avoid these injuries, the balloon is occasionally refilled with 2–5 ml of liquid after it has been completely emptied in order to minimize the formation of folds and bulges as far as possible. The slightly filled balloon increases the outer diameter of the catheter only minimally, but reduces these complications due to the smoother surface. This principle can also be applied to suprapubic indwelling catheters with balloons.
Suprapubic catheterization
In contrast to the techniques mentioned above, the catheter is not applied in a natural way, but through the abdominal wall. For this purpose, the urinary bladder is filled using a transurethral catheter and the filling is assessed using sonography . If the bladder is sufficiently filled, a local anesthetic is injected about two fingers wide above the pubic bone . The needle is advanced up to the bladder with repeated aspiration until urine can be aspirated. The skin at the puncture site is then incised to a length of 5-10 mm with a scalpel and the catheter is inserted into the bladder via a hollow needle. Once the urine is drained, the catheter is advanced further and the needle withdrawn. The hollow needle is provided with two longitudinally arranged predetermined breaking points and is now divided and removed. The catheter now has to be fixed either with a skin suture or a balloon. Finally, the puncture site is bandaged in a sterile manner.
Maintenance of a suprapubic and transurethral indwelling catheter
Every urinary catheter, whether suprapubic or transurethral, leads to a bacterial colonization of the urinary bladder after a few days. This is unavoidable. To reduce the colonization of germs, each catheter should be cleaned daily with a disinfectant that is neutral to the mucous membrane. In the case of suprapubic catheters, the dressing must be changed under sterile conditions at the puncture site every two days. Due to the germ colonization, the urinary catheter cannot remain indefinitely. Transurethral catheters are therefore changed every 2 to 3 weeks and suprapubic urinary catheters every 4 to 5 weeks.
Problems and complications
- Urinary bladder infections
- Bacterial colonization of the catheter (biofilm)
- Incrustation of the catheter (crystallization of urine components, can lead to occlusion)
- Inflammation of the renal pelvis
- Micro injuries of the urethra with scarred urethral constrictions
- Severe injury to the urethra such as perforation and formation of a wrong path, so-called via falsa
- Injury to the intestine when using a suprapubic catheter
- Bleeding
- Loss of fluid from the balloon
- Allergic reactions with latex catheters
- Bladder spasms from the foreign body
For longer catheterization periods (> 7 days), catheters made of silicone are preferred because, in contrast to latex, there is no hardening of the material and irritation occurs less often. There are also catheters with additional coatings that counteract biofilm formation and incrustation. If possible, indwelling catheters as a definitive urinary diversion should be avoided. Diapers or templates are preferable with appropriate skin care and sufficient exchange rate, unless a largely restharnfreie spontaneous evacuation is guaranteed. With higher residual urine levels, repeated single-use catheterization or self-catheterization is suitable to avoid the dreaded infections of the upper urinary tract . Drinking plenty of fluids and acidifying the urine with medication can reduce these problems. In the case of spinal cord injuries, transurethral urinary catheters are usually no longer used for permanent urinary drainage, but instead suprapubic urinary catheters, intermittent single-use catheters or condom urinals are used. In spinal cord injuries with spastic bladder paralysis, the bladder sphincter has often been surgically notched or even resected. Such a notch may need to be repeated because of scarring.
Alternative urinary diversion
As an alternative incontinence supply for men, urinary diversion can be done with a condom urinal. In a study of 75 men, doctors from the University of Michigan Medical School compared both methods and found that the silicone condom urinals suitable for long-term care, which can be worn for up to 48 hours, are better tolerated and accepted by patients than those often perceived as painful Treatment with the urinary catheter. The risk of cystitis and urinary tract infections is 80% lower for men without dementia .
Individual evidence
- ↑ Amit Verma, Deepa Bhani, Vinay Tomar, Rekha Bachhiwal, Shersingh Yadav: Differences in Bacterial Colonization and Biofilm Formation Property of Uropathogens between the Two Most Commonly used Indwelling Urinary Catheters . In: Journal of clinical and diagnostic research: JCDR . tape 10 , no. June 6 , 2016, ISSN 2249-782X , p. PC01–03 , doi : 10.7860 / JCDR / 2016 / 20486.7939 , PMID 27504341 , PMC 4963701 (free full text).
- ↑ Peter Tenke, Claus R. Riedl, Gwennan Ll. Jones, Gareth J. Williams, David Stickler: Bacterial biofilm formation on urologic devices and heparin coating as preventive strategy . In: International Journal of Antimicrobial Agents . tape 23 , Suppl. 1, March 2004, ISSN 0924-8579 , p. S67-74 , doi : 10.1016 / j.ijantimicag.2003.12.007 , PMID 15037330 .
- ↑ University of Michigan Medical School, press release of July 3, 2006: For men, catheter type makes a huge difference in urinary infection risk, UM / VA study finds ( Memento of the original of September 24, 2008 in the Internet Archive ) Info: The archive link was used automatically and not yet checked. Please check the original and archive link according to the instructions and then remove this notice.
