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Urinary Catheters and the Prevention of Urinary Tract Infections

01. August 2019

DEFINITION of urinary tract infection associated with medical care: Please see: Klavs I, Grgič-Vitek M, Škerl M, Grosek Š, Kompan L, Kramar Z, Bufon-Lužnik T. Epidemiološko spremljanje bolnišničnih okužb. V: Klavs I (ur.) Zdr var 2001, 40: (Suppl): 1-93.

PROBLEM: A catheter is a foreign body that disrupts the protective function of the mucosal barrier. A urinary catheter chemically and mechanically irritates the mucosa causing inflammation and creates a favourable milieu for bacteria to grow and multiply inside the catheter and on its outer surface. The risk of infection increases with the duration of the catheterization.

OBJECTIVE: To identify risk factors, consider catheter placement indications, and take measures to prevent hospital-acquired urinary tract infection.

AIM: To reduce urinary tract infections associated with medical care.

PATHOGENESIS, CAUSATIVE AGENTS AND AN ENTRY POINT FOR URINARY TRACT INFECTION associated with urinary catheters and the risk of infection

There are three ways in which microorganisms can enter the urinary tract:
– by catheter insertion,
– upwards through the catheter lumen when handling and hygienically maintaining the catheter and
– upwards on the outer catheter surface from the periurethral area.

Possible entry points for infection:

– ostium of the urethra and the catheter area,

– contact between the catheter and the urinary sac attachment,

– urine sampling point,

– urine release clamp,

– return of urine from the sac towards the urethra if the sac does not have a non-return valve or a dry chamber.

METHODS OF CATHETERIZATION AND RISK of urinary tract infection

The choice of the type of catheterization depends on the medical indication and the estimated duration of catheterization, which may be:

– Single catheterization;

– Intermittent catheterization;

– Short-term continuous catheterization;

– Long-term continuous catheterization;

– Condom catheter;

– Surgical stoma.

Ad bullet 1. Single catheterization is suitable for urine sampling in acutely ill patients and for the management of transitional problems with urination; bacteriuria occurs in 1 to 5% and infection in 1% of patients.

Ad bullet 2. Intermittent catheterization is occasional catheterization, mainly in young patients with spinal cord defects, which the patient can perform alone (so-called “clean” self-catheterization), in children with myelomeningocele and “neurogenic bladder” (cat. II). The risk of infection is lower than in patients with indwelling catheters.

Ad bullet 3. Short-term continuous catheterization means the insertion of a urinary catheter for less than 72 hours due to temporary incontinence. The catheter is removed as soon as it no longer has a medical indication (I B) and the probability of bacteriuria is 10 to 20%.

Ad bullet 4. Long-term continuous catheterization means the insertion of a urinary catheter for more than 72 hours:

– for measuring urine output,

– for the evaluation of perfusion after injury and surgery,

– due to urological and other medical indications.

The risk of bacteriuria is 5 to 10% per catheter day, so the catheter is removed as soon as it is no longer medically indicated.

Ad bullet 5. A condom catheter should only be used for short-term catheterization in consenting male patients (no common positions).

Ad bullet 6. Surgical stoma
Nephrostomy – with higher urinary tract obstruction,

Cystostomy – with lower urinary tract obstruction and when wish to avoid the risk of infection from prolonged continuous catheterization.

MEASURES FOR THE PREVENTION OF URINARY TRACT INFECTION

The hospital and institution performing the catheterization must have written instructions for the introduction, maintenance and nursing care of the catheter patient, as well as for the aseptic performance of the procedures. It is important to maintain a sterile, closed drainage system (I B) and the unobstructed flow of urine (I B).

 


  1. General measures

  2. Indications for the introduction of a urinary catheter

  3. Choosing devices, e.g. depending on catheter property

  4. Work procedures

  5. Documentation

  6. Recording urinary tract infections


 

Ad bullet A. General measures:

– the urinary catheter is introduced and handled by trained personnel (I B),

– procedure performed according to the introduction instructions (aseptic technique, sterile devices) (I B) in the outpatient treatment of a patient with an indwelling catheter, the use of a “clean” technique (I A),

– maintains and performs the care of a catheter patient (I B),

– choice of catheter size: the smallest size of catheter still permitting good drainage, whilst reducing urethral damage (cat. II),

– disinfection of the hands before and after handling a urinary catheter and urine bag (I B),

– periodical and regular staff training (I B),

– Patients with catheterization (short- or long-term) are not routinely prescribed antimicrobials (I B).

Ad bullet B. Indications for the introduction of a urinary catheter:
– the indication should be performed by a physician,

– the patient should only have the catheter inserted for as long as is absolutely necessary (I B); remove the postoperatively inserted catheter within 24 hours (I B) at the latest,

– catheter insertion is avoided in patients with incontinence (e.g. in nursing homes) (I B).

The main medical indications are:

– emptying of the contents of the bladder due to acute urinary retention or obstruction (I B),

– perioperative care in urological and gynaecological operations (I B),

– surgical drainage of the bladder,

– urinary diagnostics,

– bladder flushing (cat. II),

– administration of therapeutic agents acting locally in the bladder,

– accurate measurements of urinary output (shock, renal failure, etc.).

Ad bullet C. Choosing material or devices

Urinary catheter
PVC catheter for single catheterization (a hydrophilic catheter (cat. II) is preferred over a standard catheter) made of siliconized latex for short-term catheterization (cat. II);

silicone or Teflon catheter for long-term catheterization (more than 1 month) (cat. II);

hydrogel catheter for expected longer periods of time (2-3 months) (cat. II);

the use of silver-coated catheters has not significantly reduced urinary tract infections in known studies to date (No common standpoints),

the use of antibiotic-coated catheters has not significantly reduced urinary tract infections in studies known to date (No common standpoints),

there is no consensus on the use of valvular catheters in the prevention of urinary tract infections.

Urine bag
Closed system (I B),
individually packed sterile bag,

it must have a dry non-return chamber or non-return valve (I B),

at the start of the drainage tube, there must be an area for the sterile removal of urine,

there must be a special urine release clip at the bottom of the bag,

the bag must be rounded.

Sterile catheter insertion devices

Set of devices: forceps for cleaning the urethral entrance, a gauze, swabs with saline for the mucosa, forceps for urinary catheter introduction (I B),

sterile saline for periurethral cleaning; there is no consensus on the use of an antiseptic solution,

sterile single-use gel (cat. II),

sterile redistilled water (according to the manufacturer’s instructions) to fill the balloon.

 

Ad bullet D. Work procedures

Standard measures are carried out during use (I B).

The introduction of a urinary catheter

Urinary catheter replacement

Replacing and emptying the urine bag

Closed sterile drainage of urine

Maintenance of unobstructed urinary flow

Urinary catheter flushing

Medical care for patients with an indwelling urinary catheter

Medical care for patients with nephrostomy or cystostomy

Urine sampling

Ad bullet D1. The introduction of a urinary catheter

Anogenital pre-intervention care (I B),

Hand hygiene (disinfection!) (I B),

Use of sterile examination gloves (I B),

Use of sterile devices (I B),

The routine use of antiseptics is not required (cat. II).

 

Ad bullet D2. Urinary catheter replacement

No routine replacement required (I B),

The catheter is replaced with a medical indication according to the material of the catheter (as per manufacturer’s instructions).

Ad bullet D3. Replacing and emptying the urine bag

Replacing the urine bag:

There is no recommendation for the routine replacement of the urine bag (I B).

It should be replaced according to the hospital’s policy (e.g. nursing care standard, KOBO instructions), when damaged, not sealed or visibly soiled.

 

Emptying the urine bag:

The hands should be disinfected before and after the procedure; protective (examination) gloves should be used during the procedure (I B),

do not routinely empty the urine bag; it should be emptied when filled to a maximum of 2/3 (I B),

when emptying, use a clean collection container for each patient (I C),

the discharge clamp and container should not come into contact,

when the clip is closed, disinfect the surface of the clip with an alcohol-based disinfectant.

Ad bullet D 4. Closed sterile drainage of urine (I B)

Do not disconnect the system,

in case of rupture, damage or leakage, replace the drainage system completely (I B),

use a non-return valve to prevent the unintentional reflux of urine.

 

Ad bullet D 5. Maintenance of unobstructed urinary flow (I B)

 

Avoid folding and closing the tubes (I B),

the urine bag should not be filled more than 2/3,

the coated catheter should be flushed with sterile isotonic solution or, if necessary, replaced,

the urine collecting tube and the sac should always be below the level of the bladder (I B).

 

 

Ad bullet D 6. Urinary catheter flushing

Aseptic work process (hand disinfection, sterile gloves, sterile utensils, rinsing with sterile solutions) (I B),

disinfect the catheter and tube before disconnecting the tube system,

washing with antibiotic solutions to prevent infection is not effective (cat. II).

Note: rinsing should be avoided except in the case of a threatening obstruction (cat. II).

Ad bullet D 7. Medical care for patients with an indwelling urinary catheter

Disinfection of the hands before and after handling a urinary catheter (I B),

the genital area and catheter surface should be washed with lukewarm water and soap, according to the standard of care, the anogenital area should be rinsed well after cleaning with soap and then dried thoroughly (I B),

antiseptic solutions should not be used (mucosal irritation and the increased possibility of microorganism transfer) (cat. II, No common standpoints).
Ad bullet D 8. Medical care for patients with nephrostomy or cystostomy

The wound area and the area around the tube should be handled according to the standards for wound care.

Ad bullet D 9. Urine sampling
The aseptic aspiration of urine from the drainage tube (I B),

the sampling site should be disinfected before sampling and the urine sample should be taken with a sterile syringe with the smallest needle possible (I B).

Warning: disconnection or the removal of urine from the bag is not allowed (cat. II).

 

Ad bullet E. Documentation (cat. II)

The following parameters should be recorded:

time of catheter insertion and removal,

indication (cause of insertion),

catheter type,

the method and performance of all procedures associated with the catheter and urine bag use.

Ad bullet F. Recording urinary tract infections

Monitoring urinary tract infections:

– if indicated due to risk factors (cat. II),

– using standard methodology (I B).

 

MINIMUM CONDITIONS FOR PREVENTING URINARY TRACT INFECTIONS:

– sterile urine catheter, sterile urine bag,

– aseptic work procedures,

– disinfection of the hands before and after contact with the catheter and urine bag,

– use of protective gloves when performing procedures, when one could come into contact with urine,

– the urine bag should always be below the level of the bladder (I B), make sure that the tube is not folded (I B).

WARNING: in patients without indwelling urine catheters, the number of bacteria > 10,000 CFU/mL is diagnostically significant, and in patients with indwelling urinary catheters (for aseptic withdrawal with a needle and syringe from a catheter sampling site), > 100 CFU bacteria/mL urine is diagnostically significant (see definitions).

Literature
Gould CV, Umscheild CA, Agarwal RK et al. Guideline for prevention of catheter-associated urinary tract infections 2009. HICPAC, http//www.cdc.gov/
CDC guidelines for prevention of catheter-associated urinary tract infections. Am J Infect Contr 1983, 11: 28-36.
Guidelines for prevention of infections associated with the insertion and maintenance of short indwelling urethral catheters in acute care. J Hosp Infect 2001; 47(Suppl): S39- S46.
RKI. Empfehlungen zur Praevention und Kontrolle Katheter-assoziierter Harnwegsinfektionen. Bundesgesundheitsbl 1999; 42: 806-9
Zakotnik B. Okužbe sečil, povezane z zdravstvom. V: Beović B, Strle F, Čižman M, Tomažič J (ur.). Infektološki simpozij 2009. Ljubljana: Sekcija za kemoterapijo SZD, Klinika za infekcijske bolezni in vročinska stanja, UKC Lj, Katedra za infektologijo in epidemiologijo MF Univerza v Lj, 2009: 91-6.

 

Urinary tract infections (UTIs) can occur in symptomatic infections or asymptomatic bacteriuria. The uropoietic tract is usually sterile, with the exception of the lower third of the urethra in women. Pathogenic microorganisms usually pass from the urethra to the bladder and up. Infectious pathogens in the urinary tract are mainly coliform bacteria in women, while in men it is usually paraurethral bacterial flora due to obstructive disorders. Hematogenic infection is much less frequent and usually develops in patients with immune deficiency disorders.