Urinary L8.1 Flashcards
1) What is a UTI?
2) What is it caused by?
1) Infection of urinary tract
2) Bacteria, fungi, viruses
1) What is an upper UTI?
2) Lower UTI?
3) Examples of lower UTI
1) upper part of urinary tract: kidney, ureter - Pyelonephritis
2) Bladder (Cystitis)
3) Urethritis, prostatitis
NICE say lower UTI = bladder only
1) What is an uncomplicated UTI?
2) What is a complicated UTI?
1) Caused by typical uropathogens (E.coli)
Occurs in non-pregnant women
No functional issues
No predisposing cormobidities - no underlying health conditions (diabetes)
2) Increased risk of complications
-treatment failure
-persistent infection
-ascending infection (spreads to kidneyys)
Causes:
-Pregnancy
-Men (UTIs occurence less common in men, occurence often considered complicated)
-Urinary tract abnormalities (functional issue)
-Catheterisation
-Renal disease
-Immunocompromise (diabetes)
1) What are recurrent UTIs?
2) Who gets UTIs?
3) What is the difference between relapse and reinfection?
1) 2 or more episodes of UTI in 6 months or 3 or more episodes in 1 year.
2) More common in women. Women have shorter urethras
3) Relapse: same organism causes UTI comes back within 7 days. Reinfection is over 14 days and due to any organism
1) What are catheter associated UTIs?
2) What is asymptomatic bacteriuria?
1) UTI in bladder, kidney due to use of catheter (bacteria enters urinary tract via catheter)
2) Bacteria in urine but no symptoms./ signs of infections. Colonisation of urinary tract by bacteria.
Risk factors for UTI
- Age (older, increase risk)
- Female
- History of UTI
Which organisms are the most common causes of UTI?
In uncomplicated UTI
-ecoli
-staphylococcus
saprophyticus, leads to honeymooon cystitis
1) How do bacteria enter the urinary tract?
1) Retrograde: ascending infection from urethra. Bacteria from outside colonise and make its way up urethra
Via blood / lymphatics: haemotogenous spread. Rare
Direct entry: catheters, surgery
What are some virulence factors that help bacteria surpass destruction by immune system?
- Fimbriae and adhesions which allow atttchment to uroepithelium
- K antigens / slime capsule - make e coli resistant to phagocytosis
What are natural defences of body to UTI?
- Urinary system at low pH + high conc of urea. difficult for bacteria to survive + multiply
- Regular flushing of urinary system. If any bacteria present, trying to reach bladder from urethra, flushed away
- Mucin layer around bladder, harder for bacteria to penetrate through into uroepithelium
- Antibacterial secretions by urothelium in mucin layer. Kills bacteria (e.g. RNAse)
- General inflammatory reactions in response to pathogen inbasion
Why is it important for antibacterial secretions in urothelium to stay in mucin layer? *
Secreting them in mucin layer means high conc of all these peptides that can destroy / prevet infections. If secretions were secreted directly into urine, they would be too dilute
What are common symptoms of UTI?
Dysuria - burning pain, discomfort
Haematuria - blood in urine
Incontinence
Increased frequency / urgency
Cloudy urine
Abdominal pain
Fever
1) What is urethral syndrome?
2) Causes
1) Lower urinary symptoms (dysuria, frequency, urgency, suprapubic tendency) but, no urinary pathogen cultured. No positive urine culture
2)
- Infection with low bacteria count
- STIs
- Non-infective inflammations- chemical
- Infections with an organism that is not detected on normal urine culture
EXAMPLE CASE + DIFFERNTIAL DIAGNOSIS
What assesments and investigations do we carry out with a patient who has a suspected UTI?
- History: SQUITARPS; sexual history; risk factors for recurrent or
complicated UTI; family history; possibility of pregnancy and
contraception used; and treatments. - Examination; abdominal and possibly vulval/pelvic examination.
- Investigations: pregnancy test.
- Urine dipstick and/or urine culture , depending on the woman’s clinical
presentation, age, and risk factor profile.
How to investigate a patient with UTI
- Urinary symptoms in adult women <65, do not culture routinely.
- In sexually active young people with urinary symptoms, consider CHLAMYDIA
- If patient has severe symptoms, 3 or more symptoms with no vagina discharge / irritation, 90% chance positive culture. Therefore, give patient empirical antibiotic treatment.
- If patient has mild symptoms (2 or less), urine sample. If sample cloudy, perform urine dipstick.
If urine not cloudy and it is clear, 97% chance no UTI. Consider another diagnosis.
1) What is a urine dipstick test?
2) When is the best time to carry out urine dipstick test?
3) What are we looking for?
1) Simple bedisde test
2) Early morning sample
3) Nitrites - if bacteria present in urine, bacteria contain enzyme nitrate reducatse. Nitrate reductase converts nitrates in urine to nitries.
Leukocytes
RBCs
If nitrates found, 92% chance UTI
If nitrates + leukocytes found, 95% UTI
If only leukocytes, 50% UTI. Presence of leukocytes can indicate infection elsehwhere
In urine dipstick test, why is early morning sample best?
Higher conc nitrites + bacteria.
Build up over night
Not flushed out overnight
What are complications for men and women over 65 with suspected UTI?
What are symptoms for patients over 65 with UTI?
1) - Consider sepsis
- Send urine culture prior to antibioitics
2)- UTI may present atypically, temp spikes, incontinence, haematuria, new/worseing delirium
UTI worse if over 65.
1) What is a urine culture?
2) Why collect midstream?
3) Why are catheter samples and pad samples more accurate?
Collection method
-Collected mid stream urine
-Catheter technique (if patient cannot provide mid stream sample)
-Pad sample (if patient is incontinent)
- You do not collect first or last part of urine that comes out. Reduces risk of sample being contaminated with bacteria.
- Higher chance of colonisation from bacteria
1) How does sending for culture work?
1) When sending urine for culture, we are growing bacteria and testing its sensitivity to various antibiotics.
Varius antibiotics are introduced to culture and left for hours/days.
This tests whether the bacteria can grow / survive in contact with a certain antibiotic
We can tell this by diameter of inhibition zone.
If large diameter, antibioitic was effective in preventing growth of bacteria and this antibiotic should be used in treatment
When do we take cultures?
When do we NOT cukture routinely?
Do not take cultures routinely in uncomplicated UTIs
Only culture when highehr risk of complications
-Pregnancy
-Suspected UTI in men
-pyelonephritis
Describe the treatment options for an uncomplicated lower UTI for men and pregnant women
What are first line antibiotics in this situation?
non pregnant women: Short course of antibioitics, 3 days
Pregnant Women + Men: 7 days
Nitrofurantoin, trimethoprin
First line antibiotics for
1) Upper UTI
2) Pyelonephritis
1) Penicillin
2) Cephalexin, co-axoiclav
