Renal& UTIs Flashcards
(233 cards)
What anatomical feature in females means UTIs are more common?
Shorter urethra
What are the host factors contributing to UTIs?
Shorter urethra
Obstruction - enlarged prostate, pregnancy, stones, tumour
Neurological problems - incomplete emptying, residual urine
Ureteric reflux - ascending infection from bladder esp in children
WHere are common sites of urinary tract obstruction?
PUJ: calculi Ureter: Calculi, Ca, retroperitoneal fibrosis Bladder: Neuropathic bladder VUJ: calculi Bladder neck: hypertrophy Prostate: BPH/Ca Urethra: stricture
What are the bacterial factors of UTIs?
Fimbrae allow attachment to host epithelium
K antigen permits production of polysaccharide capsule
Urease breaks down urea creatinga favourable environment for bacterial growth
Haemolysins damage host membranes and cause renal damage
What are the clinical syndromes of a UTI?
Frequency and dysuria (lower UTI) Acute pyelonephritis (upper UTI) Chronic nephritis Asymptomatic (pregnancy many problems for mother and baby) Septicaemia +/- shock
What are the signs and symptoms of a lower UTI?
Low grade fever
Dysuria
Frequency
Urgency
What are the signs and symptoms of an upper UTI (pyelonephritis)?
Fever
Loin pain
May have dysuria, frequency
When are investigations of UTI needed?
Healthy women - ‘uncomplicated UTI’ no need to culture urine - nitrite/leucocyte esterase dipstick testing
Culture urine in ‘complicated UTI’ ie pregnancy, treatment failure, suspected pyelonephritis, complications, male, paediatric
How might a specimen be collected to investigate a UTI further?
MSU - cleansing not required in women Clean catch in children - no antiseptic Collection bag (20% false positives) Catheter sample Supra-pubic aspiration
How is a specimen for UTI investigation transported?
4 degrees C +/- boric acid - disolves in the urine, stops the microorganisms multiplying -> accurate results
What can be tested in a urine sample?
-Turbidity (visual inspection) DIpstick testing can detect: -Leucocyte esterase -Nitrite -Haematuria -Proteinuria
What cells will be present in a urine sample of a patient with a UTI under the microscope?
Acute - WBC and RBC
Contaminated urine - squame (epithelial cells) NOT indication of UTI
Why is a nitrite test specific but not sensitive for UTI investigation?
Specific - if nitrites present in sample, definite positive test for UTI
Sensitive - Not all bacteria produce nitrites therefore not all UTIs will produce nitrite positive test
What might make a urine culture tray turn pink?
Lactose fermentors change pH
How many colonies distinguishes bacteriuria and when is this useful?
> 10^5 cfu/ml
Asympomatic females compared with femals with pyelonephritis
What is the role of a culture of urine?
Investigation of children, males and comlicate infections Increased sensitivity Epidemiology of isolates Susceptible data Control of specimen quality
What needs to be taken into account in interpretation of a culture report for a UTI?
Clinical details - symptoms/previous antibiotics Quality of specimen Delays in culture Microscopy (if available) Organism(s) isolated
What other problems may be the cause of urethral syndrome?
Low bacteriuria Fastidious organism Vaginal infection/inflammation STI - urethritis Mechanical, physical and chemical causes
When would imaging of the urinary tract be used?
All children
Males - posterior urethral valves
Females - vesico- ureteric reflux
What might sterile pyuria be indicative of?
Antibiotics Urethritis Vaginal infection/inflammation Chemical inflammation TB Appendicitis Fastidious organism?
What is the treatment of a UTI?
Increases fluid intake
Adress underlying disorders
3 day antibiotics if uncomlicated, 5 if complicated
CSU only if symptomatic - likely false positive as it is another medium for bacteria to colonise
What is the treatment of simple cystitis?
Uncomplicated infections can be treated with trimethoprim or nitrofurantoin.
3 day course as effective as 5/7 os use minimal to reduce resistance
What antibiotics are used for complicated UTIs?
Trimethoprim, nitrofurantoin or cephalexin
Amoxicillin not appropriate as 50% resistant
How is pyelonephritis/septicaemia treated?
14 day course
Agent with systemic activity
Possibly IV initially unless good PO absorption and patient well enough
Co-amoxiclav, ciprofloxacin, gentamicin (IV only - nephrotoxic)