9 - UTI Flashcards
(26 cards)
Name common causes of lower UTI
Bacterial cystitis, abacterial cystitis and prostatitis
What are the symptoms of bacterial cystitis?
Polyuria, dysuria, pyruia (pus) and haematuria
How are bacterial and abacterial cystitis distinguished, when their symptoms are the same?
Abacterial cystitis wont have significant bacteriuria
What are the symptoms of prostatitis?
Fever, dysuria, polyuria, perineal and lower back pain
Name the common causes of upper UTI
Haematogenous and ascending routes of infections eg. Acute pyelonephritis and chronic interstitial nephritis
What are the symptoms of acute pyelonephritis?
Polyuria, dysuria, pyuria, heamaturia, fever and loin pain
What causes asymptomatic UTIs and why are they important?
Covert bacteriuria, in pregnancy high chance of developing into acute pyelonephritis (renal scarring)
What is the most common type of gram stain to see with a UTI?
Gram negative - PINK
What are the body’s defence mechanisms against UTIs?
Regular flushing of organisms from the distal urethra during voiding and antibacterial secretions in urethra and urine.
What host factors can increase chances of developing a UTI?
Shorter urethra - organisms ascend urethra between voiding, so females more likely to get UTI
Obstruction - causes incomplete emptying, enlarged prostate, pregnancy, stones and tumours
Neurological - Incomplete emptying allows bacteria to grow in bladder
Ureteric reflux - urine refluxes into bladder, ascending infection, common in children
What features do certain bacteria have that enable them to be so virulent in the urinary tract?
Urease production - break down urea, creating favourable environment for bacterial growth
Haemolysins - Damage host membranes and cause renal damage
Fimbrae - Allow attachment to host epithelium
K antigen - Allows production of polysaccharide capsule, makes ecoli harder for white cells to destroy
What does Ecoli look like on a gram stain?
Gram negative rods - pink
Define uncomplicated UTI
Infection by a usual organism in a patient with a normal urinary tract and function
Define a complicated UTI
When one or more factors are present that predispose the person to persistent/recurrent infection
What causes complicated UTIs?
Abnormal urinary tract - Indwelling catheter or vesicoureteric reflux
Virulent organism - staph aureus
Impaired host defences - Diabetes and immunosuppression
Impaired renal function - urine in bladder for longer
When is a urine dipstick not useful?
Elderly patients as often asymptomatic bacteriuria
Catheterised patients will have an inflammatory response to catheter
What is sterile pyuria?
White blood cells in urine
What causes sterlie pyuria?
Urethritis (chlamydia/gonococci)
TB
Appendicitis
Vaginal inflammation
When is asymptomatic bacteriuria a problem?
Not in elderly, only in pregnancy
How are uncomplicated UTIs treated?
Trimethoprim/nitrofurantoin for 3 days (reduces selection pressure)
How are complicated UTIs treated and what are the problems with the treatment?
Trimethoprim - Ecoli is becoming resistant
Nitrofurantion - No systemic effects but will lower GFR and elderly GFR already low
Cephalexin
5-7 days
How is pyelonephritis/septicaemia treated?
Antibiotics with systemic activity (NOT nitrofurantoin) Co-amoxiclav Gentamicin - IV only as nephrotoxic Ciprofloxacin 14 days
What antibiotics are used in prophylactic UTI treatment?
Trimethoprim
Nitrofurantoin
What factors make children likely to develop UTIs?
Posterior urethral valves in boys - membrane at top of urethra impedes flow
Duplex (abnormal) ureters - impedes flow
Vesicoureteric reflux - urine goes back into kidneys, causes scarring of kidneys
