Urological Infections Flashcards
Examples of urological infections
-Urinary Infection
=Cystitis
=Recurrent UTIs
=Pyelonephritis
=Prostatitis
=Epididymo-orchitis
=Balanitis
-Urosepsis
-Fournier’s gangrene / necrotising fasciitis
Definition and incidence of UTI
-Inflammatory response of urothelium to bacterial invasion
-Constellation of symptoms (pain, frequency, dysuria, haematuria)
-Typically defined as >103-5 cfu/ml and symptoms
-Incidence:
=Common
=Prevalence – 4% reproductive females; 20-30% Elderly women
-Sex/Gender :
=Lower prevalence in men- <1% adults, 10% elderly men
Presentation of urological infections
-Bladder infection – Cystitis – suprapubic pain, frequency, dysuria, haematuria, malodorous urine
-Kidney infection – Pyelonephritis – Loin pain, fevers, haematuria, sepsis
-Prostate infection – Acute Prostatitis – perineal pain, pain on ejaculation, tender prostate on DRE, fevers, systemically unwell
-Epididymal/Testicular infection - Epididymitis/Orchitis – testicular/scrotal pain, swelling, fevers
-Urethral infection – Urethritis – dysuria, urethral discharge, and/or pruritis
What is a complicated UTI?
-Infection associated with factors increasing colonization and decreasing efficacy of therapy. Requires one or all of following:
=Anatomic or functional abnormality of urinary tract (enlarged prostate, stone disease, diverticulum, neurogenic bladder, etc.)
=Immunocompromised host
=Multi-drug resistant bacteria
UTI Risk Factors and Mechanism
-Reduced Urinary Flow:
=BOO with incomplete bladder emptying (BPH, urethral stricture)
=Neuropathic bladder – MS, DM, Sp cord injury
=Poor fluid uptake – CVA, MS, MND, Sp cord injury
-Increased Colonisation:
=Sexual activity – increased innoculation
=Spermicide
=Oestrogen depletion/post-menopause
=Antibiotics – altered flora* Renal Tract Stones – may be caused by bacteria (struvite/MAP)… or subsequently colonised by bacteria
-Retrograde Infection/Ascent
=VUR
=Catheterisation
=Ureteric stent
=Urinary incontinence
=CUR
-General Immunosuppression
=DM, Elderly, CKD, HIV, Pregnancy
=Drugs – steroids, transplant
-General Mechanism: Ascending infection (see causes above)
=Haematogenous spread – v rare (Staph aureus from distant abscess/infection), candida fungaemia, TB
UTI: Causative Organisms
-Community Acquired UTI (from bowel flora)
=E coli (UPEC- Uropathogenic E coli)
=Proteus
=Klebsiella
=Staph saprophyticu
= E faecalis / Strep faecalis
-Nosocomial
=E coli
=Klebsiella
=Enterobacter
=Citrobacter
=Serratia
=Ps aeruginosa
=Providencia
=Staph saprophyticus
=E faecalis / Strep faecalis
-ISC/LTC
=Gardenella
=Mycoplasma
=Ureaplasma urealyticum
UTI Investigation
-All patients
=Focussed Hx, O/E
=MSU – UA: RBC, WCC, Nitrites
=MSU – Urine Culture, send culture if aged >65, haematuria for women, all for men
=DRE
-Consider:
=FBC, U&E
=Blood Cultures
=Imaging – complex UTIs – CT, Renal USS
=Flow Test & Bladder Scan - PVR
=Cystoscopy – recurrent UTIs, complex UTIs, ongoing haematuria
Management of UTI
-The type and duration of antibiotic treatment is dependent on site of infection (if known), host factors and severity of illness.
=Most antibiotics are highly concentrated in the urine and therefore are very effective at clearing bacteria from the urinary tract.
-Highest mean urine concentration (from highest to lowest):
=Cabrenicillin > Cephalexin > Ampicillin > TMP/SMX > Cipro > Nitrofurantoin
-However, in cases of pyelonephritis, prostatitis or epididymitis, proper tissue antibiotic concentrations are important
Management of uncomplicated UTI
-Trimethoprim 200mg bd for 3-5d
-Nitrofuratoin 100 mg BID x 5 days or a 3 day course of oral. 7 days for men
trimethoprim/sulfamethoxazole (TMP/SMX) is 95% effective
-If TMP/SMX resistance is > 10 – 20% (U.S. West coast, Europe), consider fluoroquinolones
Management of complicated UTI (acute pyelonephritis)
-Patients who are candidates for outpatient therapy may utilize:
-Oral ciprofloxacin 500 mg BID x 7 days
-Oral TMP-SMX DS BID x 14 days (not for Enterococcus or Pseudomonas)
-Use of initial one-time IV agent (ceftriaxone 1 g, amimoglycoside, fluoroquinolone)
-Adjust antibiotics according to culture results
Add appropriate drainage for intrarenal, perirenal or pararenal abscess
Inpatient UTI management
-IV Gentamicin + Amoxicillin
-IV fluoroquinolone (eg Ciprofloxacin)
-3rd generation cephalosporin (eg Cefotaxime, Ceftraixone)
-Extended spectrum penicillin (eg Peperacillin + Tazobactam = Tazosin)
-Carbapenem
-Blood cultures positive in 20 – 40% of patients
-Consider Switch from parenteral to oral therapy at 48 hours after clinically well
-Treat for 14 days.
Overview of pyonephrosis
Pyonephrosis is a kidney obstruction caused by infection and the formation of pus (“pyon” in Greek), which can result in rapid and complete loss of kidney function. Because the pus is thicker than urine, it blocks the passage of urine and results in the formation of an abscess. Although the condition is rare, it has been reported in adults, children, and even new-borns
Urine obstruction and hydronephrosis
-I: USS, CT, urinalysis
-M: IV abx, drainage
Management of Fournier’s Necrotising Fasciitis/ gangrene
-Aggressive Rx with Abx cover for Gm+, Gm-, Anaerobes: eg Amoxicillin + Gentamicin + Metronidazole
-Immediate recognition + Immediate aggressive Surgical debridement (necrectomy)
Management of epididymitis
Fluoroquinolones (Ofloxacin) or TMP/SMX for at least 2 weeks to obtain adequate tissue levels
Management of urethritis
Combination of Ciprofloxacin + Doxyxycline for 2 weeks
-Or Ofloxacin for 2 weeks
Management of acute bacterial prostatitis
Fluoroquinolones (Ofloxacin) or TMP/SMX for 2-4 weeks to obtain adequate tissue levels
Management of re-infection UTI
A test of cure should be undertaken by repeat culture in pregnancy, pyelonephritis, and complicated or relapsing UTI.
Management of relapsing infection
Failure to clear or completely eradicate the pathogen despite a reasonable treatment course should trigger a urologic investigation that includes imaging to define possible anatomical causes and prolonged therapy in the meantime
Management of asymptomatic bacteriuria
Generally, does not require treatment, except in pregnancy.
-Treatment is not indicated in the elderly (20-40% incidence) and patients with LTC (90-100% colonisation)
Principles of antibiotic prescribing
-In general, Abx choices for Rx simple UTIs is dependent on local guidelines, based on regional Abx resistance patterns
-Trimethoprim and Nitrofurantoin are used with Caution with CKD – not effective with advanced CKD
-Trimethoprim may increase K+ and Creat
-Gentamicin is nephrotoxic (and ototoxic) – use if required with dose adjusted for renal function
-Trimethoprim: effective against most uropathogens except Enterococcus, Pseud
-Nitrofurantoin: effective against most uropathogens except Pseud, Proteus
-Penicillins: effective against Gm +ve & some Gm –ve, may require β-lactamase inhibitor (clavulinic acid: co-amoxiclav;Tazobactam: Tazosin (piperacillin + tazobactam))
-Quinolones (Ciprofloxacin, Ofloxacin): effective against Gm –ve & some Gm +ve, including Proteus
-Aminoglycosides (Gentamicin): effective against Gm –ve, (some Gm+ve)
-Nitroimidazole (Metronidazole): effective against Anerobe
- Vancomycin: effective against Gm +ve
Overview of urethritis
-Definition: urethral infection caused by Neisseria gonorrhoeae (GU) or Chlamydia trachomatis (NGU)
-Presentation: Classically STI with urethral discharge after unprotected sex: dyuria + urethral discharge +/- pruritis
=GU: purulent discharge (white – yellow – green)
=NGU: mucoid or clear. (Generally less copious & severe than GU)
-Complications:
=Urethral stricture, orchitis, infertility, testicular atrophy
=Untreated gonococcal urethritis may disseminate → arthritis, meningitis, endocarditis.
=Untreated non-gonococcal urethritis may → reactive arthritis or infertility.
-Rx: various regimens-
=IM Ceftriaxone plus Azithromycin as a first-line regimen, preferably given together under direct observation
=Ofloxacin + Doxycyxlin
= Consult local guidelines
Overview of Fournier’s Gangrene/ Necrotising Fasciitis
-Definition: gangrene / necrotising fasciitis of the genitalia; typically with synergistic (mixed aerobic and anaerobic) infection – Urological Emergency
-Presentation: pain, sepsis, cellulitis with evidence of necrosis of the genitalia
-RFs:
=Elderly age, DM, obesity, immuno-suppression, previous genital injury/infection, recent genital/scrotal surgery (circumcision)
=If untreated or not Rx early → rapidly swelling necrotising fasciitis involving perineum, abdwall → death
-Rx:
=Resuscitate: ABC, Blood Cultures, IV Abx (IV Gent + Amox + Metronidazole) + IVF
=Emergency Surgery: Scrotal exploration, debridement, possible orchidectomy, may involve massive resection of necrotic tissue (necrectomy) including degloving of penis, removal of scrotum, debridement of skin and fascia over entire perineum, peri-anal, inguinal, lower abd,upper abd… thorax
=May require Incapacity consent
=May require joint surgery with colorectal surgeons
= Subsequent reconstructive plastic surgery (myocutaneous flaps)
Overview of prostatitis
-Acute bacterial vs chronic (bacterial, pelvic pain syndrome)
-P: acute bacterial (fever, myalgia, nausea, fatigue, sepsis), chronic (pelvic pain, LUT symptoms, sexual dysfunction, pain with bowel movements, tender and enlarged prostate
-I: dipstick, MCS, NAAT
-M: acute bacterial (admission, ciprofloxacin or trimethoprim for 2-4 weeks, analgesia, laxatives for pain during bowel movements), chronic (Tamsulosin, analgesia, psychological, abx trimethoprim or doxy for 4-6 wees, laxatives)
Overview of balanitis
Balanitis is common in young boys with a non-retractile foreskin and in the elderly where there may be predisposing factors such as malignancy or diabetes. The organisms most commonly involved are faecal bacteria and candida.
Presentation is with irritation or pain in the penis and discharge from beneath the foreskin. Inflammation is visible. Recurrent balanitis may cause a phimosis with disturbance of micturition.
-Balanitis: inflammation of glans penis/ posthitis: inflammation of foreskin
Treatment for balanitis
-Treatment depends on the cause
anyone with balanitis should be advised to (1): avoid contact with any potential skin irritants (e.g. soap), keep area clean by bathing twice daily with a weak saline solution while symptoms persist
-In consideration of men with acute balanitis
refer all men with acute balanitis and suspected urethritis, ulceration, or lymphadenopathy to a genito-urinary medicine clinic (2) with the exception of recurrent ulceration due to herpes simplex in someone with an established diagnosis
-Swab the sub-preputial space prior to starting empirical treatment (2)
-Balanitis secondary to candida responds to topical antifungal cream or oral antifungal treatment
in adults, treatment options include:
=topical imidazole e.g. econazole, ketoconazole, sulconazole,clotrimazole 1% or miconazole 2% applied twice a day till the symptoms resolve
=oral fluconazole - 150mg stat if symptoms are severe
=topical nystatin - in case of resistance and allergy to imidazole (3)
=topical terbinafine
-in children, treatment options include
=a topical imidazole e.g. clotrimazole, econazole, ketoconazole, miconazole, =sulconazole
=topical nystatin
=recommended that treatment with a topical antifungal should be continued for 2-3 days after clinical cure
-bacterial balanitis may require oral antibiotic treatment (e.g. flucloxacillin or erythromycin)
sometimes a combined steroid/antibiotic cream (e.g. hydrocortisone acetate 1%, fusidic acid 1%) or combined antifungal/steroid cream (e.g. hydrocortisone 1%, clotrimazole1%) is used to reduce inflammation caused by infection
=topical corticosteroid should be applied until the inflammation has cleared
twice a day for up to 2 weeks (3)
-Referral for consideration for circumcision may be necessary once the inflammation has settled.
-Older patients should be tested for diabetes.
