Editing UTIs

== Classification ==

* Uncomplicated
* Complicated: episode of infection with increased risk of serious complications or treatment failure
* Upper: loin pain, pyrexia, rigors, malaise
* Lower: frequency, urgency, suprapubic discomfort, dysuria and cloudy offensive urine

== Acute pyelonephritis ==

* Aetiology
** Haematogenous - often tonsils, carious teeth, cutaneous infections, renal TB
** Ascending infection - most common - a/w VUR, urinary stasis, calculi
* Microbiology
** E coli, and other gram negative organisms
** Urine goes acidic in E coli and streptococcal infections
** Proteus and staphylococci split urea to form ammonia, which makes the urine alkaline and promotes stone formation
** Nitrites in urine suggests gram negative organism
* Risk factors
** Females, especially during childhood, puberty, after intercourse, and during pregnancy
* Presentation
** Fever
** Rigors
** Flank pain
** N/V
** Costovertebral angle tenderness
** Pyuria - almost always
* Workup
** Urine MCS
** Renal USS to exclude pyonephrosis, perirenal abscess and obstruction by calculi
** CT can be done - decreased opacification of affected parenchyma, typically in patchy, wedge-shaped or linear distribution
* Special situations
** Pregnancy
*** Often presents 20-28 weeks with malaise, fever, loin pain, rigors
*** Not all women will have had LUTS
** Childhood/VUR
*** Underlying cause - urinary stasis due to VUR, detrusor-sphincter dyssinergia, poor bladder emptying habit or constipation, stones, outlet obstruction, neurological disorders such as spina bifida
*** Should be investigated after first confirmed UTI
*** Can lead to renal scarring in up to 20%, and subsequent HTN
*** VUR diagnosed with micturating cystogram
*** DMSA scan can be used to assess degree of renal scarring
*** Indications for surgery in VUR: recurrent acute pyelonephritis despite Abx or if severe reflux is accompanied by a surgically correctable malformation
** Renal cortical abscess (carbuncle)
*** Usually caused by Staph aureus, reaching the kidney through haematogenous spread
*** Risk factors: diabetics, IVDU, chronic disease, immunodeficiency
*** May have no urinary symptoms or findings if it does not communicate with collecting system
** Renal corticomedullary abscess
*** Usually results from ascending UTI in association with an underlying urinary tract abnormality
*** Usually caused by common uropathogens such as GNB/E coli
*** Can extend deep into parenchyma, penetrate capsule and form a perirenal abscess
*** Small abscesses can be treated with antibiotics, but perc drainage is often needed to stabilise the patient, and may need a nephrostomy too
** Emphysematous pyelonephritis
*** Fulminant, necrotising, life-threatening variant of acute pyelonephritis caused by gas-forming organisms
*** 90% occurs in diabetic patients
*** Gas will be seen on plain film, USS or CT
*** Broad spectrum Abx and percutaneous drainage for mildly unwell patients
*** Severely unwell patients may need nephrectomy
** Xanthogranulomatous pyelonephritis
*** Uncommon but severe chronic destructive granulomatous inflammation of renal parenchyma, associated with obstruction and infection of the urinary tract
*** Typically middle-aged women with chronic symptoms - flank pain, pyrexia, malaise
*** MCS usually positive for E coli/GNB or S aureus
*** CT - enlarged, non-functioning kidney, often with calculi and low-density masses (xanthomatous tissue) and in some cases involvement of adjacent structures - sometimes difficult to distinguish from neoplastic disease
*** Nephrectomy is usually needed
** TB of urinary tract
*** Always haematogenous - secondary TB
*** Formation of granulomas
*** Involvement of bladder secondary to renal disease
*** Generally have TB in urine

== Cystitis/lower urinary tract infection ==

* Presentation
** Frequency
** Urgency
** Suprapubic discomfort
** Dysuria
** Cloudy offensive urine
* Pathophysiology
** Often a/w upper tract colonisation
** Recurrent infection:
*** ?underlying predisposing cause
**** Incomplete emptying of the bladder - BOO, bladder diverticulum, neurogenic bladder dysfunction, decompensation of detrusor muscle
**** Calculus, foreign body or neoplasm
**** Incomplete emptying of upper tract, dilation of ureters a/w pregnancy, or VUR
**** Oestrogen deficiency - lowered local resistance
**** Colonisation of perineal skin
**** Diabetes
**** Immunosuppression
*** ?resistant organism
* Investigation
** Indications:
*** Repeated attacks in women
*** Single episode in a man
*** Single episode in a child of either sex
** Urinalysis
** Upper tract imaging
** Cystoscopy
* Special situations
** Acute abacterial cystitis - pus in urine but no organism identified. 
*** STI
*** TB
*** Carcinoma in situ
*** Mycoplasma
*** HSV
*** Cyclophosphamide
** Interstitial cystitis

[[Category:Urology]]