Urinary Tract Flashcards
What is the infection of the upper urinary tract
Pyelonephritis => May be just kidney or ureter
What is the infection of the lower urinary tract
Cystitis
Difference between complicated and uncomplicated UTIs
Complicated - patients have factors that compromise the urinary tract or host defence eg. urinary obstruction, retention due to neurological disease, immunosuppression, renal failure or transplantation, foreign bodies, pregnancy
Largest contributor to UTI
UPEC - uropathogenic e coli
How do bacteria go up the ureter and cause
Using (pyelonephritis) associated Pilli
Type I pilli
Clinical presentation of UTI in infants
In infants (<2yrs)- vomiting/fever and in elderly - less localised symptoms like confusion/falls
Symptoms of pyelonephritis
- Loin pain/flank tenderness ⇒ kidneys inflamed
- Fever/rigors
- Sepsis ⇒ If it gets into bloodstream
Symptoms of cystitis
- If only cystitis and no pyelonephritis, will have localized symptoms below
- Dysuria
- Frequency
- Urgency
- Suprapubic tenderness
causes of recurrent UTI
- Antimicrobial exposure is a risk factor
- Often MDR organisms
- Genetic - familial tendencies, susceptibility of uroepithelial cells, vaginal mucus properties,
- high grade VUR
- voiding dysfunction
frequent sexual intercourse and spermicides
treatment of recurrent infections
trial methenamine 1g every 12 hrs + OTC high dose vitamin C for 6 months
For continued recurrent infections despite treatment
Long-term prophylactic antibiotics trimethoprim 100mg. Nitrofurantoin etc. can be used as an alternatives
When should dipstick be used in UTI patients
only < 65 yo, in presence of clinical symptoms
What does the presence of indicate in dipstick tests wrt UTI
Nitrites - UTI is possible
Leukocytes- not necessarily UTI
What kind of urine sample should be used for urine culture
- Mid stream urine
- As first part will have periurethral contaminants, end part also has
- Mid stream reflects urine in bladder more accurately
Significant bacteriuria => what does it mean??
- Indicates that the number of bacteria in the voided urine exceeds the number expected from contamination from the anterior urethra
- Enough to have really established an infection
Asymptomatic bacteriuria
Significant bacteriuria but without symptoms
When is bacteriuria considered UTI
When it is symptomatic and results support clinical diagnosis
What does presence of inflammation in urine suggest
More likely to be UTI ( given presence of bacteria)
Main treatment for cystitis
Trimethoprim, if at risk for resistance give Nitrofurantoin AND eGFR >30
Recommended treatment for Pyelonephritis patients without penicllin allergy
Gentamicin, add amoxicillin if enterococcus isolated in urine in past 12 months or source of infection is unclear or patient has signs of severe sepsis
Recommended treatment for Pyelonephritis patients with penicllin allergy
vancomycin instead of amoxicillin
how to diagnose CAUTI
not dipstick or urine culture, diagnose clinically instead by exclusion
Tmeperature > 38 in younger patients, no evidence of focus of infection elsewhere
suprapubic or flank pain, frank haematuria, delirium, rigor
when should people be treated for asympt bacteriuria
only in the case of pregnant women
what are the anterior and posterior urethra
- Anterior urethra following penile and bulbourethra
- Posterior urethra = prostatic urethra
How are signals sent within the bladder
Sent within the tight junctions
Role of urothelium in bladder
Barrier and afferent signalling
Role of lamina propria in bladder
Functional centre coordinating the urothelium and detrusor
Where are nerves and blood vessels found in the bladder
Lamina propria
What happens as bladder fills
sensors detect increase in wall stretch tension → afferent neurons to dorsal horn of sacral spinal cord→ sensory/real time data on bladder state relayed to brainstem and higher centres which control bladder function
What ions does the bladder urothelium allow to pass and is it passive or active . What layer does the urothelium have
Urea, Na, K, passive, GAG layer
What nucleus modulates volitional micturition and where is it located
Pontine Micturition Centre ( Barrington’s nucleus )
Processing in Onuf’s nucleus in intermediolateral S2, S3, S4
How does muscle coordination allow voiding to occur
- Coordination of muscles allows urine to enter posterior urethra, voiding to occur
- Detrusor contraction
- Urethral relaxation
positive feedback loop of normal bladder function - what happens when detrusor contracts
Wall tension rises , results in afferent signals sent to PMC and efferent signals increasing detrusor contraction
What nerves are involved in the innervation of detrusor muscle and external sphincter and pelvic floor , what innervation and what actions involved in voiding
Detrusor - contraction - pelvic nerves ( PS motor and sensory)
External sphincter and pelvic floors - Pudendal nerve (somatic sensory and motor)
How does complete spinal cord injury affect voiding
Results in loss of central inhibition, typically reflex voiding and bladder emptying
What are the two main causes of storage LUTS
Increased urinary production or decreased storage capacity
Causes of polyuria
DM/DI, excess fluid intake
Cause of decreased bladder capacity
Reduced compliance, reduced functional capacity, neurogenic bladder=> neurological disorders like MS - bladder empties at far earlier point than functional capacity, irritation from bladder stones or tumours causing urgency and frequency
Symptoms of storage LUTS
Urgency, frequency, nocturia,
Causes of reduced compliance of bladder
could be due to increased UO as a result of renal concentrating ability decreasing with age, or bladder outflow obstruction
what is urinary incontinence
involuntary loss of urine that is a social or hygienic problem and is objectively demonstratable
Two main types of incontinence and their difference
urge = involuntary loss of urine associated with strong desire to void
stress = Involuntary loss of urine when intra-abdominal pressure rises without detrusor contraction eg. with coughing, sneezing, laughing, straining, exerting
What is a urodynamic assessment used for? and how does it work
identify underlying cause of incontinence
Pressure from bladder and rectum measured during filling and voiding and patient is asked to cough periodically . Transducers will measure pressure
what does a bladder scan show
post void residual volume
Urodynamic assessment in stress incontinence
Increased abdominal pressure with coughing related to increased urinary flow
Urodynamic assessment in unstable bladder=> what is the main problem here
peak rises in urinary flow towards end of filling phase, confirmed urinary incontinence associated with spontaneous detrusor pressure rises
Main problem here is SPONTANEOUS RISE IN DETRUSOR PRESSURE
Urodynamic assessment in BOO
Large rise in detrusor pressure associated with low urinary flow
Causes of Voiding LUTS
Decreased force of micturition usually secondary to bladder outlet obstruction(BOO, urethral stricture)
May also occur with underactive/hypocontractile bladder eg. Spinal cord injury
Symptoms of voiding LUTS
- Hesitancy → Delay in start of micturition
- Poor flow
- Intermittence → Involuntary start stop possibly due to prostatic enlargement
- Terminal Dribbling → Release of small amount of urine after micturition
- Due to release of urine retained in bulbar/prostatic urethra
- Straining→ Use of abdominal muscles to void in patients with underactive or hypercontractile ( Valsalva only normally required at end of voiding)
where are the umbrella cells found and what are they
Urothelium. Apical cells
What excitatory neurotransmitter and inhibitory neurones are involved in voluntary micturition
Ach vs GABA and glycine
What chemical is involved in relaxation of bladder neck and external urethral sphincter
NO
Treatment for unstable bladder
stress incontinence
BOO
- antimuscarinic or botox therapy in the bladder, selective B-3 adrenoreceptor agonist, intradetrusor botox
- Pelvic glood exercises, weighr loss, autologus rectus abdominis sling, artificial sphincter
- A-blockers, 5 ARI, TURP laser prostatectomy
