25: Diseases of the Prostate, Kidney, and Bladder - Pothoven Flashcards
define urinary calculi
Kidney stones are solutes that occur in amounts too high to stay dissolved (supersaturated) in urine
most commonly calcium oxalate but could also be uric acid
best imaging modality to detect urinary calculi
CT is best imaging modality to detect urinary calculi. Detects over 96% of stones
renal US is study of choice if pregnant - can detect intrarenal and hydronephrosis but not ureteral stones
Physiology of Renal Obstruction
Initial 2 hours
- Increased renal pelvic pressures
- Increased renal blood flow
- As renal pelvic pressure increases, glomerular filtration (GFR) decreases
At 6-24 hours
- Renal pelvic pressures remain elevated
- Renal blood flow diminishes
> 24 hours
- Renal pelvic pressures trend down towards baseline (but remain elevated)
- Renal blood flow continues to diminish.
- If persistent, the obstruction (high grade complete obstruction) leads to renal ischemia and permanent damage typically occurs within 2 weeks
____ of ureteral stones will pass w/i 4 wks of symptom onset
2/3
Complete obstruction is rare so risk of renal deterioration from observation is low
Medical Expulsion Therapy
Alpha blockers (relax ureteral smooth m.) Calcium channel blockers NSAIDS
Oral stone dissolution
Uric acid stones only
Urinary alkalization
Potassium citrate, sodium bicarbonate
Indications for Urgent Intervention for Urinary Stones **
- Obstructed upper tract with infection
- Impending renal deterioration
- Pain refractory to analgesics
- Intractable nausea/vomiting
- (Patient preference)
Surgical Stone Intervention
Extracorporeal Shock Wave Lithotripsy (ESWL)
- 4-15 mm stones in kidney or proximal ureter
- Stone must be radio-opaque
Ureteroscopy +/- laser lithotripsy
– All stones amendable but large renal stone treatment is tedious
Percutaneous Nephrolithotomy (PCNL)
- Renal calculi >15-20 mm
- More invasive and requires hospital observation
Open or laparoscopic lithotomy
–Most invasive, Rarely necessary
stone prevention
ADEQUATE HYDRATION!! (2.5-3 L/DAY) *
Dietary modifications
- -Low animal protein, – low sodium, low oxalate diets
- Normal dietary calcium
- Citrate therapy
Full metabolic evaluation for patients with recurrent stones or strong family history
- Serum chemistries
- 24 hour urine collection
- Medications and additional therapies directed at metabolic abnormalities
Irritative/Storage s/s for lower urinary tract
Frequency
Urgency
Nocturia
Dysuria
obstructive/voiding s/s for lower urinary tract
Hesitancy Intermittency Straining Weak stream Terminal dribbling Sensation of incomplete bladder emptying
anatomy of prostate
18-20 grams in young men
Composed of glandular (70%) and fibromuscular stromal (30%) elements
α-1A receptors predominantly in stroma mediate prostatic smooth muscle tone
which zone of prostate gives rise to BPH? to prostate cancer?
transition zone
peripheral zone
which hormone promotes prostate growth?
DHT is a more potent androgen than testosterone which binds to prostatic androgen receptors with higher affinity
DHT stimulates prostate differentiation and growth
complications of BPH
Acute urinary retention
Renal insufficiency
Chronic/recurrent UTIs
Uncontrolled gross hematuria/clot retention
Bladder calculi
pharmacotherapy for BPH
α antagonists: relaxes smooth muscle of prostate to alleviate LUTS *first choice
5 α-reductase inhibitors: reduces prostate size over 6-12 months
Combination therapy: most beneficial men with large prostate and incomplete emptying
Herbal supplements
normal bladder will hold ______ at capacity
400-600 ml
acute and chronic s/s urinary retention
Acute
- inability to urinate
- painful, urgent need to urinate
- pain or discomfort in the lower abdomen
- bloating of the lower abdomen
Chronic
- urinary frequency—urination eight or more times a day
- trouble beginning a urine stream
- a weak or an interrupted urine stream
- an urgent need to urinate with little success when trying to urinate
- feeling the need to urinate after finishing urination
- mild and constant discomfort in the lower abdomen and urinary tract
complications of urinary retention
UTI
bladder decompensation
renal damage
tx = initial bladder damage with catheterization, treatment of underlying cause
different types of UTIs
Uncomplicated UTI - infection in a healthy patient with normal GU tract
Complicated UTI - infection associated with factors that increase chance of acquiring bacteria and decrease efficacy of therapy.
Abnormal GU tract (BPH, stone, bladder diverticulum, neurogenic bladder, etc)
Immunocompromised host
Multi-drug resistant bacteria
Recurrent UTI - occurs after documented infection that had resolved
Reinfection UTI - a new event with reintroduction of bacteria into GU tract
Persistent UTI - recurrent UTI caused by same bacteria from focus of infection
s/s cystitis vs. s/s pyelonephritis
Urinary urgency Frequency Dysuria Hematuria Foul-smelling urine Suprapubic pain May have associated urethritis , prostatitis or epididymitis
PYELO: Typical symptoms of cystitis Fever Rigors Flank or abdominal pain Nausea and vomiting
most common bacteria causing UTIs
e. coli (80%)
define microscopic hematuria
greater than 3 RBC per high powered field
signs nephrologic/glomerular heamturia
Significant proteinuria (>1 gm/24 hours)
Dysmorphic red blood cells
Red cell casts
Warrants nephrology evaluation
risk factors for significant cause of heamturia
** smoking over 40 male chemical exposure pelvic radiation irritative voiding symptoms prior urologic dz
____– % of pts evaluated for hematuria will be diagnosed with urologic malignancy
10-20%
