Renal and urinary tract disorders Flashcards
What are the most common causes of acute kidney injury (AKI)?
Prerenal - hypoperfusion
- Decreased circulating volume due to dehydration (vomiting, diarrhea), overdiuresis, acute blood loss
- Decreased CO (HF, burns)
Kidney function returns to normal once underlying cause is addressed
AKI clinical presentation (general)
Similar to CKD, but occur over shorter time period (days versus over months)
- Fatigue
- Weight loss
- Anorexia
- Nocturia
- Sleep disturbance
- Pruritus
AKI clinical presentation (prerenal, intrinsic, post renal)
Prerenal → thirst, diminished urine output, dizziness, orthostatic hypotension
Intrinsic → hematuria, edema, hypertension
Post renal → urgency, frequency, hesitancy (if renal stones, flank pain and hematuria)
AKI diagnostic tests
- Creatinine
- eGFR
- BUN
- Renal US or CT to rule out outflow tract obstruction
- Bladder scan for older men with known BPH
Chronic kidney disease clinical presentation
Usually without symptoms with stages 1-3 (eGFR >30)
Stages 4 and 5 (associated with anemia and worsening renal failure) have associated comorbidities (HF)
- Fatigue
- LE or diffuse edema
- SOB
- Decreased urine output
- Urine become foamy with altered color
True/false: An elevated BUN level with normal creatinine is occasionally found in patients with healthy kidneys but with severe dehydration
True - BUN derives from breakdown of protein from dietary or other sources
CKD diagnostic testing
Similar to AKI (creatinine, BUN, eGFR) but eGFR provides more accurate assessment of kidney function than creatinine alone
- Additionally, spot albumin-to-creatinine ratio (ACR)
- ACR >300 requires referral to nephrologist
CKD staging
Stage 1 - eGFR 90 or greater
Stage 2 - eGFR 60-89
Stage 3a - eGFR 45-59
Stage 3b - eGFR 30-44
Stage 4 - eGFR 15-29
Stage 5 - eGFR less than 15 (kidney failure)
Lab testing for stage 4+ CKD
Calcium, phosphorus, PTH, alkaline phosphatase, vitamin D
- Electrolyte disorders are common with AKI and advanced CKD (stages 4 and 5) → hyperkalemia, hypercalcemia, hypernatremia
Glomerulonephritis clinical presentation
- New onset edema of face, hands, feet, abdomen
- Newly elevated BP or worsening previously present hypertension
- Headache (acute)
- SOB
- Pink or cola colored urine (hematuria)
- Foamy urine (proteinuria)
Glomerulonephritis diagnostic testing
- UA
- RBCs and RBC casts, WBCs, elevated protein
- Serum creatinine and BUN
- CT scan or kidney US to determine stage of renal damage
- Kidney biopsy to determine diagnosis
Acute glomerulonephritis treatment and management
Goal: manage underlying cause and protect kidneys from further damage
Self limiting with supportive therapy
Complications of GN - what is the recommended treatment?
Nephrotic syndrome: excessive proteinuria, hypoalbuminemia, HLD, edema)
- Monitor renal function, BP, edema, serum albumin, proteinuria
- Antihypertensive medication
- Antibiotics if infection
- Systemic corticosteroids
- Consider dialysis and renal transplant
Important findings to look out for on UA dipstick for suspected UTI
- Leukocyte esterace → >5 WBC/hpf is positive
- Nitrates
- Causative agents: e. coli, proteus, klebsiella
- Protein → trace to 30 mg/dL (1+)
- Blood
Acute, uncomplicated UTI in non pregnant women treatment
- TMP-SMX (Bactrim)
- If sulfa allergy, nitrofurantoin (Macrobid)
- Add phenazopyridine (Pyridium) for dysuria relief
Recurrent UTI (2+ within 6 months or 3+ in one year) treatment
Continuous TMP-SMX, cephalexin, or ciprofloxacin
- Alternative: postcoital prophylaxis with meds above
- Postmenopausal → topical/vaginal estrogen (encourage lactobacilli recolonization)
Acute uncomplicated pyelonephritis (outpatient therapy)
Ceftriaxone 1 g IV then ciprofloxacin or levofloxacin for 7 days
Bladder cancer clinical presentation
- Gross, painless hematuria without dysuria
- Irritative voiding symptoms and urinary frequency without fever
Bladder cancer diagnostic testing
- UA to confirm RBCs in urine
- Referral to urology for cystoscopy
- Confirmed with biopsy sample
Bladder cancer risk factors
- Smoking (most common cause)
- Male
- Family history
- Arsenic exposure (outside of U.S. mainly)
- Exposure to industrial chemicals
Bladder cancer treatment
- Transurethral resection
- Partial cystectomy
- Single immediate instillation of intravesical chemo
Urinary incontinence diagnostic testing
- UA and culture
- Urology referral indicated if these are ordered
- Cough stress test
- Postvoid residual urine volume
- Cystoscopy
Urge incontinence
- Etiology
- Clinical presentation
Cause: detrusor overactivity causing uninhibited bladder contractions
Clinical presentation:
- Strong sensation of needing to empty bladder that cannot be suppressed
- Involuntary loss of urine
Urge incontinence treatment
Behavioral therapy
- Avoid stimulants (caffeine, alcohol)
- Gentle bladder stretching by increasing voiding interval by 15-30 minutes after establishing a half-hour voiding schedule
- Sips of fluid
Medications
- Selective muscarinic receptor antagonists → tolterodine (detrol), solifenacin succinate, darifenacin (enablex)
- Mirabegron (myrbetriq), botulinum toxin injection
Stress incontinence
- Etiology
- Clinical presentation
Cause: weakness of pelvic floor, urethral muscles
Clinical presentation:
- Loss of urine with activity that causes increase in intra abdominal pressure (coughing, sneezing, exercise)
Stress incontinence treatment
- Support to area with vaginal tampon, urethral stents, periurethral bulking agent injections, pessary
- Pelvic floor rehabilitation
- Bladder training
- Kegel exercises
Medications that can lead to urinary incontinence
- Diuretics
- Anticholinergics/antimuscarinics
- First gen antihistamines
- TCAs
- Antipsychotics
- Opioids
- Alcohol
- Sedatives, hypnotics, benzos
Renal stones risk factors
- Male
- Family history
- Poor fluid intake
- Dehydration
- Diet high in protein, sodium, sugar
- Overweight or obese
- Health conditions
- Hypercalciuria, cystic kidney disease, hyperparathyroidism, renal tubular acidosis, cystinuria, gout
- Medications
- Calcium based antacids, sulfa drugs
Composition of four different renal stones and their causes
- Calcium oxalate or phosphate
- Oxalate found in fruits and vegetables, nuts, chocolate
- Uric acid → acidic urine, eat high protein diet, have gout, purine rich diet
- Struvite → kidney infections
- Cystine → genetic disorder
Renal stone (stone in ureter) clinical presentation
- Sudden onset severe flank pain
- Radiates anteriolohy and inferiorly, towards groin, testicles, vulva on side of stone
- N/V
- Waves of pain (renal colic)
- Pink, red, brown urine
Renal stone (stone in ureteropelvic junction) clinical presentation
- Mild to deep flank pain without radiation to the groin
- Irritative voiding symptoms
- Urinary frequency and urgency
- Dysuria
- Bowel symptoms
Renal stone (stone in the bladder) clinical presentation
Typically asymptomatic but can lead to urinary retention
Renal stones diagnostic testing
- UA to confirm hematuria
- 24 hour urine sample for stone analysis and guide prevention strategy
- CBC w/ diff, blood culture, urine culture
- Creatinine
- US or CT scan
- US can miss smaller stones (less than 5 mm)
- X-ray (KUB) can help assess total stone burden
- Can miss small stones and specific stones of composition
Renal stone treatment and management
- Urology referral
- IV hydration for N/V and unable to maintain hydration with oral intake
- Stones in ureter
- Stone less than 4 mm
- Analgesics (acetaminophen)
- Alpha blocker
- Stone greater than 8 mm
- Extracorporeal shock wave lithotripsy (ESWL)
- Ureteroscopy
- Stone less than 4 mm
- Stones in uteropelvic junction
- Internal ureteral stents
- Percutaneous nephrostomy
- ESWL for larger stones
Renal stone prevention
- Proper hydration (2-3 liters/day)
- Diet high in fruits and vegetables
- Reduce sodium and animal protein if calcium composition of stone
- Calcium oxalate → reduce intake of oxalate rich foods
- Rhubarb, beets, okra, spinach, Swiss chard, sweet potatoes, nuts, tea, chocolate, soy products
- Thiazide diuretics to prevent calcium stones
