Renal and Urology Flashcards
What is the definition of an Acute Kidney Injury?
Acute decline in renal filtration function characterised by a rise in serum creatinine or a fall in urine output
What are the three types of AKI?
Pre-renal
Intrinsic Renal
Post-renal
Causes of Pre-renal AKI
Impaired renal perfusion
Hypovolaemia
Heart Failure
Excess afferent vasoconstriction
Causes of Intrinsic Renal AKI
Structural Injury (Acute Tubular Necrosis)
Glomerulonephritis
Acute Interstitial Nephritis
Causes of Post-renal AKI
Obstruction between renal pelvis and urethra
Ureteric obstruction in lumen, in wall or by compression
Bladder outflow obstruction
What is the KDIGO criteria for AKI?
- Stage 1 : Serum creatinine baseline x1.5 - 1.9 or greater than 26 micromol/L increase OR less than 0.5mL/kg/h for 6-12hrs
- Stage 2 : Serum creatinine baseline x2 - 2.9 OR less than 0.5mL/kg/h for 12hrs
- Stage 3 : Serum creatinine baseline x3 or over or greater than 354 micromol/L increase OR less than 0.3mL/kg/h for 24hrs or anuria
Symptoms of AKI
- N + V
- Dehydration
- Confusion
- Reduced urine output or changes to urine colour
- High BP
- Abdominal Pain
- Slight Backache
- Oedema
Other Diagnostic Factors of AKI
- Arrhythmias
- Dizziness and other orthostatic symptoms
- Uraemia (pericarditis, encephalopathy)
- Pulmonary and peripheral oedema
Risk Factors of AKI
- Advanced age
- Underlying kidney disease
- Diabetes Mellitus
- Sepsis
- Iodinated contrast
- Surgery, trauma, haemorrhage
- Pancreatitis
- Malignant Hypertension
Primary Investigation to order for AKI
Urinalysis - Perform urine dipstick testing for blood, protein, leukocytes, nitrites and glucoses as soon as AKI suspected
U&Es - urea, creatinine, potassium
What is the diagnostic criteria for AKI?
- Increase in serum Cr by 26 umol/L or more within 48 hours
- Increase in serum Cr by 50% or more in the last week
- Fall in urine output to less than 0.5 ml/kg/hr for 6 hours
Management of AKI if patient is hypovolaemic?
- Fluid resuscitation
- Review medications and stop nephrotoxins
- Identify and treat underlying cause
- Consider vasopressor if patient remains severely hypotensive
- If refractory or complications, consider renal replacement therapy
What are the nephrotoxic medications to stop?
- D - diuretics
- A - ACEi, ARBs, Antibiotics
- M - metformin
- N - NSAIDs
Management of AKI if patient is hypervolaemic?
- Loop diuretic (under specialist supervision) and sodium restriction
- Identify and treat underlying cause
- Consider renal replacement therapy
How is hyperkalaemia treated?
- IV calcium gluconate (stabilise cardiac membrane)
- Combined insulin/dextrose infusion, Nebulised salbutamol (move K+ from extracellular to intracellular compartment)
- Calcium, loop diuretics, dialysis (remove potassium)
What is Renal Calculi and what are the other names for it?
- Presence of calculi within urinary system
- AKA urilithiosis, nephrolithiosis
What are the three places renal calculi can cause an obstruction?
- Ureteropelvic junction
- Pelvic brim
- Vesicoureteric junction
What are the types of stones formed?
- Calcium Oxalate (most common - 80%)
- Struvite
- Uric acid (not visible on X-Ray)
- Hydroxyapatite
What are the diagnostic factors for renal calculi?
- May be asymptomatic until obstruction
- Acute severe loin to groin pain (renal colic)
- N + V
- Unable to lie still/writhing in pain
- Urinary symptoms (urgency, frequency, haematuria)
What are the risk factors of renal calculi?
- Dehydration
- High protein intake
- High salt intake
- Structural abnormalities
- Previous kidney stones
- FHx of kidney stones
What are the investigations of renal calculi?
- Non-contrast CT KUB
- Urine Dipstick (blood + infection)
- Blood test (calcium, infection, kidney function)
- Abdominal X-Ray
- US KUB for pregnant women and children
What is the management for renal calculi?
- NSAIDs (diclofenac)
- IV Paracetamol
- Antiemetics for N + V (ondansetron)
- IV Antibiotics if infection
What is the surgical management based on renal stone size?
- Stone less than 10mm : offer SWL and consider URS if there is contradiction for SWL
- Stone between 10 and 20mm : consider URS or SWL or PCNL if both of those fail
- Stone larger than 20mm (incl. staghorn) : Offer PCNL or URS if PCNL is not an option
What are the surgical options for renal calculi?
- Shockwave lithotripsy SWL
- Ureteroscopy URS
- Percutaneous nephrolithotomy PCNL
- Open Surgery
What is surgical management based on ureteric stone size?
- Stone less than 10mm : Offer SWL and consider URS if not possible
- Stone between 10 to 20mm : Offer URS, consider SWL or PCNL if not possible
Prevention of renal calculi
- Increase fluid intake
- Low animal protein
- Low salt diet
- Thiazide diuretics + Potassium Citrate
- No carbonated drinks
For Oxalate Stones:
- reduce oxalate rich food e.g. spinach, beetroot, nuts
- cholestyramine and pyridoxine reduces urinary oxalate secretion
For Uric Acid Stones:
-reduce foods e.g. anchovies, spinach, tuna
- allopurinol
-urinary alkalinization e.g. oral bicarbonate
What is Nephrotic Syndrome?
Condition characterised by loss of protein in the urine due to increased glomerular permeability
Results in low serum albumin and oedema
Presence of an AKI, hypertension and an active urinary sediment
What are causes of Nephrotic Syndrome?
- Common causes : primary glomerular diseases such as minimal change disease, focal segmental glomerulosclerosis and membranous nephropathy
- Secondary causes include systemic diseases such as DM, lupus and amyloidosis
- Complications of nephrotic syndrome include infection, thrombosis and malnutrition
History and Examination of Nephrotic Syndrome
- Proteinuria, hypoalbuminuria and peripheral oedema
- Oedema, particularly around eyes, legs, hands and feet
- Fatigue, anorexia and decreased urine output
- Very important to obtain MHx of infection and medication + FHx for history of renal disease
Investigations of Nephrotic Syndrome
- First line is Urine Dipstick test to show increased levels of proteinuria
- 24 hour urine collection (protein excretion of greater than 3.5g/day = nephrotic syndrome)
- Blood tests will show hypoalbuminuria, hyperlipidemia and elevated serum creatinine
Management of Nephrotic Syndrome
- First line treatment involves corticosteroids such as prednisolone for a period of 4-6 weeks
- In cases of steroid resistance or dependence, additional immunosuppressive agents such as cyclophosphamide or mycophenolate mofetil may be used
- Diuretics can help manage oedema and anticoagulants may be required to prevent thrombosis
- Regular monitoring of BP, serum electrolytes and renal function
What is Diabetic Nephropathy?
Deterioration of kidney function due to diabetes, it is a common cause of CKD
History and Examination of Diabetic Nephropathy
- Oedema
- Diabetic Symptoms
- Lethargy
- Hypertension
Due to protein in urine:
- Oedema (especially eyes, hands, legs, feet)
- Frothy urine
- Confusion
- N+V
- Loss of apetite
What are the investigations of Diabetic Nephropathy?
- Urinalysis : ACR > 2.5mg/mol = microalbuminuria and ACR > 3mg/mol = proteinuria (screen annually)
- Renal Biopsy for Kimmelstiel-Wilson Nodules
What is the management of Diabetic Nephropathy?
- Give ACEi/ARBs if ACR > 3mg/mol (even if normotensive)
- Improve glycemic control (SGLT-2 Inhibitors)
- Smoking cessation
- Target BP 130/80
Pathophysiology of Diabetic Nephropathy
- Diabetes = Increased BGC and BP
- This leads to glomerular hypertension
- If this state is sustained it leads to microalbuminuria and then proteinuria
- This then leads to Glomerular and Interstitial Fibrosis
- This decreases GFR and leads to renal failure if not managed
What is CKD?
Chronic kidney disease, also called chronic kidney failure, involves a gradual loss of kidney function.
What are the common causes of CKD?
- Diabetic nephropathy
- Chronic glomerulonephritis
- Chronic pyelonephritis
- Hypertension
- Adult polycystic kidney disease
H&E of CKD
Usually asymptomatic
Possible late stage features
- Oedema e.g. ankle swelling, weight gain
- Polyuria
- Lethargy
- Pruritis (secondary to uraemia)
- Anorexia, which may result in weight loss
- Insomnia
- N + V
- Hypertension
What are the investigations for CKD?
- RFTs
Stage 1 - GFR>90ml/min with some sign of kidney damage on other tests
Stage 2 - 60-90ml/min with some sign of kidney damage
Stage 3a - 45-59ml/min, a moderate reduction in kidney function
Stage 3b - 30-44ml/min, a moderate reduction in kidney function
Stage 4 - 15-29ml/min, a severe reduction in kidney function
Stage 5 - <15ml/min, establish kidney failure - dialysis or a kidney transplant may be needed
Management of CKD
Hypertension:
- ACEi
- Prescribe if ACR > 70mg/mmol
- Rise in creatinine expected
- Furosemide, especially is stage 3 onwards
Anaemia:
- Oral iron, switch to IV if 10-12g/dl not reached in 3 months
- IV iron if on ESA or haemodialysis (correct deficiencies first)
- ESAs if QoL can be improved
Bone disease:
- Reduce phosphate intake
- Phosphate binders
- Vitamin D supplements
Tolvaptan shown to reduce rate of CKD progression in ADPKD, given to patients who have CKD stage 2 or 3 and is rapidly progressive.
What is a UTI?
- Presence of a pure growth of >10^5 organisms per mL of fresh MSU
- Lower - bladder, urethra, testes, prostate
- Upper - kidneys, ureters
- Urethritis, cystitis, pyelonephritis
MC caused by E.coli
H&E of UTI
MEN
- Dysuria
- Urgency
- Frequency
- Suprapubic Pain
- Costovertebral angle pain
FEMALE
- Dysuria
- New nocturia
- Cloudy urine
- Fever
RF of UTI for Men
- BPH
- Urinary tract stones
- Urological strictures
- Age > 50
- Previous UTI
- Catheterisation
RF of UTI for Women
- Sexual activity
- Spermicide use
- Post-menopause
- FHx of UTI
- Hx of recurrent UTI
- Presence of a foreign body
Investigations for UTI
- Urine dipstick - +ve for leukocytes and nitrites
- Urine culture for:
- Women > 65
- Men
- Pregnant women
- Recurrent UTI ( 2 in 6m or 3 in 12m)
- Haematuria
- MSU for MC&S (pyelonephritis will have white cell casts)
- Blood cultures if systemically unwell and risk of urosepsis
Consider:
- CT
- US
Management of UTI
Non-pregnant women:
Nitrofurantoin for 3 days
Pregnant women:
Nitrofurantoin or 7 days
Amoxicillin if near-term
Men:
Nitrofurantoin for 7 days
Catheterised:
If asymptomatic, do not treat
If symptomatic, nitrofurantoin for 7 days
Change catheter if indwelling for >7days
Signs of acute pyelonephritis:
Broad-spectrum cephalosporin or quinolone for 10-14 days
What is Benign Prostatic Hyperplasia?
Diffuse hyperplasia of the periurethral (transitional) zone
Prevalence increases with age
More common in afro-caribbeans
H&E of Benign Prostatic Hyperplasia
LUTS : storage and voiding symptoms (FUND HIPS)
- Frequency
- Urgency
- Nocturia
- Dysuria
- Hesitancy
- Incomplete voiding
- Poor stream
RF for Benign Prostatic Hyperplasia
- Age > 50
- FHx
- Afro-caribbean
Investigations for Benign Prostatic Hyperplasia
- Urinanalysis
- DRE : smoothly enlarged prostate with palpable midline groove
- U&Es
- PSA : if obstructive symptoms or worried about cancer
- International Prostate Symptom Score
- Urinary frequency-volume chart for at least 3 days
- Transrectal US-guided needle biopsy
What is the International Prostate Symptom Score (IPSS)?
0-7 : mildly symptomatic
8-19 : moderately symptomatic
20-35 : severely symptomatic
Management of Benign Prostatic Hyperplasia
Catheterisation if acute retention
Monitor symptom progression
Medication review
Selective alpha-1 blocker (Tamsulosin) if IPSS >/ 8
- Decreases smooth muscle tone of prostate
- BUT can cause dizziness, postural hypotension, dry mouth and depression
5 alpha-reductase inhibitors (Finasteride) if very large
- Blocks conversion of Test to DHT
- Can cause ED, reduced libido, ejaculation problems, gyno
Transurethral resection of prostate (TURP) if chosen or refractory
What is Bladder Cancer?
Malignancy of bladder cells
MC in males
Urothelial carcinoma - 90%
Squamous cell carcinoma - rare, associated with chronic inflammation
Adenocarcinoma
RF for the types of Bladder cancer
Urothelial - smoking, carcinogen exposure, aromatic amines, arsenic, painters and hairdressers
Squamous - Chronic UTIs, schistosoma haematobium
H&E of Bladder Cancer
Painless, macroscopic haematuria
LUTS - storage and voiding symptoms (FUND HIPS)
- Frequency
- Urgency
- Nocturia
- Dysuria
- Hesitancy
- Incomplete voiding
- Poor stream
FLAWS
Management of Bladder Cancer
Superficial lesions:
- Transurethral resection of bladder tumour (TURBT)
T2:
- Radical cystectomy and ileal conduit
- Radical radiotherapy
Higher grade/recurrence:
- Intravesical chemotherapy
What is Testicular Cancer?
MC malignancy in men 20-30 years
Around 95% of cases of testicular cancer are germ-cell tumours
Can be divided into
- Seminomas (MC)
- Non-seminomatous germ cell tumours (NSGCT): including embryonal, yolk sac, teratoma and choriocarcinoma
- Non-germ cell include Leydig cell tumours and sarcomas
RF of Testicular Cancer
- Infertility
- Cryptorchidism
- Ectopic Testes
- Testicular Atrophy
- Klinefelter’s
- Mumps orchitis
- FHx
H&E of Testicular Cancer
- Painless hard nodular testicular mass
- Unilateral
- May be associated hydrocoele
- Lymphadenopathy
- Gyno (inc. oestrogen to androgen ratio)
- Backache (due to mets)
Investigation of Testicular Cancer
Bloods
Tumour markers
- Alpha fetoprotein - elevated in non-seminomas
- Beta hCG - elevated in germ cell tumours
- LDH - can be elevated in germ cell tumours
Testicular US
CTAP - for visualisation of tumour and monitor
CXR - for mets
Management of Testicular Cancer
- Orchidectomy
- Chemotherapy and radiotherapy
What are Epididymitis and Orchitis?
- Inflammation of the epididymis or testes
- Most cases of orchitis are associated with epididymitis
- Concurrent inflammation = epididymo-orchitis
- Most cases are infective (bacterial)
- Also caused by trauma, vasculitis and medication (amiodarone)
Causes of Bacterial Epididymitis or Orchitis
If <35 years and sexually active - Chlamydia trachomatis or Neisseria gonorrhoeae (spreads from genital tract)
If >35 years and low-risk sexual history - E.coli (spreads from bladder)
RF for Epididymitis and Orchitis
- Unprotected sex
- Bladder outflow obstruction
- UTI
- Immunosuppression
H&E of Epididymitis and Orchitis
Develops over a few days
- Unilateral testicular pain and swelling
- Swollen, hot, tender erythematous scrotum
- Pyrexia
- Cremasteric reflex may be painful
- Pain eases when the testicle is lifted (+ve Prehn’s sign)
- Symptoms relating to cause
Investigations of Epididymitis and Orchitis
- Assess for STI with NAAT in younger adults
- MSU for microscopy and culture in older adults
OTHER
- Colour duplex USS if unsure of diagnosis
- Surgical exploration if testicular torsion cannot be excluded
Management of Epididymitis and Orchitis
If STI most likely, urgent referral to sexual health clinic
If organism unknown:
- IM ceftriaxone + oral doxycycline
If enteric organism:
- Oral quinolone (e.g. ofloxacin)
ALSO
Bed rest and scrotal elevation
Simple analgesia - paracetamol/ibuprofen
RF for Urinary Incontinence
- Advancing age
- Previous pregnancy and childbirth
- High BMI
- Hysterectomy
- FHx
What is Overactive Bladder/ Urge Urinary Incontinence
- Due to detrusor over-activity
- The urge to urinate is quickly followed by uncontrollable leakage ranging from a few drops to complete emptying
What is Stress Urinary Incontinence?
- Leaking small amounts when coughing or laughing
What is Mixed Urinary Incontinence?
Both urge and stress incontinence
What is Overflow Urinary Incontinence?
- Due to bladder outlet obstruction e.g. prostate enlargement
- Bladder still palpable after urination
What is Functional Urinary Incontinence?
- Comorbid physical conditions impair the patient’s ability to get to the bathroom on time
- Causes include dementia, sedating medication and injury/illness resulting in decreased ambulation
Investigations for Urinary Incontinence
- Bladder diaries should be completed for minimum 3 days
- Vaginal exam to exclude pelvic organ prolapse and ability to initiate voluntary contraction of pelvic floor muscles
- Urine dipstick and culture
- Urodynamic studies
Management of Urge Urinary Incontinence
Bladder retraining (lasts for 6 weeks minimum), gradually increase intervals between voiding
Bladder stabilising drugs (anti-muscarinics)
- Oxybutinin (immediate release, not for old ladies)
- Tolterodine (immediate release)
- Darifenacin (once daily preparation)
Beta-3 agonist (Mirabegron) useful if there is a concern about anticholinergic side-effects in older patients
Management of Stress Urinary Incontinence
Pelvic floor training
- At least 8 contractions performed 3x a day for 3 months
Surgical procedures e.g. retropubic mid-urethral tape
Duloxetine may be offered to women if they decline surgery
- combined noradrenaline and serotonin reuptake inhibitor
- inc. synaptic concentration of NA and serotonin within pudendal nerve = inc. stimulation of striated muscles within sphincter = enhanced contraction
Common causes of CKD
- Diabetic nephropathy
- Chronic glomerulonephritis
- Chronic pyelonephritis
- HT
- Adult PCKD
H&E of CKD
Usually asymptomatic
Possible late-stage features:
- oedema
- polyuria
- lethargy
- pruritis
- anorexia, may lead to weight loss
- insomnia
- N+V
- HT
Investigations for CKD
Renal function tests
eGFR, creatinine
Stages of CKD
1 - eGFR > 90 ml/min, some signs of damage on other tests
(if all other tests normal, no CKD)
2 - eGFR 60-90 ml/min, some signs of damage
(if all other tests normal, no CKD)
3 - eGFR 45-59 ml/min, moderate reduction in kidney function
4 - eGFR 15-29 ml/min, severe reduction in kidney function
5 - eGFT < 15 ml/min, established kidney failure - dialysis or transplant may be needed
Management of HT in CKD
ACEi
- Prescribe regardless of BP if ACR > 70 mg/mmol
- These drugs tend to reduce filtration pressure, a small fall in GFR and rise in creatinine expected
Furosemide, especially in stage 3 onwards
Management of Anaemia in CKD
Oral iron, switch to IV if 10-12 g/dl not reached in 3 months
IV iron if on erythropoietin-stimulating agents or haemodialysis
(correct deficiency before ESA)
ESAs such as erythropoietin and darbepoetin if likely to benefit QoL and physical function
Management of Bone Disease in CKD
Reduce phosphate intake
Phosphate binders
Vit D supplements
Importance of Tolvaptan in CKD
Shown to reduce the rate of CKD progression in PCKD
Given to patients who have CKD stage 2 or 3 and is rapidly progressive
