Nephrology Flashcards
AKI
Cause, stages sx, ix, mx
Improving Global Outcomes (KDIGO) criteria as below:
- Increase in serum creatinine by >26.5 mmol/l within 48 h, or
- Increase in serum creatinine > 1.5x the baseline within the last 7 days, or
- Urine output < 0.5 ml/kg/h for 6 hours
Causes:
Pre-renal:
- hypovolaemia
- renal artery stenosis
- NSAIDs, ACE inhibitors, ARBs, diuretics
- heart failure, sepsis
Renal:
- acute glomerulonephritis, nephrotic syndrome
- acute tubular necrosis due to ischaemia or toxins, rhabdomyolysis
- acute interstitial nephritis secondary to drugs
- renal vein thrombosis, vasculitis
Post-renal:
- stone or blocked catheter
- urethral or ureteric strictures
- abdominal or pelvic tumour
- bph
Stages:
Stage 1 - any of:
- Creatinine rise of 26 micromol/L or more within 48 hours
- Creatinine rise to 1.5-1.99x baseline within 7 days
- Urine output < 0.5 mL/kg/hour for more than 6 hours
Stage 2 - any of:
- Creatinine rise to 2-2.99x baseline within 7 days
- Urine output < than 0.5 mL/kg/hour for more than 12 hours
Stage 3 - any of:
- Creatinine rise to 3x baseline or higher within 7 days
- Creatinine rise to 354 micromol/L or more with either
- Acute rise of 26 micromol/L or more within 48 hours or
- 50% or more rise within 7 days
- Urine output < than 0.3 mL/kg/hour for 24 hours
- Anuria for 12 hours
Sx:
- may be asymptomatic
- nausea and vomiting
- confusion
- HTN
- bladder distension
- hypotension in pre-renal causes
- raised JVP
- oedema
Ix:
- urinalysis
- ECG for hyperkalaemia
- blood gas for acidosis
- U+E
- LFT
- clotting
- bone profile
- CK
- CRP
- US KUB, next line is CT
- renal biopsy
Mx:
- IV fluid resus
- catheter may be definite mx in post-renal causes due to obstruction
- suspend NSAIDs, aminoglycosides, ACE inhibitors, ARBs
-renal replacement therapy with dialysis or haemofiltration (remembered by the AEIOU mnemonic):
- Acidosis (severe metabolic acidosis with pH of <7.20)
- Electrolyte imbalance (resistant hyperkalaemia)
- Intoxication (AKI secondary to certain drugs or poisons)
- Oedema (refractory pulmonary oedema)
- Uraemia (uraemic encephalopathy or pericarditis)
BPH
Def, sx, ix, mx
non-cancerous enlargement of the prostate gland, particularly the transition zone, leading to the compression of the urethra and subsequent lower urinary tract symptoms (LUTS)
Sx:
- hesitancy
- weak stream
- frequency
- urgency
- nocturnal
- incomplete sensation
Ix:
- IPSS: Score 20–35: severely symptomatic.
Score 8–19: moderately symptomatic.
Score 0–7: mildly symptomatic.
- digital rectal exam
- PSA to rule out cancer
Mx:
- alpha blocker (tamsulosin)
- 5-alpha reductase inhibitors (finasteride)
- TURP
Bladder cancer
Cause, rf, sx, ix, mx
The most common histological subtype in developed countries is transitional cell carcinoma, accounting for 90% of all bladder cancers, followed by squamous cell carcinoma
Rf:
Transitional:
- smoking
- aromatic amines
- Cyclophosphamide
Squamous:
- schistosomiasis
- long term catheter
Sx:
- painless visible heamaturia
- recurrent UTIs
- hydronephrosis
- weight loss
- night sweats
Ix:
- urine dipstick
- CT urogram
- flexible cystoscopy
- staging with CT and MRI
Mx:
- stages CIS, Ta, T1= TURBT as gold standard, chemo, BCG immunotherapy
- stages T2 and above= radial cystectomy is gold standard, radiotherapy, chemo
CKD
Def, cause, classifications, sx, ix, mx
abnormal kidney function (A GFR below 60 ml/min/1.73m2) or structure (high albumin to creatinine ratio, haematuria, acidosis, tubular atrophy, polycystic kidneys) for over 3 months, with implications for health
Cause:
- diabetes
- HTN
- glomerulonephritis
- bph
- radiotherapy
- aminoglycosides, lithium, NSAIDs
- multisystem disease eg. HIV, SLE, amyloidosis and tuberous sclerosis
Classification:
KDIGO:
- G1= normal= GFR >90
- G2= mild= 60-89
- G3a= mild-moderate= 45-59
- G3b= moderate-severe= 30-44
- G4= severe= 15-29
- G5= renal failure= <15
Sx:
- often asymptomatic
- nausea and vomiting
- SOB
- muscle cramps at night
- bone pain
- polyuria or oliguria
- nocturia
- frothy urine
- HTN
- fluid overload
- dehydration
- ammonia-smelling breath
- palpable flank masses
Ix:
- urine dip
- Early morning albumin:creatinine ratio
- U+E
- FBC
- LFTs showing raised ALP due to bone disease
- bone profile showing high phosphate
- HbA1C
- bicarbonate low due to metabolic acidosis
- lipid profile
- PTH raised
- renal tract US
- CT KUB most sensitive for stones
- renal biopsy
Mx:
- stop nephrotoxic drugs
- treat HTN with up to 3 antihypertensives (ACE or ARB first line if no high potassium)
- statin
- aspirin
- haemodialysis
- renal transplant
Dehydration
Sx
Diabetic nephropathy
Def, cause, classification, sx, ix, mx
kidney damage due to long-standing hyperglycaemia in the context of diabetes (either type 1 or 2). It is characterised by albuminuria and/or impaired renal function. Basement membrane damage is a key feature that manifests clinically with albuminuria and proteinuria
Classification:
1= Mild or nonspecific changes on light microscopy; glomerular basement membrane thickening on electron microscopy
2= Diffuse mesangial expansion
3= Nodular sclerosis (Kimmelstiel-Wilson lesions)
4= Advanced diabetic glomerulosclerosis affecting more than 50% of glomeruli
Sx:
- asymptomatic until late stage
- fatigue
- weight loss
- nausea and vomiting
- taste disturbance
- itch
- SOB
- bone pain
- frothy urine
- poly or oliguria
- HTN
- oedema
- uraemic odour
- encephalopathy
Ix:
- early morning urinary albumin:creatinine ratio
- urinalysis
- U+Es
- HbA1c
- bone profile
- bicarbonate for acidosis
- renal US
- renal biopsy
Mx:
- diabetic control
- antihypertensives
- ACE are first line
- SGLT2 inhibitors for ACR more than 30
- statin
- dialysis
- renal transplant
Epididymitis and orchitis
Def, cause, sx, ix, mx
inflammation of the epididymis and the testicle
Cause:
- STIs (most commonly chlamydia and gonorrhoea)
- UTI (e.coli most common)
- mumps
- TB
Sx:
- acute scrotal pain
- swelling and tenderness
- fever
- dysuria
- discharge
- Prehn’s positive (lifting up testicle relieves pain due to inflammation)
- cremasteric reflex intact (so no torsion)
Ix:
- history and exam
- urinalysis
- NAATs
- urethral swab
- scrotal US to rule out torsion
Mx:
- High risk for STI: treat empirically with oral doxycycline for 10–14 days, and a single dose of IM ceftriaxone if gonorrhoea is suspected
- E.coli or UTI is the most likely cause: treat with levofloxacin (10 days) or ofloxacin (14 days)
Nephrotic syndrome
Def, cause, dx, sx, ix, mx
excessive loss of protein in the urine, leading to hypoalbuminemia and peripheral oedema
Causes:
- damage to the glomerular basement membrane
- minimal change disease (most commonly for young children)
- focal segmental glomerulosclerosis
- membranous nephropathy (most common in older people)
- membranoproliferative glomerulonephritis
- multiple myeloma
- lupus nephritis
- bisphosphonates, NSAIDs
Dx:
- Proteinuria > 3.5 grams/24 hours
- Serum albumin < 30 grams/litre
- Peripheral oedema
Sx:
- frothy urine
- oedema
- weight gain
- Muehrcke’s lines refers to paired white transverse lines across the nails that may occur secondary to hypoalbuminemia
- xanthelasma
- dull bases on lung percussion with decreased air entry
Ix:
- urine dip
- urine protein:creatinine ratio should be over 2 or 24 hour collection
- LFTs for hypoalbuminemia
- U+Es for renal function
- bone profile may show hypocalcemia secondary to decreased calcium absorption due to vitamin D deficiency
- HbA1c
- autoimmune and infection screen
- renal biopsy is key ix
Mx:
- fluid (<1.5L) and salt (<2) restriction
- corticosteroids as 1st line
- diuretics if oedema
- ACE inhibitors
- renal replacement therapy
Prostate cancer
Def, cause, rf, sx, ix, mx
majority of prostate cancers are adenocarcinomas, and they usually primarily affect the peripheral prostate. They spread lymphatically first via the obturator nodes
Rf:
- African
- BRCA mutation
- fhx
- age
- obesity
- smoking
- high animal fats and dairy
Sx:
- poor stream
- blood in sperm
- pelvic discomfort
- bone pain (metastases)
- erectile dysfunction
Ix:
- digital rectal exam and urine dip
- PSA
- Multi-parametric MRI is the gold standard radiological investigation
- TNM staging
Mx:
- T1= surveillance, radial prostatectomy for select cases
- T2= radial prostatectomy (standard), external beam radiation therapy, brachytherapy, surveillance for low risk
- T3= hormone therapy, radial prostatectomy for select cases, external beam radiation therapy
- T4= palliative hormonal and radiation therapy
- M1= androgen deprivation, Chemotherapy (docetaxel, cabazitaxel), Targeted therapy (abiraterone, enzalutamide), Immunotherapy (sipuleucel-T)
Testicular cancer
Cause, rf, sx, ix, mx
The majority of testicular cancers are germ cell (95%), and these can be seminomas, or non-seminoma subtypes. Non-germ cell testicular cancers include leydig tumours and sarcomas.
- Seminoma (55% of cases)
- Teratoma (33% of cases)
- Mixed seminoma teratoma (12% of cases)
Rf:
- <45
- Caucasian
- undescended testicles
- HIV
- mumps orchitis infection
- klinefelters
Sx:
- painless lump
- gynaecomastia if germ cell
Ix:
- first line is scrotal US
- serum tumour markers
Mx:
- radial or hide Tommy
- radiotherapy
- chemo (cisplatin-based regimens)
Urinary tract calculi
Cause, sx, ix, mx
Cause:
- calcium oxalate (70%)= radiopaque, form in any pH, associated with low urine volume and hypercalciuria
- calcium phosphate (10%)= radiopaque, form in alkaline urine, associated with renal tubular acidosis and primary hyperparathyroidism
- uric acid (10%)= radiolucent, form in acidic urine, associated with diabetes, obesity and gout
- struvite (5%)= radiopaque, associated with alkaline urine
- cystine (1%)
- medication induced (1%)
Sx:
- asymptomatic if small
- renal colic
- loin to groin pain
- renal angle tenderness
- haematuria
- dysuria
Ix:
- urinalysis
- urine MC&S
- 24 hr urine collection
- infection bloods
- U+Es showing obstruction
- blood gas may show acidosis and low bicarbonate if there is underlying renal tubular acidosis
- non-contrast CT KUB with suspected renal colic
- US KUB
- abdominal x ray
- stone analysis
Mx:
- NSAIDs first line analgesia
- medical expulsive therapy can be considered for patients with distal ureteric stones < 10mm, this involves using an alpha-blocker (e.g. tamsulosin)
- suspected infection secondary to renal stones should be treated urgently with IV antibiotics (e.g. gentamicin, co-amoxiclav)
- obstruction and hydronephrosis require urgent decompression with nephrostomy insertion
- ESWL and ureteroscopy is first line if stone <1 cm
Urinary incontinence
Causes, types, sx, ix, mx
Causes:
- urge: idiopathic, neuro conditions, inflammation and bladder irritants
- stress: urethral hypermobility and intrinsic sphincter deficiency
- overflow: enlarged prostate (bph, cancer and inflammation), diabetes, obstructing masses, fistulas, spinal cord injuries and anticholinergic meds
Transcient causes:
• D – elirium
• I – nfection
• A – thropy
• P – harmaceuticals
• E – xcess excretion
• R – estricted mobility
• S – tool impaction
Ix:
- bladder diary
- urinary stress test
- urinanalysis
- renal function tests
- PSA
- post void residual bladder scan
- renal Uss
- MRI
Mx:
• Self-monitoring
• Bladder training - Kegles
• Lifestyle changes
- Absorbent materials, urine bottles, vaginal pessaries
- Caffeine reduction
- Weight loss
• Medical equipment
• Surgery
• Drug review
• Medication -Antimuscarinics, topical oestrogen, alpha-adrenergic antagonists (selective vs non-selective), 5-alpha reductase inhibitors
Urinary tract infection (UTI)
Stages, types, sx, dx, ix, mx
Types:
- Cystitis: lower UTI- urethra or bladder infection, prostitis, often uncomplicated but can progress to upper or complicated UTI.
- Pyelonephritis: upper –or complicated UTI, or ureters, kidney infection usually due to bacterial ascent.
- Typical: Uncomplicated, self-resolving. Common pathogens include uropathogenic E. coli, Klebsiella pneumoniae, and Enterococcus faecalis.
- Atypical: Seriously ill, Poor urine flow, Abdominal/bladder mass, Raised creatinine,Septicaemia, Failure to respond to Abx in 48 hours, Non-E.coli organisms.
- Recurrent: Two or more UTIs in six months or three or more in 12 months.
- Catheter associated UTI
Sx:
- Lower: urinary frequency, urinary urgency, suprapubic pain, dysuria, heamaturia
- Upper: fever, chills, flank pain, nausea, vomiting, costovertebral or renal angle tenderness, recurrent lower UTI symptoms
Dx:
- Nitrites: strongly suggestive of bacteriuria, as nitrates are broken down into nitrites only in the presence of bacteria.
- Leukocyte esterases: an enzyme leukocytes produce in response to bacteria in the urine.
- On MC&S, the following findings would be consistent with a UTI:
- Bacteriuria: the presence of bacteria in urine. Historically, ≥ 105 bacterial colonies/mL of urine were needed to diagnose a UTI. However, a UTI can be diagnosed if the symptoms are present with as low as 102 bacterial colonies/mL. If there is bacteriuria without symptoms, this is termed asymptomatic bacteriuria. It is more common in older patients, and asymptomatic bacteriuria is only treated in pregnant women, before urological operations or if there are associated symptoms.
- Pyuria: the presence of WBCs in the urine. Sterile pyuria (WBCs in the urine, without infection) can indicate a range of diagnoses, including renal malignancy, pelvic malignancy and genitourinary tuberculosis
Ix:
- renal US
- USS
- CT (acute)
Mx:
- personal hygiene
- vit c supplement
- D-mannose, cranberry products
- analgesia
- first line is nitrofurantoin or trimethoprim
- for men and older people the course is 7 days
- for women it is 3
- avoid trimethoprim in the first trimester and nitrofuratoin in the final and course is 7 days
Diabetes insipidus
Def, types, cause, sx, ix, mx
characterised by either an inadequate production (AVP-D) or an insufficient renal response (AVP-R) to arginine vasopressin (AVP), also called antidiuretic hormone (ADH).
Cause:
AVP deficiency:
- head trauma
- sarcoidosis
- meningitis
- sickle cell disease
AVP resistance:
- lithium
- metabolic disturbance
- chronic renal disease
Sx:
- Large volumes of dilute urine (>3 litres in 24 hours and a urine osmolality of <300 mOsm/kg)
- Nocturia
- Excessive thirst
Ix:
- U+E showing raised Na
- blood glucose to rule out mellitus
- urine dip
- urine osmolality (raised (>295 mOsm/kg) with inappropriately dilute urine (urine osmolality < 300 mOsm/kg))
- water deprivation test (In AVP-D, urine osmolality increases with ADH administration. In AVP-R, urine osmolality remains low/unchanged despite ADH administration)
Mx:
- AVP-D= desmopressin and Na monitoring
- AVP-R= correct metabolic abnormalities, high dose desmopressin, thiazide diuretic
