Renal System 🫘 Flashcards
What is metabolic acidosis commonly classified according to?
Anion gap
Metabolic acidosis is categorized into normal anion gap and raised anion gap.
What are some causes of normal anion gap metabolic acidosis? (4)
- Gastrointestinal bicarbonate loss: diarrhoea, ureterosigmoidostomy, fistula
- Renal tubular acidosis
- Drugs: e.g. acetazolamide, ammonium chloride injection
- Addison’s disease
What conditions are associated with raised anion gap metabolic acidosis? (4)
- Lactate: shock, hypoxia
- Ketones: diabetic ketoacidosis, alcohol
- Urate: renal failure
- Acid poisoning: salicylates, methanol
What causes metabolic alkalosis?
- Loss of hydrogen ions
- Gain of bicarbonate
It is mainly due to problems of the kidney or gastrointestinal tract.
List some causes of metabolic alkalosis.
- Vomiting / aspiration
- Diuretics
- Liquorice, carbenoxolone
- Hypokalaemia
- Primary hyperaldosteronism
- Cushing’s syndrome
- Bartter’s syndrome
- Congenital adrenal hyperplasia
What conditions may lead to respiratory acidosis?
- COPD
- Decompensation in respiratory conditions (e.g. life-threatening asthma, pulmonary oedema)
- Sedative drugs: benzodiazepines, opiate overdose
What are common causes of respiratory alkalosis? (6)
- Anxiety leading to hyperventilation
- Pulmonary embolism
- Salicylate poisoning
- CNS disorders: stroke, subarachnoid haemorrhage, encephalitis
- Altitude
- Pregnancy
What is the most commonly isolated pathogen in acute bacterial prostatitis?
Escherichia coli
What are risk factors for acute bacterial prostatitis?
- Recent urinary tract infection
- Urogenital instrumentation
- Intermittent bladder catheterisation
- Recent prostate biopsy
What are the features of acute bacterial prostatitis?
- Pain referred to perineum, penis, rectum, or back
- Obstructive voiding symptoms
- Fever and rigors
- Tender, boggy prostate gland on digital rectal examination
What accounts for 25% of drug-induced acute kidney injury?
Acute interstitial nephritis
List some common causes of acute interstitial nephritis.
- Drugs: particularly antibiotics (e.g. penicillin, rifampicin, NSAIDs, allopurinol, furosemide)
- Systemic disease: SLE, sarcoidosis, Sjogren’s syndrome
- Infection: Hanta virus, staphylococci
What are the histological features of acute interstitial nephritis?
Marked interstitial oedema and interstitial infiltrate in the connective tissue between renal tubules
What are common symptoms of tubulointerstitial nephritis with uveitis (TINU)?
- Fever
- Weight loss
- Painful, red eyes
How is acute kidney injury (AKI) characterized?
Reduction in renal function following an insult to the kidneys
What percentage of hospitalized patients develop acute kidney injury (AKI)?
Approximately 15%
What are the traditional categories of causes of AKI?
- Prerenal
- Intrinsic
- Postrenal
What are examples of prerenal causes of AKI?
- Hypovolaemia secondary to diarrhoea/vomiting
- Renal artery stenosis
What intrinsic causes may lead to AKI?
- Glomerulonephritis
- Acute tubular necrosis (ATN)
- Acute interstitial nephritis (AIN)
- Rhabdomyolysis
- Tumour lysis syndrome
What are examples of postrenal causes of AKI?
- Kidney stone in ureter or bladder
- Benign prostatic hyperplasia
- External compression of the ureter
What are risk factors for acute kidney injury (AKI)?
- Chronic kidney disease
- Other organ failure/chronic disease
- History of acute kidney injury
- Use of nephrotoxic drugs
- Age 65 years or over
- Oliguria
- Neurological or cognitive impairment
What are two key ways AKI may be detected?
- Reduced urine output (oliguria)
- Fluid overload
What blood tests are commonly used to detect AKI?
- Sodium
- Potassium
- Urea
- Creatinine
What criteria can be used to diagnose acute kidney injury (AKI)?
- Rise in serum creatinine of 26 micromol/litre or greater within 48 hours
- 50% or greater rise in serum creatinine within the past 7 days
- Fall in urine output to less than 0.5 ml/kg/hour for more than 6 hours
What is the management approach for AKI?
Supportive management focusing on careful fluid balance and reviewing medications
Which drugs should be stopped in AKI as they may worsen renal function? (8)
- NSAIDs
- Aminoglycosides
- ACE inhibitors
- Angiotensin II receptor antagonists
- Diuretics
- Metformin
- Lithium
- Digoxin
What is the role of renal replacement therapy in AKI?
Used when a patient is not responding to medical treatment of complications
What are the phases of acute tubular necrosis (ATN)?
- Oliguric phase
- Polyuric phase
- Recovery phase
What is the most common inherited cause of kidney disease?
Autosomal dominant polycystic kidney disease (ADPKD)
What are the two disease loci identified in ADPKD?
- PKD1
- PKD2
What are the ultrasound diagnostic criteria for ADPKD in patients with a positive family history?
- Two cysts, unilateral or bilateral, if aged < 30 years
- Two cysts in both kidneys if aged 30-59 years
- Four cysts in both kidneys if aged > 60 years
What is a common acute phase protein measured in acutely unwell patients?
CRP
What are some examples of acute phase proteins?
- CRP
- Procalcitonin
- Ferritin
- Fibrinogen
- Alpha-1 antitrypsin
- Caeruloplasmin
- Serum amyloid A
- Serum amyloid P component
- Haptoglobin
- Complement
What are the two types of Autosomal Dominant Polycystic Kidney Disease (ADPKD)?
ADPKD type 1 and ADPKD type 2
ADPKD type 1 accounts for 85% of cases, while type 2 accounts for 15%.
What chromosome is associated with ADPKD type 1?
Chromosome 16
What chromosome is associated with ADPKD type 2?
Chromosome 4
What is the screening investigation for relatives of ADPKD patients?
Abdominal ultrasound
What are the ultrasound diagnostic criteria for ADPKD in patients with a positive family history aged < 30 years?
Two cysts, unilateral or bilateral
What are the ultrasound diagnostic criteria for ADPKD in patients aged 30-59 years?
Two cysts in both kidneys
What are the ultrasound diagnostic criteria for ADPKD in patients aged > 60 years?
Four cysts in both kidneys
What medication may be used for select patients with ADPKD?
Tolvaptan
What are the features of ADPKD?
- Hypertension
- Recurrent UTIs
- Flank pain
- Haematuria
- Palpable kidneys
- Renal impairment
- Renal stones
What is the most common extra-renal manifestation of ADPKD?
Liver cysts
What percentage of ADPKD patients develop liver cysts?
70%
What is Alport’s syndrome usually inherited as?
X-linked dominant pattern
What defect causes Alport’s syndrome?
Defect in the gene coding for type IV collagen
What are common features of Alport’s syndrome?
- Microscopic haematuria
- Progressive renal failure
- Bilateral sensorineural deafness
- Lenticonus
- Retinitis pigmentosa
What is the characteristic finding in renal biopsy for Alport’s syndrome?
Longitudinal splitting of the lamina densa of the glomerular basement membrane
What is amyloidosis?
Extracellular deposition of an insoluble fibrillar protein termed amyloid
What is the most common form of amyloidosis?
AL amyloidosis
What precursor protein is associated with AL amyloidosis?
Immunoglobulin Light chain fragments
What diagnostic test shows apple-green birefringence in amyloidosis?
Congo red staining
What is the normal range for anion gap?
8-14 mmol/L
What are causes of normal anion gap metabolic acidosis?
- Gastrointestinal bicarbonate loss
- Renal tubular acidosis
- Drugs (e.g. acetazolamide)
- Addison’s disease
What is Anti-glomerular basement membrane (GBM) disease commonly known as?
Goodpasture’s syndrome
What are the main features of Anti-GBM disease?
- Pulmonary haemorrhage
- Rapidly progressive glomerulonephritis
What is the main complication of Anti-GBM disease?
Pulmonary haemorrhage
What is the cause of Autosomal Recessive Polycystic Kidney Disease (ARPKD)?
Defect in a gene located on chromosome 6 which encodes fibrocystin
What are the risk factors for Benign Prostatic Hyperplasia (BPH)?
- Age
- Ethnicity (black > white > Asian)
What are the storage symptoms associated with BPH?
- Urgency
- Frequency
- Nocturia
What is the International Prostate Symptom Score (IPSS) range for severely symptomatic patients?
20-35
What is the most common type of bladder cancer?
Urothelial (transitional cell) carcinoma
What is the primary risk factor for urothelial carcinoma of the bladder?
Smoking
What is the staging classification for bladder cancer associated with no evidence of tumor?
T0
What percentage of patients with T2 bladder cancer are expected to have a good prognosis?
60%
What condition is characterized by recurrent renal stones due to a defect in membrane transport?
Cystinuria
What test is used to diagnose cystinuria?
Cyanide-nitroprusside test
What is a key feature of chronic pyelonephritis?
Scarring of the renal parenchyma
What is the genetic basis for cystinuria?
Defect in the SLC3A1 gene on chromosome 2 and SLC7A9 on chromosome 19
What are the common symptoms of diabetes insipidus?
Decreased secretion of antidiuretic hormone (ADH)
What is the mnemonic for arginine?
COLA
Which chromosomes contain the SLC3A1 and SLC7A9 genes?
Chromosome 2 (SLC3A1), Chromosome 19 (SLC7A9)
What is a classic feature of recurrent renal stones?
They are classically yellow and crystalline, appearing semi-opaque on x-ray
Which test is used for the diagnosis of renal stones?
Cyanide-nitroprusside test
What is the management for renal stones?
- Hydration
- D-penicillamine
- Urinary alkalinization
What characterizes diabetes insipidus (DI)?
Decreased secretion of antidiuretic hormone (ADH) or insensitivity to ADH
What are the causes of cranial diabetes insipidus?
- Idiopathic
- Post head injury
- Pituitary surgery
- Craniopharyngiomas
- Infiltrative diseases (e.g., histiocytosis X, sarcoidosis)
- DIDMOAD syndrome
- Haemochromatosis
What are the causes of nephrogenic diabetes insipidus?
- Genetic mutations affecting ADH receptors or aquaporin 2 channel
- Electrolyte imbalances (e.g., hypercalcaemia, hypokalaemia)
- Lithium
- Demeclocycline
- Tubulo-interstitial disease
What are the main features of diabetes insipidus?
- Polyuria
- Polydipsia
What findings would you expect in the investigation of diabetes insipidus?
High plasma osmolality, low urine osmolality
What is the urine osmolality threshold that excludes diabetes insipidus?
> 700 mOsm/kg
What is a management option for nephrogenic diabetes insipidus?
- Thiazides
- Low salt/protein diet
What is the most common cause of end-stage renal disease (ESRD) in the western world?
Diabetic nephropathy
What percentage of patients with type 1 diabetes mellitus develop diabetic nephropathy by age 40?
33%
What histological changes are associated with diabetic nephropathy?
- Basement membrane thickening
- Capillary obliteration
- Mesangial widening
- Kimmelstiel-Wilson nodules
What are the modifiable risk factors for developing diabetic nephropathy?
- Hypertension
- Hyperlipidaemia
- Smoking
- Poor glycaemic control
- Raised dietary protein
What are the non-modifiable risk factors for developing diabetic nephropathy?
- Male sex
- Duration of diabetes
- Genetic predisposition
What effect do thiazide diuretics have on serum potassium levels?
They decrease serum potassium levels
What is the mechanism of action of ezetimibe?
Inhibits cholesterol receptors on enterocytes, decreasing cholesterol absorption
What is familial hypercholesterolaemia (FH)?
An autosomal dominant condition resulting in high levels of LDL-cholesterol
What are the Simon Broome criteria for diagnosing definite FH?
- Total cholesterol (TC) > 7.5 mmol/l and LDL-C > 4.9 mmol/l
- Tendon xanthoma or DNA-based evidence of FH
What is Fanconi syndrome?
A generalized reabsorptive disorder of renal tubular transport in the proximal convoluted tubule
What are the features of Fanconi syndrome?
- Type 2 renal tubular acidosis
- Polyuria
- Aminoaciduria
- Glycosuria
- Phosphaturia
- Osteomalacia
What is the primary use of fibrates?
Management of hyperlipidaemia, particularly raised triglycerides
What is focal segmental glomerulosclerosis (FSGS)?
A cause of nephrotic syndrome and chronic kidney disease, presenting in young adults
What are the common causes of focal segmental glomerulosclerosis?
- Idiopathic
- Secondary to other renal pathology (e.g., IgA nephropathy)
- HIV
- Heroin
- Alport’s syndrome
- Sickle-cell
What is the triad of symptoms in haemolytic uraemic syndrome?
- Acute kidney injury
- Microangiopathic haemolytic anaemia (MAHA)
- Thrombocytopenia
What is the most common cause of typical haemolytic uraemic syndrome in children?
Shiga toxin-producing Escherichia coli (STEC) 0157:H7
What is Henoch-Schonlein purpura (HSP)?
An IgA mediated small vessel vasculitis usually seen in children following an infection
What are the common features of Henoch-Schonlein purpura?
- Palpable purpuric rash
- Abdominal pain
- Polyarthritis
What is the management for hypercalcaemia?
- Rehydration with normal saline
- Bisphosphonates
- Calcitonin
- Steroids in sarcoidosis
What is the management for hyperkalaemia?
Management may include stabilization of cardiac membrane, short-term potassium shift, and removal of potassium from the body
What ECG changes are associated with hyperkalaemia?
- Tall-tented T waves
- Loss of P waves
- Broad QRS complexes
- Sinusoidal wave pattern
What characterizes hungry bone syndrome?
Occurs after parathyroidectomy with rapid bone remineralization and systemic hypocalcaemia
Fill in the blank: Familial hypercholesterolaemia affects about 1 in _____ people.
500
What are the initial management steps for hyperkalaemia?
- Address precipitating factors
- Stop aggravating drugs
What is the frequency of horseshoe kidney in the general population?
1 in 500
What is the frequency of horseshoe kidney in Turner’s syndrome?
1 in 20
What is the initial treatment for severe hyperkalaemia (≥ 6.5 mmol/L)?
Emergency treatment is required, including IV calcium gluconate, insulin/dextrose infusion, and possibly nebulised salbutamol
IV calcium gluconate stabilizes the myocardium. Insulin/dextrose infusion helps shift potassium from extracellular to intracellular fluid.
What is the Fredrickson classification used for?
It classifies types of hyperlipidaemia based on genetic factors
The classification includes types I to V, each with specific genetic abnormalities.
What is the cause of type I hyperlipidaemia in the Fredrickson classification?
Lipoprotein lipase deficiency and apolipoprotein C-II deficiency
These deficiencies lead to impaired lipid metabolism.
List the causes of hypocalcaemia.
- Vitamin D deficiency (osteomalacia)
- Chronic kidney disease
- Hypoparathyroidism
- Pseudohypoparathyroidism
- Rhabdomyolysis
- Magnesium deficiency
- Massive blood transfusion
- Acute pancreatitis
Contamination with EDTA can falsely lower calcium levels.
What are the clinical features of hypocalcaemia?
- Tetany
- Perioral paraesthesia
- Depression (chronic)
- Cataracts (chronic)
- Prolonged QT interval on ECG
Neuromuscular excitability is a significant feature due to low extracellular calcium.
What is Trousseau’s sign?
Carpal spasm induced by inflating a blood pressure cuff above systolic pressure
It is seen in around 95% of patients with hypocalcaemia.
What conditions can cause hypokalaemia with hypertension?
- Cushing’s syndrome
- Conn’s syndrome (primary hyperaldosteronism)
- Liddle’s syndrome
- 11-beta hydroxylase deficiency
Carbenoxolone and excess liquorice can also lead to hypokalaemia associated with hypertension.
What is the management for acute severe hyponatraemia?
Administer hypertonic saline (typically 3% NaCl) and monitor closely
Patients should preferably be monitored in a high-dependency unit or above.
What can cause osmotic demyelination syndrome?
Over-correction of severe hyponatraemia
Symptoms may include dysarthria, dysphagia, and ‘locked-in syndrome’.
What are the consequences of hypophosphataemia?
- Red blood cell haemolysis
- White blood cell and platelet dysfunction
- Muscle weakness and rhabdomyolysis
- Central nervous system dysfunction
Hypophosphataemia can result from conditions like alcohol excess and diabetic ketoacidosis.
What is IgA nephropathy also known as?
Berger’s disease
It is the most common cause of glomerulonephritis worldwide.
What is the main symptom of post-streptococcal glomerulonephritis?
Proteinuria
This condition is often associated with low complement levels.
What is the typical presentation of lower genitourinary tract trauma?
Most bladder injuries occur due to blunt trauma, often associated with pelvic fractures
Up to 10% of male pelvic fractures can result in urethral or bladder injuries.
What is the recommended investigation for urethral injury?
Ascending urethrogram
This helps to assess the extent of the injury.
What is the most common cause of hypopituitarism?
Compression of the pituitary gland by non-secretory pituitary macroadenoma
Other causes include pituitary apoplexy and Sheehan’s syndrome.
What is an ascending urethrogram?
An investigation technique used to visualize the urethra.
What management is indicated for suprapubic catheter placement?
Surgical placement, not percutaneously.
What are common causes of external genitalia injuries?
- Penetration
- Blunt trauma
- Continence- or sexual pleasure-enhancing devices
- Mutilation
What are the two types of bladder rupture?
- Intra-peritoneal
- Extra-peritoneal
What symptoms suggest a bladder or urethral injury?
History of pelvic fracture and inability to void.
What investigation is used to confirm bladder injury?
IVU or cystogram.
What is the management for intraperitoneal bladder injury?
Laparotomy.
What is Medullary cystic disease?
An autosomal dominant condition leading to progressive tubulointerstitial fibrosis and renal failure.
What are the characteristic features of Medullary cystic disease?
- Renal failure
- Small kidneys
What is another name for Membranoproliferative glomerulonephritis?
Mesangiocapillary glomerulonephritis.
What is the most common cause of Type 1 Membranoproliferative glomerulonephritis?
Cryoglobulinaemia, hepatitis C.
What is the hallmark appearance of Type 1 Membranoproliferative glomerulonephritis on renal biopsy?
‘Tram-track’ appearance due to immune deposits.
What is Type 2 Membranoproliferative glomerulonephritis also known as?
‘Dense deposit disease.’
What are common causes of Type 2 Membranoproliferative glomerulonephritis?
- Partial lipodystrophy
- Factor H deficiency
What is the recommended management for Membranous glomerulonephritis?
- ACE inhibitor or ARB
- Immunosuppression if severe
What is the prognosis for Membranous glomerulonephritis?
One-third spontaneous remission, one-third remain proteinuric, one-third develop ESRF.
What is metabolic acidosis classified by?
Anion gap.
What is the normal range for anion gap?
10-18 mmol/L.
What causes normal anion gap metabolic acidosis?
- Gastrointestinal bicarbonate loss
- Renal tubular acidosis
- Addison’s disease
What are common causes of raised anion gap metabolic acidosis?
- Lactate
- Ketones
- Urate
- Acid poisoning
What is the typical presentation of Minimal change disease?
Nephrotic syndrome.
What is a common cause of Minimal change disease?
Idiopathic.
What is the treatment for Minimal change disease?
Oral corticosteroids.
What is Nephroblastoma also known as?
Wilm’s tumours.
At what age does Nephroblastoma usually present?
In the first 4 years of life.
What are the three components of Nephrotic syndrome?
- Proteinuria (> 3g/24hr)
- Hypoalbuminaemia (< 30g/L)
- Oedema
What are primary causes of Nephrotic syndrome?
- Minimal change disease
- Focal segmental glomerulosclerosis
- Membranous nephropathy
What is the pathophysiology of Nephrotic syndrome?
Damage to the glomerular basement membrane leads to increased permeability to proteins.
What are common complications of Nephrotic syndrome?
- Increased risk of thromboembolism
- Hyperlipidaemia
- Increased risk of infection
What defines contrast media nephrotoxicity?
A 25% increase in creatinine within 3 days of contrast media administration.
What are risk factors for contrast-induced nephropathy?
- Known renal impairment
- Age > 70 years
- Dehydration
- Cardiac failure
What preventive measure is recommended for high-risk patients before contrast procedures?
Intravenous 0.9% sodium chloride.
What is Oxalate nephropathy caused by?
- Ethylene glycol ingestion
- Vitamin C overdose
What are common causes of polyuria?
- Diuretics, caffeine & alcohol
- Diabetes mellitus
- Lithium
- Heart failure
What is Post-streptococcal glomerulonephritis associated with?
Recent group A beta-haemolytic Streptococcus infection.
What laboratory finding confirms recent streptococcal infection in Post-streptococcal glomerulonephritis?
Raised anti-streptolysin O titre.
What is the most common cause of infravesical outflow obstruction in males?
Posterior urethral valves.
What is the primary treatment for prostate cancer?
Radical prostatectomy.
What is the normal upper limit for PSA?
4 ng/ml.
What grading system is used for prostate cancer?
Gleason grading system.
What is the management for early prostate cancer?
Watch and wait.
What percentage of testosterone is derived from the testis?
95%
What is the preferred option for low-risk men with prostate cancer according to NICE?
Active surveillance
What clinical criteria suggest a candidate for active surveillance in prostate cancer?
- Clinical stage T1c
- Gleason score 3+3
- PSA density < 0.15 ng/ml/ml
- Cancer in < 50% of biopsy cores
- < 10 mm of any core involved
What are the treatment options for localized prostate cancer?
- Active monitoring
- Watchful waiting
- Radical prostatectomy
- Radiotherapy (external beam and brachytherapy)
What complications are associated with radical prostatectomy for localized advanced prostate cancer?
Erectile dysfunction
What is the aim of hormonal therapy in metastatic prostate cancer?
Reducing androgen levels
What is the initial effect of GnRH agonists on testosterone levels?
Testosterone level will rise initially for 2-3 weeks before falling to castration levels
What is a common anti-androgen medication used in prostate cancer treatment?
Bicalutamide
What is the classical triad of symptoms for renal cell cancer?
- Haematuria
- Loin pain
- Abdominal mass
What are the management options for renal cell cancer confined to the kidney?
- Partial nephrectomy
- Total nephrectomy
What is pseudohyperkalaemia?
A rise in serum potassium due to excessive leakage during or after blood collection
What is rapidly progressive glomerulonephritis characterized by?
Rapid loss of renal function with formation of epithelial crescents
What causes renal papillary necrosis?
- Severe acute pyelonephritis
- Diabetic nephropathy
- Obstructive nephropathy
- Analgesic nephropathy
What percentage of renal stones are calcium oxalate stones?
85%
What urinary pH conditions favor the formation of calcium phosphate stones?
Normal to alkaline urine (>5.5)
What is the recommended analgesia for renal colic according to NICE?
NSAID
What is the risk of over-diagnosis associated with PSA testing in prostate cancer?
High risk
What is the PSA threshold for men aged 50-59 years?
> 3.5 ng/ml
True or False: PSA testing should be postponed for at least 6 weeks after treatment for prostatitis.
True
What is the significance of a PSA level of 4-10 ng/ml?
Around 33% of men will be found to have prostate cancer
What is a common feature of nephroblastoma?
It accounts for 80% of all genitourinary malignancies in those under 15 years
What is Stauffer syndrome associated with?
Renal cell cancer
How does analgesic nephropathy contribute to renal papillary necrosis?
It is one of the causes of coagulative necrosis of the renal papillae
What analgesia is recommended by both BAUS and NICE for renal colic?
NSAID
Non-steroidal anti-inflammatory drugs are the first-line treatment for managing pain in renal colic.
Which NSAID has traditionally been used for renal colic but carries increased cardiovascular risks?
Diclofenac
Diclofenac and ibuprofen are noted for their increased risk of cardiovascular events.
What is recommended by NICE if NSAIDs are contraindicated or ineffective for pain relief?
IV paracetamol
Intravenous paracetamol is suggested for patients who need effective pain management.
What type of medication do alpha blockers represent in the management of renal colic?
Smooth muscle relaxants
Alpha blockers help dilate the ureter and may facilitate stone passage.
For distal ureteric stones less than what size do NICE recommend the use of alpha blockers?
< 10 mm
Alpha blockers are particularly considered for smaller distal ureteric stones.
What initial investigations are recommended for renal colic?
Urine dipstick and culture, serum creatinine and electrolytes, FBC/CRP, calcium/urate
These tests help assess renal function and identify underlying causes.
What imaging technique should be performed on all patients with renal colic within 24 hours of admission?
Non-contrast CT KUB
This imaging modality is essential for diagnosing ureteric stones.
What is the sensitivity and specificity of CT KUB for ureteric stones?
Sensitivity: 97%, Specificity: 95%
These high rates make CT KUB a reliable diagnostic tool.
What is the first-line management for renal stones < 5 mm according to NICE?
Watchful waiting
Stones smaller than 5 mm are likely to pass spontaneously.
What procedure is recommended for renal stones measuring 10-20 mm?
Shockwave lithotripsy or ureteroscopy
Both options are viable for managing stones of this size.
What is shockwave lithotripsy?
A procedure that generates shock waves to fragment stones
It is an external method used to treat renal stones.
What is a potential complication of shockwave lithotripsy?
Solid organ injury
The procedure can lead to injury due to the passage of shock waves.
What is the role of ureteroscopy in the management of renal stones?
Used for complex stone disease and when lithotripsy is contraindicated
Ureteroscopy allows direct access to stones via the ureter.
What is percutaneous nephrolithotomy?
A procedure to access the renal collecting system for stone removal
This method is used for larger stones that cannot be managed with other techniques.
What dietary recommendations can help prevent calcium stones?
- High fluid intake
- Add lemon juice to drinking water
- Avoid carbonated drinks
- Limit salt intake
These lifestyle changes can reduce the risk of stone formation.
What is a risk factor for urate stones?
Gout
Gout can lead to elevated uric acid levels, increasing the risk of urate stones.
What is the appearance of calcium oxalate stones on X-ray?
Opaque
Calcium oxalate stones are the most common type and can be easily identified on radiographs.
What is the major histocompatibility complex (MHC) in humans known as?
HLA system
The HLA system plays a crucial role in immune response and organ transplantation.
What is the relative importance of HLA antigens when matching for a renal transplant?
DR > B > A
DR antigen compatibility is prioritized over B and A antigens.
What is the 1-year graft survival rate for cadaveric transplants?
90%
This statistic reflects the success of cadaveric renal transplants at the one-year mark.
What type of urinary cast is associated with glomerulonephritis?
Red blood cell casts
These casts indicate damage to the glomeruli.
What is hyperacute rejection in the context of renal transplantation?
Rejection occurring minutes to hours due to pre-existing antibodies
This is a severe form of rejection that necessitates immediate graft removal.
What are the common causes of acute graft failure?
- Mismatched HLA
- Cytomegalovirus infection
Acute graft failure typically occurs within the first six months following transplantation.
What can cause chronic graft failure after renal transplantation?
Fibrosis from both antibody and cell-mediated mechanisms
Chronic allograft nephropathy is a common cause of long-term graft failure.
What is Wilms’ nephroblastoma?
One of the most common childhood malignancies
Typically presents in children under 5 years of age, with a median age of 3 years old.
What syndrome is associated with Wilms’ tumour?
Beckwith-Wiedemann syndrome
Also associated as part of WAGR syndrome with Aniridia, Genitourinary malformations, and mental Retardation.
What is a common genetic mutation found in Wilms’ tumour cases?
Loss-of-function mutation in the WT1 gene on chromosome 11
Around one-third of cases are associated with this mutation.
What is the most common presenting feature of Wilms’ tumour?
Abdominal mass
What are some other features of Wilms’ tumour?
- Painless haematuria
- Flank pain
- Anorexia
- Fever
What percentage of Wilms’ tumour cases are unilateral?
95%
In what percentage of patients are metastases found in Wilms’ tumour?
20%
Most commonly to the lung.
What should be done for children with an unexplained enlarged abdominal mass?
Arrange paediatric review within 48 hours
What is the primary management for Wilms’ tumour?
- Nephrectomy
- Chemotherapy
- Radiotherapy if advanced disease
What is the prognosis for Wilms’ tumour?
Good, with an 80% cure rate
What are the histological features of Wilms’ tumour?
- Epithelial tubules
- Areas of necrosis
- Immature glomerular structures
- Stroma with spindle cells
- Small cell blastomatous tissues resembling the metanephric blastema