Renal medicine Flashcards
How is AKI diagnosed?
By measuring the serum creatinine
What are the NICE criteria for AKI?
Rise in creatinine >25micromol/L in 48 hours
Rise in creatinine >50% in 7 days
Urine output of <0.5ml/kg/hour for >6 hours
Give examples of 2 iatrogenic causes of AKI
Nephrotoxic medications such as NSAIDs and ACE-i
Use of contrast medium in CT scans
Give 3 pre-renal causes of AKI
Dehydration
Hypotension
Heart failure
Give 3 renal causes of AKI
Glomerulonephritis
Interstitial neprhitis
Acute tubular necrosis
Give 4 post-renal causes of AKI?
Kidney stones
Masses in abdomen or pelvis
Ureter or urethral strictures
Enlarged prostate
What are the investigations for AKI?
Urinalysis
Ultrasound
Blood
What is the management of AKI?
Correct underlying cause
Stop nephrotoxic drugs
Relieve obstruction
What are some possible complications of AKI?
Hyperkalaemia
Fluid overload
Metabolic acidosis
Uraemia (leads to encephalopathy or pericarditis)
What are potential symptoms of CKD?
Usually asymptomatic Prurituis Loss of appetite nausea Oedema Muscle cramps Peripheral neuropathy Pallor HTN
What are the investigations and results for CKD?
Bloods (decreased eGFR)
Urine albumin:creatinine ratio >3mg/mmol
Haematuria
Renal ultrasound
How is CKD diagnosed?
Decreased eGFR 3 months apart
How is CKD staged?
Using the G (eGFR) and A (ACR) scores.
G1 = eGFR >90 G2 = eGFR 60-89 G3a = eGFR 45-59 G3b = eGFR 30-44 G4 = eGFR 15-29 G5 = eGFR <15 (known as “end-stage renal failure”)
A1 = < 3mg/mmol A2 = 3 – 30mg/mmol A3 = > 30mg/mmol
If someone, being investigated for CKD, has a score of G1 A1, what severity is their CKD?
They have perfectly healthy kidneys
How can metabolic acidosis in CKD be managed?
Oral sodium bicarbonate
How can anaemia in CKD be managed?
Iron and erythropoietin
Which antihypertensive is first line in patients with CKD?
ACE-i
Serum potassium must be monitored because ACE-i and CKD both cause hyperkalaemia
What are the features of renal bone disease?
Osteomalacia
Osteoporosis
Osteoclerosis
What are the X ray changes seen in renal bone disease?
Sclerosis at both ends of the vertebra and oestomalacia in the middle. This is known as “rugger jersey” because it is stripey and the radiologist who named it must have been a Tory
What are the indications for acute dialysis?
AEIOU A-acidosis E-electrolyte abnormalities I-intoxication O-oedema U-uraemia
Which kind of catheter is used in peritoneal dialysis?
Tenckhoff catheter
What are the potential complications of peritoneal dialysis?
Bacterial peritonitis
Peritoneal sclerosis
Ultrafiltration failure
weight gain
What are the two access options for haemodialysis?
Tunnelled cuffed catheter
AV fistula
What is heard on auscultation of A-V fistula?
Machinery murmur
What is STEAL syndrome?
Develops when there is an AV fistula whihc “steals” blood from the distal limb. It causes distal ischaemia
Which scar is given in renal transplant?
Hockey stick
What is the usual immunosuppressant regime for renal transplant?
Tacrolimus
Mycophenolate
Prednisolone
What are the 3 complications of transplant?
Rejection
Failure
Electrolytes imbalances
What are the features of nephritic syndrome?
Haematuria
Oliguria
Proteinuria (<3g/24hrs if more then nephrotic)
Fluid retention
What are the features of nephrotic syndrome?
Peripheral oedema
Proteinuria (>3g/24hrs)
Serum albumin less than 25g/L
Hypercholesterolaemia
What is interstitial nephritis?
There is inflammation of the space between the cells and tubules
What can cause glomerulosclerosis?
Glomerulonephritis, obstructive uropathy, focal segmental glomerulosclerosis
How is glomerulonephritis treated?
Immunosuppression (steroids)
Blood pressure control
What is the most common cause of primary glomerulonephritis?
IgA nephropathy (Berger’s disease)
What is seen on histology of IgA nephropathy (Berger’s disease?
IgA deposits and glomerular mesangial proliferation
What is the presentation of Goodpasture’s syndrome?
AKI and haemoptysis
What causes Goodpasture’s syndrome?
Anti-GBM antibodies attck the glomerulus and pulmonary basement membranes. This causes glomerulonephritis and pulmonary haemorrhage
What is the anti-hypertensive class of choice in diabetes?
ACE-i. Protects against diabetic nephropathy
What are the 2 types of interstitial nephritis?
Acute interstitial nephritis and chronic tubulointerstitial nephritis
What causes acute interstitial nephritis?
It is usually a hypersensitivity reaction to drugs or infection
What are the features of acute interstitial nephritis?
Rash
Fever
Eosinophilia
What causes acute tubular necrosis?
Ischaemia or toxins
How long does it take to recover from acute tubular necrosis?
7-21 days
What is found in the urine in acute tubular necrosis
Muddy brown casts
What is the management of acute tubular necrosis?
Supportive management
IV fluids
Stop nephrotoxic medications
Treat complications
What is renal tubular acidosis?
There is metabolic acidosis due to pathology in the tubules of the kidney
What is type 1 renal tubular acidosis?
There is pathology in the distal tubule which means it is unable to excrete hydrogen ions
What is the management of type 1 renal tubular acidosis?
oral bicarbonate
What is the main cause of type 2 renal tubular acidosis?
Fanconi’s sydrome
What causes type 4 renal tubular acidosis?
Reduced aldosterone
How is type 4 renal tubular acidosis managed?
Fludrocortisone
What causes Haemolytic uraemic syndrome?
When there is thrombosis in small blood vessels throughout the body. Usually triggered by shiga toxin
What is the shiga toxin produced by?
e.coli
How does HUS present
e.coli causes bloody diarrhoea. About 5 days after this HUS occurs Reduced urine output Haematuria Abdo pain Lethargy Confusion Bruising HTN
How is HUS managed?
It is a medical emergency. It is self limiting and requires supportive management
What is rhabdomyolisis?
A condition when skeletal muscle breaks down and releases breakdown products into the blood
Which breakdown product of rhabdomyolyosis is the most dangerous?
potassium. Causes hyperkalaemia which can lead to cardiac arrest
Why can rhabdomyolysis lead to AKI?
Myoglobin is a breakdown product which is toxic to the kidneys in high concentrations
What can cause rhabdomyolysis?
Prolonged immobility
Extremely rigorous exercise
Crush injuries
seizures
What are the signs and symptoms of rhabdomyolysis?
Muscle aches and pains Oedema Fatigue Confusion red-brown urine
What are the investigations for rhabdomyolysis?
Blood tests: high CK, U&Es chaotic
ECG for hyperkalaemia (long QRS, peaked T)
What is the management of rhabdomyolysis?
IV fluids
IV sodium bicarbonate
IV mannitol to increase GFR
What is the main complication of hyperkalaemia?
Cardiac arrhythmia, particularly VF
What are the main conditions which can cause hyperkalaemia?
AKI/ CKD
Rhabdomyolysis
Adrenal insufficiency
Tumour lysis sundrome
Which medications can cause hyperkalaemia?
Aldosterone antagonists ACE-i Angiotensin II receptor blockers NSAIDs Potassium supplements
What can result in a falsely raised potassium?
Haemolysis of the sample
What are the ECG findings in hyperkalaemia?
Tall peaked T waves
Flattening or absence of p waves
Broad QRS
What is the mainstay of treatment in hyperkalaemia?
Insulin and dextrose infusion (drived K+ into cells) and IV calcium gluconate (stabilise heart muscle)
What is the level of potassium which needs treating?
> 6.5mmol/L
If >6.mmol/L do ECG and treat as well if it has changes
What are the associated findings of polycystic kidney disease found outside of the kidney?
Hepatic cyst
Cerebral aneurysms
What is the inheritance pattern of PKD?
There is an autosomal dominant and autosomal recessive type. The dominant type is more prevalent
How is PKD diagnosed?
Ultrasound scan and genetic testing
What are the genes associated with PKD?
PKD-1 and PKD-2
How is PKD managed?
Tolvaptan (vasopressin receptor antagonist)
