Kidney Disease Flashcards
List classic clinical features of kidney disease
Loin pain Haematuria Dysuria Proteinuria (frothy) Oligouria Appetite and weight Asymptomatic
The kidney is involved in excretion of urea. What happens if this is impaired?
Uraemia (urea over 40 before manifests)
Can lead to pericarditis, encephalopathy, neuropathy etc.
The kidney is involved in fluid balance. What happens if this is impaired?
Fluid retention (oedema)
The kidney is involved in electrolyte balance. What happens if K becomes too high?
Hyperkalaemia can cause arrhythmias
The kidney is involved in acid-base balance. What is the classic breathing sign of an acidotic patient?
Metabolic acidosis leads to Kussmaul’s respiration
Which class of drug has to be closely monitored and can potentially cause renal failure?
ACE inhibitors/ARBs
What are the effects of NSAID on the kidney?
Allergic reaction Reduce GFR (inhibit prostaglandin production) due to vasoconstriction of afferent arteriole
Which antibiotics can insult to the kidney?
Gentamicin
Trimethoprim
Penicillins
What might radiology contrast cause within the kidney?
Contrast nephropathy
What does specific gravity in urinalysis tell us?
Urine concentration
Define heavy proteinuria
1-3g of protein in the urine per day
Define acute kidney injury
Decline in GFR over hours/days/weeks with/without oliguria in a patient with normal or impaired renal function
How much urine a day is classed as oliguria?
Less than 400ml a day
Which equation is used to provide estimated GFR (eGFR)
MDRD4 equation
Encompasses serum creatinine, age, sex and race
eGFR overestimates GFR if high muscle mass. True/False?
False
eGFR overestimates GFR is muscle mass is low, and underestimates GFR if muscle mass is high
Define stage 1 CKD
Normal GFR (90 or over) Evidence of kidney damage (proteinuria, haematuria, abnormal US)
Define stage 2 CKD
GFR 60-89
Evidence of kidney damage (proteinuria, haematuria, abnormal US)
Define stage 3 CKD
Define stage 3a and 3b
GFR 30-59
A = 45-59
B = 30-44
Define stage 4 (severe) CKD
GFR 15-29
Define stage 5 CKD (renal failure)
GFR less than 15 or renal replacement therapy
Patients with proteinuria are more likely to progress to CKD. True/False?
True
More proteinuria = faster progression
List common causes of chronic kidney disease
Diabetes (commonest) Hypertension Vascular disease Chronic glomerulonephritis Reflux nephropathy Polycystic kidneys
Symptoms due to reduced GFR don’t occur until late. True/False?
True
GFR less than 20 usually
List methods of slowing progression of CKD
Reduce proteinuria + control BP - ACE inhibitors, spironolactone
Glycaemic control in diabetes
Smoking cessation
What is the initial danger of ACE inhibitors for kidney disease?
Cause initial fall in GFR which leads to hyperkalaemia
i.e. short term pain, long term gain
How does anaemia arise in CKD?
Erythropoietin production declines in CKD
How is anaemia in CKD rectified?
IV iron
Erythropoietin injection
How does bone disease arise in CKD?
Impaired vitamin D hydroxylation in damaged kidney leading to reduced calcium absorption (secondary followed by tertiary hyperparathyroidism)
How is bone disease in CKD rectified?
Alfacalcidol (active vitamin D) Phosphate intake Phosphate binders (calcium carbonate, calcium acrete, sevalema)
If initial CKD therapy is unsuccessful, what are the treatment options for renal failure?
PREP FOR RENAL REPLACEMENT THERAPY Haemodialysis Peritoneal dialysis Transplant (within 6 months of dialysis) Conservative/palliative management (epo and symptom control)
What is the best form of access for dialysis?
Arteriovenous fistula (AVF) - wait 6 weeks to mature
Acute kidney injury is defined using creatinine and urine output. Define acute kidney injury
Increase in creatinine greater than 26.4 micomol//L, or by 50% or reduction in urine output in less than 48 hours
How is acute kidney injury classified due to cause?
Pre-renal (functional)
Renal (structural)
Post-renal (obstruction)
List pre-renal causes of acute kidney injury
Hypovolaemia (haemorrhage)
Hypotension (shock)
Hypoperfusion (NSAID, ACEI)
Pre-renal AKI is reversible. True/False?
True
Outline the pathophysiology of AKI due to volume depletion
Decreased effective intravascular volume causes increased ADH and aldosterone release, causing salt and water retention, leading to oliguria and AKI
What is the commonest form of AKI in hospital?
Acute tubular necrosis due to decreased renal perfusion
Outline treatment for AKI
Treat cause/factors 0.9% saline +/- inotropes/ vasopressors Antibiotic if sepsis Stop nephrotoxines Dialysis if anuric and uraemia
What is the main vascular cause of renal AKI?
Vasculitis
What is the main glomerular cause of renal AKI?
Glomerulonephritis
List tubular causes of AKI
Ischaemia
Drugs (e.g. antibiotics - gentamicin, paracetamol)
Contrast nephropathy
Rhabdomyolysis
Dark urine in AKI may be a sign of what?
Rhabdomyolysis (myoglobin in urine)
Destruction of skeletal muscle
List initial investigations for AKI
U+Es FBC, coagulation, CK Urinalysis (haematuria, proteinuria) Ultrasound Antibodies (ANA, ANCA, GBM)
What are the indications for renal biopsy?
Rapidly progressive glomerulonephritis
+ve antibodies
Not improving
List life-threatening complications of AKI
Hyperkalaemia (K >5.5) Pulmonary oedema Acidosis (pH <7.15) Uraemic pericardial effusion Severe uraemia (UR > 40)
Trimethoprim can cause AKI. True/False?
True
List the main causes of post-renal AKI
Obstruction from stones/cancer
Stricture
Extrinsic pressure
Outline management of post-renal AKI
Catheter
Nephrostomy
Refer to urology (ureteric stenting)
How is hyperkalaemia complicating AKI treated acutely?
PROTECT MYOCARDIUM: 10mls 10% Calcium gluconate (Ca chloride second line)
MOVE POTASSIUM BACK INTO CELLS: 10 units of
insulin and 50mls 50% dextrose
List investigations used in kidney disease
GFR Abdominal imaging Blood pressure ECG Urinalysis looking for proteinuria and haematuria --> PCR if positive
What is malignant/accelerated hypertension? What are the signs?
Diastolic BP >120
Papilloedema, headache, haematuria
End-organ complication (encephalopathy, fits, HF, acute RF)
List late symptoms of CKD
Tiredness
Poor appetite
Itch
Sleep disturbance
What is usually the first early sign of CKD?
Impaired urine concentrating ability - early nocturia
How is AKI staged?
3 stage KDIGO scale
List risk factors for AKI
Age HF CKD/ previous AKI Diabetes Liver disease PVD Exposure
List interstitial causes of AKI
Drugs
Infection (TB)
Systemic disease (sarcoid)
List symptoms of AKI
Itch, fatigue
Nausea, vomiting
Anorexia, weight loss
High blood pressure, peripheral oedema
State the main complication to be aware of in post-renal AKI. How is it diagnosed?
Hydronephrosis
US
What is the first line investigation for a patient with suspected hyperkalaemia? What would the results be?
ECG
Tall T waves, reduced P waves, broad QRS
