Nephrology Flashcards
How can Addisonian crisis present?
- can present vaguely with fever, abdo pain and collapse
- can cause hyperkalaemic hyperchloraemic (normal anion gap) metabolic acidosis due to loss of aldosterone
- even when managed with steroids, think of triggers e.g. recent infection
What are the main extra renal manifestation of ADPCKD?
liver cysts (70% - the commonest extra-renal manifestation): may cause hepatomegaly
berry aneurysms (8%): rupture can cause subarachnoid haemorrhage
cardiovascular system: mitral valve prolapse, mitral/tricuspid incompetence, aortic root dilation, aortic dissection
How does acute interstitial nephritis present? What will be seen on investigation?
Usually drug induced kidney injury
Triad of rash, fever and eosinophilia
Common to see arthralgia
Sterile pyuria and white cell casts on investigation
What blood result would make you think of dehydration as the cause of AKI?
rise in urea proportionally bigger than rise in creatinine
Drugs to stop in AKI?
(DAMN AKI)
Diuretics
Aminoglycosides and ACE inhibitors
Metformin
NSAIDs (bar aspirin at cardioprotective dose and paracetamol)
What are the indications for haemodialysis in a patient with acute kidney injury?
haemodialysis always pulls up
Hyperkalaemia (severe)
Acidosis
Pulmonary oedema
Uraemia- (encephalopathy or pericarditis)
What serum urea:creatinine ratio indicates a likely pre-renal cause of AKI?
do urea/creatinine/1000 to calculate - above 100 is likely a prerenal injury
What is Alport’s syndrome? Describe the key features and how it is diagnosed
Alport syndrome : inherited defect in IV collagen (X linked dominant) that usually presents in childhood
- GBM abnormality (splitting of lamina densa on microscopy)
- progressive renal failure (microscopic haematuria)
- sensorineural hearing loss
- ocular issues, smooth muscle tumours (leiomyomas) and rarely aortic dissection
Diagnosed with genetic testing and renal biopsy
Give 3 causes of acidosis with a raised anion gap
Sepsis, DKA and methanol poisoning all cause metabolic acidosis with a raised anion gap
-they all result in the formation of a new anion that is not included in the calculation- lactic acid, ketones and formic acid
How long does an AV fistula take to develop?
6-8 weeks
CKD commonly causes anaemia, due to reduced EPO , toxic effects of uraemia on bone marrow and reduced iron absorption. What features might this present with, and how should treatment be optimised?
Features:
Classical signs of anaemia e.g. fatigue and pallor
Aortic flow murmur (soft ejection systolic murmur)
Tx optimisation:
Iron deficiency should be corrected (eg with ferrous sulphate) before starting erythropoiesis-stimulating agents
Patients on haemodialysis often require IV iron
target haemoglobin of 10 - 12 g/dl
What is the most common cause of death in CKD patients on haemodialysis?
Ischaemic heart disease
When should a GP consider referring to a nephrologist (eGFR)?
if eGFR falls below 30 or progressively by > 15 in a year
What variables are considered to affect eGFR in the Modification of Diet in Renal Disease (MDRD) equation?
eGFR variables
- CAGE - Creatinine, Age, Gender, Ethnicity
Outline the management of bone mineral disease in CKD
- reduced dietary intake of phosphate is the first-line management
- phosphate binders
- vitamin D: alfacalcidol, calcitriol
- parathyroidectomy may be needed in some cases
What should you give in CKD when concerned about fracture risk? (e.g. when post menopausal/ has fam hx to exacerbate bone mineral disease)
alendronic acid - a bisphosphonate that reduces the rate of bone turnover and strengthens the bone.
What should be done in all patients with a clinically raised ACR (albumin:creatinine ratio >3mg/mmol) and co-existent diabetes mellitus?
ACE-i should be commenced to reduce risk of diabetic nephropathy
What type of diabetes insipidus is commonly caused by lithium (mood stabiliser)?
Nephrogenic DI- lithium desensitizes the kidney’s ability to respond to ADH in the collecting ducts
What is diabetes insipidus? How do you test for it?
Diabetes insipidus is a condition characterised by either a decreased secretion of ADH from the pituitary (cranial DI) or an insensitivity to ADH (nephrogenic DI).
Causes polyuria and polydipsia.
Investigation:
- high plasma osmolality, low urine osmolality
- a urine osmolality of >700 mOsm/kg excludes diabetes insipidus
- can do a water deprivation test
What is involved in annual screening for diabetic nephropathy? Why is it done?
urinary albumin:creatinine ratio (ACR)
- should be an early morning specimen
- ACR > 2.5 = microalbuminuria
ACR may be measured on a spot sample if a first-pass sample is not provided (but should be repeated on a first-pass specimen if abnormal)
Microalbuminuria is the earliest, clinically detectable manifestation of classic diabetic kidney disease
What investigation should be carried out for older patients with iron deficiency anaemia?
refer for endoscopy/colonoscopy to rule out GI cancer
What diagnoses should be considered when AKI develops after initiating ACEi?
In young women - think fibromuscular dysplasia (causing renal artery stenosis)
In older pts - think atherosclerosis of renal arteries
What are the requirements for maintenance fluids?
25-30 ml/kg/day of water
approximately 1 mmol/kg/day of potassium, sodium and chloride
approximately 50-100 g/day of glucose to limit starvation ketosis
What is the risk when using 0.9% Sodium Chloride for fluid therapy in patients requiring large volumes?
hyperchloraemic metabolic acidosis
Which cancer is most commonly associated with varicocele?
RCC
When should a 2 week wait referral happen for haematuria?
Aged > 45 years AND:
-unexplained visible haematuria without urinary tract infection, or
- visible haematuria that persists or recurs after successful treatment of urinary tract infection
Aged > 60 years AND have unexplained nonvisible haematuria and either dysuria or a raised WCC
What is HUS? What are the common causes? Tx?
Haemolytic uraemic syndrome is generally seen in young children and produces a triad of:
- AKI
- microangiopathic haemolytic anaemia
- thrombocytopenia
Often follows diarrhoeal infection
Common cause - E.coli (shiga tox) , pneumococcus, HIV
Give supportive tx only unless underlying infection to correct
What is Henoch-Schonlein purpura (HSP)? How should it be managed?
an IgA mediated small vessel vasculitis, commonly seem in children (following infection)
classically presents with abdominal pain, arthritis, haematuria and a purpuric rash over the buttocks and extensor surfaces of arms and legs
blood pressure and urinalysis should be monitored to detect progressive renal involvement
Tx is usually supportive as it is self-limiting
Outline the key steps in management of hyperkalaemia
Always do an ECG first in new hyperkalaemia
If K+ > 6.5 mmol/l or if there are ECG changes:
Administer calcium gluconate 10% 10-20ml by slow IV injection titrated to ECG response
Give 10 U Actrapid in 50 ml of 50% glucose over 10-15 minutes
Consider use of nebulised salbutamol (temporarily lower K+)
Consider correcting acidosis with sodium bicarbonate infusion
What can happen when hyperkalaemia goes untreated?
Untreated hyperkalaemia can cause ventricular tachycardia- reduced CO, hypotension, and dyspnoea from pulmonary congestion
How does IgA nephropathy (Berger’s disease) typically present?
Frank haematuria following upper respiratory tract infection in young people
It is the commonest cause of glomerulonephritis worldwide!
What malignancy is associated with membranous glomerulonephritis?
prostate, lung, lymphoma, leukaemia
How does aspirin overdose present? Tx?
initially presents with nausea, vomiting, tinnitus and headache
In more severe overdoses, hyperventilation and a secondary respiratory alkalosis develops
Over ~24 hours, this progresses to a metabolic acidosis and hypokalaemia. Confusion, coma, seizures, hypoglycaemia and fever may also develop.
Tx: IV sodium bicarb
What is the most common cause of peritonitis secondary to peritoneal dialysis? Tx?
Coagulase-negative Staphylococcus e.g. staph epidermidis
vancomycin (or teicoplanin) + ceftazidime added to dialysis fluid OR vancomycin added to dialysis fluid + ciprofloxacin by mouth
What hormonal change may be seen in nephrotic syndrome?
Low total thyroxine
Describe hyperacute rejection and acute graft failure following renal transplant
Hyperacute rejection (minutes to hours)
- pre-existing antibodies against ABO or HLA antigen (type II hypersensitivity reaction)
- leads to widespread thrombosis of graft vessels → ischaemia and necrosis of the transplanted organ
- no treatment is possible and the graft must be removed
Acute graft failure (< 6 months)
- usually due to mismatched HLA. Cell-mediated (cytotoxic T cells)
- usually asymptomatic and is picked up by a rising creatinine, pyuria and proteinuria
- may be reversible with steroids and immunosuppressants
Most common viral infection in solid organ transplant patients? Tx?
Cytomegalovirus- Ganciclovir is the treatment of choice
Patients on long-term immunosuppression for renal transplantation require regular monitoring for complications such as:
Cardiovascular disease - tacrolimus and ciclosporin can cause hypertension and hyperglycaemia so patients should be monitored for accelerated CVD
Renal failure - due to nephrotoxic effects of tacrolimus and ciclosporin/graft rejection/recurrence of original disease
Malignancy - patients should be educated about minimising sun exposure to reduce the risk of squamous cell carcinomas and basal cell carcinomas
Name the diagnosis from each urine microscopy finding:
- Hyaline casts
- Brown ‘muddy’ granular casts
- Red cell casts
- ‘Bland’ urinary sediment
1.seen in normal urine, after exercise, during fever or with loop diuretics
2. Acute tubular necrosis
3. nephritic syndrome
4. pre-renal uraemia (azotemia)
When should patients with CKD be started on an ACEi?
if they have an ACR > 30 mg/mmol
What is the potential complication for patients with CKD who take calcium based phosphate binders?
hypercalcaemia and vascular calcification
Why is Nephrotic syndrome associated with a hypercoagulable state?
Loss of antithrombin 3 by the kidneys
Most likely diagnosis in an older patient with painless visible haematuria?
TCC of the bladder
What vitamin D supplement is used in end-stage renal disease?
Alfacalcidol is used as a vitamin D supplement in end-stage renal disease because it does not require activation in the kidneys
Spot diagnosis- haemoptysis + sudden onset AKI/proteinuria/haematuria ?
Goodpasture’s: anti-glomerular basement membrane (GBM) disease
small-vessel vasculitis associated with pulmonary haemorrhage and rapidly progressive glomerulonephritis
The disease is more common in men and can be exacerbated by a respiratory tract infection
Causes of a normal anion gap metabolic acidosis?
ABCD
Addison’s
Bicarb loss- e.g. diarrhoea
Chloride (ammonium chloride injection)
Drugs- e.g. acetazolamide
First line tx for ascites?
spironolactone
What can spironolactone be replaced with in cases of troublesome gynaecomastia?
Eplerenone
How do you differentiate between IgA nephropathy and Post-streptococcal glomerulonephritis when they both present with nephritic syndrome following an infection? (just based on clinical picture)
Post-streptococcal glomerulonephritis is more delayed (occurs 7-14 days after infection) and the infection is always streptococcal e.g. tonsilitis
What is the first line investigation for rhabdomyolysis? What is the treatment?
Serum creatine kinase
rapid IV fluid rehydration- normal saline
What drug should all CKD patients be started on?
a statin
What are the main complications of haemodialysis?
CHASED
Cardiac arrhythmia
Hypotension
Air embolus
Stenosis/infection at the site
Endocarditis
Disequilibration syndrome
What are the main complications of peritoneal dialysis?
Peritonitis
Catheter blockage/infection
Fluid retention
Constipation
Hyperglycaemia
Hernias
What are the main complications of renal transplantation?
Graft rejection
Disease recurrence
Opportunistic infection
Malignancy (esp lymphoma and skin cancer)
DVT/PE
Urinary tract obstruction
The symptoms of renal failure that is not being adequately managed with RRT are:
breathlessness
fatigue/insomnia
pruritus
poor appetite
swelling
weakness
weight gain/loss
abdominal cramps and nausea
muscle cramps
headaches
cognitive impairment
anxiety and depression
sexual dysfunction
One of the best ways to differentiate between AKI and CKD is renal ultrasound - most patients with CKD have bilaterally small kidneys.
Exceptions to this rule include:
autosomal dominant polycystic kidney disease
diabetic nephropathy (early stages)
amyloidosis
HIV-associated nephropathy
What feature on blood tests can help you to differentiate between acute and chronic kidney injury?
Calcium levels
Hypocalcaemia = CKD
In chronic kidney disease, the kidneys cannot activate vitamin D effectively, meaning less calcium is absorbed from the gut, causing its levels to fall.
How can you prevent contrast induced nephropathy?
Volume expansion with 0.9% saline pre and post procedure
What is required in all patients with AKI of unknown cause?
renal USS
AKI with raised urinary sodium makes you think of…
acute tubular necrosis (ATN) (the most common renal cause of an AKI)
The kidneys lose their ability to retain sodium
What is seen on histology in membranous glomerulonephritis?
basement membrane thickening on light microscopy
subepithelial spikes on silver stain
positive immunohistochemistry for PLA2
How should membranous glomerulonephritis be managed?
all patients should receive an ACE inhibitor or an angiotensin II receptor blocker (ARB)
immunosuppression (only patients with severe or progressive disease) :
A combination of corticosteroid + another agent such as cyclophosphamide is often used
consider anticoagulation for high-risk patients- increased risk of VTE
Prognosis of membranous glomerulonephritis?
rule of thirds:
one-third: spontaneous remission
one-third: remain proteinuric
one-third: develop ESRF
What patient factors may affect eGFR result?
pregnancy
muscle mass (e.g. amputees, body-builders)
eating red meat 12 hours prior to the sample being taken
What should be prescribed to reduce the rate of CKD progression in ADPKD?
Tolvaptan - selective vasopressin antagonist
reduces cell proliferation, cyst formation and fluid excretion
What can be used to treat hyperphosphataemia in patients with CKD mineral bone disease?
Sevelamer - a non-calcium based phosphate binder
How do you manage nephrogenic diabetes insipidus?
thiazides, low salt/protein diet
What is the SALT LOSS mnemonic for sxs of hyponatraemia?
stupor
anorexia
lethargy
tendon reflexes decreased
limp muscles
orthostatic hypotension
stomach ache
seizures
