Nephrology Flashcards
List examples of loop diuretics
furosemide, bumetanide
How do loop diuretics work?
inhibit the Na/K/Cl co transporter in the loop of henle so reduce the absorption of NaCl
What are the adverse effects of loop diuretics?
hypokalaemia, hypomagnesaemia, hypocalcaemia, hyponatraemia
hypotension
gout
List examples of thiazide diuretics
indapamide , bendroflumethiazide
How do thiazide diuretics work?
inhibit the sodium reabsorption in the distal convoluted tubule by blocked Na/Cl symporter
What are the adverse effects of thiazide diuretics?
dehydration hyponatraemia, hypokalaemia gout postural hypotension impaired glucose tolerance
List examples of potassium sparing diuretics and how they work
sodium channel blockers -> amiloride
aldosterone antagonists at the mineralocorticoid receptor at the DCT -> spironolactone
What are the adverse effects of potassium sparing diuretics?
dizziness
malaise
AKI
hyperkalaemia *
What is creatinine?
product of muscle metabolism and measure of kidney function
Where does sodium reabsorption occur?
70% - proximal tubule
25% - loop of henle
5% - DCT
Describe how blood pressure is controlled by the kidney?
- low blood pressure detected by the afferent arteriole in the kidney
- juxtaglomerular apparatus activated
- kidney secretes renin
- renin converts angiotensinogen to angiotensin 1
- ACE converts angiotensin 1 to angiotensin 2
- activates aldosterone in the adrenal glands to stimulate reabsorption of salt and water
- acts directly on blood vessels to cause vasoconstriction
- results in rise in blood pressure
List the 5 functions of the kidney
- remove waste products in the urine (e.g. drugs, toxins, products of metabolism)
- regulates water in body and blood pressure
- produces EPO for RBC production
- activates vitamin D into 1- hydroxy- vitamin D
- acid base balance (removes H+ and absorbs HCO3)
Define AKI?
acute insult in GFR from baseline, increase in creatinine +/- oliguria (<0.5 ml/kg/hr)
List the pre renal causes of AKI
= problems in other major organs causing impaired renal perfusion
renal artery stenosis heart failure sepsis ischaemia hypovolaemia e.g. vomiting, diarrhoea hypotension hepatorenal syndrome
List the intrinsic causes of AKI
= damage to the glomeruli, renal tubules or interstitium of the kidneys
glomerulonephritis acute tubular necrosis toxins and drugs interstitial nephritis IgA nephropathy tumour lysis syndrome rhabdomyolysis
List the post renal causes of AKI
= problems after the kidneys e.g. obstruction to urine coming from kidneys
INTRINSIC - stones, tumour, pyelonephritis
EXTRINSIC - BPH, tumour, retroperitoneal fibrosis
Which drugs are nephrotoxic and can cause an AKI
NSAIDS ACE-I ARBs gentamicin diuretics omeprazole anti fungals rifampicin radio iodine contrast lithium
List the risk factors for an AKI
elderly drugs and toxins IV contrast organ dysfunction e.g. liver disease, CKD, heart failure, diabetes multiple myeloma
How does AKI present?
often asymptomatic and found on bloods but can cause…
reduced urine output (<0.5 ml/kg/hr) **
nausea and vomiting
peripheral oedema
uraemia signs
What is the criteria for an AKI?
** rise in creatinine >26mmol/l in 48 hrs **
How is an AKI staged?
stage 1 =
1.5- 1.9 X baseline creatinine OR
UO <0.5 ml/kg/hr for 6-12 hours
stage 2 =
2-2.9 x baseline creatinine
UO <0.5 ml/lg/hr for >12 hours
stage 3 = 3 x baseline creatinine
UO <0.3 ml/kg/hr for >24 hrs
How is AKI diagnosed and investigated?
U&E
Creatinine elevated (normal 0.7 -1.2 mg/dL) - not best early indicator as wont change until next day so measure UO
high serum potassium
metabolic acidosis
** renal ultrasound **
do 24 hrs after AKI if dont know cause
find the cause…
urine dip and urinanalysis, FBC, ECG, blood cultures, vasculitis screen, renal biopsy
How is AKI managed?
- ABCDE - fluids
- review medication
stop nephrotoxic drugs or renally excreted drugs - monitor urine output - catheterise
- treat hyperkalaemia
- if not responding, RRT
When is RRT indicated in AKI?
uraemia no urine output and fluid overload severe resistent hyperkalaemia severe metabolic acidosis overdose of lithium
Which drugs are renally excreted and should be stopped in AKI to prevent toxicity?
metformin
lithium
digoxin
opioids e.g. codeine, tramadol
Define CKD
> 3 months of proteinuria or haematuria +/- reduction in GFR to <60ml/min/1.73m^2
What are the causes of CKD?
Diabetic nephropathy **
hypertension *
renal vascular disease*
+
glomerulonephritis (nephrotic/ nephritic) - focal segmental glomerulosclerosis, membranous nephropathy, lupus nephritis, amyloidosis
PKD
obstructive uropathy e.g. myeloma, renal tumour
what are the symptoms of CKD?
extreme fatigue ** weakness * peripheral oedema ** pruritus anorexia / weight gain / poor appetite
What are the complications of CKD?
anaemia ** (reduced EPO and iron deficiency)
renal osteodystrophy (due to decreased phosphate excretion)
CV disease
hyperkalaemia
pulmonary oedema
metabolic acidosis
secondary hyperparathyroidism
Why do pts get anaemia in CKD?
Lack of EPO produced by kidneys + iron deficiency
What are the stages of CKD?
STAGE 1 - eGFR >90
STAGE 2 - eGFR 60-89
STAGE 3a - eGFR 45-59
STAGE 3b - eGFR 30-44
STAGE 4- eGFR 15-29
STAGE 5 - eGFR <15 (start RRT)
How is the eGFR calculated?
estimate of renal function using a formula that calculates it by:
- creatinine
- age
- ethnicity
- gender
How is CKD investigated?
- serum creatinine
- renal USS
- eGFR <60
- urine albumin creatinine ratio (proteinuria) HIGH
How is CKD managed?
- find the cause -> control diabetes, statins, weight loss, smoking cessation
- manage HTN -> ACE-I with target <130/90
- manage anaemia -> epoitin alfa + ferrous sulphate (side effects of EPO = urticaria, HTN, bone aches)
- manage oedema -> loop diuretic, restrict salt
- manage renal bone disease -> vit D, calcium rich diet
- RRT if stage 5 (5-7 eGFR) or palliative care
What are the options in renal replacement therapy?
- haemodialysis
- peritoneal dialysis
- renal transplant
Who is haemodialysis most suitable for?
elderly, frail, if unsuitable for surgery or at home dialysis (most common for)
How can you maximise your kidney function before starting haemodialysis?
smoking cessation manage HTN good glycemic control in diabetics salt restriction activated VIT D supplement weight loss
how does haemodialysis work?
- blood removed from AV fistula on the arterial side
- blood enters dialyzser
- dalteparin added to prevent clots
- blood passed over semi permeable membrane against dialysis fluid - small solutes diffuse across along conc gradient and waste products diffuse out
- blood travels through venous pressure monitor and air detector
- waste products in dialysis fluid removed
- clean purified blood returned to vein in AV fistula
Where do they get access for haemodialysis?
via arterio-venous fistula **
created 8 weeks before start dialysis
What are the adverse effects of an AV fistula?
bulging veins
cold hands
gangrene
heart failure
What is the regimen for haemodialysis?
3 x a week at the hospital for 4 hours at a time
OR 5 x per week for 2-3 hours at home
How do patients feel after haemodialsysi?
tired, hypotensive, dizzy, unwell, sweaty
What are the short and long term complications of haemodialysis?
access complications e.g. infection, thrombus, endocarditis
no urine output
fluid restrictions e.g. 500ml-1L a day
feel unwell: nausea, vomiting, headache, tired
pyschosocial impact and lifestyle change
hyperparathyroidism
cardiac arrhythmias
Who is peritoneal dialysis suitable for?
young, independent, lack of access to healthcare, eGFR 11-12
How does peritoneal dialysis work?
- dialysate fluid infused into peritoneal cavity via catheter
- high dextrose conc solutions draws water via osmosis and waste products via diffusion from the blood into the abdo cavity via peritoneum
- after several hours of dwell time, dialysis solution drained and remove waste products from body
- exchange for new dialysis solution
What is the regimen for peritoneal dialysis?
- CONTINUOUS AMBULATORY PERITONEAL DIALYSIS - each exchange 30 mins and dwell time 4-8 hours, pt can go about normal activities during that time
- AUTOMATED PERITONEAL DIALYSIS
3-5 exchanges over 8-10 hours overnight when pt asleep
What are the contraindications for peritoneal dialysis?
abdo adhesions previous mutliple abdo surgery stoma obesity intestinal disease
What are the complications of peritoneal dialysis?
- peritonitis **
- catheter problems e.g. infection, leak, blockages
- constipation
- weight gain, fluid retention
- hernia
When would you suspect peritonitis in PD?
cloudy PD effluent
abdo pain
fever
tenderness
How is peritonitis in PD pts treated?
gentamicin or vancomycin
What are the advantages of kidney transplants?
increased survival
enable pregnancy
reverse SE e.g. anaemia, renal bone disease
increased quality of life
Who are kidney transplants suitable for?
young, fit patients that still have 5 years of good quality of life after transplant
What are the 2 types of kidney transplant?
- cadaveric ** - 10-12 years lifespan
2. living donor- 12-15 years lifespan
What are the disadvantages of kidney transplant?
long waiting time (>3 years wait)
technical - difficulty storing and retrieving
rejection
disease recurrence
operation complications e.g. infection, pain, DVT
side effects of immunosuppression: skin cancer, infection
What do the pts need to match to receive a kidney transplant?
- ABO blood group
- HLA tissue match
- antibody screening
Describe the procedure for a kidney transplant?
- induction with basiliximab and IV methylpred
- surgery - donor kidney transplanted into the groin connecting to the external iliac veins
- long term immunosuppression - increases risk of skin cancer and CMV
Which medication for immunosupression are pts on after a kidney transplant?
- prednisolone
- calcineurin inhibitors e.g. tacrolimus, ciclosporin
- azathioprine
What are the 4 types of rejection after a kidney transplant?
- HYPERACUTE (mins)
- ACCELERATED (days) -> fever, swollen kidney, rising creatinine
- ACUTE CELLULAR (weeks) -> fluid retention, rising BP, rising creatinine
- CHRONIC (years) -> graft biopsy shows fibrosis, atrophy and vascular changes
acute <6 months
chronic >6 months
What type of cancer is common in Renal cell carcinoma?
adenocarcinoma from the proximal tubule epithelium (COMMONLY CLEAR CELL)
What are the possible risk factors for RCC?
smoking * hypertension * irradiation FH Von Hippel Lindau disease obesity renal transplant and dialysis
How does RCC present?
TRIAD OF:
- haematuria
- loin pain
- abdominal mass
+ weight loss, malaise, anorexia, L varicocele (compresses the L testicular vein)
How can RCC spread?
25% have mets at presentation
LOCAL -> Renal vein
LYMPH -> to para aortic and hilar lymph nodes (cause CANON BALL LUNG METS)
BLOOD -> bone, liver, lung
How is RCC diagnosed?
- BP rise (renin secretion from tumour)
- urine microscopy and culture - haematuria
- FBC, ESR, U&E - polycythaemia (EPO secretion from tumour), raised ESR
- ULtrasound or CT
How is RCC managed?
- radical nephrectomy
2. biological therapies e.g. sunitib (tyrosine kinase inhibitors)
How is RCC staged using TNM?
T1 - confined to kidney and <7 cm
T2 - confined to kidney and >7cm
T3 - major veins or adrenals
T4 - beyond gerota fascia
Which bacteria causes pyelonephritis?
E.coli **
klebsiella
proteus
(bacteria ascends from lower urinary tract or spreads haematogenously)
What are the risk factors for pyelonephritis?
- age - elderly, young
- foreign bodies - catheter, cystoscopy, stones
- anatomical variants - PKD, horseshoe kidney, double ureter
- obstruction- BPH, stones, neurogenic bladder, bladder neck obstruction
- immunocompromised - diabetes, transplant pts, HIV, alcohol
- male sex
- pregnancy
How does pyelonephritis present?
- loin pain
- fever
- renal tenderness
+ malaise, UTI symptoms (dysuria, increased urgency and frequency), rigors, nausea and vomiting
What are the complications of pyelonephritis?
urosepsis renal failure abscess formation parenchymal renal scarring (look for hydronephrosis on USS) recurrent UTIs
How is pyelonephritis investigated?
- urine dipstick + midstream urinanalysis and MC&S - +ve WBC, RBC, gram stain
- septic screen - FBC, U&E, LFT, blood culture, ESR/CRP, ABG
- renal ultrasound and contrast CT
How is pyelonephritis managed?
- IV ciprofloxacin 500mg (amoxicillin/ cefalexin for pregnancy)
- IV fluids
- IV paracetemol
List the causes of hyperkalaemia
renal - AKI, CKD, renal tubular acidosis
drugs - potassium sparing diuretics, ACE-I, ARBs, NSAIDS, ciclosporin, beta blockers
metabolic acidosis
rhabdomyolysis
blood transfusion
Addisons
diet - banana, kiwi, orange, avocado
How does hyperkalaemia present?
weakness and fatigue
flaccid paralysis
arrhythmias and chest pain
depressed tendon reflexes
How would you investigate hyperkalaemia?
- 12 lead ECG
- ABG - metabolic acidosis
- U&E - high serum K
- review medication
What changes would you see on ECG in hyperkalaemia?
tall tented T waves
loss of p waves
wide QRS
VF!!!
How is hyperkalaemia managed?
- ABCDE and 12 lead ECG
- IV 10ml of 10% calcium gluconate - stabilises cardiac membrane (give up to 4 doses)
- insulin / 10% dextrose infusion of 250ml over 15 mins (shifts K to intracellular compartment)
- nebulised salbutamol
How can polycystic kidney disease be inherited?
- AUTOSOMAL DOMINANT - more common
2. autosomal recessive - less common
What happens in autosomal recessive PKD and how does it present?
defect in chromosome 6 encoding fibrocystin (needed fro renal tubule development)
detected on prenatal USS or early infancy
presents as potter syndrome or end stage renal failure
What are the 2 types of autosomal dominant PKD?
ADPKD 1 -> chromosome 16 encoding polycystin 1 **
ADPKD 2 -> chromsome 4 encoding polycystin 2
What does polycystin (the defect in ADPKD) do and how does it cause pathology?
polycystin 1 and 2 combine to make a protein complex in calcium regulation at actin and intermediate filaments
- > disruption of polycystin causes imapired cell signalling and causes proliferation
- > there is cyst expansion by fluid secretion
- > cysts compress normal architecture and intrarenal vasculature
- > leads to interstitial fibrosis and tubular atrophy
How does AD PKD present?
abdo discomfort **
haematuria
hypertension **
+ palpable kidneys, hepatomegaly, UTI
What are the possible complications of AD PKD?
CKD end stage renal failure SAH hypertension hepatomegaly* (due to liver cysts) mitral valve prolapse
How is AD PKD diagnosed?
abdominal ultrasound and need:
- 2 cysts unilateral or bilateral if <30 y/o
- 2 cysts in both kidneys if 30-60 y/o
- 4 cysts in both kidneys if >60 y/o
+ genetic testing
What is important to do in PKD?
family testing !! screen for SAH and HTN
HOW is PKD managed?
- HTN -> ACE-I / ARB for life
- for ESRF -> RRT
- to slow progression -> tolvaptan (vasopressin receptor 2 antagonist)
What are the causes of nephrotic syndrome?
Minimal change disease (children *)
focal segmental glomerulosclerosis (younger adults)
membranous glomerulonephritis (older adults)
amyloidosis
diabetic nephropathy
What is the triad for nephrotic syndrome?
- peripheral oedema
- proteinuria
- hypoalbuminaemia
what are the complications of nephrotic?
hyperlipidaemia
increased risk of thrombosis (renal vein thrombosis) -> loss of anti thrombin, protein C/S
increased risk of infection -> loss of IgG
hypocalcaemia -> vit D and albumin lost in urine
AKI
How is nephrotic syndrome managed?
- find cause (renal biopsy = definitive **) and treat
- anti coagulant
- steroids
- penicillin prophylaxis and pneumococcal vaccination
- fluid restrict, restrict salt
- statin
How is nephritic syndrome caused?
IgA nephropathy (Bergers disease) - post URTI
Alport syndrome
Goodpastures syndrome
vasculitis - wegeners, polyangitis
What are the clinical features of nephritic syndrome?
- haematuria
- hypertension
- AKI
+ proteinuria, malaise, weight loss, fever, skin rash, abdo pain
How is nephritic syndrome managed?
IV prednisolone
What are the signs of uraemia?
altered mental state
pericarditis
arrhythmias
itch
List the signs of rhabdomyolysis
tea coloured urine (myoglobin in urine)
confused
List the signs O/E of CKD?
pallor peripheral oedema hypertension brusing uraemia tinge excoration
list the side effects of ACE-I
dry cough nephrotoxic - cause AKI hypotension hyperkalaemia urticaria
How does rhabdomyolysis cause AKI?
breakdown of skeletal muscle causes release of creatinine kinase - causes acute tubular necrosis and creatinine obstructs tubercles
List the causes of rhabdomyolysis?
fall/ prolonged lying excessive exercise crush injuries burn drugs e.g. statin neuroleptic malignant syndrome seizures
what is found in the urine in rhabdomyolysis?
urinary myoglobin
what is the microscopy of the urine in rhabdomyolysis?
muddy brown granular casts
what is found on histology of IgA nephropathy?
mesangial proliferation
IgA deposits
C3 deposits
