Renal Medicine Flashcards
Define AKI and what determines diagnosis?
A sudden decline in renal function significant to produce uraemia and often oliguria (500umol/L
Normal U&E levels
Na : 135-145 mmol/L K : 3.5-5 mmol/L Creatinine : 70-150 umol/L Urea : 2.5-6.7 mmol/L eGFR : >90
RIFLE criteria
RISK - SCr raised 1.5/2 x baseline or GFR decreased >25%. Also urine output
INJURY - SCr raised 2/3 x baseline or GFR decreased >50%. Also urine output 3 x baseline or GFR decreased >75%. Also urine output 4 weeks therefore requiring dialysis
ESRF - failure >3 months. Dialysis required
Nephrotoxic Drugs
Diuretics
NSAIDS (dilate efferent arteriole)
ACEi (dilation of efferent & afferent)
(commonest)
All cause pre-renal failure with NSAIDS also causing ATN.
Aminoglycosides Cephalosporins Cocaine Lithium Penicillins Valporate (less common)
How do you assess fluid status?
Clinically -
BP (esp postural) Oedema JVP Peripheral perfusion (cap. refill) Pulse Basal crackles (pulmonary oedema) (*most useful*)
Skin turgor
Sunken eyes
Mucous membranes
(less useful)
Define nephrotic syndrome
Hypoalbuminaemia
Oedema
Proteinuria
Commonest cause of nephrotic syndrome (children vs adults)
Children - minimal change (nothing seen on light microscopy but on electron microscopy podocyte effacement seen)
Adults - Membranous (or FSGS or diabetes)
Define nephritic syndrome
Haematuria
Hypertension
Uraemia
RBC casts form (ie ‘casts’ of the tubule made from clotted blood) giving urine smoky colour
Causes of nephritic syndrome
(two classic Dxes)
Post - strep glomerulonephritis (weeks post-URTI)
Rapidly progressive glomerulonephritis (crescentic)
Goodpastures (anti-GBM)
Vaculitic (Wegner’s p/c ANCA)
IgA nephropathy (1/2 days post-URTI)
SLE
Hep B/C
Vasculitis (Henoch-Schonlein purpura)
Treatment of hyperkalaemia
Calcium Gluconate 10ml 10% Glucose and Insulin Salbutamol neb Calcium Resonium Possible dialysis?
ECG changes in hyperkalaemia
Peaked T waves (usually the earliest sign of hyperkalaemia)
P wave widens and flattens
PR segment lengthens
P waves eventually disappear
Prolonged QRS
sine wave appearance
Asystole
Ventricular fibrillation
PEA
Causes of hyperkalaemia
Renal (Failure and K+ sparing diuretics) Metabolic Acidosis Addisons Drugs (ACEi, B-Blockers, NSAIDS) Rhabdomyolysis
Post-surgery causes of reduced UO
Radio-contrast (Nephrotoxic) Anaesthetic agents Blood Loss (hypovolaemia) Age If vasculopath then atherosclerosis of kidney vessels Nil by mouth for surgery
Features of a sick AKI patient
Tachycardia Hypotension Oliguria Metabolic Acidosis Hypoxamia Peripheral shutdown
Possible tests in AKI
ECG (K+) Inflam markers Imaging (Ultrasound/CT) Urine Dip (Protein, blood) Microscopy Immunology U&Es and repeat ABG Bone Profile FBC Cultures LFTs
‘Red flags’ in renal disease hx/examn
Acute on chronic or acute? Renal tract obstruction Hypovolaemia Vascular occlusion - bruits? Extra-renal involvement
When should you stop and ACEi due to decreasing renal function?
NICE guidelines suggest if <30% raise in Cr then repeat test in 2 weeks
Post-surgical op, a patient develops incontinence. What is the first thing to do?
Examine the abdomen for distended bladder
What is a delayed nephrogram?
When contrast remains in a kidney for longer than a few minutes following a KUB study
What are the indications for an acute haemodyalisis?
Hyperkalaemia (RESISTANT)
Uraemia (pericarditis)
Severe acidosis
Pulmonary oedema
Following catheter insertion in an obstructed bladder, what piece of management should you initiate?
IV fluids - following obstruction, the kidneys kick start again and produce over a litre of urine meaning fluids are required for euvolaemia.
What biochemical tests are altered by CKD?
Increase ALP, anaemia and normal K+
What mechanism caused renal osteodystrophy?
CKD -> Decreased phosphate extcretion-> Increase phosphate and decreased calcium -> Increase PTH production -> Renal osteodystrophy
Bone pain, deformation and fracture
What is the commonest cause of macroscopic haematuria (esp prevalent in young men)?
IgA nephropathy - classically this occurs in responce to a (throat) infection
What are some of the common risk factors of kidney disease?
HTN Diabetes CV disease Structural renal disease Multisystem disease with renal involvement Metabolic Syndrome
What is nephritic syndrome?
Haematurea, proteinurea, HTN, oligurea
with rising urea and creatinine
(E.g. post-strep glomerulonephritis)
What should you always consider when faced with a young patient with proteinurea?
Vasculitis - ask about nosebleeds, joint pain, eye pain, rashes
In someone with poorly purfused kidneys, what dangerous side effect can metformin have?
Lactic acidosis - preform urgent ABG. Expect Kussmaul breathing
What are the classic SLE symptoms and how can the kidneys become involved?
Young woman with joint pain and mouth ulcers.
SLE can result in nephritis resulting in proteinurea via glomerular damage.
Treatment of SLE nephritis?
Threefold:
- decrease proteinurea with ACEi
- Manage HTN
- Slow renal disease with immunosupresion (steroids +/- cyclophosphamide)
What should you be trying to rule out is a patient presents with AKI?
Common causes - hypovolaemia and distal obstruction
Even if the bladder is not palpable then check for a more proximal obstruction with a USS of the bladder and kidneys
Increased VTE risk in nephrotic syndome?
Loss of clotting factors in urine (PTIII)
Acture tubular necrosis
Worsening renal function with muddy brown casts
Underlying aetiology
Features of renal cell carcinoma
Triad of haematuria, loin pain, abdo. mass
PUO
L. Varicocele from occlusion of l testicular vein
Commonest post transplant infeciton
CMV
Management of contrast in CKD3
IV 0.9% saline pre- and post-procedure
Screening for ADPKD
US
Mechanism of renal osteodystrophy
Secondary hyperparathyroidism
Worsening renal function results in decreased vit d conversion to active form. Dereased secretion of phosphate.
Hypocalcaemia therefore results
Increased PTH -> increased osteoclastic activity -> OD
