Week 4 - D - Presentation of kidney disease Flashcards
Why does kidney failure lead to hypertension?
This is due to the kidneys being unable to excrete urine and this therefore leads to a buld up in pressure and the blood pressure rises
What are urinary casts a really specific sign of?
These are a very specific sign that the haematuria/pyuria is originiating in the kidneys
If on urinalysis, there is proteinuria and haematuria, where do you think the problem has arisen?
In the kidneys (glomeruli)
Why can the kidneys causes secondary hyperparathyrodisim?
This is because the kidneys hydroxylate 25hydroxy vit D(calcidiol) to 1,25dihydroxyvitD (cacitriol) If the kidneys are not working, this can stop this and the vitamin D is required for calcium reabsorption in the gut The parathyroid hormone will sense the decreased calcium and therefore promote the excretion of more PTH Secondary parathyroid - means low calcium and high PTH
What is a major disease that can account for loss of kidney fnction?
Diabetes - can cause astheroscelrosis of the arteries decreasing perfusion and can increase glomeruloscelrosis causing the glomeruli to function less also
In relation to loss of renal fucntion, what can patients often complain of?
Tiredness, fluid retention, bone pain anaemia
Why is there bone pain associated with a loss of renal function? Why is there anaemia (renal anaemia) associated with a loss of renal function?
Bone pain - due to the decreased calcium absorption, PTH resorbs more bone to make up calcium levels and this causes weak bone Renal anaemia - kidneys produce erythropoeitin, this is a hormone which stimulates the formation of red blood cells in the bone marrow - loss of renal function stops this being produced
What are the urinary questions asked in a systemic enquiry for renal?
Ask about, pain or burning when peeing, any loin pain or masses, any problems with emptying bladder ie flow of stream problems, polyuri, oligouria , nocturia
In taking a renal history, it is important to know past medical history What types of imaging can be damaging to the kdiney?
CT and MRI imaging CT contrast (iodinated) causes contrast induced nephropathy MRI contrast (gadolinium) causes nephrogenic systemic sclerosis
Asking about drugs is also important What drugs are nephrotoxic? STOP NEPHROTXINS IN AKI & CKD
Aminoglycosides - gentamicin Penicillins Analgesics - NSAIDs PPIs, loops and ACE inhibitors
What drug used to treat UTIs can be nephrotoxic to the kidneys?
Sulfonamides such as sulfamethoxazole (given in the community to treat complicated UTIs)
Why are NSAIDs contraindicated in renal impairment?
They inhibit the COX1&2 therefore preventing the formation of prostoglandins which dilate the afferent arteriole This therefore causes vasconstriction leading to decreased GFR
What is hypertension known as?
A blood pressure greater than 140/90 - Most patinets with CKD have HBP
When is high blood pressure a medical emergency? What are symptoms?
This is accelerated/malignant hypertension - systolic over 180 and diastolic over 120 Causes blurred vision, headaches, can be nauseas and vomiting
Acclerated hypertension can cause swelling of the optic disc What does the fundus of the eye look like in accelerated hypertension?
Swollen optic Loss of disc margins Flame haemorrhages Cotton wool patches Can have the silver/copper wiring of the vessels
How can renal failure end up causing gout tophi?
There will be a decreased uric acid excretion from the kidneys This will lead to a build up of uric acid which is converted to monosodium urate crystals which are small and sharp and can inflame the joint A build up of these crystals is known as gout tophi
What does this child have?
Child has Henoch Schnolein Purpura
What type of glomerulonephritis is HSP associated with? How does HSP present?
Associated with IgA nephropathy Healthy child experiences palpable purpuric rash on the buttocks and extremities 2weeks post upper rep tract infection Also has abdominal pain, sore joints and haematuria
How is HSP treated?
Is generally self limiting so analgesics and supportive care Can give oral steroids if severe
Patient presents with haematuria and heamoptysis What do you think? If they have a rash on their face like a butterfly?
ANCA related or anti-GBM Butterfly rash - malar flush so measure ANA as you are thinking SLE
When doing urinalysis, what things are important to look for?
Specific gravity Leucocytes Nitrites Red blood cell pH - usually alkaline if a renal impairent preventing acid excretion Proteinuria
What should the pH of the urine be between? Which UTI causing organism does not actually show for the presence of nitrites?
Should be between 4.5-7 Enterococcus doesnt show the presence of nitrites in the urine
If there is protein in the urine, this suggests a kindey problem What syndrome can it point towards and what does the protein in the urine level have to be? (how is this measured)
Indicates nephrotic syndrome 24 hour protein collection - greater than 3g/day Protein/creatinine ratio - greater than 300-350mg/mmol
What is a normal urine 24 hour protein count? What is a normal urine protein/creatinine ratio?
24hour protein - normal for <150mg PCR normal - less 50mg/mmol
Urine microscopy can be carried out to look for any organisms and to look at red cells What are dysmorphic and isomorphic red blood cells on urine microscopy?
B - Dysmorphic -likely to have come through the glomerulus as they are squashed - pathology A - Isomorphic - lower urinary tract bleed
If there is a presence of urinary casts on microscopy, this is highly suggestive that the haematuria/pyuria originates where?
Glomerular or tubular origin
Urinary casts are formed by precipitation of Tamm-Horsfall mucoprotein which is secreted by renal tubule cells. What are the four types of urinary casts?
Hyaline Leucocyte Red cell Granular
For urinary casts, which is usually benign and which is usually associated with nephritic syndrome?
Hyaline casts - usually benign Red cell casts - nephritic syndrome
What do leucocyte and granular casts indicated?
C - Leucocyte casts - indicate infection
D - Granular casts - indicate chronic kidney disease, acute tubular necorosis
A - hyaline
B - red cell
What type of urinary casts is pathognomonic of acute tubular necrosis?
This would be a muddy brown granular cast
What forms the urinary casts in disease states?
Foromed by the precipitation of Tamm Horsfall mucoproteins which is secreted by the tubular cell
o Crystals on urine microscopy Looks for the cause of the renal stones What are the types of crystals?
Calcium oxalate Uric acid Phosphate (aka triple phosphate = struvite) Cystein
Which urine microscopy crystals are envelope shaped? Which are hexagonal shaped?
A - envelope - calcium oxalate B - uric acid (messy shapes) C - Phopshate D - hexoagnoal shaped - cysteine
What are the five stages of chronic kidney disease?
Stage 1 - GFR greater than 90 with evidence of kidney damage Stage 2 - GFR 60-90 with evidence of kidney damage Stage 3 - GFR 30-60 Stage 4 - GFR 15-30 Stage 5 - GFR <15 or on dialysis
What is seen as evidence of kidney damage?
Hameturia + proteinuria
What is acute kidney injury defined as?
• Rise in serum creatinine >26.4 µmol/l in 48 hours • Or increase in serum creatinine by >50% over 7 days • Or urine output 6 consecutive hours (<400ml urine output/day)
Describe the features of nephrotic syndrome?
Proteinuria - greater than 3g/day Hypoalbuminaemia Oedema - swelling affects everywhere Hyperlipidaemia also Frothy urine in a patinet due to the protein
What are the feautures of nephritic syndrome?
Oliguria Hypertension Oedema Haematuria + can have a little proteinuria
What is seen in the active urinary sediment?
red cell casts
If patinet has an abornaml urinalysis, what should you carry out also? (using stehtascope)
Carry out a blood pressure reading to make sure there is no increased or decreased BP
