Flashcards in Lecture 7 Deck (37):
What are the type of problems in renal disease?
1. Generalised parenchymal.
2. Collecting system.
3. Focal lesions - masses in the kidneys.
Describe the clinical presentation of a generalised parenchymal renal disease?
1. Haematuria - leakage of blood.
2. Proteinuria - leakage of protein in the urine.
3. Acute nephritisis syndrome.
4. Nephrotic syndrome.
5. Chronic renal failure.
Describe the clinical problem of a generalised parenchymal renal disease?
Describe the clinical presentation of a collecting system renal disease?
3. Renal colic.
4. Chronic renal failure.
Describe the clinical problem of a collecting system renal disease?
2. Cause of obstruction.
Describe the clinical presentation of a focal lesions renal disease?
Describe the clinical problem of a focal lesions renal disease?
1. Exclude malignancy.
Describe glomerular function?
In terms of kidney failure think of it like a blocked filter - waste product is not being excreted into the urine. If there are problems with blood in the urine, think of it as a leaky urine.
What happens when there is a blocked filter?
Decreased GFR - could be acute kidney injury or chronic kidney disease.
Kidney handles 150L filtrate a day including 60-80g/L of protein. Normal humans have <150mg/24h urinary protein. the barriers to urinary protein:
1. Glomeruli - filters proteins.
2. Tubules - reabsorbs and degrades most of filtered protein.
Mainly lose albumin, lose other proteins in small amounts. The most formal way to measure this is to do a 24hr urine collect (most people don’t want to do this, so you can measure the albumin: creatinine ratio or protein: creatinine ratio).
Describe a leaky filter?
Leaking of blood or protein though the glomerulus. Kidney function may be normal. If you increase the pressure, you damage the filter more.
What is microalbuminuria?
30-300mg albumin in 24hours. and a 2.5-25mg/mmol of AC ratio indicates MA. Diabetes can cause MA.
What is nephrotic syndrome?
>3.5g/day urinary protein. There is low serum albumin and oedema. Their urine is frothy. There is hypercholesterolaemia and blood clots. When you’re leaking protein int he urine, kidney function maybe normal or impaired.
What is the mechanism for oedema?
There is increased a,cumin excretion. The liver can’t keep up. There is a reduction in oncotic pressure. There is egression of fluid into the interstitial space (trying to even up the hydrostatic and oncotic pressure between the blood vessels and the tissues).
Describe starling’s equation?
Flux = capillary permeability (intravascular hydrostatic pressure - interstitial hydrostatic pressure) - (intravascular oncotic pressure - interstitial oncotic pressure).
Describe capillary hydrostatic pressure?
It pushes fluid out of the vessel if it is high.
Describe capillary oncotic pressure?
It pulls fluid into vessel if it is high, it is derived from plasma proteins.
What happens in nephrotic syndrome?
There is low albumin, there is low oncotic pressure and high hydrostatic pressure. Water is pushed from intravascular compartment into the tissue (more water in the extravascular space). They have glomerular injury, so they leak protein. There is stimulation of the renin-angiotensin system, there is sodium and water retention, there is expansion of sodium and oedema.
What else goes wrong in nephrotic syndrome?
The low plasma oncotic pressure, the liver tries to play catch up so it increases lipoprotein, this will increase cholesterol production.
Increased risk of DVT, the leg will be painful and red and swollen. The clot can become an embolus and go to the lungs.
What also occurs in patients with nephrotic syndrome?
They are also at risk of infection. There is reduction of antibodies being produced and there is decreased complement pathway. There is an increase in bacterial infections and an increase in chicken pox in children.
What also occurs in patients with nephrotic syndrome?
There is also malnutrition
Describe renal function in nephrotic syndrome?
It can be normal, you can also have AKI or CKD.
Describe diabetic nephropathy?
When you have high blood glucose sugar levels, there is a high filtration rate (high GFR). If you do nothing, GFR decreases.
What happens if you have acute glomerulonephritis?
You have leakage as well as a blockage. They may leak blood and or protein. They may have nephritic syndrome (people become unwell, oliguric, hypertensive, volume overload, signs of other multi-system disease - haemoptysis, rash, arthritis, fever.
What is the difference between nephrotic syndrome and nephritic syndrome?
Nephritic = AKI, hypertension and RBC in urine.
Nephrotic = Oedema, proteinuria, renal function normal or impaired.
How do you treat proteinuria?
Need to find the cause of proteinuria. Generally need a kidney biopsy.
What is haematuria?
Any blood in the urine. It can be differentiated between microscopic blood in the urine or macroscopic blood in the urine. Microscopic is where you can only see RBC in the urine under a microscope. However, lots of blood in the urine, the urine will look red.
What are the origins of haematuria?
Bleed from somewhere in the urinary tract: glomerular, collecting system or focal lesion (tumour). [If there is blood in the urine need to make sure they don’t have cancer].
What is glomerular haematuria?
It is often microscopic. Often (not always) associated with proteinuria.
What is haematuria from the collecting system?
Haematuria from a tumour of kidney stone (quite common) are usually macroscopic, no/little proteinuria. People get very severe loin-groin pain (excruciating), the pain is colic (comes and goes). Sometimes people get vomiting and nausea, and if stones are bilateral you can get anuria.
How do you diagnose a kidney stone?
Radiologically - generally use CT. Sometimes pass people stones passively or get them removed surgically.
Describe focal lesions as a cause of haematuria?
Essentially a tumour - cause macro or microscopic haematuria. Often asymptomatic. Could have back-ache and mass. Cancers can happen anyway. In terms of renal cell carcinomas we diagnose them in terms of CT scans.
Describe renal cell carcinomas?
They account for 90% of renal cancer. The trio for male:female is 2:1, the peak age is 60yos. Aetiology is smoking, and there is genetic - von Hippel-Lindau disease (sporadic cases also have 3p abnormalities).
Describe renal cell carcinomas macroscopic?
There is a well circumscribed mass. Mottled red, yellow and brown mass. It is part cystic and it may invade the renal vein.
Describe the clinical features of a renal cell carcinoma?
The symptoms occur late. There may be haematuria (may be clots). There is flank pain. There can be a palpable abdominal mass. There is also ectopic hormone production:
4. Crushing’s syndrome.
5. Feminisation or masculinisation.