Medicine - Renal Flashcards
What are the 2 main types of dialysis?
Haemodialysis
Peritoneal dialysis
What is required for haemodialysis?
- Dialysis machine (patient’s blood is pumped OUTSIDE the body and through this machine)
- Vascular access is required via an AV fistula (longterm), or a temporary CVC
What happens inside a haemodialysis machine (broadly)?
Blood flows through tiny semi-permeable tubes surrounded by a dialysis solution (dialysate)
Filtration occurs via osmosis and diffusion - dialysis fluid contains solutes at a similar level to the level they would be in a healthy patient’s blood
Can add bicarbonate (to combat acidosis), EPO and drugs if needed
Heparin always added
How often should haemodialysis be performed?
4 hour treatment 3 times per week
What are the 3 main possible complications of dialysis
- Blood infection (more common in peritoneal dialysis)
- Thrombosis
- Internal bleeding (due to added heparin)
What is peritoneal dialysis?
Dialysis fluid is introduced into the patient’s abdominal cavity for several hours, and the peritoneum serves as the natural filter
Can be done automatically at night during sleep
Recall some pros of peritoneal dilaysis
- Offers more flexibility (can be done overnight)
- Is better tolerated by patients
- Less expensive
What is a tesio line?
- Tunneled dual lumen central line
- Used as a ‘bridge’ before an AV fistula can be put in
- One lumen enters the right atrium, the other
sits outside the RA in the vena cava - Both lumens exit the body (with a central line, only 1 lumen enters the skin)
Why is a normal vein unsuitable for haemodialysis, and why is an AV fistula used?
Normal vein would easily collapse/ thrombose with recurrent venepuncture
Vein in an AV fistula hypertrophies in response to turbulent flow of blood from artery and so can withstand repeated venepuncture
Recall some contra-indications to renal biopsy in acute renal failure
- Obvious pre or post renal cause (these are contra-indications)
- Significant coagulopathy
- Infection at the site
What group of diseases is the most common cause of nephritic syndrome?
Proliferative glomerulonephritis
Recall 5 causes of the nephrotic syndrome
Amyloidosis
Diabetes
Focal segmental glomerulosclerosis
Membranous glomerulonephritis
Minimal change disease
What are the most common causes of AKI?
Remember STOP:
- Sepsis/dehydration
- Toxins (NSAIDs, nephrotoxic drugs),
- Obstruction in the urinary tract
- Parenchymal kidney disease
What are the most common causes of CKD?
Diabetic nephropathy
Hypertensive nephropathy
What are the primary functions of the kidney?
Balance:
- Water
- Electrolyte
- Acid-base
Endocrine:
- erythropoietin
- vit D activation
- renin-angiotensin system
- BP control
Excretion:
- Waste
- Metabolites
What symptoms might you expect from someone with CKD?
Fluid overload (pedal oedema, pleural effusion, ascites, tiredness)
Anaemia (SOB, tiredness, LoC, headcaches)
Hyperkalaemia (palpitations, cardiac arrest, asymptomatic)
Uremia (pruritis, confusion, pericarditis, encephalopathy)
Acidosis (nausea, vomiting,
tiredness)
Increased drug action (e.g. opioid side effects)
Reduced urine output
What diet should be followed in patients with very low creatinine clearance?
Low phosphate
(eg. avoid chocolate, shellfish, nuts)
Low potassium (avoiding chocolate, bananas etc)
Fluid restricted (avoiding alcohol, avoid too much tea/coffee)
Low salt (avoiding processed foods)
Can take phosphate binders if diet restriction alone doesn’t succeed