Renal failure

Question 1

What are the different management options for renal failure?

Answer 1

-Haemofiltration (quicker than dialysis)
-RRT (if GFR <10)
-Renal transplant
-Haemodialysis
-Peritoneal dialysis

Question 2

What are the complications of renal replacement therapies?

Answer 2

-Uraemia –> encephalopathy, pericarditis, coagulopathy
-Hyperkalaemia
-Fluid overload
-Metabolic acidosis

Question 3

What are the basic principles behind dialysis?

Answer 3

-Exists in 2 forms (haemo- and peritoneal)
-Aims to remove accumulated metabolic waste products and correct electrolyte imbalance
-Also removed excess fluids by means of ultrafiltration

Question 4

How does haemodialysis work?

Answer 4

-Solute-rich blood flows in opposite direction to dialysate, so they diffuse across to the dialysate
-Urea, creatinine and potassium are all removed this way
-If water is required to be cleared, pressure on blood side of the membrane must be increased to force fluid to the other side
-Arteriovenous fistula is created to create a larger vessel, enabling more regular puncturing

Question 5

How does peritoneal dialysis work?

Answer 5

-Sterile cleansing fluid is put into the stomach via a catheter
-Once filtering process is finished, fluid leaves via catheter

Question 6

What is the difference between haemofiltration and haemodialysis?

Answer 6

-Haemofiltration uses a positive pressure to drive water and solutes across the membrane instead of a dialysate
-Filtered fluid is discarded and replacement is added according to desired fluid balance
-Allows better control of blood pressure / less risk of hyperlipidaemia

Question 7

What are indications for dialysis on ICU?

Answer 7

-Diuretic-resistant pulmonary oedema
-Hyperkalaemia (refractory to treatment)
-Metabolic acidosis (refractory to treatment)