L6. Clinical renal failure Flashcards
What is kidney/renal failure
Reduction in kidney function: Glomerular filtration rate below 90 ml/min. This can be acute or chronic.
What are the main signs of kidney failure
Vomiting, loss of appetite, Hypertension–> oedema/chest pain,
- Blood tests: Elevated Creatinine from muscle and Urea
- GFR which can be accurately measured from insulin clearance, Cr-EDTA clearance which are impractical for everyday clinical use so eGFR is using plasma creatinine
How does weight, age, gender, race affect eGFR
Weight: allows estimation of muscle mass but not as accurate
Age: associated with reduction in muscle mass and nephrons
Gender: Male muscle mass>female. female more stable muscle mass.
Ethnicity: african american 1st
How does eGFR: estimated glomerular filtration rate compared to GFR
It is a surrogate measure for how much muscle waste product is produced as well as how well the kidney gets rid of the waste but GFR is more accurate because it accounts for muscle mass ie. same eGFR can have different GFR
Similarities and differences of acute and chronic renal failure
Both have high creatinine/urea and low GFR.
Acute kidney injury is rapid reduction in GFR over days/weeks usually reversible and mostly due to external problem.Leads to reduced urine output
Chronic kidney disease: Gradual decline in renal function over months/years which is irreversible, usually normal urine output
What are the 3 types of acute renal failure
Pre-renal, renal , post-renal
What are the common causes of pre-renal kidney failure, blood test results and treatment
Most common
Caused by absolute or relative loss of fluid in the plasma. Low BP= not enough blood to the kidneys
Could be due to sepsis, cardiogenic shock, haemorrage/dehydration
- Generally urine output is low <1 L/day
Blood tests: Hyperkalaemia, high phosphate, may be low Ca2+ - Treated by fixing the underlying problem, but depending on how long there can be some acute tubular necrosis
What is the treatment of Acute Tubular Necrosis after correction of underlying pre-renal condition or due to drugs, toxins and what is the treatment
Requiring 4-6 weeks for recovery. Same signs as pre-renal failure.
Treated by trying to maintain normal BP and treating underlying problem. If GFR <10ml/min Dialysis.
Those recovering can have a Polyuric phase: tubules can’t concentrate urine so make 20L of urine/day and need IV fluid replacement until recovery.
What is Rapidly progressive glomerulonephritis? presentation and diagnosis
Acute renal injury due to glomerular disease- acute inflammation.
Usually presents with blood and or other protein in the urine.
It is diagnosed by renal biopsy
What are the common causes of post-renal kidney failure, and treatment
Most common
It is blockage of the outflow of the kidneys: blockage/compression of ureter, bladder neck or urethra.
This can be due to stones, tumour, prostate hypertrophy or urinary retention
Causes a backflow of urine causing hydronephrosis.
Treated by addressing the underlying cause
What are the common causes of Chronic kidney disease, blood test and treatment
Scarring of the glomeruli and interstitium. Commonly caused by Diabetes, glomerulonephritis and hypertension etc
Diagnosed by BT: gradual elevation creatinine, urea but normal urine output. Hb low
Early symptoms: hypertension- oedema, raised JVP,
until uraemia,
Treated by delaying the progression, control complications by controlling BP to preserve kidney function- <130/80 w ACE inhibitors.
What is Uraemia
Symptoms that signal kidney failure
- anorexia, nausea, vomiting
- itchiness
- ShortOB
- Cold intolerance
- Swelling
- Seizures
- Coma
What do the stages of chronic kidney disease tell us
At different stages, there are different associated conditions- more when severe
How and why are there associated complications of chronic kidney disease
- Low Hb due to insufficient Erythropoietin- produced by kidney
- Renal osteodystrophy: insufficient 1-hydroxylase produced by kidney which converts Vit D to active form for absorption of Ca2+ and phosphate.
- High serum phosphate: excreting less phosphate in urine causes
- High serum K+: cardiac arrhythmias.
