Lecture 18: Clinical problem solving: Renal failure

Question 1

What is the main definition of Kidney Failure?

Answer 1

A reduction in Glomerular Filtration rate. (You may also get high K+, uraemia, high creatinine or oliguria, but not necessarily)

Question 2

What do you wanna do when you get a patient

Answer 2

Check History Examination

Question 3

What do you want to know when history taking?

Answer 3

Has she been peeing (at night?) Breathless Abdo pain Vomiting blood? Vomiting/ diarrhoea? Past diabetic history? Fever?

Question 4

Examination

Answer 4

Fever? Looks unwell? BP? Dryness of skin> Chest auscultation JVP (1-2cm normal)

Question 5

High vs low JVP?

Answer 5

High= fluid overload Low= Less fluid volume (volume depleted)

Question 6

What does it mean if creatinine is really high (normal ~ 70)

Answer 6

Represents diminished kidney function as the kidneys are unable to remove this waste product

Question 7

Which blood test is most important for distinguishing between acute and chronic Renal failure?

Answer 7

Haemaglobin! The kidneys make erythropoietin (turns bone marrow cells into RBCs) When renal failure occurs, obviously this stops happening BUT as RBC have a 120day lifespan, this can only be seen in bloodtests in CHRONIC kidney failure. (takes a while to become anaemic from this)

Question 8

3 roles of the kidney

Answer 8

1) Remove fluid and electrolytes 2) Produce Erythropoietin 3) alpha hydroxylate vitamin D (Storage to active)

Question 9

Acute Renal Failure

Answer 9

Acute deterioration of kidney function over a short period of time. Usually reversible Usually associated with another illness (eg vomiting/diarrhoea leads to dehydration)

Question 10

Pre-renal Acute Kidney failure

Answer 10

-Due to decreased perfusion of the kidneys -Generally low BP (bleeding, sepsis, dehydration, HF) Some progress to intrinisic renal damage (ATN)

Question 11

Renal Acute Kidney Failure

Answer 11

-Mainly Acute Tubular Necrosis -Mainly from pre-renal that wasn’t treated in time -Also RPGN

Question 12

RPGN

Answer 12

Rapidly Progressive Glomerulonephritis -rapid acute renal failure -cresecents in glomeruli on biopsy - Red cells and casts in urine

Question 13

Whats the best what to test for Post-renal Acute renal failure

Answer 13

Ultrasound as usually a blockage (stone etc) (hydronephrosis) (also palpation of bladder)

Question 14

High BP Oedema High urea, creatinine, phosphate Low Albumin Low Haem eGFR 6 What do they have?

Answer 14

Chronic kidney disease!

Question 15

Signs/symptoms of fluid overload

Answer 15

EdemaDifficultly breathing lying down crackles on auscultation High BP JVP increase Dyspnea Strong rapid pulse

Question 16

Signs of CKD

Answer 16

No acute presentation until function is REALLY bad! -Malnutrition -Fluid Overload (high BP, oedema, pulm oedema) -Rash -Pericardial rub

Question 17

Apart from haem, what are some other tests helpful in confirming the diagnosis

Answer 17

Kidney Size <8cm (normal 10-11cm) Presence of obstruction

Question 18

Whats the best treatment for CKD

Answer 18

Treat the high BP!! (<130/80) Best BP treatment are ACE inhibitors (but many people are also on Beta-blockers, diuretics etc)

Question 19

Whats the most likely cause of CKD?

Answer 19

Diabetes (rates increasing!) Hypertension Glomerular disease

Question 20

Purpose and mechanism of ACE inhibitors.

Answer 20

Because this increased pressure leads to increase damage. By blocking RAAS you decrease Na+ and water retention. Act on efferent arteriole to VD leading to decreased blood pressure.