Acute kidney injury

What are the excretory functions of the kidney? (4)

1. Remove XS fluid

2. Remove waste products

3. Regulate acid/base balance

4. Regulate electrolyte levels.

What are the secretory functions of the kidney? (3)

1. Renin: BP regulation

2. EPO: RBC production

3. Vit D: calcium uptake.

What is acute kidney injury

sudden loss of kidney function 

reversible

What is chronic kidney disease?

Slow loss of renal function over time and lower ability to remove waste products from body. Duration over several years and can lead to established or end-staged renal failure.

tissue is scarred

Can acute lead to chronic

yes - if persistent.

What is Glomerulonephritis

• Damage to the glomeruli, leading to leakage of blood and/or protein into the urine.

• GN can be acute or chronic; some forms are treatable, while others may not 

What are the causes of AKI

1. Pre renal : Reduced renal perfusion from shock , caused by sepsos , acute heart failure , hypovolemia (blood loss) , anaphylaxis

2. Intrisic : direct damage to kideny tissue from toxic drugs , autoimmune disease , allergies

3. Post renal causes : Blockage of urine outflow causes by kidney stones (will make it appear on x-ray as the stones have calcium), large prostat/pelvic cancer

What is KDIGO stages of AKI

Stages are determined by the change in serum creatinine and urine output

What are the treatment options for established renal failure? (3)

1. Dialysis

2. Transplantation

3. Supportive care.

How is CKD clinically defined? (2)

1. GFR of <60 ml/min/1.73m^2 (normal is 125).

2. Presence of kidney damage for 3+ months.

What is the glomerular filtration rate?

Sum of all nephron filtration rates and best index of overall function. Equates to % of kidney function.

How is CKD classified by GFR?

Stage 1 - minor abnormalities with >90 GFR.

Stage 5 - major abnormalities with <15.

How is normal GFR age-related?

In healthy individuals, eGFR will fall by up to 10 ml/min (10% per decade). An 80 year old man has an expected eGFR of 50-60 ml/min.

What are the 8 major risk factors for CKD? (8)

1. Diabetes

2. High BP

3. +60

4. Smoking

5. Obesity

6. FH of kidney disease

7. Ethnic minority

8. Established CV disease.

What are 4 factors affecting eGFR?

1. creatinine

2. ethnicity (no longer used).

3. age

4. sex

How is ischemic damage to tubular cells caused by

reduced renal perfusion

what is ATN

Acute tubular necrosis - Caused by cell death and inflammation 

when low oxygen /toxin → apoptosis → triggers and inflammatory response → acute kidney injury

What are the primary diagnoses for patients who start dialysis?

Diabetes is major cause of end-stage renal disease, with hypertension being 2nd most common. But many diabetics have hypertension as a major contributing factor to loss of renal function.

What can determine if the kidney function is restored or if permanent damage?

Adaptive and maladaptive repair mechanisms 

if there  scar tissue outweighs healthy issue → leads to poor kidney function 

What are the general symptoms related to renal failure? (3)

1. Tiredness/fatigue - renal anaemia.

2. Salt + water retention - oedema, hypertension, SOB/pulmonary oedema.

3. Itching - uraemia or phosphate retention.

How can you monitor someone with CKD? (3)

1. Check and monitor BP

2. Monitor creatinine and eGFR

3. Check urine for protein and blood.

How can AKI occur? (5)

1. Haemodynamic

2. Septic

3. Immunological

4. Nephrotoxic

5. Obstructive

What is the staging of AKi , in terms of serum creatinine

Stage 1 → 1.5-1.9

stage 2 → 2.0-2.9

Stage 3 → 3.0

What is the staging of AKi , in terms of urine output

Stage 1 → <0.5ml/kg for 6-12 hrs

stage 2 → <0.5ml/kg/h for 12hrs

Stage 3 → 3.0 <0.3ml/kg for more than 24hrs or ANURIA for more then 12 hrs.