Chronic kidney disease

Question 1

How is kidney function measured?

Answer 1

eGFR- estimated glomerular filtrate rate
This can be measured by isotope GFR or 24hr urine collection +blood tests but the main method is creatinine serum levels. Creatinine serum levels will increase with decreasing GFR but the creatinine levels do not go above normal range until 60% of total kidney function is lost (so GFR is less than 50% of the normal).
Mostly the MDRD 4 variable equation is used now, this takes in to account, age, gender and race.

Question 2

What are the problems with creatinine levels being used to estimate GFR?

Answer 2

Creatinine levels can vary due to many different variable from person to person: age, ethnicity,gender,weigh, muscle mass.
Also creatinine levels don’t go above normal until 60% of normal kidney function has been lost.

Question 3

What is CKD stage 1?

Answer 3

Normal or high GFR->90?

Question 4

What is a normal GFR for an adult?

Answer 4

> 90 ml/min/1.73m squared

Question 5

Define stage 2 CKD.

Answer 5

Mild reduction in GFR 60-89

Question 6

What is the GFR value for stage 3 CKD?

Answer 6

Moderately impaired
This is split in to 2 subsections
3a 45-59 (most people with CKD are in this group- e.g. elderly patients with hypertension and diabetes)
3b 30-44

Question 7

Define stage 4 CKD

Answer 7

Severely impaired- 15-29

Question 8

What is stage 5 CKD?

Answer 8

Advanced on dialysis <15

Question 9

Define chronic kidney disease

Answer 9

Chronic kidney disease is defined either by the presence of kidney damage (abnormal blood, urine ir x-ray findings) or GFR<60ml/min/1.73m squared, that is present for 3+ months.

Risk of CVD and mortality increases with worsening renal function (and therefore increasing CKD staging).

Question 10

What causes CKD and what are the symptoms?

Answer 10

There can be many and mixed caused of CKD including diabetes, hypertension, polycystic kidney disease, glomeulonephritis.
Most patients are asymptomatic but patients could present with: anemia, anorexia, vomiting, taste (these 3 with advanced CKD), polyuria, oliguria, nocturia, haematuria, proteinuria, cognitive changes/impairment, shortness of breath.

Question 11

What possible investigations can you do?

Answer 11

Bloods: U&Es, FBC,creatinine level,platelets, LFTs
Histology - renal biopsy
Radiology
Urine dipstick test

Question 12

How is CKD managed?

Answer 12

BP control
Control proteinuria
Treat underlying cause
end stage disease has to be treated with renal replacement therapy (dialysis)

Question 13

What are two main group of drugs you have to be careful with in CKD?

Answer 13

ACEi- angiotensin converting enzyme inhibitors

ARBs- angiotensin II receptor blockers