AKI and CKD

Question 1

Causes of acute kidney injury

Answer 1

Pre-renal: renal hypoperfusion which reduces glomerular pressure. Can be caused by hypovolemia (dehyration, haemorrhage) or hypotension (MI, heartF, renal artery stenosis). May be drug indiced (NSAIDs, ACEi)

Intrinsic: primary renal disease (glomerulonephritis), secondary renal disease (SLE, diabetes, myeloma), interstitial nephritis (drugs, infection, hypercalcaemia), acute tubular necrosis (ischaemia, drugs, toxins)

Post-renal: due to bladder outflow obstruction. e.g. BPH, tumour, kidney stone.

Question 2

Tests used for renal dysfunction

Answer 2

Urine dipstick

U+E (eGFR, Cr, Na, K, HCO3, Ca2+)

FBC - infection, low Hb may indcate bleeding

Immunology (autoimmune disease)

Monitor urine output

Renal USS and CXR

Question 3

Clinical signs of dehydration

Answer 3

decaeased skin turgor

low JVP

low bp

weight loss

dry mucous membranes

Question 4

Severe complications od AKI

Answer 4

Hyperkalemia

Pulmonary oedema

Bleeding

Question 5

Initial management fo a patient with AKI

Answer 5

Treat hyperkalemia - calcium gluconate, insulin/dextrose, NaHCO3

Manage any fluid overload/hypotension

Treat underlying cause

Question 6

Cause of outflow obstruction below the bladder neck

Answer 6

BPH

Prostate cancer

Urethral stricture

Posterior urethral valve (cogenital)

Cord compression

Question 7

How is CKD monitored

Answer 7

eGFR

Damage cannot be reversed, management involves preveting further damage e.g. hypertension, blood glucose, electrolytes.

Question 8

Risk factors for CKD

Answer 8

Increasing age

Hypertension and CV disease

Diabetes

Also: Urimary outflow obstruction, Smoking

Question 9

Diagnosis of CKD

Answer 9

Persistent microalbuminuria

Persistent proteinuria

Persistent haematuria when other causes have been excluded

Structural abnormalities of the kidneys

Histological diagnosis of glomerulonephritis

Question 10

What is CKD

Answer 10

Progressive and irreversible loss of renal function.

Over months>years

Loss of excretory and hormone functions

Question 11

QoF guidelines for the management of CKD

Answer 11

1. GP register patients with CKD 3-5
2. Record and monitor BP
3. Aim for BP of 140/85
4. Hypertensive patients should be on ACEi

Question 12

Stages of CKD

Answer 12

Stage 1&2 normal: GFR 60-90 with other evidence of kidney damage. Monitored every year

Stage 3: GFR 30-59 with/without evidence of kidney damage Test every 6 months

Stage 4: GFR 15-29 with/withuot kidney damage. Test every 3 months

Stage 5: Renal failure GFR <15. Test every 6 weeks

Question 13

Causes of CKD

Answer 13

Commonest causes: diabetes, hypertension, reflux nephropathy, polycystic kidney disease

Intrinsic renal: glomerulonephritis, chronic pyelonephritis, polyccystic kidneys, etc..

Systemic: diabetes mellitus, hypertension, heart failure, SLE

Drugs: ciclosporin, analgesics, gold

Question 14

Investigations in a patient with suspected CKD

Answer 14

Urine analysis: blood, protein, WBCs, ACR ratio

U+E: low eGFR, urea, creatinine, electrolytes

Radiology: USS for kidney size, CXR pulmonary oedema

Biopsy: if cause unclear

Question 15

Complications of CKD

Answer 15

Renal osteodystrophy - failure to activate VitD leads to hypocalcaemia and impaired bone mineralisation. More PTH released which increases bone reabsorption.

Anaemia - reduced EPO production. Normochromic normocytic

Fluid retention - pulmonary/peripheral oedema, hypertension

Uraemia - Inability to excrete nitrogenous waste can lead to high BUN. Causes itching, nausea/vomiting and neuromuscular symptoms.