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Phase II: General Medicine Pt1 > AKI and CKD > Flashcards

Flashcards in AKI and CKD Deck (65):
1

What variables are used to estimate eGFR from serum creatinine?

Creatinine
Age
Gender
Ethnicity

2

What is uremia?

Excessive urea (and other amino acid and protein metabolism end products) in that blood.

These would normally be excreted in the urine.

3

What test can be done to differentiate pre-renal uraemia and acute tubular necrosis?

Urinary sodium.

Pre-renal uraemia: <20 mmol/L
ATN: >30 mmol/L

4

How does Stage 1 AKI present?

Serum creatinine increase of 1.5-1.9x baseline

Urine output of <0.5ml/kg/hr for >6h

5

How does Stage 2 AKI present?

Serum creatinine increase of 2.0-2.9x baseline.

Urine output of <0.5ml/kg/h for >12h

6

How does Stage 3 AKI present?

Serum creatinine increase of >3x baseline

Urine output of <0.3ml/kg/h for >24h, or anuric for 12h

7

What is the name of the syndrome presenting with: acute renal failure, microangiopathic haemolytic anaemia, and thrombocytopenia?

Haemolytic uraemic syndrome

8

List 4 causes of haemolytic uraemic syndrome

Post-dysentery - E. coli
Tumours
Pregnancy
Ciclosporin and COCP
SLE
HIV

9

What nephrotic syndrome typically occurs in children and young adults?

Minimal change glomerulonephritis

10

What is the definition of contrast media nephrotoxicity?

25% increase in creatinine occurring within 3 days of IV administration of contrast media.

11

What are the risk factors for contrast media nephrotoxicity?

Known renal impairment - especially diabetic nephropathy
Age >70
Dehydration
Heart failure
Nephrotoxic drugs

12

What is the best preventative measure of contrast media nephrotoxicity?

IV 0.9% saline for 12h pre- and post-procedure

13

When is a reduced eGFR not diagnosed as CKD?

If eGFR is >90, or 60-90, but the renal tests are normal (normal U&E with no proteinuria)

14

What is Stage 1 CKD?

eGFR >90 ml/min, with some sign of kidney damage on other tests

15

What is Stage 2 CKD?

eGFR 60-90 ml/min with some sign of kidney damage

16

What is Stage 3a CKD?

eGFR 45-59 ml/min

17

What is Stage 3b CKD?

eGFR 30-44 ml/min

18

What is Stage 4 CKD?

eGFR 15-29 ml/min

19

What is Stage 5 CKD?

Renal failure

eGFR <15 ml/min

20

What is the purpose of EPO injections in CKD?

Treatment for CKD-associated anaemia. Improves exercise tolerance.

21

What adult polycystic kidney screening test is recommended for family members?

Ultrasound abdomen

22

Name 3 classifications of AKI

KDIGO staging*
RIFLE
AKIN

23

Define Acute kidney injury (AKI)

Abrupt deterioration in renal function, over hours-days.

Usually reversible over days-weeks.

24

Describe the broad aetiology of AKI

Pre-renal
Intrinsic renal
Post-renal

25

List 3 causes of pre-renal AKI

Hypovolaemia: haemorrhag, severe DaV, burns, diuresis

Hypotension: shock, sepsis, anaphylaxis

Hypoperfusion: HF, cirrhosis, AAA, renal artery stenosis, NSAIDs, COX-2 inhibitors

26

How do NSAIDs and COX-2 inhibitors cause pre-renal AKI?

Inhibits COX enzymes which are needed for prostaglandin synthesis, a vasodilator.

27

List 4 causes of intrinsic renal AKI

Glomerular disease: glomerulonephritis, thrombosis, SLE, haemolytic uraemic syndrome

Tubular injury: ATN, nephrotoxins

Vascular: Vasculitis, renal artery stenosis, thrombosis

Multiple myeloma

Eclampsia

28

List 4 causes of post-renal AKI

Ureteric: Bilateral renal stones, retroperitoneal fibrosis, tumours

Bladder: Acute urinary retention, blocked catheter

Urethral: Prostate enlargement, renal stones

29

What are 4 risk factors for AKI?

Age >75
Chronic disease: CKD, HF, PVD, Chronic liver disease, DM.
Drugs
Sepsis
Poor fluid intake/XS losses
Hx of urinary symptoms

30

What symptoms can occur in AKI?

Oliguria or anuria
NaV
Dehydration
Confusion

31

What signs can occur in AKI?

Hypertension
Enlarged bladder if chronic urinary retention
Dehydration with postural hypotension
Fluid overload, raised JVP, peripheral and pulmonary oedema

32

What steps can be taken to prevent AKI?

Regular monitoring of renal function in chronic diseases.

Close monitoring in acute illness, especially if dehydration or DaV is present.

Optimise doses of drugs with nephrotoxic potential.

Consider stopping ACEi and ARBs if DaV or sepsis occurs.

Consider admitting to hospital if hypovolaemic, for IV fluids.

33

What electrolyte disturbances occur in AKI?

Hyperkalaemia
Hyponatraemia
Metabolic acidosis

34

What is the goal of initial investigations in suspected AKI?

To define the syndrome as pre-renal, intrinsic, or post-renal.

Decide if it is acute or acute-on-chronic kidney disease.

35

What initial investigations should be undertaken for suspected AKI?

-A-E assessment
-Volume status: BP, JVP, skin turgor, cap refill, urine output (catheter)
-Serum K+ (VBG)
-ECG for hyperkalaemia
-Bloods
-Urine dipstick/blood film for glomerulonephritis
-KUB USS for urinary tract obstruction

36

What ECG changes occur in hyperkalaemia?

Tall tented T waves
Small/absent p waves
Increased PR interval
Widened QRS
Sine wave pattern
Asystole

37

What is the immediate treatment of life-threatening hyperkalaemia?

10ml of 10% calcium gluconate IV via big vein. (cardioprotective)

IV insulin + glucose

Definitive Tx: renal clearance or haemodialysis

38

What blood tests should be done in suspected AKI?

FBC and blood films for glomerulonephritis

U&Es, creatinine, CRP

Coagulation for DIC associated with sepsis

CK for rhabdomyolysis

Bence Jones' protein for myeloma

ANA and anti-dsDNA for SLE
ANCA for vasculitis and GPA

39

What features suggest acute-on-chronic kidney disease rather than AKI?

Long Hx of nocturia
KUB USS: small, scarred kidneys
Anaemia of chronic disease
HyperPTH
Renal osteodystrophy

40

Outline the management of AKI

-Fluid and electrolyte monitoring BD. Aim for euvolaemia.
-Stop nephrotoxic drugs and adjust renal excreted drugs.
-Maintain nutrition. Restrict K+ and Na+.

Pre-renal: correct fluid depletion, treat sepsis, refer to ICU if enter shock.

Post-renal: catheterise and consider CTKUB. Discuss with urology if signs of obstruction or hydronephrosis.

41

What are the indications for Renal Replacement Therapy (RRT)?

eGFR <10ml/min
Refractory pulmonary oedema
Persistent hyperkalaemia (>7mmol/L)
Severe metabolic acidosis (pH <7.2)
Uraemic complications
Uraemic pericarditis
Drug OD (BLAST*)

*Barbituates, Lithium, Alcohol, Salicylates, Theophyline

42

Name 4 complications of AKI

Hyperkalaemia
Pulmonary oedema
Uraemia
Acidaemia

43

What are the consequences of uraemia?

Encephalopathy
Pericarditis

44

Outline the treatment of pulmonary oedema

Sit up and give high-flow O2
Venous vasodilator (Diamorphine + antiemetic)
Furosemide
CPAP

If no response: urgent haemodialysis or filtration

45

Name the types of Renal Replacement Therapy (RRT)

Haemodialysis
Haemofiltration
Haemodiafiltration
Peritoneal dialysis
Renal transplant

46

Which types of RRT are suitable for AKI?

Haemodialysis
Haemofiltration

47

Describe the process of haemodialysis

Blood and dialysis fluid flow in opposite directions on different sides of a semi-permeable membrane.

Water and solutes diffuse across this membrane into the dialysis fluid, across a -ve transmembrane pressure.

This allows removal of several litres of excess fluid over 3-5 hours.

48

What routes of administration are used in haemodialysis?

IV catheter (central vein): If urgent dialysis needed. Slower rate, infection and stenosis risk.

AV fistula: Lowest risk of infection, takes weeks to be ready. Risk of aneurysm.

AV graft: Increased risk of infection. Used if poor veins or arterial disease.

49

Compare haemodialysis and haemofiltration

Haemodialysis removes solutes by diffusion. Given for short periods. Better solute clearance, but requires patients to be haemodynamically stable.

Haemofiltration removes soluted by convection (water pressure). Given continuously, typically on ICU. Provides better control of blood pressure.

50

What are the problems with haemodialysis?

Dialysis disequilibrium syndrome
Arrhythmias
Time consuming, inflexible, dietary restrictions
Fistula: thrombosis, stenosis, aneurysm, steal syndrome, ischaemia
Temporary line: infection, blockage

51

What are the benefits of haemodialysis?

Fast clearance rate
Short periods of treatment with return to normal lifestyle in between treatments.

52

What is dialysis disequilibrium syndrome?

A rare syndrome of neurological symptoms due to cerebral oedema occurring after haemodialysis.

More commonly seen in first dialysis sessions, elderly and paediatric patients, pre-existing CNS lesions, and severe metabolic acidosis.

Tends to be self-limiting. Dialysis will need to stop if severe.

53

What is steal syndrome?

Arterial stenosis upstream of an anastomosis (fistula/graft), which prevents the necessary increase in flow. This causes distal peripheral ischaemia.

54

How often is haemodialysis required on a weekly basis?

3 sessions a week of 4-5hr duration.

55

Describe the process of peritoneal dialysis

Dialysate is inserted into the peritoneal cavity via a catheter. Waste products cross into the cavity. This is left in the abdomen for 3-5 hours before being exchanged and repeated.

56

What are the benefits of peritoneal dialysis?

Patient freedom and control.
Less fluid and food restrictions.

57

What are the problems with peritoneal dialysis?

Patients are responsible for continuous care, and need 3-5 exchanges a day.

Bacterial peritonitis
Sclerosing peritonitis (causes potentially fatal repeated small bowel obstruction)
Catheter exit-site infections
Obesity, due to glucose in dialysate
Hernias and back pain

58

How common are renal cysts?

Common, especially with advancing age.
50% of over 50yrs have one or more renal cysts

59

What is the clinical significance of renal cysts?

No special significance except in the differential diagnosis of renal tumours.

Often an asymptomatic incidental finding. May cause pain and/or haematuria if large.

60

What is renal cystic degeneration? Explain its clinical significance

The formation of multiple cysts that enlarge with time.

Cystic degeneration occurs regularly in non-functioning kidneys of patients with ESRD treated by dialysis and/or transplantation.

These acquired cysts have malignant potential.

61

Define Autosomal dominant polycystic kidney disease

Inherited disorder that is characterised by the development of multiple renal cysts, and associated with extrarenal (mainly hepatic and CV) abnormalities.

62

Outline the epidemiology of Autosomal dominant polycystic kidney disease

Most common inherited nephropathy
3-10% of all patients commencing regular dialysis

63

Describe the clinical presentation of Autosomal dominant polycystic kidney disease

Occur from second decade onwards

Loin pain and/or haematuria
Loin or abdominal discomfort
Subarachnoid haemorrhage: berry aneurysm rupture
Complications of HTN
Complications of associated liver cysts (50%)

CKD associated uraemia and/or anaemia

64

Name 3 conditions associated with Autosomal dominant polycystic kidney disease

Progressive CKD*: faster deterioration than other primary renal disorders

Renal calculi (10-20%): often urate and radiolucent
Hypertension: early and common feature
Left ventricular hypertrophy
Mitral valve prolapse
Hepatic cysts
Berry aneurysm -> Subarachnoid haemorrhage

65

Outline the management of Autosomal dominant polycystic kidney disease

ACEi/ARBs for HTN
Dialysis or renal transplant
Liver transplant if portal HTN