Renal Therapeutics

Question 2

What is creatinine?

Answer 2

A waste product that comes from the digestion of dietary protein and the normal breakdown of muscle tissue.

Question 3

What is creatinine plasma concentration measured for?

Answer 3

To determine kidney function, severity of kidney damage or the progression of kidney disease.

Question 4

What is CrCl?

Answer 4

Is the volume of blood plasma (ml) cleared of creatinine per unit of time (min).

Question 5

How do you interpret CrCl rate?

Answer 5

The higher the level of creatinine in the blood, the lower the creatinine clearance (mL/min), the slower the kidneys are working.

Question 6

What are the benefits and limitations of measuring creatinine in blood plasma?

Answer 6

Benefits - Is more practical than measuring creatinine in urine (24-hour collection) and less invasive, time consuming and expensive than injecting inulin.

Limitations - Creatinine levels can be affected by factors such as diet, muscles, malnutrition and chronic illnesses.

Question 7

What variables does the chronic kidney disease epidemiology collaboration formula take into account?

Answer 7

body surface area, serum creatinine, age, sex and race

Question 8

What is an apparent weakness or limitation of the cockcroft-gault formula?

Answer 8

The formula does not correct for race.

Question 9

What are some factors that could interfere with cockcroft-gault formula?

Answer 9

Patient sex, patient race, diet, muscle mass, drugs, exercise and muscle

Question 10

What are some ways kidney disease is diagnosed?

Answer 10

Blood tests, ultrasound, CT scan, urinalysis, Intravenous excretory urogram, biopsy, Magnetic resonance imaging (MRI)

Question 11

What are some indications for abnormal renal function?

Answer 11

Elevated serum creatinine levels and decreased CrCL rate

Question 12

What is an apparent effect of damaged kidneys with regards to the urine?

Answer 12

Albumin would present in the urine.

Question 13

What are some symptoms that would lead to one suspecting AKI in a patient who has an acute illness?

Answer 13

Nausea, vomiting, diarrhoea, confusion, fatigue, Age > 65 years, reduced urine output, previous AKI, with cognitive impairment or disability

Question 14

State the various stages of AKI and their mechanisms?

Answer 14

Pre-renal AKI - Occurs due to reversible decrease of renal perfusion through hypoperfusion of the kidneys.

Post-renal AKI - Occurs due to an obstruction in the urinary tract.

Intrinsic/Intra- Renal AKI - Caused by renal parenchyma injury.

Question 15

What are some diagnostic tests for AKI?

Answer 15

Tests for Serum creatinine, a fall in urine output

Question 16

What are the tests for identifying the causes for diagnosis in AKI?

Answer 16

Urinalysis and Ultrasound

Question 17

What are some managements for the stages of AKI?

Answer 17

Pre-renal - Hydration with IV fluids.
Post- renal - Refer patient to a urologist.
Intrinsic - Treat the damage….if treatable.
Hold nephrotoxic medications.
Adjust doses of all other prescribed medications.

Question 18

What does the STOP management of AKI entail?

Answer 18

Treating Sepsis - if present
Avoiding nephrotoxins
Optimize/restoring haemodynamic stability.
Preventing damage: identifying the underlying cause.

Question 19

What are nephrotoxic drugs?

Answer 19

Drugs with the potential to generate kidney damage and to reduce renal function.

Question 20

Medications with nephrotoxic potential?

Answer 20

NSAIDs, ACEIs, Diuretics and ARBs

Question 21

Mechanisms of action of nephrotoxic medications

Answer 21

GFR Alteration
Tubular Cell Toxicity
Crystal Nephropathy
Interstitial Nephritis

Question 22

What is the nephrotoxic mechanism of ACE inhibitors?

Answer 22

Reduction of blood pressure which could worsen renal failure

Question 23

What is the nephrotoxic mechanism of NSAIDs?

Answer 23

Inhibit prostaglandin production, thus vasodilation of afferent arteriole thus reduce kidney perfusion

Question 24

Renal failure is characterised by

Answer 24

Reduced renal perfusion

Question 25

Effect of ACEi and NSAIDs on renal function

Answer 25

significant nephrotoxicity

Question 26

What is chronic kidney disease

Answer 26

Abnormalities of kidney function or structure that have been present for more than 3 months, with significant health implications.

Question 27

Risk factors of CKD

Answer 27

Diabetes, Age >60, Obesity, Smoking, Hypertension and family history

Question 28

Diagnosing CKD

Answer 28

Blood and urine test Ultrasound scan MRI scan or CT scan: for morphology and blockage Kidney biopsy: for signs of damage/cancer

Question 29

Symptoms of CKD

Answer 29

Weight loss Poor appetite Tiredness Haematuria Shortness of breath

Question 30

CKD management

Answer 30

Lifestyle changes Dialysis and kidney transplant Medicines to control associated problems: High blood pressure, high cholesterol, high potassium and anaemia

Question 31

Issues encountered in renal impairment

Answer 31

Some drugs are not effective when renal function is reduced. Patients with renal impairment poorly tolerate many side effects. Sensitivity to some drugs is increased even if elimination is unimpaired. Reduced renal excretion of a drug may cause toxicity.

Question 32

How renal failure can affect the pharmacokinetics of drugs?

Answer 32

Absorption Distribution Excretion - reduced renal excretion of a drug may cause toxicity Metabolism - Kidney failure results in drugs no longer being metabolised, thus decreasing their effects.