lecture 7

Question 1

4 things that happen when kidneys stop working

Answer 1

loss of excretory function, homeostatic function, endocrine function, abnormality of glucose homeostasis

Question 2

result of loss of excretory function

Answer 2

accumulation of waste products

Question 3

result of loss of homeostatic function

Answer 3

disturbance of electrolyte balance, loss of acid-base control, inability to control volume homeostasis

Question 4

result of loss of endocrine function

Answer 4

loss of erythropoeitin production, failure to 1-a hydroxylase vitamin D

Question 5

result of abnormality of glucose homeostasis

Answer 5

decreased gluconeogenesis

Question 6

what are clinical features of kidney dysfunction determined by

Answer 6

rate of deterioration

Question 7

causes of lethargy and anorexia in patients with kidney disease: failure of excretion

Answer 7

accumulation of nitrogenous waste products, hormones, peptides and “middle-sized” molecules

Question 8

causes of lethargy and anorexia in patients with kidney disease: failure of homeostasis

Answer 8

acidosis, hyponatraemia, volume depletion causing hypotension

Question 9

causes of lethargy and anorexia in patients with kidney disease: failure of endocrine function

Answer 9

anaemia

Question 10

normal salt and water imbalance in renal dysfunction

Answer 10

difficulty in excreting salt and water, causing Na+ retention and subsequent hypertension, oedema and pulmonary oedema

Question 11

when can salt and water loss be present

Answer 11

tubulointerstitial disorders where concentrating mechanisms have been damaged

Question 12

causes of salt and water imbalance (low)

Answer 12

inability to decrease Na+ excretion when Na+ depleted, osmotic diuresis caused by high concentration of small MW waste substances e.g. urea, resultant volume depletion causing hypotension

Question 13

what are chronic kidney disease and acute kidney injury associated with

Answer 13

hyponatraemia (low blood Na+) - serum Na+ levels are not equal to total bod Na+

Question 14

what causes metabolic acidosis

Answer 14

decreased excretion of H+ ions and retention of acid bases

Question 15

what buffers metabolic acidosis and impact

Answer 15

H+ ions passing into cells in exchange for K+ ions, so tendency of hyperkalaemia

Question 16

other compensation for metabolic acidosis (respiratory)

Answer 16

increasing loss of CO2 through lungs, causing Kussmahl respiration (air hunger)

Question 17

2 other central and local mechanisms caused by acidosis

Answer 17

exacerbation of anorexia and increased muscle catabolism

Question 18

cause of hyperkalaemia

Answer 18

failure of distal tubule to secrete K+

Question 19

how does metabolic acidosis exacerbate hyperkalaemia

Answer 19

causes shift of K+ from IC to EC space

Question 20

what can hyperkalaemia cause (CV)

Answer 20

asystole; cardiac arrythmias (initial loss of P waves and bradycardia), arrest

Question 21

what other activity can hyperkalaemia affect

Answer 21

neural, muscular

Question 22

hyperkalaemia ECG

Answer 22

tall, tented T-waves; lose P-waves; broadening of QRS complex until becomes asystole

Question 23

what causes anaemia in kidney dysfunction

Answer 23

decreased erythropoietin production

Question 24

what do low 1,25 vitamin D levels cause

Answer 24

poor intestinal Ca2+ absorption, hypocalcaemia (short term), hyperparathyroidism (long term)

Question 25

how does chronic renal failure cause hyperparathyroidism

Answer 25

causes PO4 3- retention which leads to low levels of calcitriol, which can cause hypocalcaemia and directly/indirectly hyperparathyroidism

Question 26

what is the major predictor of end stage renal failure

Answer 26

chronic kidney disease

Question 27

what is the major outcome for a patient with chronic kidney disease

Answer 27

cardiovascular disease

Question 28

4 ways in which there is an increased CV risk

Answer 28

hypertension, secondary cardiac effects, endothelial effects, lipid abnormalities

Question 29

differences in consequences of acute and chronic loss of kidney function (ultrasound and history)

Answer 29

acute: renal size unchanged, previously normal creatine; chronic: renal size often reduced, previously abnormal creatine, chronic uraemic symptoms

Question 30

initial management of patient (4 things)

Answer 30

IV normal saline to rehydrate, IV NaHCO3 to correct acidosis, IV insulin and dextrose to lower plasma K+ by driving K+ ions back into cells, transfer for dialysis

Question 31

traditional poor, laborious or expensive methods of assessing GFR

Answer 31

urea, creatinine, creatinine clearance, inulin clearance (best test but laborious), radionuclide studies (e.g. EDTA)

Question 32

why is urea a poor indicator of GFR

Answer 32

confounded by diet, catabolic state, GI bleeding, drugs, liver function

Question 33

why is creatinine a poor indicator of GFR

Answer 33

affected by muscle mass, age, race (afro-caribbean, caucasian, asian), sex

Question 34

why is creatinine clearance a poor indicator of GFR

Answer 34

difficult for elderly patients to collect accurate samples, overestimates GFR at lot GFR

Question 35

how is GFR assessed

Answer 35

serum creatinine equation presenter ml/min per 1.73^2 using age and ethnicity

Question 36

when is the GFR equation unreliable

Answer 36

if >60ml/min, or patient very obese or very thin

Question 37

NICE guideline classification for chronic kidney disease

Answer 37

albumin:creatinine ration

Question 38

long term management of kidney dysfunction (4) causing poor quality of life

Answer 38

remain on regular haemodialysis, low K+ diet and fluid restriction, erythropoietin injections to correct anaemia, 1,25 vitamin D supplements to prevent hyperparathyroid bone disease