Kidney function in the pregnant and elderly

Question 1

What are the structural and functional changes in the kidney that occur in the elderly?

Answer 1

Renal weight decreases
Progressive glomerulosclerosis (40 onwards)
Tubular volume and function decreases
Reduced GFR, so reduced clearance

Question 2

Why isn’t there a large rise plasma creatinine with age?

Answer 2

As you age, GFR and therefore clearance decreases, however there is also decreasing muscle mass and body weight with age. Therefore less creatinine produced

Question 3

Problems associated with renal decline in the elderly

Answer 3

Reduced ability to concentrate urine
Reduced sodium retention
Loss of hormonal function (1a-OHase and EPO)
Reduced clearance of drugs
Reduced renal homeostasis (ability to adapt reduced, electrolyte problems develop quickly)

Question 4

how are drug doses adjusted in elderly patients?

Answer 4

Can use priming dose, maintenance dose or interval dosing.

Question 5

Changes in renal function in pregnancy

Answer 5

Increases in early pregnancy. Afferent and efferent arterioles become dilated.

GFR increases by 50%. Serum creatinine falls. Therefore non-pregnant (normal range) creatinine may represent renal impairment

Ability to concentrate urine is reduced. May exacerbate illnesses which cause dehydration e.g. gastroenteritis, pyelonephritis

Question 6

Renal disease in pregnancy

Answer 6

Bacteriuria and infection common

Patients with renal disease may have a decline in function in pregnancy e.g. hypertension and hyperfiltration. May cause ESRD

Question 7

Causes of acute renal failure in pregnancy

Answer 7

haemorrhage
hyperemesis
Pre-eclampsia
Drugs
Pyelonephritis

Must exclude obstruction

Question 8

Pregnancy risks in patients with CKD

Answer 8

Premature delivery
Foetal death
Low birth weight