Physiological changes in the elderly

Question 1

Most common type of incontinence in the elderly?

Answer 1

Urge incontience - due to detrusor muscle overactivity

Question 2

Renal changes in age?

Answer 2

Decreased renal mass
Decreased GFR
Decreased sodium conservation
Increased UTI’s due to reduced lactobacilli (decreased perioxide secretion)

Question 3

Changes in adrenals in elderly?

Answer 3

Decreased renin
Reduction in aldosterone
Decrease in aldosterone with increased risk of hyperkalaemia

Question 4

What is the most important change in the liver of the elderly?

Answer 4

Reduction in liver blood flow - interferes with drug clearance

Question 5

What occurs to the albumin in the elderly?

Answer 5

It does not change in the well elderly

Question 6

Changes in cardiac function in the elderly?

Answer 6

Cardiac output at rest does not change
Decreased max heart rate
Increase in LV wall thickness and atrial size
Increase in systolic BP but diastolic remains the same
Decreased arterial compliance and valve mobility
Reduced heart rate response to stress and respiration

Question 7

Respiratory changes in ageing?

Answer 7

FEV1 and FVC decrease
RV increases
V/Q mismatching increases due to increased physiological dead space
Blunted responses to PCo2 and PO2 (blunted respiratory drive)
Decreased mucociliary clearance

Question 8

Immunological changes with ageing?

Answer 8

Autoantibodies more common
Smaller antibody response to a stimulus
IgG and IgA increase but total the same

Question 9

Changes in endocrine system with ageing?

Answer 9

increase in PTH
increased vasopressin with increased risk of hyponatremia
rise in FSH/LH
reduced growth hormone
decreased male testosterone

Question 10

What changes in pharmacokinetics occur in ageing?

Answer 10

Absorption unchanged
Reduced first pass metabolism * most important - due to reduction in hepatic blood flow
Reduction in lean body mass
Increased fat
e.g lipid soluble drugs like diazepam have a greater volume of distribution with prolonged T1/2 life
water soluble drugs (dig and ETOH) have reduced volume of distribution and higher concentration
Decreased renal clearence

Question 11

What muscles fibres are predominantly lost in ageing?

Answer 11

Fast twitch greater then slow twitch
Fast twitch (Type 2) = fine motor
Slow twitch (Type 1) = gross motor