6.3 Geriatrics

Question 1

Physiological changes seen with ageing are as follows

Central nervous system:

myelin sheath / senisitivity to la

Answer 1

Central nervous system:

the nerve fibres lose their myelin sheath and are more sensitive to
local anaesthetics

Question 2

Physiological changes seen with ageing are as follows

dura permeability

Answer 2

there is increased permeability of the dura

Question 3

Physiological changes seen with ageing are as follows

CSF volume
spec gravity

dose?

Answer 3

there is a decrease in

cerebrospinal fluid volume

and an increase in

specific gravity of cerebrospinal fluid,

which may explain the lower
dose of local anaesthetic required in the elderly.

Question 4

Physiological changes seen with ageing are as follows

Baroreceptor sens

any type of blockade?

Answer 4

there is a decrease in sensitivity of the baroceptors

there is physiological beta blockade

Question 5

SVR change?

why

what lead to?

Answer 5

there is increase in systemic vascular resistance as the arteries lose
their elastic fibres (leading to hypertension)

Question 6

LV?

Volume o/load tolerance?

IHD AFIB VALVE

Answer 6

there is

left ventricular hypertrophy

and

intolerance to volume overload

and a high incidence of
ischaemic heart disease,
atrial fibrillation
and sclerosis of the valves.

Question 7

Changes in epidural space with age

Answer 7

1
decrease in fat

2
sclerotic changes at intervertebral foramina
(decrease in size)

3
increase in compliance of epidural space

4
decrease in resistance (hence higher cephalad spread).

Question 8

Effect of epidural space changes

Answer 8

All these changes lead to

faster onset of block and

greater cephalad spread of local anaesthetic.

Question 9

Test dose in elderly? epi

Answer 9

Due to physiologic beta blockade,

epidural test dose (lignocaine with epinephrine)
is unreliable.

Question 10

relationship between LA dose and spread

Answer 10

There is a non-linear
relationship between
local anaesthetic dose required

per segment and
spread of analgesia.

Question 11

Absorption of LA in Geri

Answer 11

In geriatric patients,

there is biphasic absorption
of local anaesthetics
from the epidural space.

Question 12

Initial absorption

Answer 12

There is an initial rapid
absorption phase from increased
vascularity of the epidural space.

Question 13

Second phase of absorption

Answer 13

This is followed by a

slower phase of absorption
because of uptake
from the epidural fat.

Question 14

Intrathecal absorption elderly vs adults

why

Answer 14

However, the initial absorption
of local anaesthetic after intrathecal
injection is slower because

of poor perfusion of subarachnoid space

Question 15

Depending on the clearance, local anaesthetics are classified as:

Answer 15

high hepatic extraction ratio –
clearance depends on hepatic blood flow (lignocaine)

low hepatic extraction ratio –
clearance depends on enzymatic
activity (bupivacaine).

Question 16

How is hepatic flow affected in elderly

Answer 16

In geriatric patients,

both the hepatic blood
and hepatic enzyme activity
are reduced.

Question 17

How is clearance of lignocaine and bupivacaine changed

Answer 17

Therefore, the clearance of
both lignocaine and bupivacaine is
reduced in the elderly.

Question 18

Is dose and frequence different in elderly

why

Answer 18

This also explains the need for
reduced doses as well
as frequency of doses.

n geriatric patients, both the hepatic blood
and hepatic enzyme activity
are reduced.

Question 19

Opioids dose change?

Answer 19

There is increased sensitivity to opioids, and so

their doses must be reduced.

Question 20

Advantages of central neuraxial anaesthesia over general anaesthesia

Answer 20

Advantages of central neuraxial anaesthesia over general anaesthesia
are:

decrease in blood loss

decrease in stress response

decrease in thromboembolic phenomenon

decrease in mortality immediate and at 1 month

Question 21

Post op cognitive dysfunction less with neuraxial?

Answer 21

However, the incidence of post-operative cognitive dysfunction is similar with both.