hypotension and shock

Question 1

what is shock

Answer 1

medical emergency associated with high mortality

Question 2

underlying causes of shock must be corrected and include the following (3)

Answer 2

haemorrhage, sepsis, myocardial insufficiency

Question 3

profound hypotension and shock must be treated promptly to prevent (2)

Answer 3

tissue hypoxia and organ failure

Question 4

Volume replacement is essential to correct the hypovolaemia associated with haemorrhage and sepsis, but may be detrimental in this type of shock

Answer 4

cardiogenic shock

Question 5

Depending on haemodynamic status, cardiac output may be improved by the use of sympathomimetic inotropes e.g.

Answer 5

adrenaline/epinephrine, dobutamine or dopamine HCl

Question 6

In septic shock, when fluid replacement and inotropic support fail to maintain BP, what can you consider

Answer 6

vasoconstrictor noradrenaline/norepinephrine may be considered

Question 7

what is peripheral resistance

Answer 7

the resistance in the circulatory system that is used to create blood pressure, the flow of blood and is also a component of cardiac function

if peripheral resistance is low = dilated BV = low BP
if peripheral resisteance is high = hypertension

Question 8

in cardiogenic shock peripheral resistance is freq high and to raise it further can worsen the following (2)

Answer 8

myocardial performance and exacerbate tissue ischaemia

When blood vessels narrow (vasoconstriction), this increases peripheral resistance, which can lead to higher blood pressure. However, in cardiogenic shock, although the blood pressure may initially increase due to this narrowing, the heart is too weak to maintain adequate blood flow. As a result, blood pressure often drops despite the vasoconstriction, because the heart simply cannot pump effectively against the increased resistan.

Question 9

how do vasoconstrictor sympathomimetics work to raise BP

Answer 9

raise BP transiently by acting on alpha adrenergic receptors to constrict peripheral vessels

sometimes used as an emergency method of elevating BP where other measures have failed

e.g. noradrenaline

Question 10

what is the danger of vasoconstrictors

Answer 10

although they raise BP, they also reduce perfusion or vital organs such as the kidneys

Question 11

Spinal and epidural anaesthesia may result in sympathetic block with resultant hypotension .

management may include

Answer 11

IV fluids (usually given prophylactically), oxygen, elevation of legs, injection of a presser drug such as ephedrine hydrochloride

Question 12

ephederine constricts peripheral vessels but also accelerates HR by acting on

Answer 12

b receptors

Question 13

As well as constricting peripheral vessels ephedrine also accelerates HR by acting on beta receptors . This dual action is good for managing associated ……… in spinal and epidural anaestheisa which may result in sympathetic block with resultant hypotension

However, IV injection of … can also be used if bradycardia persists

Answer 13

Dual action is useful in managing associated bradycardia, although IV injection of atropine may also be required if bradycardia persists

Question 14

name 2 ionotropic sympathomimetics used in shock

Answer 14

dobutamine
dopamine

Question 15

name a sympathomimetic vasocontrictor that is used for severe orthostatic hypotension due to autonomic dysfunction when corrective factors have been ruled out and other forms of treatment are inadequate

Answer 15

midrodrine

Question 16

midodrine shouldd not be taken at night true or false

Answer 16

true
last daily dose should be taken at least 4h before bedtime