Shock

Question 1

shock

Answer 1

bp unable to maintain tissue perfusion

Question 2

shock - response

Answer 2

release of histamine, prostaglandins, bradykinin, serotonin = capillary dilatation which increases capillary dilation and further reduces bp and cardiac output

Question 3

signs of shock

Answer 3

low arterial bp 
weak rapid pulse
cold, pale, sweaty
rapid breathing 
dry mouth
reduced urine output
anxiousness

Question 4

shock - causes

Answer 4

haemorrhage
burns
dehydration
vomiting and diarrhoea
bacterial septicemia
MI
PE

Question 5

types of shock

Answer 5

hypovolemic - reduction in circulating volume
cariogenic - reduce CO due to pump failure
SEPTIC – mass vasodilation
ANAPHYLACTIC - ALLERGIC reaction and release of vasodilation mediators
spinal - disruption of neuronal control on vascular tone and CO

Question 6

management of shock

Answer 6

dependent on underlying cause

e.g. vom/diarrhoea = electrolyte replacement

Question 7

sympathomimetic amines - type

Answer 7

adrenaline
noradrenaline
phenylephrine
ephedrine

raise bp at the expense of other organs e.g. kidneys
raise peripheral resistance

Question 8

sympathomimetic amines - Moa

Answer 8

adrenaline and noradrenaline are agonists at alpha and beta adrenoceptors. phenylephrine is an alpha 1 agonist. ephendrine is beta agonist and causes noradrenaline release

Question 9

sympathetic amines - indication

Answer 9

hypotension caused by spinal or epidural anaesthesia
hypotension
shock
cardiac arrest prevention –> adrenaline

Question 10

shympathetic amines - don’t

Answer 10

not to htn or pregnant

tacky anxiety insomnia and arrhythmias and cold extremities

Question 11

dopamine /dobutamine

Answer 11

dopamine is the precursor of noradrenaline. it activates dopamine and alpha/ beta receptors.

iv dopamine acts on

• dopamine receptors = vasodilation in the kidneys
• a1 receptors = vasoconstriction in other vasculature
• b1 receptors causing positive inotropic and chronotropic effects

dobutamine activates b1 adrenoceptors

maintains renal perfusion and inhibits the ras system

Question 12

dopamine /dobutamine - indication

Answer 12

chf (emergency)
cariogenic shock
septic shock
hypovolaemic shock
cardiomyopathy 
cardiac surgery

Question 13

vasopressin (ADH)/ desmopressin

Answer 13

antidiuretic peptides

vasopressin = short acting (10 mins)
desmopressin = long acting (75 mins)

Question 14

vasopressin (ADH)/ desmopressin - moa

Answer 14

activate V1 receptors on smooth muscle cells = stimulates phospholipase C = contraction. activate V2 receptors on tubular cells of kidney = stimulate adenylyl cyclase = increase permeability of these cells to water +reduced sodium and water excretion.

vaso = higher affinity for V2 receptors
demo = higher affinity for V1

Question 15

vasopressin (ADH)/ desmopressin

Answer 15

pituitary diabetes insipidus

no longer in shock

Question 16

guidelines manage

Answer 16

In cardiogenic shock secondary to a large myocardial infarction, urgent re-vascularisation of the coronary arteries, either by angioplasty or by surgery, lowers mortality. [64]

Cardiac tamponade needs drainage; pericardiocentesis under ECG monitoring can have an effect by draining as little as 30 mL, but this may be unsuccessful if the blood is clotted. A pericardial drain or surgical pericardial window may be required.

In pulmonary embolism, shock is the most widely accepted indication for thrombolysis. [78] Emergency embolectomy is an alternative, especially when thrombolysis is contra-indicated, or is an additional option when thrombolysis fails.

For anaphylactic shock, intramuscular adrenaline (epinephrine) is recommended as the most important treatment by all major guidelines, supplemented by high-dose corticosteroids and antihistamines. [43] [44]

Septic shock warrants generous fluid resuscitation and early treatment with broad-spectrum antibiotics.

with vasopressors - noradrenaline first line then dopamine or vasopressin

cariogenic = iv fluids but look for signs of overload such as pulmonary oedema and be careful.

also in haemorragic as you can increase bleeding risk

Question 17

guidelines shock

Answer 17

carry out a venous blood test for the following:

blood gas including glucose and lactate measurement

blood culture

full blood count

C-reactive protein

urea and electrolytes

creatinine

a clotting screen

give a broad spectrum antibiotic as well

For adults, children and young people aged 12 years and over with suspected sepsis and any high risk criteria and lactate over 4 mmol/litre, or systolic blood pressure less than 90 mmHg:

give intravenous fluid bolus without delay (within 1 hour of identifying that they meet any high risk criteria in an acute hospital setting) in line with recommendations in section 1.8 and

refer[4] to critical care[5] for review of management including need for central venous access and initiation of inotropes or vasopressors.