Shock Flashcards
1
Q
what are the different types of shock?
A
distributive
obstructive
hypovolaemic
cardiogenic
2
Q
what is shock?
A
life-threatening disorder of circulatory system
resulting in inadequate organ perfusion and tissue hypoxia, causing metabolic disturbances and irreversible organ damage
3
Q
shock index - calculation
A
pulse rate/systolic BP
4
Q
normal shock index
A
0.4-0.7
5
Q
shock index when shock is present
A
> 1
6
Q
causes of hypovolaemic shock
A
haemorrhage
non-haemorrhagic fluid loss
7
Q
haemorrhage causes
A
postpartum
upper GI bleed
blunt/penetrating trauma
8
Q
non-haemorrhagic fluid loss
A
diarrhoea vomiting increased insensible fluid loss - burns third space fluid loss renal fluid loss
9
Q
clinical features of hypovolaemic shock
A
hypotension tachycardia weak pulse cold, clammy, pale extremities slow capillary refill decrease preload decreased cardiac output increased afterload increased total peripheral resistance increased systemic vascular resistance decreased mixed venous oxygen saturation
10
Q
treatment of hypovolaemic shock
A
fluid resuscitation
management of haemorrhage
possibly blood transfusion
11
Q
causes of cardiogenic shock
A
arrhythmias MI valve defects heart failure cardiomyopathy myocarditis drugs blunt cardiac trauma
12
Q
clinical features of cardiogenic shock
A
hypotension tachycardia weak pulse cold, clammy, pale extremities slow capillary refill increased/decreased preload decreased cardiac output increased afterload increased total peripheral resistance increased systemic vascular resistance decreased mixed venous oxygen saturation
13
Q
treatment for cardiogenic shock
A
diuretics
inotropic therapy
14
Q
causes of obstructive shock
A
cardiac tamponade PE tension pneumothorax constrictive pericarditis restrictive cardiomyopathy large systemic emboli aortic dissection aortic stenosis
15
Q
clinical features of obstructive shock
A
hypotension tachycardia weak pulse cold, clammy, pale extremities slow capillary refill increased/decreased preload decreased cardiac output increased afterload/total peripheral resistance increased SVR decreased mixed venous oxygen saturation
16
Q
treatment for obstructive shock
A
decompression
17
Q
what are the types of distributive shock?
A
septic
anaphylactic
neurogenic
18
Q
causes of septic shock
A
infection
bacteraemia
19
Q
clinical features of septic shock
A
flushed dry, warm skin tachycardia hypotension fever decreased preload increased cardiac output decreased afterload/total peripheral resistance decreased systemic vascular resistance increased mixed venous oxygen saturation
20
Q
treatment of sepsis
A
fluid resuscitation
vasopressors
broad-spectrum empirical antibiotic therapy
21
Q
causes of anaphylactic shock
A
drug reactions
insect stings/bites
food allergies
22
Q
clinical features of anaphylaxis
A
flushed dry, warm skin tachycardia hypotension itchy skin hives bronchospasm laryngeal oedema swelling of tongue uvula angioedema decreased preload increased cardiac output decreased afterload/total peripheral resistance decreased systemic vascular resistance increased mixed venous oxygen saturation
23
Q
treatment for anaphylaxis
A
fluid resuscitation vasopressors adrenaline antihistamines glucocorticoids
24
Q
causes of neurogenic shock
A
spinal cord injury
traumatic brain injury
cerebral haemorrhage
25
clinical features of neurogenic shock
```
flushed
dry, warm skin
bradycardia
hypotension
neurological deficits
decreased preload
decreased cardiac output
decreased afterload/ total peripheral resistance
decreased systemic vascular resistance
decreased mixed venous oxygen saturation
```
26
treatment for neurogenic shock
fluid resuscitation
vasopressors
atropine for bradycardia
27
diagnosis of shock
```
assess HR, BP and oxygen sats
measure CVP - central venous catheter
catheterise bladder to monitor urine output
renal function tests
ABG
clotting parameters
LFTs
electrolytes
```
28
Renal function tests for shock
blood urea nitrogen is raised
| creatinine
29
shock electrolytes
sodium
potassium
calcium
30
shock ABG
lactic acidosis
31
shock LFTs
hyperbilirubinaemia
| increased AST/ALT
32
what is the end stage of shock?
DIC
| disseminated intravascular coagulation
33
what are the stages of shock?
preshock
shock
end organ dysfunction
34
pre shock
non progressive phase
| activation of compensatory neurohumoral reflexes to maintain vital organ perfusion
35
clinical features of pre-shock
peripheral vasoconstriction
cold, clammy extremities
increased capillary refill time
decreased capillary hydrostatic pressure - increased absorption of interstitial fluids into intravascular space to maintain BP
tachycardia - absent in neurogenic shock
no peripheral vasoconstriction in distributive shock
oligouria
36
shock
progressive phase
37
clinical features of shock
worsening hypotension
hypoperfusion of peripheral tissues
generalised hypoxia
anaerobic metabolism in underperfused organs
lactic acidosis
worsening tachypnoea
precapillary dilation and postcapillary constriction of vessels
pooling and stasis of blood in capillary bed
decreased CO
formation of microthrombi in capillaries
DIC
hypoxic injury
acidosis
cerebral hypoperfusion = altered mental status
38
end organ dysfunction
irreversible phase
decompensation
irreversible tissue damage
39
clinical features of end organ dysfunction
```
cerebral hypoxia
autonomic dysfunction
myocardial ischaemia - ACS
decreasec CO
widespread cell necrosis
bowel ischaemia
```
40
widespread cell necrosis
```
release of lysozymal enzymes
further tissue injury
worsening of shock
activation of immune system
release of cytokines
DIC
further tissue damage
```
41
DIC
blood clots form in small blood vessels
ischaemia of organs
organ failure
clotting uses up clotting factors and platelets so there is excessive bleeding
clotting activated throughout the body
inhibition of clotting control mechanisms
clotting and bleeding together
42
signs/symptoms of DIC
```
blood in stool/urine
headaches - brain bleeds
bruises
petechiae
wound/surgical sites bleeding
mucosal bleeding
organ dysfunction
blackening of skin - ischaemia
chest pain
haemoptysis
difficulty breathing
heart attack symptoms
stroke symptoms
```
43
how to manage shock?
warm
lay flat
peripheral IV line using large calibre catheter
intraosseous route if IV unavailable
oxygen therapy
ventilation
monitoring of HR, BP, CRT, RR, urine output and presence of skin mottling
44
target oxygen sats
94-98% unless hypercapnic/ type II respiratory failure = 88-92%
45
treating cardiogenic shock
```
wide bore cannula
crystalloid fluids
reassess haemodynamic status
examine for fluid overload
vasopressor if hypotension or continued hypoperfusion despite fluids
```
46
crystalloid fluid resuscitation
0.9% saline or hartmann's solution
| 200-250ml over <15 mins bolus
47
target MAP
65mmHg if cause of shock is unknown
48
treatment for fluid overload/ pulmonary oedema?
loop diuretic
IV furosemide
or vasodilator if systolic BP is over 90mmHg
49
vasopressor
causes vasoconstriction
e.g. noradrenaline, metaraminol, dopamine, vasopressin, adrenaline, inotrope - dobutamine if there is impaired cardiac function/CO
50
treatment for haemorrhagic shock
```
major haemorrhage protocol
blood products
reverse anticoagulation
IV tranexamic acid in trauma
fluid resus
hypovolaemic shock = blood products
```
51
blood products for haemorrhagic shock
RBCs
fresh frozen plasma - FFP
1:1 ratio in trauma or 1:2 in non-trauma
platelets
cryoprecipitate or fibrinogen concentrate if low fibrinogen
52
target haemoglobin in haemorrhagic shock
7-9g/dL or 70-90g/L
53
What does tranexamic acid do?
clot formation
| antifibrinolytic
54
how to treat obstructive/ distributive/ non-haemorrhagic shock?
```
crystalloid fluid resus
reassess haemodynamic status
examine for fluid overload
vasoactive drug - vasopressor/ inotrope
arterial line and central venous catheter
```
