An Overview of Circulatory FailureAqua Asif | @AquaOishee | LearnMedicine

Shock

ACUTE CIRCULATORY FAILURE

INADEQUATE TISSUE PERFUSION

Cellular damage Cellular dysfunction Failure of major organ systems

Maintained by arterial blood pressure (MAP)

MAP = SVR × CO

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Classification

SHOCK

COLD WARM

MAP = SVR × ↓CO MAP = ↓SVR × CO

Cardiogenic Hypovolaemic Obstructive

Septic Anaphylactic NeurogenicHaemorrhagic Non- haemorrhagic

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‘COLD’ SHOCK

Pump fa

ilure

E.g. Congesti

ve

heart fa

ilure

/

acute m

yoca

rdia

l infa

rctio

n

2Hyp

otensio

n

This is

picked up b

y baro

rece

ptors

→ they t

ry to

counte

r this.

..

3Vaso

const

rictio

n

This th

en redire

cts blood to

the

vital o

rgans →

cold

extre

miti

es

4Decr

eased ve

nous retu

rn

Blood ends

up backin

g up in

the

pulmonary

vess

els → leadin

g to

pulmonary

oedema

Cardiogenic

1

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Intra

vasc

ular volu

me

E.g. PPH, t

raum

a, varic

eal bleeds

/// fluid

loss

(D&V, b

urns)

2Decr

eased ve

nous retu

rn

If th

ere’s

less in

trava

scular v

olum

e,

venous r

eturn

will

also d

rop and...

3Decr

eased ca

rdiac o

utput

Simila

r to

card

iogenic sh

ock,

periphera

l vaso

constr

iction occ

urs

4Vaso

const

rictio

n

This th

en redire

cts blood to

the

vital o

rgans →

cold

extre

miti

es

Hypovolaemic

1

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Physica

l obst

ruct

ion

E.g. te

nsion

pneumoth

orax,

card

iac ta

mponade, P

E

2Decr

eased p

ump fu

nctio

n

If th

e heart is

preve

nted fro

m

pumpin

g pro

perly…

3Decr

eased ca

rdiac o

utput

Simila

r to

th

e oth

er ty

pes,

periphera

l vaso

constr

iction occ

urs

4Vaso

const

rictio

n

This th

en redire

cts blood to

the

vital o

rgans →

cold

extre

miti

es

Obstructive

1

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‘WARM’ SHOCK

Sepsis

E.g. infe

ctive endoca

rditi

s, SA,

menin

gitis,

pyelonephrit

is...

2M

acrophage act

ivatio

n

IL-1, IL

-6, T

NFα re

leased, a

long with

nitric oxid

e...

3Vaso

dilatio

n

This th

en causes p

atients

to appear

warm and flush

ed...

4Thro

mboplast

in

Inte

resti

ngly,

this

activate

s th

e

coagulatio

n cascade → leadin

g to

dissem

inate

d

intra

vasc

ular

coagulatio

n

Septic

1

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Inju

ry to

the C

NS

E.g. spin

al cord

traum

a, TBI,

intra

cere

bral h

aemorrh

age

2Loss

of sym

pathetic

tone

Usually

the sy

mpath

etic sy

stem

stim

ulates c

ardiac outp

ut...

3In

crease

d para

sym

pathetic

Inste

ad, th

e para

sym

pathetic

syste

m w

ill dom

inate

...

4Vaso

dilatio

n

Incre

ased para

sym

pathetic

action

will lead to

perip

heral v

asodila

tion

→ warm

and flushed!

Neurogenic

1

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Wors

t alle

rgic

react

ion

E.g. peanuts…

those

darn

peanuts

can b

e deadly.

..

2Ty

pe 1 hyp

ersensit

ivity

This leads t

o IgE-m

ediated re

lease

of antib

odies...

3M

ast ce

lls

Mast

cell a

ctivatio

n leads t

o release

of hist

amin

e and bra

dykin

in...

4Vaso

dilatio

n

This th

en causes p

atients

to appear

warm and flush

ed...

Anaphylactic

1

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Renal Failure

Acute Kidney Injury

Pre-renal

● Hypovolaemia

● Sepsis

● Low cardiac output

Renal

● Ischaemic injury○ Hypoxia

○ Hypoperfusion

Postrenal

Kidneys can’t function without adequate perfusion

AKI can lead to hyperkalaemia and pulmonary oedema

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Metabolic Acidosis

Impaired tissue perfusion Renal failure

High Anion Gap

LOW pH LOW HCO3- NORMAL pCO2

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A-E Assessment

Assessment

Circulation

ASSESS TREAT

CHECK REQUEST MONITOR INVESTIGATE MANAGE

HYPOTENSIVE?

HAEMORRHAGE?

TRAUMA?

BLOODS

CANNULATE

BLOOD PRESSURE

CAP REFILL TIME

PULSE ECG CATHETERISE

URINE OUTPUT

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Classification

SHOCK

COLD WARM

MAP = SVR × ↓CO MAP = ↓SVR × CO

Cardiogenic Hypovolaemic Obstructive

Septic Anaphylactic NeurogenicHaemorrhagic Non- haemorrhagic

Aqua Asif

KAHOOT!

THANK YOU! Aqua Asif

@AquaOishee

LearnMedicine