shock

Question 1

Criteria of shock

Answer 1

0 inadequate o2 perfusion to tissue to meet demand

• altered mental state
• mottled clammy skin
• oligouria (inadequate perfusion to kidney)
• elevated blood lactate (anerobic metabolism taking over bcc of lack of oxygen) dominatinf > 2mmmol)
• the more severe the shock the higher the blood lactate.

0 Hypotension & compensentary tachycardia.

cardiogenic 
- coronaery artery d - MOST COMMON
- myocardditis 
-drug overdose (ccaine
Valvular disease 
- aortic stenosis 
- acute mitral valve rupture
- arrythmia 
(VT , HB , profound tacycardia)
hypovolemic
- reduced cardiac output (preload)
- low circulating volume 
haemorrhage (trauma , internal bleeding (e.g. bleed into gi TRACT) , RETROPERINEAL)
- BURNS 
- GI LOSSES E.G VOMITING DIARRHOEA

0 Obstructive = tamponade
(Mechanical onstruction to filling - tension pneumothorax , massive PE ,
(presents similarly to cardiogenic shock - echo useful in differientaion)

( first 3 - associated with low cardiac output)
distributive / septic shock - MOST COMMON
(associated with low cardiac output)
(excessive dilatation - causing imapired perfusion to vital organs (heart , brain , kidneys)

caused by release of inflammatry mediators
- sepsis is most common cause
anaphylaxsis
neurogenic
adrenal insufficiency (rare but dont forget)

Question 2

some calc

Answer 2

cardiac output x oxygen carried in blood x hb x 1.34 + (PA02 X 0.003))

0.003 = CONSTANT 
PA02 = AMOUND DISSOLVED IN BLOOD
D= Q X (HB X SA02 X 1.34 ) + (PA02 X0.003)
Q = CARDIAC OUTPUT 
SA02 = AMOUNT OF O2 CARRIED IN BLOOD

Question 3

assessment of shock

Answer 3

clinical - BP , RR , HR

ATERIAL BLOOD GAS
- PH , BASE DEFICIET

foccussed ECHO
(bedside - looking at heart chamber size , IVC diameter (whether it collapsing with breathing )

left / right ventricular contractiity
identifying pericardial effusion

Question 4

fluid therapy

Answer 4

crystalloid vs colliod (cystalloid is 1st line)

0 lactatated ringers (hartmas solution)
0 normal saline
Bleeding - need blood not fluid. (Haemostatic resucitation
now a move away from giving crystaliod if bleeding –> straight to blood products

saline - is acidic & has high CL content
(may make metabolic acidosis worse)

fluid challenge - done when person is not clear that someone is hypovolemic
(give fluid fast - if no improvement (change in BP , Stroke volume , CVP ) not really hypotensive .

• straigh leg raising test - quick method of doing a fluid challenge