Shock Flashcards
What is shock?
Clinical syndrome of tissue hypoperfusion due to circulatory failure
What can arise due to hypoperfusion?
Systemic acidosis (pH<7.35)
Microcapillary thrombus
Cellular necrosis
Irreversible tissue damage
What is Cutis Marmorata?
Physioogical response to cold in neonates
What are ways to recognise shock?
Mottling
GCS <15
Confusion, agitation
Urine output <0.5ml/kg/h
How can you confirm shock?
Lactate levels
0.75mmol/L higher than normal carries worse prognosis
>2mmol/L arguably diagnostic
>4mmol/L significant mortality
Describe Cardiogenic shock?
Reduced force of cardiac contraction and stroke volume and therefore cardiac output and mean arterial pressure.
Compensatory increase in SVR, resulting in cool, clammy peripheries
What are treatments of cardiogenic shock?
Arrythmia - drugs/cardioversion poisoning - drugs/dialysis MI - drugs + PCI Cardiomyopathy -drugs Valve failure - drugs/surgery
Describe destructive shock?
Obstruction to cardiac outflow (otherwise similar to cardiogenic shock)
Evidence of raised jugular venous pressure and distended neck veins may be prmoninent
What does obstructive shock lead to?
Venous back pressure and blockage
What are treatments of obstructive shock?
Trauma - pericardiocentesis
Aortic dissection - thoractomy +/- surgery
Pleural pathology - Thoracostomy +/- surgery
Stasis - anticoagulation +/- thrombolysis or direct lysis
What are pathologies of obstructive shock?
Cardiac tamponade
Tension pneumothorax
Pulmonary embolus
Describe hypovalaemic shock?
Reduced blood volume
Lower venous return
Reduced force of cardiac contraction and cardiac output (Frank-Starling Law)
Describe distributive shock?
Reduced systemic vascular resistance due to vasodilatation with warm, red peripheries
Reduced mean arterial pressure
Compensatory increase in cardiac output
How do you assess shock?
ABCDE
Does noradrenaline cause vasoconstriction or vasodilation?
Vasoconstriction - which will bring up the blood pressure
