Haemodynamic Shock Flashcards
What is haemodynamic shock?
Acute condition of inadequte blood flow throughout the body
How can shock occur?
Fall in CO
Fall in TPR beyond capacity of heart to cope
What causes shock due to fall in CO?
Cardiogenic shock
Mechanical shock
Hypovolaemic shock
What is cardiogenic shock?
Acute failure of the heart to maintain CO
What is mechanical shock?
Obstructive
- ventricle cannot fill properly
What is hypovolaemic shock?
Reduced blood volume leads to poor venous return
What can cause cardiogenic shock?
MI
Arrhythmias
Acute heart failure
What happens in cardiogenic shock?
Heart fills but unable to pump properly
Dramatic drop in arterial BP
Tissues poorly perfused
- coronary arteries - exacerbate problem
- kidneys - oliguria
What is cardiac rest?
Unresponsiveness associated with lack of pulse
What is asystole?
Loss of electrical and mechanical activiry
What is PEA?
Pulseless electrical activity
What is ventricular fibrillation?
Uncoordinated electrical activity
What can cause mechanical shock?
Cardiac tamponade
Pulmonary embolism
How does cardiac tamponade cause mechanical shock?
Blood/fluid in pericardial space
- restricts filling of heart
High central venous pressure
Low arterial blood pressure
How does PE cause mechanical shock?
PE occludes a pulmonary artery
High pulmonary artery pressure
Ventricle cannot empty
High central venous pressure
Low arterial blood pressure
What is the most common cause of hypovolaemic shock?
Haemorrhage
What are the signs of hypovolaemic shock?
Tachycardia
Weak pulse
Pale skin
Cold clammy extremities
What is the compensatory response in hypovolaemic shock?
Low BP detected by baroreceptors Sympathetic stimulation Tachycardia Peripheral vasoconstriction Venoconstriction
What is the danger of hypovolaemic shock?
Tissue damage due to hyoxia
Lack of perfusion to organs
What is distributive shock?
Low resistance shock
- profound peripheral vasodilation
- reduces TPR
What can cause distributive shock?
Toxic shock
Anaphylactic shock
What causes toxic shock?
Sepsis
How does sepsis cause shock?
Bacteria release endotoxins Cause inflammatory response Causes vasodilation Fall in TPR Impaired perfusion of organs
Reduced blood volume
- leaky capillarys
What causes anaphylactic shock?
Severe allergic reaction
