L6 classification of shock Flashcards
what is shock
Shock is a life threatening condition of circulatory failure with inadequate tissue perfusion and oxygen delivery
CO= HRxSV Stroke volume is determined by preload, myocardia l contractility afterload
SVR is governed by what
vessel length, blood viscosity snd vessel diameter
4 types of shock
hypovolaemic
cardiogenic
obstructive
distributive
what is Hypovolaemic shock ( cold shock)
Cardiac output inadequate as the quantity of fluids inside the vessels is unable to fill them in ( loss of intravascular volume )
signs and symptoms of hypovoalmic shock
- Inadequate fluid intake
- Loss of fluid via vomit, diarrhoea, profuse sweating, polyuria, ileostomy, bowel obstruction, burns, pancreatitis, diabetic ketoacidosis etc
- Loss of blood – gastrointestinal, uterine (post partim) , surgery , traumas , intrathoracic/abdominal etc
reduced preload reduced EDV therefore reduced stroke volume reduced CO hypotension increased SVR reduced mixed venous oxygen saturation
what is cardiogenic shock
CO is inadequate because of poor pumping action of the heart as a result of myocardial abnormalities (normal intravascular volume)
causes of cariogenic shock
- Ischemia
- Myocarditis – typically viral
- Infective endocarditis
- Severe arrhythmias
- Septal/ventricular rupture
- Severe acidosis
signs and symptoms of cardiogenci shock
- Reduced stroke volume due to reduced pump action
- Reduced CO, hypotension
- Increased SVR and increased preloads (which is unable to improve the CO) – no reduction in the volume of fluid. (hypo have decreased preload) pump function impaired so even if you had more blood it doesn’t work.
- Reduced mixed venous oxygen saturation
what is obstructive shock
CO is inadequate as a result of obstructed blood flow in the lungs or heart
different causes of obstructive shock
intracardiac and extra cardiac
- Intracardiac obstruction – PE, valve obstruction (thrombosis, myxoma) etc
- Extracardiac obstruction – cardiac tamponade( needle to drain), tension pneumothorax , restrictive pericarditis etc
signs and symptoms
- Variable preload (often reduced with inadequate ventricular fillign0
- Reduced stroke volume
- Reduced CO (cardiac outflow obstruction with increased afterload)
- Hypotension
- Increased SVR
- Reduced mixed venous oxygen saturation
what is distributive shock
CO is relatively inadequate because the size of the vascular system is increased by vasodilation even though the blood volume Is normal
examples of distributive shock
- Septic shock
- Anaphylaxis
- Neurogenic
- Angioedema
- Adrenal insufficiency
- Thyroid insufficiency
signs and symptoms of distributive shock
Decreased preload Variable CO increased in elderly , septic shock fluhed, warm skin) Decreased systemic vascular resistance Decreased afterload Hypotension Inadequate end-organ perfusion
what do you give in anaphylactic shock
adrenaline as vasoconstrictor - also give steroids and anti-hsitmaines
