Shock Flashcards
(34 cards)
What is shock?
inadequate tissue perfusion resulting in decreased oxygen delivery & oxygen consumption leading to cell death
What is the pathophysiology of shock?
1) inadequate perfusion
2) cell hypoxia
3) lactic acid accumulation & fall in pH -> anaerobic
metabolism
4) metabolic acidosis
5) cell membrane dysfunction & failure of sodium pump
6) intracellular lysosomes release digestive enzymes ->
efflux of potassium & influx of sodium & water
7) toxic substance enter circulation
8) capillary endothelium damaged
9) further destruction, dysfunction & cell death
What are the pro-inflammatory mediators of shock?
- IL-1 alpha & beta
- IL-2
- IL-6
- IL-8
- interferon
- TNF
- Platelet activating factor
What are the anti-inflammatory mediators of shock?
- IL-4
- IL-10
- IL-13
- Prostaglandin E2
- TGF beta
What is the main trigger of shock?
loss of blood volume
What are the types of shock?
- hypovolemic (reduced preload)
- restrictive (obstructive)
- redistributive (severe peripheral vasodilatation0
- cardiogenic
What are the causes of hemorrhagic hypovolemic shock?
HEMORRHAGIC
- traumatic vascular injury
- multiple fractures
- ruptured abdominal aortic or left ventricle aneurysm
- gastrointestinal bleeding
- aortic-enteric fistula or ruptured hematoma
- hemorrhagic pancreatitis
- postpartum hemorrhage
What are the non-hemorrhagic causes of hypovolemic shock?
- diarrhea or vomiting
- burns
- diabetes (urinating a lot)
- third space losses into extravascular space or body
What is the normal amount of blood in an average person?
80cc per kg
losing <750mL of blood will lead to what stage of hypovolemic shock?
Class I
<15%
How much blood is lost in Class II hypovolemic shock?
750-1500mL 15-30% tachycardia BP is orthostatic patient is anxious
What are the 3 vital organs?
brain
heart
kidney
What’s the normal urine output?
1mL-2mL / Kg / hour
How do we know a patient is in class III hypovolemic shock?
patient is confused tachycardia hypotension loss of 1500-2000mL of blood 30-40%
What occurs in class IV of hypovolemic shock?
loss of >2000mL of blood >40% tachycardia severe hypotension obtunded patient
What are the causes of obstructive shock?
pulmonary vascular (right ventricular failure)
- hemodynamically significant pulmonary embolism
- severe pulmonary hypertension
- severe stenosis of pulmonary or tricuspid valve
mechanical
- tension pneumothorax
- pericardial tamponade
- constrictive pericarditis & restrictive cardiomyopathy
- abdominal compartment syndrome
What is the most common cause of distributive shock?
SIRS —> septic shock (infection)
vasodilation
What are the causes of distributive (septic) shock?
- burns
- pancreatitis
- post-myocardial infarction, cardiac arrest, or coronary bypass
- viscus perforation
- fat embolism, idiopathic systemic capillary leak syndrome
What are the types of distributive shock?
- SIRS
- Septic shock
- Neurogenic shock
- Anaphylactic shock
What occurs in neurogenic shock?
- spinal injury at or above thoracolumbar sympathetic nerve roots leading to interruption of autonomic pathways
- loss of sympathetic tone to vascular system causing vasodilation
What is the cause of anaphylactic shock?
severe IgE mediated allergic reactions to insect stings, food, & drugs
What are the cardinal signs of anaphylactic shock?
bronchospasm & increased airway resistance
hemodynamic collapse
What are the types of cardiogenic shock?
- cardiomyopathic
- arrhythmic
- mechanical
What are the causes of cardiomyopathic shock?
- MI is most common
- severe right ventricular infarction
- acute heart failure with severe dilated cardiomyopathy
- myocardial depression due to advanced septic or
neurogenic shock - myocarditis
