Critical Illness Flashcards
What is the definition of shock?
Acute circulatory failure with inadequate or inappropriately distributed tissue perfusion (systolic<90mmhg)
What is hypovolaemic shock, and what can cause it?
Loss of intravascular volume, caused by: - Haemorrhagic shock (trauma, GI bleeding, AAA) - DKA - GI fluid loss - Extensive burns - Fluid loss from fistulae or drains
How is hemorrhagic shock classified?
1 - <750ml lost, no physiological changes 2 - 750-1500ml lost, pale/cold/clammy, parameters raised 3 - 1500-2000ml lost, altered mental state 4 - >2000ml lost, close to cardiac arrest As stages increase, pulse pressure becomes narrower, resp rate and heart rate increase, and urine output decreases
What is distributive shock, and what causes it?
Vasodilation with increased capillary permeability and reduced vascular resistance, caused by: - Sepsis - Anaphylaxis - Neurogenic shock (spinal cold injury) - Endocrine failure (Addison’s)
What is obstructive shock, and what causes it?
Physical obstruction to blood flow in the great vessels or the heart itself, caused by: - Tension pneumothorax - Massive PE - Cardiac tamponade
What is cardiogenic shock, and what causes it?
Pump failure, caused by: - MI - Arrythmia - Myocarditis - Cardiac tamponade
What is dissociative shock, and what causes it?
Oxygen unable to enter the cells, due to: - Cyanide poisoning
What are some compensatory mechanisms in shock?
Increased RR - blow off C02 from acidosis Vasoconstriction - adrenaline released in response to hypotension Decrease in urine output - low BP causes ADH production
What are the four stages of shock?
- Initial 2. Compensatory 3. Progressive - failure of compensatory mechanisms 4. Refractory - vital organs have failed, death imminent
How should anaphylactic shock be managed?
IM adrenaline (500mcg) IV fluid bolus Steroids (hydrocortisone) Antihistamines (chlorphenamine)
How should cardiogenic shock be managed?
MONA (morphine, oxygen, nitrates, aspirin) DONT give fluids
How should tension pneumothorax be managed?
Needle thoracocentesis - to drain air 02
How should hemorrhagic shock be managed?
FIND THE CAUSE AND TREAT IT RESTORE CIRCULATING VOLUME - O negative blood (large bore IV), IV fluids STOP BLEEDING Tranexamic acid (stop bleeding)
How should septic shock be managed?
Sepsis 6 3 in - o2, antibiotics (tazocin + gentamicin), fluids (20ml/kg crystalloid) 3 out - lactate, UO, blood cultures
How should hypovolaemic shock be managed?
Treat underlying cause Give fluid bolus Raise LEGS