Shock Flashcards
What is clinical shock?
Acute circulatory failure leading to inadequate perfusion and cellular hypoxia
What are some clinical signs of shock? (5)
Tachycardia, tachypnoea, confusion, pallor, MAP<8kPa
What can cause low BP (shock)?
Low cardiac output or low systemic vascular resistance
What are some causes of reduced cardiac output? (2 categories)
Reduced preload: tension pneumothorax, PE, haemorrhage
Decreased contractility: CVD, hypoxia, drugs, pH or electrolyte disturbance
What are causes of low SVR?
Often pathogens. Bacterial toxins-> sepsis. Excess NO from macrophages
What is compensated shock?
Body control mechanisms are able to keep working
What is decompensated shock?
End organs not perfused and eventually fail.
What are the 4 kinds of shock?
Obstructive, distributive, hypovolaemic, cardiogenic
What are the signs of hypovolaemic shock?
Low BP, tachycardia, confusion, cold clammy skin, slow capillary refill, greyish pallor, oliguria, absent bowel sounds
What are the signs and symptoms of cardiogenic shock?
Chest pain, dyspnoea, diaphoresis, nausea, pulmonary oedema, tachycardia, very little urinary output
How do you treat cardiogenic/ hypovolaemic shock?
Expand circulating volume using CVP as a guide
What are the signs and symptoms of sepsis?
Low BP, tachy etc. FEVER, chills, rigors, fatigue, nausea, confusion
Signs and symptoms of obstructive shock?
Abrupt onset pleuritic pain, dyspnoea, hypoxia, tracheal deviation
Causes of obstructive shock?
PE or pneumothorax
Immediate compensatory responses to shock?
SNS up up, reduced urine and sodium excretion
Longer term compensatory responses to shock?
Inc renin from kidney, inc aldosterone from adrenal cortex. Thirst stimulated. Inc plasma proteins released from liver. EPO from peritubilar fibroblasts
How does septic shock happen?
LPS in gram negative bacteria-> neutrophils and monocytokines-> inflammation-> micro vascular damage-> reduced SVR
Management of shock? (4)
Lying down with head and heart level. Restore circulating BV. Standard vasopressor drugs. Appropriate antimicrobials.
Therapeutic goals of managing songs?
CVS: 8-12mmHg
MAP: over 65mmHg
Urine output: 0.5mL/kg/h
SVC: over 70%
