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Flashcards in Shock Deck (15)
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1
Q

What is shock?

A

Clinical syndrome of tissue hypoperfusion due to circulatory failure. It is common, life-threatening and acute

2
Q

What does inadequate perfusion cause?

A
  • Systemic acidosis, further worsening global enzyme function and cellular performance
  • Micro-capillary thrombus with patchy tissue injury (image shows micro-circulatory changes in health-A and in septic shock-B) and even large vessel thrombus with organ infarction
  • Eventual cellular necrosis results in mortality
  • In survivors, a degree of tissue injury may be irreversible, contributing to chronic mortbidity
3
Q

How is shock recognised?

A
  1. Mottling of the skin
  2. GCS <15, confusion, agitation
  3. Urine output <0.5ml/kg/hr (oliguria)
4
Q

How is shock confirmed?

A

Lactate levels - >2mmol/L arguably diagnostic >4mmol/L significant mortality

5
Q

What is the mechanism of action in cardiogenic shock?

A
  1. Reduced force of cardiac contraction and stroke volume and therefore cardiac output and mean arterial pressure
  2. Compensatory increase in SVR, resulting in cool, clammy peripheries
6
Q

How is cardiogenic shock treated?

A
  • HR - drugs +/- cardioversion if arrhythmia, drugs +/- dialysis if poisoning
  • Stroke volume - drugs +/- PCI if MI, drugs if cardiomyopathy, drugs +/- surgery if valve failure
7
Q

What is obstructive shock?

A
  1. Obstruction to cardiac outflow - otherwise similar to cardiogenic shock
  2. Evidence of raised JVP and distended neck veins may be prominent
8
Q

How is obstructive shock treated?

A
  • Cardiac tamponade - pericardiocentesis if trauma, thoracotomy +/- surgery if aortic dissection
  • Tension pneumothorax - thoracentesis if trauma, thoracostomy +/- surgery if pleural pathology
  • Pulmonary embolus due to stasis- anti-coagulation +/- thrombolysis or direct lysis
9
Q

What is the mechanism of action in hypovolaemic shock?

A
  1. Reduced blood volume
  2. Lower venous return to the heart
  3. Reduced force of cardiac contraction and cardiac output
10
Q

If someone had a volume loss of >40%=over 2000ml, what would you expect their ABCDE to show?

A
  • A + B = resp rate >35
  • C = heart rate >140
  • C = decreased blood pressure
  • D = lethargic
  • E = urine output negligible
11
Q

How is hypovolaemia treated when the cause is haemorrhage?

A
  • Temporising measures - pressure, splint, binding
  • Find and stop bleeding - endoscopy, surgery
  • Cross-match, blood, blood products
12
Q

How is hypovolaemia treated when dehydration is the cause?

A
  1. Fluids, electrolytes if GI loss
  2. Specialist unit care if burns
  3. Steroids/insulin if renal/cellular loss e.g. DKA or Addisonian crisis
13
Q

What is distributive shock?

A
  1. Reduced systemic vascular resistance due to vasodilatation with warm, red peripheries
  2. Reduced mean arterial pressure
  3. Compensatory increase in cardiac output
14
Q

What are some of the inflammatory causes of distributive shock and how are these managed?

A
  1. Sepsis - antibiotics +/- NA
  2. SIRS, including pancreatitis and burns - supportive therapy
  3. Anaphylactic shock - adrenaline
15
Q

How is a neurogenic cause of distributive shock managed?

A
  • Spinal cord damage - neurosurgery
  • Iatrogenic (spinal/epidural) - support +/- vasopressors