SHOCK

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SHOCK
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Objectives

• Understand what shock is
• Define types of shock
• Understand Pathophysiology of shock
• Understand how to treat shock

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WHAT IS SHOCK?

• Inadequate Tissue Perfusion

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Symptoms of Shock
General Symptoms
Specific Symptoms

• Anxiety /Nervousness
• Dizziness
• Weakness
• Faintness
• Nausea Vomiting
• Thirst
• Confusion
• Decreased UO

• Hx of Trauma / other illness
• Vomiting Diarrhoea
• Chest Pain
• Fevers / Rigors
• SOB

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Signs of Shock

• Pale

Cold Clammy
Sweating
Cyanosis
Tachycardia
Tachypnoea
Confused / Aggiatated
Unconscious
Hypotensive
Stridor / SOB
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Circulatory Homeostasis
Tissue perfusion is driven by blood pressure

• BP CO X PVR

CO Cardiac Output PVR Peripheral Vascular
resistance
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Cardiac Output

• CO SV X HR
• This means that
• BP SV X HR X PVR
• Blood Pressure Stroke Volume X Heart Rate X
  Peripheral Vascular Resistance

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Stroke Volume

• Volume of Blood pumped by the heart during 1
  cycle

What affects Stroke volume?
Rhythm Problems
Blood Volume
Heart Muscle Damage
MechanicalObstruction
Mechanical Obstruction
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What makes up blood volume
Plasma
RBCs
Platelets
WBCs
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What Alters Blood Volume?

• Haemorrhage
• Plasma Loss
• Redistribution of Extracellular Volume

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Heart Rate

• Heart rate increases as a compensatory response
  to Shock
• Rarely you get
• High Output failure
• Heart rate too fast to allow adequate refilling
  of heart between beats

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Peripheral Vascular Resistance

• PVR regulated by ARTERIOLAR tone.
• Dilatation opens Arteriovenous beds increases
  volume of circulatory system

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What Alters PVR?

• Circulation cytokines Inflammatory mediators
  (e.g. Histamine)
• Endotoxins
• Drugs (e.g. Nitrates)

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Blood Volume
Mechanical Obstruction
Heart Damage / Rhythm
Heart Rate
Stroke Volume
PVR
Blood Pressure
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Types of Shock

• Hypovolaemic
• Cardiogenic
• Redistributive

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Hypovolaemic

• Volume Loss
• Blood loss -Haemorrhage
• Plasma Loss -Burns / Pancreatitis
• ECF Loss - VD

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Cardiogenic

• Pump Failure
• May be due to
• inability of heart to Contact
• Inability of heart to pump blood

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Redistributive

• Decreased Peripheral Vascular Resistance
• Septic Shock
• Spinal / Neurogenic Shock
• ANAPHYLACTIC shock

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Pathophysiological Response

• Flight or fight response
• Increased Catecholamine release
• Activation of Renin-Angiotensin system
• Increase glucocorticoid and mineralcorticoid
  release
• Activation of Sympathetic nervous system

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Treatment of Shock

• ABC

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Treatment of Shock

• Ensure Adequate Intravascular Volume
• Support Pump

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Anaphylactic Shock

• Caused by a hypersensitivity reaction to an
  allergen in a previously sensitised patient

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Common Allergens

• Nuts
• Bee / Wasp Stings
• DRUGS

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Common Features

• Angio-oedema
• Bronchoconstriction
• Vasodilatation and hypotension
• Urticareal rash

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Angio-oedema
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Treatment

• RECOGNISE THE PROBLEM
• GET HELP
• ABC

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Treatment

• Ensure Airway is adequate
• Oxygen
• IV access early
• IV fluids
• ADRENALINE 0.5ml 1 in 1000 IM
• Bronchodilators
• Steroids

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SHOCK

• Clinical Scenarios

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• 1) A 26 year old man with a comminuted closed
  fracture of the femur shaft undergoes
  intramedullary nail fixation. Two days post
  operatively, he develops a pyrexia, shortness of
  breath and tachycardia.
• Discuss the emergency management?

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• 2) A 72 year old man develops sudden back pain
  and is brought to the emergency department with a
  swollen ,tense abdomen. He is tachycardic ,with a
  low volume pulse and low BP.
• Discuss the emergency management?

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• 3) A 72 year old man with an underlying prostate
  carcinoma sustains a femoral shaft fracture .He
  undergoes intramedullary nail fixation. At post
  operative day 7 he develops a shortness of breath
  ,hypotension and a tachycardia
• Discuss the emergency management?