Hypovolemic shock

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Shock
General Surgery Orientation Medical Student
Lecture Series Dr. Peter Meade
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• SHOCK

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SHOCK

• Burning building

• Desert

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SHOCK

• Lack of Oxygen Delivery
• Low blood pressure
• i
• Decreased perfusion of tissues with Oxygen
• i
• Inflammatory Response
• Cell Damage

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SHOCK

• Lack of Oxygen Delivery
• (Hypoperfusion)
• i
• Cellular Damage
• i
• Inflammatory Response
• Hypoperfusion causes Inflammation
• Inflammation causes Hypoperfusion

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• What causes.
• SHOCK

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SHOCK

• Most common forms in surgery
• Hypovolemic
• Septic
• Cardiogenic

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SHOCK

• Lack of Oxygen Delivery
• (Hypoperfusion)
• h
• Hypovolemia
• Bleeding / Hemorrhage
• Vomiting
• Pancreatitis
• Burns
• Trauma
• Hypoperfusion causes Inflammation
• Inflammation causes Hypoperfusion

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SHOCK HYPOVOLEMIChemorrhagic
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SHOCK HYPOVOLEMICNon-hemorrhagic fluid losses

• Open wounds

• Burns- incredible fluid losses !

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SHOCKSEPTIC Endotoxins from bacteria Shock!
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SHOCK

• Lack of Oxygen Delivery
• (Hypoperfusion)
• h
• Septic
• Septicemia, Endotoxins, Vasodilatation,
• pneumonia,
• urinary tract infection,
• dead intestine,
• necrotic tissue
• Hypoperfusion causes Inflammation
• Inflammation causes Hypoperfusion

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SHOCK CARDIOGENIC

• Pump Failure

• Cardiogenic Shock

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SHOCK

• Lack of Oxygen Delivery
• (Hypoperfusion)
• h
• Cardiogenic
• Acute Myocardial infarction
• Aortic or mitral valve dysfunction
• Dysrhythmia
• Cardiac contusion
• Massive Pulmonary embolism
• Cardiac Tamponade
• Congestive Heart Failure
• Hypoperfusion causes Inflammation
• Inflammation causes Hypoperfusion

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SHOCK

• Lack of Oxygen Delivery
• (Hypoperfusion)
• i
• Cellular Damage
• i
• Inflammatory Response
• Hypoperfusion causes Inflammation
• Inflammation causes Hypoperfusion

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Inflammatory Response

• Vasoconstriction
• Vasodilation
• Capillary leak
• Nitric Oxide, PG2, kinins, histamine serotonin
• White Cells/ Polymorphonuclear cells
• Phagocytosis proteases, Interleukins

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Inflammatory Response

• Platelet Activation
• PDGF
• TGF-B
• WBC Products
• P-seletin
• E-selectin
• ICAM 1

• WBC Proteases
• IL-1, IL8
• TNF

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The Inflammatory ResponseIt can be like using a
machine gun to kill a fly on the wall.You might
get the fly, but the wall gets hit too!
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Hypoperfusion

• Anaerobic glycolysis
• Lactic Acidemia
• Low bicarbonate
• Low pH
• Multisystem Organ Failure

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• Krebs Cycle
• 36 ATPs

• Anaerobic glycolysis
• 2 ATPs

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Burning glucose without Oxygen lactic
acidosisBurning wet sticks smoke
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TREATMENT OF SHOCK

• Treat the primary cause
• Source Control
• Hemorrhagic / Hypovolemic
• Stop the bleeding
• Replace blood loss, volume
• Septic
• Drain the abscess
• Treat with antibiotics, volume, pressor agents

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Starling Curve

• Preload
• Contractility
• Afterload

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Starling Curve

• Preload
• Contractility
• Afterload

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Hypovolemic Shock

• Loss of circulating blood volume (Plasma)
• Normal Blood Volume
• - 7 IBW in adults
• - 9 IBW in children

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Hypovolemic Shock

• Hemorrhagic shock (3 categories)
• 1. Compensated
• 0-20 of blood loss
• Blood pressure is maintained
• increased vascular tone
• increased blood flow to vital organs

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Hypovolemic Shock

• The bodys response
• Compensated shock Baroreceptor mediated
• vasoconstriction
• Increased epinephrine, vasopressin, angiotensin
• Results in
• Tachycardia
• Tachypnea
• Lowered pulse pressure
• Slightly lowered urine output

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Hypovolemic Shock

• The Organs who win
• Brain
• Heart
• Kidneys
• Liver
• The Organs who lose
• Skin
• GI tract
• Skeletal Muscle

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Hypovolemic Shock

• But why
• The body will make whatever adjustsments it can
  to maintain.
• Adequate
• Cardiac
• Output
• Brain and heart perfusions remain near normal
  less critical organ systems stressed by
  ischemia.

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Hypovolemic Shock

• 2. Uncompensated
• 20-40 loss of blood volume
• Decrease in BP
• Tachycardia

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Hypovolemic Shock

• The bodys response
• Uncompensated shock
• vasoconstrictive mechanisms
• FAIL to maintain systemic perfusion pressure.
• Increased cardiac output
• Increased respiration
• Sodium retention

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Hypovolemic Shock

• 3. Lethal exsanguination
• 40 loss of blood volume
• Profound hypotension and inability to
  perfuse vital organs

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Hypovolemic Shock

• Volume Resuscitation What are my goals?
• 1. Rapid Responder
• Give 500cc-1 Liter crystalloid ? rapid
  improvement of BP/HR/Urine output
• lt 20 blood loss
• Surgery consult

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Hypovolemic Shock

• Volume Resuscitation What are my goals?
• 2.Transient Responder
• 500cc-1 Liter crystalloid ?
• improves briefly then deteriorates
• 20-40 blood loss
• Continue crystalloid infusion /- Blood
• Surgery consult

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Hypovolemic Shock

• Volume Resuscitation What are my goals?
• 3. Non Responder
• Give 2 Liters crystalloid/ 2 units Blood ? no
  response
• gt 40 blood loss
• STAT Surgery consult!

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Hypovolemic Shock

• Is my volume resuscitation adequate/inadequate?
• Urine output
• Vital signs
• Skin perfusion
• Pulse Oximetry
• Acidemia

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Septic Shock

• exaggerated endogenous inflammatory response to
  invasive infection leading to
• -circulatory collapse
• -multiple organ failure
• -death

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Septic Shock

• Mortality
• over 35 (sepsis with hypotension)
• 45 (sustained septic shock)

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Septic Shock

• Management
• Identify and treat the infectious source
• eg simple incision drainage?
• Exploratory laparotomy?
• Amputation?
• Volume resuscitation
• Restoration of perfusion pressure (may need
  pressors!)

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Cardiogenic Shock

• Acute hypotension
• low cardiac output
• inadequate LV outflow
• Poor end organ perfusion!

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Cardiogenic Shock

• Causes most likely to see on the surgery wards
• Acute MI
• Arrhythmia (A. fib)
• Cardiac Contusion
• Cardiac Tamponade
• Massive Pulmonary Embolism
• Decompensated Congestive Heart Failure