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

2. SHOCK

4. SHOCK
Burning building
Desert

5. SHOCK
Low perfusion Low Oxygen Delivery Cells deprived of Oxygen Glucose incompletely metabolized Lactic Acidosis

6. Burning glucose without Oxygen = lactic acidosis Burning wet sticks = smoke

7. Krebs Cycle
36 ATPs
Anaerobic glycolysis
2 ATPs

8. Hypoperfusion Anaerobic glycolysis Lactic Acidemia
Low bicarbonate
Low pH
Multisystem Organ Failure

9. SHOCK Lack of Oxygen Delivery Low blood pressure Cell Damage
Decreased perfusion of tissues with Oxygen
Cell Damage
Inflammatory Response

10. Lack of Oxygen Delivery Inflammatory Response
SHOCK
Lack of Oxygen Delivery
(Hypoperfusion) i
Cellular Damage
Inflammatory Response
Hypoperfusion causes Inflammation
Inflammation causes Hypoperfusion

11. What causes….
SHOCK

12. SHOCK
Hypovolemic Obstructive Cardiogenic Distributive

13. SHOCK Hypovolemic -Hemorrhagic Obstructive Cardiogenic Distributive
-Non-hemorrhagic
dehydration, burns, GI losses, pancreatitis
Obstructive
Cardiogenic
Distributive

15. SHOCK HYPOVOLEMIC hemorrhagic

16. Lack of Oxygen Delivery
SHOCK
Lack of Oxygen Delivery
(Hypoperfusion) h
Hypovolemia
Bleeding / Hemorrhage
Hypoperfusion causes Inflammation
Inflammation causes Hypoperfusion

17. SHOCK HYPOVOLEMIC Non-hemorrhagic fluid losses
Open wounds
Burns- incredible fluid losses !

18. Treat the primary cause
TREATMENT OF SHOCK
Treat the primary cause
“Source Control”
Hemorrhagic / Hypovolemic
Stop the bleeding
Replace blood loss, volume

19. Starling Curve
Preload
Contractility
Afterload

20. Starling Curve
Preload
Contractility
Afterload

21. 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

22. Hypovolemic Shock The body’s response:
Compensated shock Baroreceptor mediated
vasoconstriction
Increased epinephrine, vasopressin, angiotensin
Results in:
Tachycardia
Tachypnea
Lowered pulse pressure
Slightly lowered urine output

23. Hypovolemic Shock 2. Uncompensated: 20-40% loss of blood volume
Decrease in BP
Tachycardia

24. Hypovolemic Shock 3. Lethal exsanguination: 40% loss of blood volume
Profound hypotension and inability to perfuse vital organs

25. Hypovolemic Shock Volume Resuscitation ~ What are my goals?
1. Rapid Responder
Give 500cc-1 Liter crystalloid  rapid improvement of BP/HR/Urine output
< 20% blood loss
Surgery consult

26. 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

27. Hypovolemic Shock Volume Resuscitation ~ What are my goals?
3. Non Responder
Give 2 Liters crystalloid/ 2 units Blood  no response
> 40% blood loss
STAT Surgery consult!

28. Hypovolemic Shock Is my volume resuscitation adequate/inadequate?
Urine output
Vital signs
Skin perfusion
Pulse Oximetry
Acidemia

29. Hypovolemic Shock Loss of circulating blood volume (Plasma)
Normal Blood Volume:
- 7% IBW in adults
- 9% IBW in children

30. SHOCK
Hypovolemic Obstructive Cardiogenic Distributive

31. SHOCK Hypovolemic Obstructive Cardiogenic Distributive
poor diastolic filling:
-tension pneumothorax -pericardial tamponade
-abdominal compartment syndrome
poor systolic contraction:
-pulmonary embolus
-aortic dissection, tumors
Cardiogenic
Distributive

32. SHOCK Obstructive decreased venous return

34. SHOCK
Hypovolemic Obstructive Cardiogenic Distributive

35. SHOCK CARDIOGENIC
Pump Failure
Cardiogenic Shock

36. SHOCK Hypovolemic Obstructive Cardiogenic Distributive
Myocardial infarction, contusion,
myocarditis
Mechanical valve failure, VSD, ventricular wall defects
Distributive

37. Lack of Oxygen Delivery
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

38. Cardiogenic Shock Acute hypotension low cardiac output
inadequate LV outflow
Poor end organ perfusion!

39. SHOCK Hypovolemic Obstructive Cardiogenic Distributive
Septic, anaphylactic, neurogenic, pharmacologic, endocrinologic

40. SHOCK: SEPTIC: Endotoxins from bacteria = Shock!

41. Lack of Oxygen Delivery
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

42. Septic Shock
exaggerated endogenous inflammatory response to invasive infection leading to:
-circulatory collapse
-multiple organ failure
-death

43. Septic Shock Mortality over 35% (sepsis with hypotension)
45% (sustained septic shock)

44. Treat the primary cause
TREATMENT OF SHOCK
Treat the primary cause
“Source Control”
Septic
Drain the abscess
Treat with antibiotics, volume, pressor agents

45. Lack of Oxygen Delivery Inflammatory Response
SHOCK
Lack of Oxygen Delivery
(Hypoperfusion) i
Cellular Damage
Inflammatory Response
Hypoperfusion causes Inflammation
Inflammation causes Hypoperfusion

46. The Inflammatory Response It 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!

47. Inflammatory Response
Vasoconstriction
Vasodilation
Capillary leak
Nitric Oxide, PG2, kinins, histamine serotonin
White Cells/ Polymorphonuclear cells
Phagocytosis: proteases, Interleukins

48. Inflammatory Response
Platelet Activation PDGF TGF-B WBC Products P-seletin E-selectin ICAM 1
WBC Proteases IL-1, IL8 TNF