1. Shock Scott G. Sagraves, MD, FACS Assistant Professor
Trauma & Surgical Critical Care
Associate Director of Trauma
UHS of Eastern Carolina

2. Objectives Define & classify shock Outline management principles
Discuss goals of fluid resuscitation
Understand the concepts of oxygen supply and demand in managing shock.
Describe the physiologic effects of vasopressors and inotropic agents

3. Goals Review hemodynamic techniques in the ICU
Introduce the concept of the cardiac cycle
Review of the pulmonary artery catheter parameters
Utilize the presentation to analyze clinical cases and to feel comfortable with pa-c parameters.

4. “A momentary pause in the act of death.” -John Collins Warren, 1800s
Shock:
“A momentary pause in the act of death.”
-John Collins Warren, 1800s

5. Hypotension In Adults: systolic BP  90 mm Hg
mean arterial pressure  60 mm Hg
 systolic BP > 40 mm Hg from the patient’s baseline pressure

6. Definition
SHOCK: inadequate organ perfusion to meet the tissue’s oxygenation demand.

7. “Hypoperfusion can be present in the absence of significant hypotension.”
-fccs course

8. Pathophysiology ATP + H2O  ADP + Pi + H+ + Energy
Acidosis results from the accumulation of acid when during anaerobic metabolism the creation of ATP from ADP is slowed.
H+ shift extracellularly and a metabolic acidosis develops

9. Pathophysiology
ATP production fails, the Na+/K+ pump fails resulting in the inability to correct the cell electronic potential.
Cell swelling occurs leading to rupture and death.
Oxidative Phosphorylation stops & anaerobic metabolism begins leading to lactic acid production.

10. Why Monitor? Essential to understanding their disease
Describe the patient’s physiologic status
Facilitates diagnosis and treatment of shock

11. History
1960’s
low BP = shock; MSOF resulted after BP restored
1970’s
Swan & Ganz - flow-directed catheter
thermistor  cardiac output
1980’s
resuscitation based on oxygen delivery, consumption & oxygen transport balance.

12. Pulmonary Artery Catheter

13. Pulmonary Artery Catheter
INDICATIONS
volume status
cardiac status
COMPLICATIONS
technical
anatomic
physiologic

14. PLACEMENT

15. West’s Lung Zones Zone I - PA > Pa > Pv
Zone II - Pa > PA > Pv
Zone III - Pa > Pv > PA
PA = alveolar
Pa = pulmonary artery
Pv = pulmonary vein

16. Correct PA-C Position

17. Standard Parameters Measured Calculated Blood pressure
Pulmonary A. pressure
Heart rate
Cardiac Output
Stroke volume
Wedge pressure
CVP
Calculated
Mean BP
Mean PAP
Cardiac Index
Stroke volume index
SVRI
LVSWI
BSA

18. Why Index? Body habitus and size is individual
Inter-patient variability does not allow “normal” ranges
“Indexing” to patient with BSA allows for reproducible standard

19. Index Example PATIENT A PATIENT B CI = 2.4 L/min/m2 CI = 1.5 L/min/m2
60 yo male
50 kg
CO = 4.0 L/min
BSA = 1.86
CI = 2.4 L/min/m2
PATIENT B
60 yo male
150 kg
CO = 4.0 L/min
BSA = 2.64
CI = 1.5 L/min/m2

20. PA Insertion 20 15 10 5
RA = 5
RV = 22/4
PA 19/10
PAOP = 9

21. CVP CVP of SVC at level of right atrium pre-load “assessment”
normal mm Hg
limited value

22. PAOP End expiration Reflection changes with positive pressure
Waveforms change  every 20 cm

23. Waveform Analysis A wave - atrial systole
C wave - tricuspid valve ventricular systole
V wave - venous filling of right atrium

24. Cardiac Cycle pulmonary Right ventricle Left ventricle systemic MPAP
PVRI
MPAP
pulmonary
PCWP
RVSWI
Right ventricle
Left ventricle
LVSWI
MAP
CVP
systemic
SVRI

25. Hemodynamic Calculations
Parameter Normal
Cardiac Index (CI)
Stroke Volume Index (SVI)
Sys Vasc Resistance Index (SVRI)
Left Vent Stroke Work Index (LVSWI)

26. Cardiac Index C.I. = HR x SVI
SVI measures the amount of blood ejected by the ventricle with each cardiac contraction.
Total blood flow = beats per minute x blood volume ejected per beat

27. Vascular Resistance Index
SYSTEMIC (SVRI)
MAP - CVP CI
 SVR = vasoconstriction
 SVR = vasodilation
PULMONARY (PVRI)
MPAP - PAOP CI
PVR = constriction
PE, hypoxia
x 80
x 80
Vascular resistance = change in pressure/blood flow

28. LVSWI = (MAP-PAOP) x SVI x 0.0136
Stroke Work
LVSWI = (MAP-PAOP) x SVI x
normal =
VSWI describe how well the ventricles are contracting and can be used to identify patients who have poor cardiac function.
ventricular stroke work =  pressure x vol. ejected

29. Too Many Numbers

30. Definitions
O2 Delivery - volume of gaseous O2 delivered to the LV/min.
O2 Consumption - volume of gaseous O2 which is actually used by the tissue/min.
O2 Demand - volume of O2 actually needed by the tissues to function in an aerobic manner
Demand > consumption = anaerobic metabolism

31. Rationale for Improving O2 Delivery
Insult
Tissue Hypoxia
Demands are met
Increased Delivery
Increased Consumption

32. Critical O2 Delivery VO2I DO2I The critical value is variable
& is dependent upon the patient, disease, and the metabolic demands of the patient.
DO2I

33. Oxygen Calculations
Arterial Oxygen Content (CaO2)
Venous Oxygen Content (CvO2)
Arteriovenous Oxygen Difference (avDO2)
Delivery (O2AVI)
Consumption (VO2I)
Efficiency of the oxygenation of blood and the rates of oxygen delivery and consumption

34. Arterial Oxygen Content
CaO2 = (1.34 x Hgb x SaO2) + (PaO2 x )
If low, check hemoglobin or pulmonary gas exchange

35. Arteriovenous Oxygen Difference
avDO2 = CaO2 - CvO2
Values > 5.6 suggests more complete tissue oxygen extraction, typically seen in shock

36. Oxygen Delivery (DO2I) O2AVI = CI x CaO2 x 10
Normal values suggests that the heart & lungs are working efficiently to provide oxygen to the tissues.
< 400 is bad sign

37. If VO2I < 100 suggest tissues are not getting enough oxygen
Oxygen Consumption
VO2I = CI x (CaO2 - CvO2)
If VO2I < 100 suggest tissues are not getting enough oxygen

38. SvO2
VO2
SvO2 = 1-
DO2

39. Oxycalculations

40. Resuscitation Goals CI = 4.5 L/min/m2 DO2I = 600 mL/min/m2
VO2I = 170 mL/min/m2
NOT ALL PATIENTS CAN ACHIEVE THESE GOALS
Critically ill patients who can respond to their disease states by
spontaneously or artificially meeting these goals do show a
better survival.

41. Break Time…

42. “Shock is a symptom of its cause.”
-fccs course

43. Signs of Organ Hypoperfusion
Mental Status Changes
Oliguria
Lactic Acidosis

44. Components

45. Categories of Shock
HYPOVOLEMIC
CARDIOGENIC
DISTRIBUTIVE
OBSTRUCTIVE

46. Goals of Shock Resuscitation
Restore blood pressure
Normalize systemic perfusion
Preserve organ function

47. In general, treat the cause...

48. Hypovolemic Shock Causes hemorrhage vomiting diarrhea dehydration
third-space loss
burns
Signs
 cardiac output
 PAOP
 SVR

49. Classes of Hypovolemic Shock

50. Treatment - Hypovolemic
Reverse hypovolemia vs. hemorrhage control
Crystalloid vs. Colloid
PASG role?
Pressors?

51. Resuscitation
Transport times < 15 minutes showed pre-hospital fluids were ineffective, however, if transport time > 100 minutes fluid was beneficial.
Penetrating torso trauma benefited from limited resuscitation prior to bleeding control. Not applicable to BLUNT victims.

52. Fluid Administration 1 L crystalloid  250 ml colloid
crystalloids are cheaper
blood must supplement either
FFP for coagulopathy, NOT volume
Watch for hyperchloremic metabolic acidosis when large volumes of NaCl are infused
NO survival benefit with colloids

53. Role of PASG?
Houston - Higher mortality rate in penetrating thoracic, cardiac trauma
No benefit in penetrating cardiac trauma
Role undefined in rural, blunt trauma
Splinting role

54. Cardiogenic Shock Cause Signs defect in cardiac function
 cardiac output
 PAOP
 SVR
 left ventricular stroke work (LVSW)

55. Coronary Perfusion Pressure
Coronary PP = DBP - PAOP
coronary perfusion =  P across coronary a.
GOAL - Coronary PP > 50 mm Hg

56. The Failing Heart
Improve myocardial function, C.I. < 3.5 is a risk factor, 2.5 may be sufficient.
Fluids first, then cautious pressors
Remember aortic DIASTOLIC pressures drives coronary perfusion (DBP-PAOP = Coronary Perfusion Pressure)
If inotropes and vasopressors fail, intra-aortic balloon pump

57. Distributive Shock Types Signs Sepsis Anaphylactic
Acute adrenal insufficiency
Neurogenic
Signs
± cardiac output
 PAOP
SVR

58. SIRS - Distributive Shock
Prompt volume replacement - fill the tank
Early antibiotic administration - treat the cause
Inotropes - first try Dopamine
If MAP < 60
Dopamine = g/kg/min
Norepinephrine = titrate (1-100 g/min)
R/O missed injury

59. Adrenal Crisis Distributive Shock
Causes
Autoimmune adrenalitis
Adrenal apoplexy = B hemorrhage or infarct
heparin may predispose
Steroids may be lifesaving in the patient who is unresponsive to fluids, inotropic, and vasopressor support. Which one?

60. Obstructive Shock Causes Signs Cardiac Tamponade Tension Pneumothorax
Massive Pulmonary Embolus
Signs
 cardiac output
 PAOP
 SVR

61. Endpoints?
ACS CoT ATLS - restoration of vital signs and evidence of end-organ perfusion
Swan-guided resuscitation
C.I.  4.5, DO2I  670, VO2I  166
Lactic Acid clearance
Gastric pH

62. Summary Type PAOP C.O. SVR HYPOVOLEMIC    CARDIOGENIC   
DISTRIBUTIVE  or N varies 
OBSTRUCTIVE   

63. Vasopressor Agents?
Augments contractility, after preload established, thus improving cardiac output.
Risk tachycardia and increased myocardial oxygen consumption if used too soon
Rationale, increased C.I. improves global perfusion

64. Vasopressors & Inotropic Agents
Dopamine
Dobutamine
Norepinephrine
Epinephrine
Amrinone

65. Dopamine Low dose (0.5 - 2 g/kg/min) = dopaminergic
Moderate dose (3-10 g/kg/min) = -effects
High dose (> 10 g/kg/min) = -effects
SIDE EFFECTS
tachycardia
> 20 g/kg/min  to norepinephrine

66. Dobutamine -agonist 5 - 20 g/kg/min
potent inotrope, variable chronotrope
caution in hypotension (inadequate volume) may precipitate tachycardia or worsen hypotension

67. Norepinephrine Potent -adrenergic vasopressor
Some -adrenergic, inotropic, chronotropic
Dose g/min
Unproven effect with low-dose dopamine to protect renal and mesenteric flow.

68. Epinephrine - and -adrenergic effects
potent inotrope and chronotrope
dose g/min
increases myocardial oxygen consumption particularly in coronary heart disease

69. Amrinone
Phosphodiesterase inhibitor, positive inotropic and vasodilatory effects
increased cardiac stroke output without an increase in cardiac stroke work
most often added with dobutamine as a second agent
load dose = mg/kg  g/kg/min drip
main side-effect - thrombocytopenia

70. Dilators
- inotropes
+ inotropes
Pressors

71. Summary `pressors & inotropes
dilator
Dobutamine
Milrinone/Amrinone
Labetalol
Ca+2 blocker
ACE inhibitor
hydralazine
nitroglycerine
Nipride
-dopamine
Isuprel
Digoxin
Calcium
-blocker
- inotrope
+ inotrope
epinephrine
-dopamine
norepinephrine
pressor
neosynephrine

72. Case Studies

73. GSW
24 year old male victim of a shotgun blast to his right lower quadrant/groin at close range.
Hemodynamically unstable in the field and his right lower extremity was cool and pulseless upon arrival to the trauma resuscitation area.

74. Shotgun Blast

75. Post-op
Patient received 12 L crystalloid, 15 units of blood, 6 units of FFP, and 2 6 packs of platelets.
HR 130, BP 96/48, T 34.7° C
PAWP 8, CVP 6, CI 4.2, SVRI 2700, LVSWI 42.
Diagnosis? Treatment?

76. SHOCK/HYPOVOLEMIA FLUIDS… FLUIDS… FLUIDS… BLOOD & PRODUCTS TRANSFUSION
CORRECT
ACIDOSIS
COAGULOPATHY
HYPOTHERMIA

77. MVC
38 year old female restrained driver who was involved in a high speed MVC.
She sustained a pulmonary contusion and fractured pelvis.

78. ICU Course Intubated and monitored with PA-C
PCWP = 22, CI = 3.5, SVRI = 2400, LVSWI = 39.8
HR = 120, BP = 110/56, SpO2 = 91, UOP = 25 cc/hr
What do you think...

79. ADJUST YOUR WEDGE FOR THE PEEP
HYPOVOLEMIA
ADJUST YOUR WEDGE FOR THE PEEP

80. Wedge Adjustment Measured PAOP - ½ PEEP = “real PAOP”
PEEP = 28, therefore “real wedge” = 8

81. Auto-Pedestrian Crash
Thrown from the rear bed of pick up truck during a MVC at 60 mph.
Hemodynamically unstable
Pain to palpation of the pelvis
Hematuria with Foley® insertion

84. ICU Course Pelvis “closed” QID Dressings, intubated, PA-C inserted
PCWP = 20, CI = 5.2, SVRI = 280, LVSWI = 24.5, PEEP = 8
Diagnosis? Treatment?

85. Sepsis Fluids Correct the cause Vasopressors Antibiotics Debridement
Phenylephrine
Levophed

86. Initial Resuscitation
CVP: mm Hg
MAP  65 mm Hg
UOP  0.5 cc/kg/hr
Mixed venous Oxygen Sat  70%
Consider:
Transfusion to Hgb  10
Dobutamine up to 20 g/kg/min

87. Vasopressors Assure adequate fluid volume Administer via CVL
Do not use dopamine for renal protection
Requires arterial line placement
Vasopressin:
Refractory shock
Infusion rate 0.01 – 0.04 Units/min

88. Steroid Use in Sepsis
Refractory shock mg/day of hydrocortisone in divided doses for 7 days
ACTH test
Once septic shock resolves, taper dose
Add fludrocortisone 50 g po q day

89. Geriatric Trauma 70 year old female
MVC while talking on her cell phone
ruptured diaphragm and spleen s/p OR
Intubated and PA-C

90. ICU Course PCWP = 28, CI = 1.8, SVRI = 3150, LVSWI = 20.7
Diagnosis? Treatment?

91. Cardiogenic Shock Preload augmentation - Consider Fluids Contractility
dopamine
dobutamine
phosphodiesterase inhibitor
Afterload reduction
nitroglycerin

92. Shock: “rude unhinging of the machinery of life.”
Don’t forget...
Shock: “rude unhinging of the machinery of life.”
-Samuel D. Gross, 1872