Shock Management

1. Shock
AKAMAH ASAA SOLOMON, RN, CCN

2. Objectives:
At the end of this Lecture you would be able to :
Define and Classify Shock.
Differentiate the various Categories of Shock.
Describe Pathophysiology of Shock.
Identify Etiology and Clinical Features of Shock.

3. Definition
A condition in which the Cardiovascular System fails to perfuse
tissues adequately resulting in decreased tissue oxygen delivery.
Life-threatening medical emergency characterized by inability of the
body to adequately circulate blood to the body cells to supply
enough oxygen and nutrients to meet tissue requirements and
remove metabolic waste.

4. Definition
•It can also be defined as a life-threatening in which blood
flow to the organs is low, decreasing delivery of oxygen,
nutrients and removal of waste thus causing organ damage
and sometimes death.

5. Definition of hemodynamic terms
•Perfusion: supply of Oxygen and nutrients to and removal
of wastes from cells and tissues of body as a result of
adequate flow of blood through capillaries.
•Hypoperfusion: inability of body to adequately circulate
blood to body’s cells to supply them with oxygen, nutrients
and remove waste.

6. Definition of hemodynamic terms
• Stroke Volume (SV): amount of blood pumped into aorta by
contraction of left ventricle per heart beat.
• Cardiac Output (CO): amount of blood pumped into aorta by
contraction of left ventricle in one minute.

7. Hypotension:
•Hypotension is the medical term for low Blood Pressure-
less than 90/60.
•In Adults:
•Systolic BP  90mmHg.
•Mean Arterial Pressure  60 mmHg.
•Decreased Systolic BP > 40 mmHg(not always the
case) from the patient’s baseline pressure.

8. Note
Hypoperfusion can be present in the absence of
significant Hypotension.”
“Shock can occur with normal Blood Pressure and
Hypotension can occur without Shock”. Example, in
cardiogenic shock

9. Physiological principles
Tissue Perfusion is driven by Blood Pressure
Blood Pressure = Cardiac Output x Systemic Vascular
Resistance OR Total Peripheral Resistance (TPR)
(BP = CO X SVR)
Cardiac Output = Stroke Volume x Heart Rate
(CO = SV x HR)

10. Basic pathophysiology
• 1. Fall in Flow:
• Haemorrhage
• Diarrhoea/vomiting
• Burns
• PE
• Tension Pneumothorax
• Tamponade
• Myocardial Infarction
• Cardiac Failure
Volume Loss
(Hypovolemic
)
Fall in Flow
(Low Cardiac Output)
Fall in Filling
(Obstructive)
Fall in
Contractility
(Cardiogenic)

11. Basic Pathophysiology
• 2. Fall in Resistance:
• Sepsis
• Anaphylaxis
• Spinal Cord Injury
• Liver Failure
• Vasodilation results in a drop in Systemic or Peripheral Vascular
Resistance.
• In order to maintain Blood Pressure, Cardiac Output increases resulting in
warm peripheries with a rapid, bounding pulse (high output” shock).
Vasodilation
(Distributive)
Fall in
Resistance

12. Compensatory Mechanisms
Most immediate of compensatory mechanisms are those of
Sympathetic Nervous System and Renin Angiotensin Mechanism.
Sympathetic Nervous System:
NE, Epinephrine, and Cortisol released
Cause vasoconstriction, increase in HR, and increase of
Cardiac Contractility (Cardiac Output)
Renin-Angiotensin mechanism:
Water and Sodium Conservation and Vasoconstriction
(aldosterone)
Increase in Blood Volume and Blood Pressure
12

13. Cellular Response to Shock
Blood
Loss
Inadequate
Perfusion
Cellular
Hypoxia
Aerobic
Metabolism
Anaerobic
Metabolism
Lactic
Acid
Cellular
Edema
Acidosis
Cellular
Death

14. Classification of Shock
4 main etiologies of shock include:
Hypovolemic: Low cardiac output due to low intravascular volume.
Cardiogenic: Low cardiac output despite adequate intravascular
volume.
Distributive: Low total peripheral or systemic vascular resistance,
usually septic.
Obstructive: Low cardiac output due to outflow obstruction.

15. Hypovolemic shock
1. Hemorrhage
a. Trauma
b. Gastrointestinal hemorrhage
c. Postsurgical, post procedural bleeding
d. Intra-abdominal (e.g., abdominal aortic
aneurysm, ruptured ectopic pregnancy)
2. Volume depletion
a. Vomiting
b. Diarrhea
c. Excessive diuresis (from diuretics or
uncontrolled diabetes). D: Burns

16. Cardiogenic shock
Poor contractility:
1. Myocardial infarction (MI)
2. Myocarditis

17. Obstructive shock
Outflow Obstruction:
a. Aortic stenosis
b. Hypertrophic cardiomyopathy
c. Pulmonary embolism (PE)
Reduced filling
a. Constrictive pericarditis
b. Tension pneumothorax
c. Mitral stenosis

18. Distributive shock
1. Septic shock; as a result of severe infection in the blood.
2. Anaphylactic shock; as a result of severe allergic reaction.
3. Neurogenic shock; as a result of injury to the spinal cord.

19. Stages of shock
•Initial stage- tissues are under perfused, decreased cardiac
output without signs and symptoms.
•Compensatory/reversible stage- activation of sympathetic
nervous system and renin-angiotensin system.

20. Stages of shock
Progressive stage- if there is no interventions or if
interventions fails, compensatory mechanisms worsen cardiac
state leading to anerobic metabolic metabolism and acidosis.
Cardiologist care required for cardiogenic shock.
Refractory/irreversible stage- survival is extremely limited,
complications such as cardiopulmonary arrest, dysrhythmias,
multiple organ failure, stroke and death.

21. Classification of hypovolemic shock
Class I Class II Class III Class IV
Blood Loss- ml < 750ml 750-1500ml 1500-2000ml >2000ml
Blood Loss-%
Volume
<15% 15-30% 30-40% >40%
Pulse rate <100/min >100/min 120-140/min >140/min
Blood Pressure Normal Normal  
Pulse Pressure Normal   
Capillary refill Normal + + +
Respiratory rate 14-20/min 20-30/min 30-40/min >40/min
Urinary output >30ml/Hour 20-30 ml/Hour 5-15ml/Hour Anuria
Mental status Mild anxiety Anxiety Confused Lethargic
Fluid Crystalloid Crystalloid Blood Blood

22. Pathophysiology of Hypovolemic Shock

23. Clinical Presentation of Hypovolemic Shock
Tachycardia and tachypnea
Weak, thread, fast pulses
Hypotension
Skin cool & clammy
Mental status changes
Decreased urine output: dark & concentrated
Signs
•  cardiac output
•  SVR

24. Shock Index (SI)
Heart Rate divided by Systolic Blood Pressure. (Normal range- 0.5 to 0.7
in healthy adults).
Suggested as marker used to predict severity of Hypovolemic Shock.
Classification of Hypovolemic Shock based on SI enables fast and reliable
assessment of Hypovolemic Shock in emergency department.
SI <0.6 (No Shock), SI ≥0.6 to <1.0 (Mild Shock), SI ≥1.0 to <1.4
(Moderate Shock) and SI ≥1.4 (Severe Shock).

25. Classification of Hypovolemic Shock based on the Shock Index (SI)
Class I Class II Class III Class IV
Shock No Shock Mild Shock Moderate Shock Severe Shock
SI at admission <0.6 ≥0.6 to <1 ≥1 to <1.4 ≥1.4
Need of Blood
products
Observe Consider use of
Blood products
Prepare Transfusion Prepare massive
Transfusion
SI based classification is an easy and reliable tool to identify trauma
patients at risk for the need of blood products.

26. Mgt of shock
• Assessment- ABCDE approach
• High concentration of oxygen
• Keep patient warm
• Specific treatment dependind on cause of shock.
• Transport

27. Initial management of hypovolemic shock
Management Goal: Restore Circulating Volume, Tissue
Perfusion, & Correct Cause:
Early Recognition- Do not rely on BP! (30% fluid loss).
Control Hemorrhage.
Restore Circulating Volume.
Optimize Oxygen Delivery.
Vasoconstrictor if BP still low after Volume Loading.

28. Management of hypovolemic shock cont.
ABCs.
Establish 2 large bore IVs or a Central Line.
Crystalloids
Normal Saline or Lactate Ringers
Up to 3 liters using fluid challenge.
Packed Red Blood Cells
O Negative or Cross Matched.
Control any Bleeding.
Arrange Definitive Treatment.

29. Fluid Challenge
250-500ml over 5-15 min
Assess response:
No response
Transient response
Sustained response
If no/transient response- REPEAT
If you suspect Cardiac cause, or patient known to have Heart Failure- use
100-200ml instead

30. Clinical presentation of cardiogenic shock
Signs:
Cool, mottled skin
Tachypnea
Hypotension
Altered Mental Status
Narrowed Pulse Pressure
Rales, Murmur
Defined as:
SBP < 90 mmHg
CI: <1.8 L/min per m2
without support)

31. Management of cardiogenic shock:
Goals- Airway stability and improving Myocardial Pump
Function.
Cardiac Monitor, Pulse Oximetry.
Supplemental Oxygen, IV access.
Be prepared to give Fluid Bolus

32. QUESTIONS