Shock

Question 1

Describe the 4 stages of shock

Answer 1

1. Initial- tissues under perfused, increased metabolic rate and lactic acid accumulation
2. Compensatory - Sympathetic NS activated
3. Progressive - failing compensatory mechanisms, metabolic acidosis due to ischemia and lactic acid production
4. Refractory - cellular necrosis and multiple organ dysfunction syndrome

Question 2

Pathophysiology of shock x4

Answer 2

1. Decreased myocardial contractility
2. Systemic lactic acidosis
3. Decreased vascular tone
4. Decreased BP, preload and CO

Question 3

External fluid loss causes of hypovolemic shock x5

Answer 3

External fluid loss:
Hemorrhage
Dehydration- Vomiting, diarrhea, burns, massive diuresis

Question 4

Internal fluid loss causes of hypovolemic shock x3

Answer 4

Loss of vascular integrity
Increased capillary membrane permeability
Decreased colloidal osmotic pressure

Question 5

Hypovolemic shock therapy x5

Answer 5

ABC
Stop obvious bleeding
Insert IV lines and take GXM
Give rapid bolus and reassess
Investigations vs surgery

Question 6

Signs of cardiogenic shock x6

Answer 6

Raised JVP
Cold skin
Tachycardia
Engorged liver
Peripheral edema
Added heart sounds S3(V gallop) S4(A gallop)

Question 7

Causes of cardiac shock x5

Answer 7

Acute myocardial infarction
Severe arrhythmias
Severe valve disease
Tension pneumothorax
Tamponade (obstructive too)

Question 8

Mechanical complications of myocardial infarction that cause CG shock x3

Answer 8

Papillary muscle rupture
Ventricular aneurysm
Ventricular septal rupture

Question 9

Decreased how CG shock can cause pulmonary edema x5

Answer 9

Decreased CO> increased LV filling pressure(preload) > increased LA filling pressure> increased capillary pressure> interstitial and intra alveolar edema

Question 10

Interpretation of MAP- mean arterial pressure x2

Answer 10

<70mmHg = compromised coronary perfusion
<60mmHg = compromised renal perfusion

Question 11

Signs of tension pneumothorax x5

Answer 11

Raised JVP
Tracheal deviation
Reduced chest expansion
Hyperresonant percussion
Diminished breath sounds

Question 12

Treatment aim for CG shock x4

Answer 12

Treat reversible causes
Increase myocardial O2 delivery
Maximizing CO
Decreased LV workload

Question 13

How to reduce myocardial damage during myocardial infarction x5

Answer 13

Vasoactive drugs- dopamine
Inotropic agents
Cautious administration of fluids
Intra aortic balloon pump
Transplantation
Short acting B blockers- reduced contractility of heart hence less o2 needed

Question 14

Function of dobutamine x2

Answer 14

B1 receptor agonist - promotes cardiac stimulation
Mild B2 effects- vasodilation

Question 15

Characteristics of distributive shock x2

Answer 15

Leaky blood vessels due to infection
Vasodilation > reduced vascular resistance

Question 16

Describe how distributive shock results in decreased tissue perfusion

Answer 16

Vasodilation > decreased vascular resistance > blood moving too fast > less time to unload oxygen
OR
Decreased bp > less pressure to push out blood from vessels to tissues

Question 17

Causes of distributive shock x3

Answer 17

Septic shock
Anaphylactic shock
Neurogenic shock

Question 18

Anaphylactic response x5

Answer 18

Vasodilation, increased capillary permeability
Bronchoconstriction, increased mucus production
Increased inflammatory mediators
Recruitment to sites of antigen interaction

Question 19

Management of anaphylactic shock x5

Answer 19

Airway support
Epinephrine IV
Antihistamines
Corticosteroids
Positive inotropes
Vasopressors

Question 20

Pathophysiology of neurogenic shock x5

Answer 20

Disruption in sympathetic nervous system
Decreased sympathetic tone
Arterial and venous vasodilation
Decreased venous return, SV, CO
Impaired tissue perfusion and cellular metabolism

Question 21

Goals of therapy in neurogenic shock x2

Answer 21

Treat and prevent CVS instability
Promote optimal tissue perfusion

Question 22

Define septic shock

Answer 22

A life threatening organ dysfunction caused by dysregulated host response to an infection

Question 23

3 Risk factors for sepsis

Answer 23

Reduced immunity
Extremes of age limiting communication
Recent surgery, invasive procedure, pregnancy or miscarriage

Question 24

Conditions which increase risk of sepsis x5

Answer 24

Diabetes
HIV/AIDS
Liver cirrhosis
SCD, Splenectomy
Autoimmune diseases

Question 25

Pathophysiology of septic shock x4

Answer 25

1.Vasodilation and increased capillary permeability
2.Endotoxins release inflammatory mediators
3.Cell walls of organisms release endotoxins
4. Initiated by gram neg and gram positive

Question 26

Describe 2 phases of septic shock

Answer 26

Warm- early, vasodilation, hyperdynamic response
Cold- late, hypodynamic response, decompensated state