Review And Shock Flashcards Preview

Cardiovascular > Review And Shock > Flashcards

Flashcards in Review And Shock Deck (27):
1

How can stress tests be carried out?

Exercise
Pharmacological (beta adrenoceptor agonist)

2

Why might some patients not experience pain in MI?

Diabetic patients - neuropathy

3

Describe the progression of ECG changes in a STEMI

First change = ST elevation
After a few hours = decreased height of R wave and pathological Q waves form
After 1-2 days = T wave inversion
Weeks later = everything may normalise except pathological Q waves remain

4

Describe cardiac arrest

Unresponsiveness associated with lack of pulse
Heart has stopped or has ceased to pump effectively

5

What are the 3 types of cardiac arrest?

Asystole (loss of electrical and mechanical activity)
Pulseless electrical activity (no link between electrical and mechanical)
Ventricular fibrillation (uncoordinated electrical)

6

What 3 things commonly lead to VF?

MI
Electrolyte imbalance
Arrhythmias

7

How does defibrillation work?

Depolarises all the cells to put them in the refractory period
Allows coordinated electrical activity to restart

8

What is haemodynamic shock?

Acute condition of inadequate blood flow throughout the body with a catastrophic fall in arterial BP

9

What is the BP equation?

BP = CO x TPR

10

What 2 things can cause shock?

Fall in cardiac output
Fall in TPR

11

What is cardiogenic shock?

Pump failure
Ventricle cannot empty properly
Decreased output

12

What is mechanical shock?

Ventricle cannot fill properly
Decrease output (Starling's law)

13

What is hypovolaemic shock?

Reduced blood volume
Poor venous return
Decreased output

14

Name 3 causes of cardiogenic shock

after MI
Arrhythmias
Acute worsening of HF

15

What is the equation for CO?

CO = HR x SV

16

What are the 2 main causes of mechanical shock?

Cardiac tamponade
Pulmonary embolism

17

What percentage of blood has to be lost to show signs of shock?

20-30% some signs of shock
30-40% serious shock response

18

What is the compensatory response due to haemorrhage?

Arterial BP fall detected by baroreceptors
Increase SNS output
Tachycardia, increase force of contraction and cause venoconstriction and vasoconstriction

19

How would a patient with hypovolaemic shock present?

tachycardia
Weak pulse
Pale skin
Cold, clammy extremities

20

Other than haemorrhage, what else can cause hypovolemic shock?

Severe burns
Severe diarrhoea/voting (loss of Na+)

21

What is the danger of hypovolemic shock?

Decompensation
The vasoconstriction causes impaired tissue person therefore the tissue releases chemical mediators to cause vasodilation
TPR falls - BP falls
Can lead to multi system failure

22

What is distributive shock?

Low resistance - vasodilation causing a decrease TPR
Toxic or anaphylactic

23

What causes vasodilation in anaphylaxis?

Severe allergic reaction causing histamine to be released from mast cells - decrease TPR

24

Chemical mediators in anaphylactic shock also cause ...

Bronchoconstriction
Laryngeal oedema
(Difficulty breathing)

25

How does a patient with anaphylactic shock present?

Difficulty breathing
Collapsed
Rapid HR
Red, warm extremities

26

What do you give as treatment in anaphylaxis?

Adrenaline - to cause vasoconstriction

27

Which 3 sites does regulation of BP occur at?

Heart
Kidneys
Vasculature