Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Karan - MBBS Year 1: Cardiovascular - Week 3 > Shock and Hypotension *** > Flashcards

Shock and Hypotension *** Flashcards

1
Q

Define circulatory shock

A
  • Generalised loss of blood flow to organs - causing necrosis and death
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Link the following equations to shock:
- 𝑄=Δ𝑃/𝑅
- 𝐡𝑃=𝐢𝑂 π‘₯ 𝑇𝑃𝑅
- 𝐢𝑂=𝐻𝑅 π‘₯ 𝑆𝑉

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Describe hypovolaemic shock.

A
  • Arises from loss of blood or blood fluid
  • BP affected by reduction in SV (due to loss of fluid)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

How does blood pressure become reduced by hypovolaemic shock?

A
  • Reduction in blood volume
  • Decreased venous return
  • Decreased preload
  • Decreased SV and CO
  • Decreased BP
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Give examples of factors that can cause hypovolaemic shock.

A
  • Trauma
  • Postpartum haemorrhage
  • Burns
  • Vomiting
  • Diarrhoea

(ANYTHING CAUSING A LOSS OF FLUID FROM CVS)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are the long- and short-term responses to hypovolaemic shock?

A
  • SHORT-TERM: Vasoconstrictor activity by sympathetic NS and catecholamines - increase TPR
  • LONG-TERM: RAAS
  • Heart rate increases - causes rise in CO to compensate for decrease in SV
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Why don’t the compensatory effects of hypovolaemic shock, last for significant periods of time?

A
  • Increased vascular resistance
  • Reduced blood flow to organs
  • Can progress to tissue ischaemia
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Describe cases that can lead to cardiogenic shock.

A
  • CHF - leading to cardiac hypertrophy - reduced pumping ability and space for ventricular filling. Reduced SV
  • MI - damage to myocardium. Reduction in pumping ability and ability to contract quickly
  • Myocarditis
  • Congenital heart defects
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Describe cardiogenic shock.

A
  • Reduced perfusion due to problems with heart
  • Caused by any condition affecting pumping of heart
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Describe the steps by which myocardial failure can lead to cardiogenic shock. PART 1

A
  • Increased ESV
  • Increased preload and LV diastolic filling pressure
  • Raised pressure in LA
  • Congestion of blood in pulmonary circulation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Describe the steps by which myocardial failure can lead to cardiogenic shock. PART 2

A
  • Raised hydrostatic pressure of blood in lungs
  • Fluid pushed out of pulmonary circulation into lungs - causes pulmonary oedema
  • Reduced ability for lungs to absorb O2 and deliver it to circulation
  • Exacerbates myocardial failure
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Why might S3 be heard during myocardial failure?

A
  • Raised ESV
  • LV overfilling
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q
A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

SLIDE 8 ***

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Describe septic shock. PART 1

A
  • Entry of bacteria or fungi into bloodstream and release toxins. Gram-negative release endotoxins. Opposite for gram-positive
  • Toxins travel in bloodstream - direct cell damage.
  • Activate mast cells to release pro-inflammatory mediators
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Describe septic shock. PART 2

A
  • Mediators cause widespread vasodilation - reduced TPR
  • Increased permeability of blood vessels and leakage into tissues
  • Reduced CO
15
Q

Describe anaphylactic shock.

A
  • Response to allergic reaction
  • Inhalation of allergen activates basophils and mast cells - release histamines
  • Cause vasodilation and raised permeability of capillaries
  • Reduced TPR and CO
16
Q

What would patients with septic and anaphylactic shock present with?

A
  • Raised temperature - due to increase in systemic vasodilation
  • Pyretic response by toxins in septic shock
17
Q

Describe neurogenic shock.

A
  • Occurs in patients with SCI, concussion or under anaesthesia
  • Occurs in absence of any loss of blood volume
  • Increased vascular capacity - loss of sympathetic tone
  • Loss of vascular resistance
  • Reduced BP and venous return
18
Q

What are the 3 stages of circulatory shock?

A
  • NON-PROGRESSIVE - where normal physiological mechanisms can overcome loss of flow/pressure
  • PROGRESSIVE - shock becomes worse without treatment
  • IRREVERSIBLE - tissue/organ damage so severe no current treatments can save patient from dying
19
Q

When is a patient considered truly in clinical circulatory shock and how will they present?

A
  • On reaching progressive stage
  • KEY FEATURE - Hypotension
  • Don’t respond to IV fluid administration
20
Q

What are baroreceptors and what is their role in shock?

A
  • Baroreceptors in aortic arch, carotid sinus and RA detect decreases in BP and blood volume
  • Reduced venous return leads to reduced CO in all cases of shock
  • Decreased BP - detected by baroreceptors
21
Q

What are the responses caused by baroreceptors?

A
  • Signal to vasomotor regions of medulla
  • Peripheral vasoconstriction by catecholamines, sympathetic NS activation and raised RAAS activity by raised renal sympathetic nerve activity
  • BP and blood volume raised back to normal
22
Q

What is a downside of the baroreceptor-induced compensatory mechanisms in cardiogenic shock?

A
  • Increased blood volume
  • Increased preload
  • Raised burden on heart

Karan - MBBS Year 1: Cardiovascular - Week 3 (9 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions