Shock Flashcards
1
Q
What ways can absolute fluid loss occur?
A
- External haemorrhage
- Internal haemorrhage
o Concealed and revealed
Concealed may come out mouth or anus - Plasma loss (burns)
- Water and minerals
o Dehydration
o Diarrhoea and vomiting
o Decreased fluid intake
o Excessive diuresis
2
Q
What constitutes as a significant haemorrhage?
A
- Adults – 1,000mls
- Child – 500mls
- Infant - 100 – 200mls
3
Q
What are signs and symptoms of a PT with absolute fluid loss or a significant haemorrhage?
A
- Altered conscious state
o Most likely later sign - Skin – pale, cool, clammy
- Dizziness
- Nausea +/- Vomiting
o Consequence of vagal stimulation - Increase respirations
- Increased Heart rate – rapid weak thread
- BLOOD PRESSURE – Hypotension as a late sign
o This will be maintained during the compensatory process as adults generally have extra blood vessels floating about.
4
Q
What is relative fluid loss?
A
- Blood volume remains essentially the same, but the blood vessels capacity is increased due to vasodilation.
- Plasma moves into the interstitial space due to increased permeability of vessel walls.
o This can be seen in anaphylaxis
5
Q
What does relative fluid loss mean for the bodies blood volume?
A
- It will remain essentially the same, but the ability of the cardiovascular system to maintain adequate perfusion pressure is adversely affected.
6
Q
What are causes of relative fluid loss?
A
- Neural mediated causes o Syncope / fainting o Pain o Emotion - Sepsis - Anaphylaxis - Vasoactive drugs and substances o For example, GTN, morphine - Spinal injury
7
Q
What are signs and symptoms of relative fluid loss?
A
- Altered conscious state
- Nausea, dizziness +/- vomiting
- Skin; may be warm and flushed due to pooing in the periphery of pale and cool.
- Tachypnoea
- Tachycardia
- Hypotension
o Recent collapse or fainting
8
Q
What causes may impair oxygen transport?
A
- Insufficient cardiac output
o Myocardial hypoxia
Form of hypoxia due to the myocardium being able to transport oxygen to the tissues - Low RBC count
o Anaemic hypoxia - Low systemic vascular resistance and perfusion pressure
o This is generally neuro mediated
9
Q
What are the results of impaired oxygen transport?
A
- Anaerobic metabolism
- Failure of sodium-potassium pumps
- Acidosis
- Sever tissue ischemia/tissue death
- Death of the organism
10
Q
What are the mechanics of blood pressure?
A
- Blood pressure is reliant upon two main factors, stroke volume and peripheral resistance.
11
Q
What occurs when BP drops ion the body?
A
- The body initiates compensatory mechanisms
o Increasing myocardial contractility (Cardiac output) also referred to as inotroping
o Promote peripheral vasoconstriction
o Tachycardia may accompany this increase myocardial contractility but they are not actively linked together.
12
Q
Define shock.
A
- A continuing process defined by a chain of events leading to widespread reduction in tissue perfusion and subsequent impairment of cellular metabolism
- Shock is a continuing process not a condition.
o Shock will continue until interventions are initiated. - Shock may result from a variety of disease states and injuries. If the process involved in the condition are not stopped the patients will die.
13
Q
What is shock in terms related to body systems?
A
- An inability of the cardiovascular system to adequately maintain perfusion
14
Q
What is perfusion mediated by?
A
- Perfusion is mediated by the cardiovascular system which is reliant upon the following three mechanisms.
o Heart as a pump
o Vessels as a container both the arterial arteries and veins
o Blood as it creates volume.
15
Q
What are the stages of shock if left untreated?
A
- Compensation
- Decompensation
- Irreversible
16
Q
What factors determine how fast a PT will travel through the stages of shock?
A
- It is highly dependent on what has caused it and what interventions are put in place.
17
Q
How is blood pressure determined?
A
- Heart Rate X Stroke Volume = Cardiac Output X Peripheral Vascular Resistance = Blood Pressure
- ↑ HR x SV = CO x PVR = BP
18
Q
What factors are altered for BP to be maintained in compensated shock?
A
- When need to increase our cardiac output or peripheral vascular resistance to maintain blood pressure.
o Heart Rate may be increased (cronotroping)
o Stroke volume with definitely be increased (inotroping, increasing the force of contraction)
19
Q
What are you signs in symptoms in PT that is in a compensating state?
A
- Tachycardia
- Slightly Pale
- BP will remain stable. However, you may see a slight rise in systolic BP as pulse pressure increases.
20
Q
What are some warning signs of the PT that is in the compensatory stage?
A
- A reduced mental state/ agitation in this Pt is likely due to decreased cerebral perfusion.
- The Pt stating that they feel as though they are going to die is highly likely that they are.
o This statement lets us need to know what we have missed and act on it! - These Pt may be difficult to cannulate due to the peripheral vasoconstriction.
21
Q
What compensatory mechanisms are seen at the initial offset of shock?
A
- Sympathetic response
- Hormonal response
- Adrenal response
22
Q
What is the max compensating HR?
A
- 140 to 160 BPM
23
Q
In the decompensating PT what are we likely to see in regards to how our BP is obtained?
A
- Heart Rate X Stroke Volume = Cardiac Output X Peripheral Vascular Resistance = Blood Pressure
- ↑ HR x SV = CO x PVR = BP
o Increased HR
o Decreased SV
o Decreased CO
o Increased Peripheral Vascular Resistance
o Decreased BP
24
Q
What is our Decompensating PT likely to present as?
A
- Hypotension – pulse pressure redcued
- Tachycardia
- Tachypnoea
- Pale and severely diaphoretic
- Developing Altered conscious state (agitation/irritability)
- Delayed Cap refill.
o This will be a Pt with a cap refill of two seconds. A healthy pt has a cap refill of less than 2 seconds.
25
Describe Irreversible Shock
- Cellular ischemia and necrosis lead to release of contents into circulation
- Acidosis worsens
- Sludging of blood flow in capillary beds leads to formation of micro emboli
- Cerebral hypoxia
o This PT If they survive will have brain damage.
26
What are signs and symptoms of irreversible shock?
- The myocardium become hypoxic which has the potential to lead to the following.
o Dysrhythmias and infarctions
- Sympathetic response fails
o In the short term this fail in sympathetic response leads to the following
Unbated hypotension
o In the long term this fail in sympathetic response leads to the following
Disseminating intravascular coagulation, Adult raspatory distress syndrome and organ failure
27
What are the PT presentation of irreversible shock?
```
- Bradycardia
o If they have a HR
- Life threatening dysrhythmias
- Sever unabated hypotension
- Abnormal respiratory patterns
o Due to cerebral hypoxic effects on the respiratory drive
- Alt conscious state – normally unconscious
- Cyanosis and mottling of the skin
- Death
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28
What factors may cause shock to process at different rates and stages?
- Age
- Paediatric patients do not have the ability to compensate as well
- Pre- e existing disease, what condition is the PT in before this occurs?
- The PT ability to activate compensatory mechanisms.
o This becomes more challenging as the PT becomes older
- Mediations
o Beta blockers, Diuretics
- Specific organs that are affected by trauma or disease
29
What are the TYPES of Shock?
- Cardiogenic
o Occurs as a result of an inability of the heart to adequately to pump.
o These Pts will generally skip compensatory phase as these mechanisms are compromised.
For example, APO PT with hypotension
- Neurogenic
o Occurs as a result of reduced peripheral vascular resistance
Compensatory are not activated as there is no sympathetic response
- Anaphylactic
o Caused by a severe allergic reaction
This causes a relative fluid shift
• And compensatory mechanisms fail due to the vasodilation
- Septic
o Occurs due to gross overwhelming infection
Often seen in those with low immune systems or low mobility (OLD CUNTS)
• The process of septic shock is as follows
o Release of bacterial toxins
o Vasodilation and permeability of vessel walls
o Relative fluid loss
o Cellular necrosis and inflammatory response interferes with compensatory mechanisms
- Hypovolemic
o Fluid loss may be absolute or relative
Offset by compensatory methods initially
o Loss of whole blood, plasma or interstitial fluid
o Renal compensatory methods
30
What are common causes of cardiogenic shock?
- AMI
- Tension pneumothorax
- Cardiac tamponade
- Pulmonary Embolism
- Valvular disease
- Cardiomyopathies
31
What are management options in the setting of cardiogenic shock?
- Reperfusion strategies
- Possible circulatory support
o Fluid replacement – MICA Only
- Drug Therapy
o Vasodilators to reduce afterload
o Positive inotropes to increase Stroke Volume and contractility
o Positive chronotropes to increase HR
32
Why is systemic Inflammatory Response Syndrome (SIRS) important in regards to septic shock?
- It is a key component due to the inflammatory response in this condition
33
What is the PT presentation of Septic Shock?
- Low arterial pressure
- Low Systemic Vascular resistance
o This is due to vasodilation
- Tachycardia
- Temperature instability
o You can have hot or cold sepsis
This depends on the type of injection and its impact on the temperature regulatory systems
- Affected organ systems
o Renal, resp and brain
34
What is the treatment of septic shock?
- Management of hypovolemia if present
- Correction of metabolic acid-base imbalances
- fluid resuscitation
- Respiratory support
- Vasopressors to improve cardiac output
- Thorough history to identify the source of sepsis
35
What are the causes of hypovolaemic shock/
- Haemorrhage
- Burns (plasma loss)
- Dehydration
o Through diarrhoea, vomiting, diuresis and diabetes
36
How will a PT with hypovolaemic shock present?
- Poor perfusion
- Poor skin turgor
o This shows significant fluid loss
- Thirst
- Oliguria
- Need to elicit good history with these PT
37
What are key factors that need to be recognised for positive PT outcome for severe haemorrhage or shock?
- Rapid recognition
- Early initiation of treatment
- Prevention of additional injury
- Rapid transport to appropriate hospital
- Advance notification to receiving facility
38
What is the best way to achieve fluid resuscitation
- Blood transfusions are the most effective way, but fluids will buy time for the PT.
39
What reasons do we administer fluid replalcement?
- In volume depleted patients
- To expand the fluid volume, for example, anaphylaxis
o Must be careful once conditions has reversed not to place these PT into APO
- As a fluid challenge in PEA/EMD
- Vehicle for drug administration
- TKVO
40
What type of fluid solutions are available?
- Isotonic solutions
o Concentration of solutes are the same a s those in body fluids
- Hypotonic solutions
o Solution has a lower concentration of solutes than those of body fluids
- Hypertonic solutions
o Solution ha a higher concentration of solutes than those of body fluids
41
What are the causes of aggressive fluid resuscitation?
- Additional bleeding, clot dissolution and dilution of clotting factors
o All this adds to increase in haemorrhage.
