Assessment of Shock Flashcards
What is shock? What does it result in?
Inadequate O2 delivery to cells
- Inadequate cellular energy production
- Cellular dysfunction
- Organ dysfunction
What determines O2 delivery to cells? (The tree of life)
Delivery of oxygen is a consequence of cardiac output and Hb conc.
Define: Stroke volume Preload Afterload Contractility Systemic vascular resistance
Stroke volume: Volume of blood ejected from LV
Preload: LV vol at end fo diastole
Afterload: Load that the heart must eject blood against
Contractility: intrope
SVR: resistance to bloodflow determined by vasomotor tone
Where on the tree of life is affected by shock?
Cardiac output
Blood pressure
How does shock differ from dehydration?
Shock is a decrease of IV fluid, is life-threatening.
Dehydration is a decrease of interstitial fluid, not imminently life threatening.
What are the clinical signs of dehydration?
Tacky mm
Skin tenting
Dry tear film/sunken eyes
Which clinical signs of shock are assessed?
HR Pulse quality MM colour CRT Extremity/body temp Mentation
What are the normal HR for dogs and cats? How does shock affect HR?
D - 60-120bpm
C - 160-200bpm
+ Tachycardia due to compensation
+ Bradycardia in cats
+ Bradycardia due to decompensation
How should HR be monitored?What are DDx for tachy/bradycardia in shock?
ECG
T - hypoxaemia, anaemia, pain, arrhythmia
B - arrhythmia, increased intracranial pressure
How is pulse quality assessed? Where can the pulse be taken?
Auscultate at the same time as assessing pulses to check for cardiac deficits, quality and speed.
- Femoral
- Metatarsal
How might shock affect mm colour? What are the DDx?
Pale - anaemia, hypoxaemia
Hyperaemic - gingivitis
What do decreased extremity and body temps indicate in shock?
E - Mild/moderate shock
B - cats, severe shock in dogs
How might mentation by affected by shock?
Obtunded
Stuporous
Comatosed
What can be used as markers of shock later on?
Lactate level >2.5mmol/L
BP decrease
What are the 4 types of shock?
Hypovolaemic
Obstructive
Cardiogenic
Vasodilatory
What can cause hypovolaemic shock?
Dehydration V/D Haemorrhage 3rd space loss PU
What can cause obstructive shock?
GDV
Pericardial effusion
Pneumothorax
What can cause cardiogenic shock?
Arrhythmia
Systolic dysfunction
Poor contractility
How do the 6 clinical signs vary with mild-moderate-severe vasoconstrictive shock?
HR
Mild - Increased +
Moderate - Increased ++
Severe - Decreased +
Pulse quality
Mild - Increased or decreased
Moderate - Decreased ++
Severe - Decreased +++
MM
Mild - Pale pink (1.5-2CRT)
Moderate - Pale (2-3CRT)
Severe - Very pale (>3CRT)
Extremity/Body temp
Mild - Decreased +
Moderate - Decreased ++
Body temp - D in cats (+)
Severe - Cats and dogs decreased BT +
How are the three types of vasoconstrictive shock diagnosed?
History
PE
Diagnostic tests
What are the clinical signs of hypovolaemic shock?
Dehydration
Pleural effusion
Abdominal distension
Free fluid on US
What are the clinical signs of obstructive shock?
Distended abdomen
Decreased H and L sounds
How is cardiogenic shock diagnosed?
History
PE - juglar distension, thoracic asuc
ECG
Echo
What can cause vasodilatory shock?
SIRS
Sepsis
Anaphylaxis
Anaesthesia
What are the clinical signs that differentiates vasoconstrictive and vasodilatory shock?
mm colour
pale - vasoconstrictive
dark - vasodilatory
What mechanisms cause vasodilatory shock?
Decreased vasomotor tone
Increased capillary permeability
Decreased oncotic pressure
What is SIRS? How does it differ from sepsis?
Systemic inflammatory response syndrome > Pro-inflammatory responses overwhelm anti-inflammatory responses and causes systemic inflammation
Sepsis = SIRS + infection
What are the imortant points to remember about shock?
Bradycardia > Cardiac arrest
Vasodilatory shock > Dark MMs
Can have more than one type of shocl
