Emergency Medicine Flashcards
What are the three reasons for an animal to go into shock?
Failure of circulatory system to deliver blood to tissues
Failure of blood to carry enough oxygen
Failure of tissues to utilise oxygen (rare)
What can circulatory shock be further divided into?
Hypovolaemic - Maldistributive - Cardiogenic - Obstructive
What happens during hypovolaemic shock?
Lack of circulating volume - Tissue hypoperfusion - Commonest form - Due to haemorrhage
What happens during maldistributive shock?
Inappropriate vasodilation - Global release of inflammatory mediators - Hypoperfusion
What happens during cardiogenic shock?
Failure of heart as a pump - Secondary to cardiac diseases
What happens during obstructive shock?
Obstruction to blood flow - Secondary to pericardial effusion/massive pulmonary thromboembolism
How do you determine a patient is in shock?
Physical exam
During hypovolaemia, which fluid compartment is fluid lost from?
Intravascular
During dehyrdration, which fluid body compartment is fluid lost from?
All 3 - Intracellular, interstitial and intravascular
What do you treat an animal which is dehydrated?
Crystalloid fluid slowly over 24 hour period
What clinical signs would you see in a dog in severe hypovolaemic shock?
170-220 bpm - Gray, white or muddy MM - Prolonged capillary refill - Decreased pulse amplitude and width - Absent metatarsal pulse
What is the hallmark of maldistributive shock?
Inappropriately red mucous membranes
What other signs are normally seen with a dog with cardiogenic shock? Why?
Respiratory signs - Due to congestive heart failure
Westie with markedly increase heart rate (160), poor pulses, pale mucous membranes, is subsequently identified to have a haemorrhagic abdominial effusion (haemoabdomen) and a PCV of 17% (normal being 37-55%) and total plasma protein of 35 g/L (reference range 54-70 g/L). The dog weighs 11 kg. What should be the next step for stabilising this patient?
Place an IV catheter in a peripheral vein (short, large bore catheter) and a bolus of fluid at 30 mL/kg over 20 minutes
A dog presents to you in a collapsed state. Examination of the cardiovascular system reveals a heart rate of 260 bpm with poor peripheral pulses and pale mucous membranes with a CRT of 2s. The dog is tachypnoeic and has crackles on thoracic auscultation. What is the most likely cause of shock in this dog?
Cardiogenic