N.4 Shock Flashcards
Do all animals with dehydration exhibit shock?
No, all animals that have dehydration have some degree of hypovolemia, but they do not all exhibit shock.
What is hypovolemic shock?
Hypovolemic shock occurs when there is a decrease in the effective circulating volume.
What are the three broad categories of shock mentioned in older references?
- Hypovolemic
- Cardiogenic
- Distributive (vasodilatory)
What is the definition of shock?
Shock is defined as the state in which profound and widespread reduction of effective tissue perfusion leads first to reversible, and then if prolonged, to irreversible cellular injury.
What are common examples of distributive shock?
- Sepsis
- Systemic inflammatory response syndrome
- Neurogenic shock
- Anaphylactic shock
What is a common clinical sign found across all types of shock?
Altered mental status, which can range from obtunded to comatose.
What is the primary characteristic of distributive shock?
Distributive shock is characterized by a decrease in systemic vascular resistance.
What defines cardiogenic shock?
Cardiogenic shock is defined by the heart’s failure to generate adequate forward flow.
What is metabolic shock and what are its examples?
Metabolic shock occurs when oxygen delivery is adequate but oxygen consumption is deranged, with examples including cytopathic hypoxia.
How can the clinical signs of shock vary?
The clinical signs of shock can vary based on the underlying cause and whether the shock is compensated or uncompensated.
What causes hypoxic shock?
Hypoxic shock is caused by a decrease in arterial oxygen content.
What are examples of conditions that can lead to obstructive shock?
- Cardiac tamponade
- Gastric dilatation-volvulus
What additional signs may indicate progression from compensated to early decompensated shock?
- Prolonged capillary refill time
- Poor pulse quality
- Cold extremities
What is a common measurement finding in shock?
Hypotension is usually revealed upon measurement of blood pressure.
What compensatory mechanisms occur as cardiac output and blood pressure decrease in shock?
- Increase in sympathetic tone
- Peripheral vasoconstriction
- Increased heart rate
- Increased respiratory rate
What fluids are recommended for blood volume expansion in shock treatment?
- 0.9% NaCl
- Lactated Ringer’s solution
- 0.7% NaCl (hypertonic saline) with hetastarch if not hydrated
What happens to urine output as shock worsens?
Initially, urine output may decrease, but as hypotension worsens, it can lead to oliguria.
What initial steps should be taken in the therapy of shock?
- Obtain history
- Perform physical examination
- Place a jugular catheter
- Obtain blood for various tests
What are the signs of late decompensated or irreversible shock?
- Bradycardia
- Comatose state
- Prolonged capillary refill time
- Weak to absent pulses
- Marked hypothermia
What are some clinical signs of compensated shock?
- Pale mucous membranes
- Tachycardia
- Tachypnea
What is the recommended action if the hematocrit is below 20%?
Replace red blood cells.
What should be done if the pulse is weak or not palpable?
Blood pressure needs to be increased immediately.
What should be given if the hematocrit and total protein are very low?
Fresh or stored blood.
What can be used to improve contractility and increase cardiac output in severe shock?
Epinephrine.
