Shock Mar 5 Flashcards
Define shock
Inadequate perfusion of oxygen and nutrients to cells.
What is the relationship of shock to supply and demand?
Shock is a supply vs demand problem where injuries and illness either increase demand or deplete supply.
What are the stages of death in shock?
- Death of cells
- Death of tissue
- Death of organs
- Death of systems (MODS)
- Death of patient
What can a good practitioner identify in a patient experiencing shock?
The stage of shock the patient is in to prevent progression to later stages.
What factors influence the progression of shock?
Progression can take days or minutes, depending on the pathology.
What is the role of epinephrine in compensated shock?
- Increases heart rate (Chronotropy)
- Increases conduction velocity (Dromotropy)
- Increases contractility (Inotropy)
- Improves relaxation (Lusitropy)
How does epinephrine affect the lungs and body during shock?
- Bronchodilation
- Muscular vasodilation
- Glycogenolysis
- Gluconeogenesis
- Mydriasis
- Decreased inflammation
What physiological changes occur during decompensated shock?
- Lactic Acidosis
- Epi Dysfunction
- Decreased perfusion
- Failure of Compensatory Mechanisms
What are the key changes in irreversible shock?
- Lactic Acidosis
- Epi Failure
- Tissue Death
- Failure of Compensatory Mechanisms
What is the goal of treatment for shock?
To give the body the resources it needs to stop the cycle of shock.
What treatments are used in shock management?
- Oxygen & Ventilation
- Epi 1:1000
- NaCl 0.9%
List the types of shock.
- Hypovolemic
- Metabolic
- Septic
- Neurogenic
- Anaphylactic
- Psychogenic
- Cardiogenic
- Obstructive
What are the two types of hypovolemic shock?
- Relative (High Space)
- Absolute (Fluid Loss)
What is hemorrhagic shock?
Hypovolemic shock that can be external or internal.
What should be considered in any shock without a clear mechanism?
It should be considered hemorrhagic until proven otherwise.
What defines Stage 1 of hypovolemic hemorrhagic shock?
Mild shock with less than 15% blood volume loss (~500 mls) and little to no compensatory changes.
What are the signs of Stage 2 moderate hypovolemic hemorrhagic shock?
- 20-25% blood volume loss (~1 L)
- Tachycardia
- Tachypnea
- Thirst
- Pallor
- Exertional dyspnea
What characterizes Stage 3 severe hypovolemic hemorrhagic shock?
- 30-35% blood volume loss (~1.5L)
- Compensatory mechanisms activated
- Altered LOC
- Hypotension
- Organ injury
What defines Stage 4 catastrophic hypovolemic hemorrhagic shock?
- Greater than 40% blood volume loss (~2L)
- Near death
- Failure of compensation
- Permanent organ damage likely
What do chemoreceptors sense?
Changes in chemical levels (e.g., oxygen levels, CO2 levels, glucose levels, acid-base balance)
Chemoreceptors play a crucial role in maintaining homeostasis in the body.
What do baroreceptors sense?
Decrease in blood pressure
Baroreceptors help the body respond to changes in blood pressure to maintain perfusion.
What is the initial compensatory mechanism in hypovolemia?
Draw fluid from the interstitium into the vasculature to compensate for fluid loss
This mechanism aims to maintain blood volume and pressure.
What happens if fluid boluses are not given quickly in hypovolemic patients?
Fluid boluses will quickly be pulled osmotically back into the hypertonic interstitium
Delayed administration can lead to ineffective rehydration.
What are common mechanisms of injury (MOI) in hemorrhagic hypovolemia?
Abdominal pain, chest pain consistent with thoracic aneurysm, history of alcohol abuse, recent surgical history
These factors can contribute to internal bleeding and fluid loss.