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.
What is the ‘Triad of Death’ in hemorrhagic hypovolemia?
Hypothermia, coagulopathy, metabolic acidosis
This triad represents critical conditions that worsen outcomes in hemorrhagic shock.
What is the initial treatment for hemorrhagic hypovolemia?
Stop the bleed, direct pressure with hemostatic agent, tourniquet if necessary
Rapid intervention is crucial to prevent further blood loss.
What are examples of fluid loss in hypovolemic metabolic conditions?
Diarrhea, vomiting, sweating, heat exhaustion, burn blisters
These conditions can lead to significant fluid and electrolyte imbalances.
What are signs of compensated hypovolemic metabolic shock?
Tachycardia, tachypnea, pale cool skin, thirst, generalized weakness, anxiety, lethargy, normotension/HTN
These signs indicate the body is attempting to compensate for fluid loss.
What are signs of decompensated hypovolemic metabolic shock?
Weak, thready pulses, decreased body temperature, decreased LOC, hypotension
These signs indicate failure of compensatory mechanisms.
True or False: Blood pressure can be used as a linear representation of fluid status in hypovolemic shock.
False
Blood pressure is not a reliable indicator of fluid status due to compensatory mechanisms.
What is the treatment for hypovolemic metabolic shock?
Stop or limit fluid loss, monitor LOC, airway management, O2, maintain warmth, IV therapy, ECG
Comprehensive management is necessary to stabilize the patient.
What causes septic shock?
Toxins released from systemic infective agents, usually bacteria
These toxins lead to vasodilation and hypotension.
What are signs of compensated septic shock?
Fever, localized rash, tachycardia, tachypnea, thirst, generalized weakness, anxiety, lethargy, normotension
These signs indicate that the body is still compensating for infection.
What are signs of decompensated septic shock?
Generalized rash, purple discoloration, weak thready pulses, decreased LOC, hypotension
These signs indicate a progression to severe shock.
What is the SIRS criteria for septic shock?
Suspected infection + 2 of the following: fever > 38 C or < 36 C, tachycardia > 90, tachypnea > 20 or ETCO2 < 30, elevated WBC, altered LOC
SIRS criteria help in identifying systemic inflammatory responses to infections.
What is the treatment for septic shock?
Maintain body temperature, monitor LOC, airway management, O2, IV therapy aiming for systolic of 90, ECG
Timely intervention can significantly affect outcomes in septic shock.
What characterizes neurogenic shock?
Injury to spinal cord causing vasodilation and rapid onset of hypotension due to limited compensatory mechanisms
Neurogenic shock often results from trauma or injury to the spinal column.
What are common signs of neurogenic shock?
Sensory and motor deficits to lower extremities, rapid onset of hypotension, normal HR, decreased body temperature, decreased LOC
These signs indicate a loss of autonomic control following spinal cord injury.
What is anaphylactic shock?
Severe allergic reaction due to overreaction of the immune system to an allergen.
What triggers anaphylactic shock?
Insect stings, nuts, seafood, medicines.
What chemicals are released by mast cells during anaphylaxis?
Histamines and heparin.
What effect do histamines have during anaphylaxis?
Cause vasodilation and fluid shifting out of vasculature.
What is the role of B cells in anaphylaxis?
B cells produce immunoglobulins (IgE) that trigger allergic reactions.
What happens during the first exposure to an allergen?
Mild symptoms occur and sensitization begins.
What occurs during the second exposure to an allergen?
Anaphylaxis occurs, triggering severe symptoms.
Name three symptoms of anaphylaxis.
- Altered LOC * Laryngeal edema * Bronchospasm
What are the criteria for diagnosing anaphylaxis?
Acute onset with skin/mucosal signs and symptoms plus respiratory signs or hypotension.
What are some compensated symptoms of anaphylactic shock?
- Flushed skin * Urticaria * Tachycardia
What is the treatment for anaphylactic shock?
- Monitor LOC * Airway management * IM Epi 0.3mg x 3
What is the function of epinephrine in anaphylaxis?
Counters bronchospasm and vasodilation, stabilizes mast cells.
What is hypovolemic psychogenic shock?
Fainting due to overstimulation of the CNS leading to systemic vasodilation.
What are the signs of hypovolemic psychogenic shock?
Sudden collapse, potential hyperventilation, stable vital signs.
What are the types of hypovolemic shock?
- Relative * Absolute * Septic * Neurogenic * Anaphylactic * Psychogenic * Metabolic * Hemorrhagic
What characterizes cardiogenic shock?
Myocardial damage leading to inadequate stroke volume or pressure.
What is a common cause of cardiogenic shock?
Myocardial Infarction (MI).
What are some compensated symptoms of cardiogenic shock?
- Chest pain * SOB * Pale, cool skin
What is obstructive shock?
Physical obstruction leading to inadequate pump function or blood flow.
What are common traumatic causes of obstructive shock?
- Tension pneumothorax * Pericardial tamponade
What are the signs of compensated obstructive shock?
- Tachycardia * Chest pain * Anxiety
What is the treatment for obstructive shock?
- Treat underlying cause * Monitor LOC * Airway management
What special considerations are there for pediatric patients in shock?
Can become shocky with minimal blood loss; capillary refill is more accurate.
What special considerations are there for geriatric patients in shock?
Compensatory mechanisms may be less effective and lead to rapid deterioration.
What are the dangers of compensatory mechanisms in shock?
Increased myocardial workload and bleeding risks.
What is the initial management for neurogenic shock?
- Monitor LOC * Airway management * IV therapy
