SHOCK Flashcards
Define shock
- Shock is a life threatening condition of inadequate circulatory functioning
- Inadequate tissue perfusion resulting in impaired cellular metabolism and functioning
- potentially life-threatening
Discuss the pathophysiology relating to the four stages of shock
Initial stage:
- hypo-perfusion begins
- imbalance between supply and demmand
- anaerobic metabolism begins
- cellular acidosis is developing
Compensatory stage:
- Compensatory mechanisms activated (decreased CO stimulates baroreceptors and chemoreceptors –> adrenaline and noadrenaline released)
- Blood flow to the heart lungs and brain is maintained (decreased blood flow to the kidneys, RAAS activated, ADH released)
Progressive stage:
- compensatory mechanisms fail
- Decreased ATP production
- Hypoxia of vital organs
- decreased cellular perfusion and tissue ischaemia
- Failure of sodium-potassium pump
- Altered cell membrane permeability
- Metabolic acidosis
- Decreased CO
- Myocardial Ischaemia
- Increased gastric ulcers and GI bleeding
- Increased risk of disseminated intravascular coagulation
- Acute renal failure
- Aggressive management required to prevent MODS
Irreversible/Refractory stage:
- Compensatory mechanisms overwhelmed
- severe tissue hypoxia with ischaemia, necrosis and death of cell
- build up of toxins
- MODS
- recovery unlikely
Identify the clinical manifestations of the four stages of shock
- hypotension
- hypoxia
- tachy/bradycardia
- decreased UO
- diaphoresis
Identify the four classifications of shock
- Cardiogenic
- Hypovolaemic
- Distributive
- Obstructive
Identify the three types of distributive shock
- Septic shock
- Anaphylactic shock
- Neurogenic shock
List the causes of the types of distributive shock
- Septic shock (infection - inflamm)
- Anaphylactic shock (allergic reaction - allergen)
- Neurogenic shock (lesions or pressure on the spinal cord)
Discuss ‘cold’ shock
- Usually a late and ominous stage of septic shock
- Generally irreversible and indistinguishable from terminal hypovolaemic shock
- Characterised by a decreased cardiac output, low temperature, and low WCC
Discuss ‘warm’ shock
- Usually 1st phase of septic shock preceding cold shock
- characterised by high cardiac output and low peripheral vascular resistance
- fluid begins to shift into third spaces
Identify the three primary aims in the management of shock
- fluid replacement
- reperfuse
- identify and treat cause
- prevent MODS
Outline the aims of ED management for Hypovolaemic shock
Airway - assess and secure Breathing - Maximise O2 carrying capacity - Assess RR/WOB/SpO2/ABG’s (PaO2>80mmHg) - apply O2T - appropriate ventilation Circulation - Assess: – Source of fluid loss, – HR, BP, Cap refill, Peripheral pulses, U/O, ECG/CCM Interventions: – Control external bleeding – Two large bore IVC – Fluid resuscitation – CVC – Artline – IDC – Where indicated adrenaline NOT NORADRENALINE
Compare the administration of crystalloid and colloid for fluid resuscitation
Crystalloids:
- salts and electrolytes
- commonly used for intravascular expansion
- low molecular weight
- inexpensive
- readily available
- short half-life
- extravascular space expander
Colloids:
- large molecules
- provide oncotic pressure as well as intravascular volume
- longer half life
- risk of anaphylaxis
- not readily available
- intravascular space expander
Discuss the administration of blood products to a patient in a shock state
- Blood products are most suitable in a hypovolaemic shock from an origin of blood loss
- blood products should be used cautiously as it is a colloid solution and cannot pass through the membrane. Therefore could cause fluid overload.
Define systemic inflammatory response syndrome (SIRS)
Systemic inflammatory response syndrome (SIRS) is an inflammatory state affecting the whole body. It is the body’s response to an infectious or noninfectious insult. Although the definition of SIRS refers to it as an “inflammatory” response, it actually has pro- and anti-inflammatory components.
Define multiple organ dysfunction syndrome (MODS)
Medical Definition of multiple organ dysfunction syndrome.: progressive dysfunction of two or more major organ systems in a critically ill patient that makes it impossible to maintain homeostasis without medical intervention and that is typically a complication of sepsis and is a major factor in predicting mortality
List the causes / predisposing factors for MODS
Sepsis and septic shock are most common causes Other triggers: – Burns, – Acute pancreatitis – Major surgery – Severe trauma – Circulatory shock – ARDS – Necrotic tissue
Discuss pro-inflammatory and anti-inflammatory mediators
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Discuss the mechanism of tissue injury in MODS
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Discuss the ED management of a patient with MODS
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Define the terms positive and negative inotrope
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Define the terms ‘positive chronotrope’ and ‘negative chronotrope’
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Define cholinergic transmission
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List the two types of adrenergic receptors and their location
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Describe the effects when adrenergic receptors are stimulated
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List the location and action of dopaminergic receptors
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