Question | Answer |
shock | A life-threatening response to alterations in circulation that results in inadequate delivery of oxygen to tissues and cells, and their subsequent dysfunction and death. |
Cardiac system | Heart
Blood
Vascular bed
Microcirculation |
Functions of Cardiac System | Delivers oxygen and nutrients
Remove waste products
Regulation of blood volume
Constrict or dilate to regulate blood flow |
When does shock begin? | Shock begins when cardiovascular system fails |
Shock involves one or more of these events | Blood volume decreases (volume problem)
Heart failure as an effective pump (pump problem)
Peripheral vessel dilation (tank problem) |
Identify the three events that lead to the development of shock: | Blood volume decrease (volume problem).
Heart failure as an effective pump (pump problem).
Peripheral blood vessel dilation (tank problem) |
How is shock classified? | Hypovolemic
Distributive
Obstructive
Cardiogenic |
Hypovolemic Shock | Most common cause
Decrease in fluid volume |
types of causes for hypovolemic shock | Hemorrhage
Prolonged vomiting or diarrhea
Burns
Large, draining wounds
Reduced fluid intake
Diabetes insipidus, DKA |
Distributive Shock | Volume is adequate, but perfusion is inadequate
Vascular beds are dilated
Blood flow is not sufficient |
Types of Distributive Shock | Neurogenic
Septic
Anaphylactic |
Causes of Neurogenic Shock | Injury or disease to upper spinal cord
Spinal anesthesia
Drugs that vasodilate |
Neurogenic Shock leads to.... | vasodilation
hypvolemia
bradycardia |
Causes of Anaphylactic Shock | Anitgen-antibody response
Histamine |
Anaphylactic Shock leads to... | Capillary permeability-fluid shift
Hypovolemia |
Causes of Septic Shock | Systemic inflammatory response syndrome to toxins
Multiple organ dysfunction syndrome |
Septic shock leads to... | Fluid shift
Hypotension
Coagulation |
What is Obstructive Shock? | Compression of the heart or great vessels |
How does Obstructive shock affect circulation? | Compression reduces blood that can enter and leave the heart
Heart is unable to fill
Cardiac output is reduced |
What causes obstructive shock? | Any condition that fills the thoracic cavity with fluid, air or tissue. |
Examples of Obstructive Shock causes. | Cardiac tamponade
Tension pneumothorax
Pericarditis
Pulmonary emboli
Abdominal distention
Ascites
Positive end expiratory pressure (PEEP)
Aortic stenosis |
Cardiogenic Shock | The heart fails. |
Mortality rate of Cardiogenic Shock? | 50-80%. Most common cause... MI |
Causes of Cardiogenic Shock | Myocardial infarction
Dysrhythmias
Cardiomyopathy
Myocarditis
Valvular disease and structural disorders |
What happens with Cardiogenic Shock | Reduced contractility
Reduced stroke volume
Ventricular pressure increases
Reduced cardiac output
Reflex peripheral vasoconstriction |
Identify the four types of shock | Hypovolemic Shock
Distributive Shock
Obstructive Shock
Cardiogenic Shock |
What are the four stages of shock? | Initiation
Compensatory
Progressive
Refractory (Irreversible) |
Describe Stage 1: Initiation | Initial stage of shock characterized by subclinical hypoperfusion |
Describe stage 2: Compensatory | Activation of compensatory mechanisms to maintain hemostasis |
What 3 specific mechanisms begin to work independently during Compensatory? | Neural
Endocrine
Chemical |
Neural Compensation | Baroreceptors
Chemoreceptors
Activation of the Sympathetic Nervous System (SNS)
Stimulation of autonomic nervous system |
Endocrine Compensation | Hormonal response to low blood pressure
Stimulates the pituitary gland to release the adrenocorticotropic hormone (ACTH)
ACTH acts on the adrenal cortex to release
Renin-Angiotensin-Aldosterone Response (RAAS) |
Chemical Compensation | Respiratory rate and depth increase
Patient hyperventilates
Respiratory alkalosis occurs
Cerebral perfusion may decrease |
Describe Stage 3: Progressive | Profound hypoperfusion and further deterioration |
What is happening during Stage 3: Progressive? | Continued shunting of blood to vital organs
Sodium-potassium pump failure
Cardiac output, blood pressure, and tissue perfusion continue to decrease |
Describe Stage 4: Refractory | Irreversible
Prolonged inadequate tissue perfusion
Sympathetic nervous system dysfunction results in massive vasodilation
Lethal decrease in tissue perfusion
Unresponsive to therapy |
Physiological effects during Stage 4: Refractory | Severe tissue hypoxia
Worsening acidosis
Multiple organ dysfunction syndrome (MODS) |
Clinical Presentation of Sate 4: Refractory | Life threatening dysrhythmias
Respiratory and metabolic acidosis
Organ failure
Cerebral ischemia/infarction |
Identify the 3 compensatory mechanisms in the second stage of shock. | Neural
Endocrine
Chemical |
Impending shock systolic blood pressure | 90-100 mmHg |
Shock systolic blood pressure | 80 mmHg |
Difference between systolic and diastolic pressures. | Normal is 30-50 mmHg |
What are you looking for when assessing for shock (Cardiovascular)? | Weak and thready pulse
Tachycardia
Neck veins
Distended : cardiogenic/obstructive
Flat : hypovolemic/distributive
Delayed capillary refill |
What are you looking for when assessing for shock (Respiratory)? | Rapid and deep initially
Progress to slow and shallow
Pulse oximetry
Aterial blood gas |
What are you looking for when assessing for shock (Temperature)? | Heat regulating mechanisms are depressed.
Diaphoresis increases heat loss.
Hypothermia is characteristic, except with septic shock. |
What are you looking for when assessing for shock (CNS)? | Agitation
Anxiety
Nervousness
Restlessness
Drowsiness
Disorientation
Lethargy
Syncope |
What are you looking for when assessing for shock (Skin & Mucous Membranes)? | Depends on type of shock:
Color
Temperature
Texture
Turgor
Moisture
Rash |
What are you looking for when assessing for shock (Renal)? | Reduced renal perfusion
Vasoconstriction
Urine output
Oliguria |
What is a sensitive indicator of systemic perfusion? | Urine output: >30ml/hr |
Medical Management for shock | Intravenous therapy
Types of fluids
Crystalloids-LR, NS
Colloid-albumin, dextran, hetastarch
Fluid Resuscitation
Blood products |
How are Vasosupressors (Alpha-adrenergics) used? | Increase peripheral vascular resistance. |
How are Positive Inotropic Agents (Beta-adrenergics) used? | Increase force of myocardial contractions. |
Mechanical management used for shock | Intra-aortic balloon pump
Ventricular assist device
Pneumatic anti-shock garment (PASG) or Military anti-shock trousers (MAST) |
What types of fluids are administered to the patient with hypovolemic shock? | Crystalloid, colloid, blood. |
What are the Nursing Intervention goal? | Recognition of the early signs of shock |
What is the nursing priority with Shock? | ABC's |
How can we maximize oxygen delivery for shock? | Airway patency
Monitor respiration
Oxygenation
Airway maintenance
Suctioning
Chest physical therapy |
What are Nursing interventions for shock (circulation)? | Monitor for bleeding
Skin color and temp
LOC
VS
Heart sounds
Pulses
Patient positioning |
What are Nursing interventions for shock (Lab Values)? | Identify anemia (hypovolemic).
Identify elevated WBC count (septic).
Identify electrolyte imbalances and acid-base disturbances.
Identify thrombocytopenia and clotting abnormalities. |