Shock
Metropolitan Community College
Fall 2013
Jane Miller, RN MSN
Objectives
• Define pathophysiology of shock, including
classifications.
• Identify physiologic events during shock if
progresses.
• Identify etiology of shock including hypovolemic,
cardiogenic, distributive, and obstructive shock.
• Identify clinical manifestations, treatment
modalities, and nursing interventions for each
type of shock. Identify the potential for multiple
organs dysfunction syndrome.
• Define intervention activities for shock prevention.
Shock
• Not a disease
• Decrease in tissue perfusion due to
– Alteration in blood or plasma volume
– Alteration in peripheral vascular resistance
– Alteration in the hearts ability to pump
• Can lead to
– Multiple organ dysfunction syndrome (MODS)
– Death
Shock Syndromes
• Hypovolemic or low-volume
– loss of blood/fluid volume
• Distributive or high-space
– Factors that affect the blood vessels
• Mechanical or obstructive
– Factors that affect the heart
Blood Composition
• Red blood cells
– Transport oxygen and carbon dioxide to and
from cells
• White blood cells
– Protect against foreign matter
• Platelets
– Form a plug at the site of injury
• Plasma
– Liquid that blood cells are suspended in
Regulation of Blood Pressure
• Stroke Volume (SV)
– Amount of blood leaving the left ventricle with
each heart contraction
• Cardiac Output (CO)
– Amount of blood leaving the left ventricle per
minute
CO = HR x SV
• Peripheral Vascular Resistance (PVR)
– Resistance to the flow of blood by vascular
musculature and diameter of the blood vessels
Regulation of Blood Pressure
BP = CO x PVR
Or
BP = HR x SV x PVR
Regulation of Blood Pressure
When you have a decrease in HR, SV,
or PVR what do you get?
A decrease in BP and subsequently
tissue perfusion
Pathophysiology of Shock
• Results from inadequate tissue perfusion
• Inadequate tissue perfusion impairs
cellular metabolism
• Impaired cellular metabolism results in
impaired oxygen and glucose use
• If this is not corrected cellular death
occurs
Normal Cellular Function
• Nutrients are broken down into ATP
• ATP is used for cellular functions
• ATP can be synthesized aerobically or
anaerobically
• Aerobic metabolism is more efficient
• Anaerobic is not only less efficient it
produces lactic acid.
Pathophysiology of Shock
H2O
Sodium
This increase of
sodium and H20
into the cell
causes potassium
to exit, cellular
swelling, eventual
rupture and cell
death
Potassium
A lack of oxygen
changes the cell
metabolism
from aerobic to
anaerobic
Impaired Glucose Use
• Impaired cellular metabolism also
produces insulin resistance
• As the body responds to the stress it
produces more glucose to assist in healing
• Because the body doesn’t use the glucose
properly blood glucose levels rise
• Insulin resistance and glucose toxicity
further impair cell metabolism
SIRS
• Systemic inflammatory response syndrome
• Often associated with septic shock
• First phase of shock
• Presents much like sepsis
–
–
–
–
HR
RR
Temp
WBC
- PaCO2
Signs of Shock
• Neurological
– Altered mental status
– Seizures
– Coma
• Cardiovascular
– Cardiac output declines
– HR increases
– Dysrhythmias
– Absence of peripheral pulses
• Genitourinary
– Decreased filtration
– Decreased urinary output
• Integumentary
– Pale and fragile
• Musculoskeletal
– Weakness and wasting
• Lungs
– Increased RR
– Decreased O2 saturation
– ARDS
Shock Syndromes
• Hypovolemic or low-volume
– loss of blood/fluid volume
• Distributive or high-space
– Factors that affect the blood vessels
• Mechanical or obstructive
– Factors that affect the heart
Hypovolemic Shock
• Can result from a loss of blood, plasma, or
body fluids
• Hemorrhagic shock is most common
– Trauma, GI bleeds, ruptured AAA
• Other causes
– Diarrhea
– Vomiting
– Inadequate repletion of fluid loss
• Burns, heat stroke, third spacing
Decreased Blood Volume
Decreased Venous Return
Decreased Stroke Volume
Decreased Cardiac Output
Decreased Tissue Perfusion
Medical Management
• Correct the underlying cause
– e.g. stop the bleeding, vomiting, diarrhea
• Restore intravascular volume
• Redistribute fluid volume
Mechanical Shock
• A condition that slows or obstructs blood
flow in or out of the heart
– Ineffective pump
– Physical obstruction
• A decrease in blood flow through the heart
decreases stroke volume and cardiac
output
• Hypotension
• Decreased tissue perfusion
Decreased Cardiac Function
Decreased Stroke Volume
Decreased Cardiac Output
Decreased Blood Pressure
Decreased Tissue Perfusion
Mechanical Shock
• Two different types
– Cardiogenic
• When the heart is unable to pump effectively
• MI, ruptured ventricle, cardiomyopathy
– Obstructive
• Physical obstruction
• Cardiac tumor, massive PE, cardiac tamponade
Medical Management
• Limit further myocardial damage and
preserve healthy myocardium
• Remove source of obstruction
• Improve cardiac function by increasing
cardiac contractility and decrease
ventricular afterload
Mechanical Assistive Devices
• A mechanical assistive device may be
needed if first line treatments fail
– Intra-aortic balloon pump
– Left or right ventricular assist devices
• Last option
– Heart transplant
Distributive Shock
• A precipitating event causes massive
vasodilation
• Blood pools in the periphery
• Decreased venous return results in
decreased stroke volume and cardiac
output
• Hypotension
• Decreased tissue perfusion
Precipitating Event
Vasodilation
Maldistribution of Blood Volume
Decreased Venous Return
Decreased Cardiac Output
Decreased Tissue Perfusion
Distributive Shock
• Three different types
– Anaphylactic shock
• Insect bites, medication allergies, food allergies
– Neurogenic shock
• Spinal cord injury, anesthetic agents, severe pain
– Septic Shock
• Bacterial and viral infections
Anaphylactic Shock
•
•
•
•
•
Results from an antigen-antibody reaction
Symptoms are usually immediate
Blood pooling in the periphery
Pulmonary vasocontriction
Maintenance of an airway is critical
Neurogenic Shock
• Imbalance between the sympathetic and
parasympathetic stimulation of vascular
smooth muscle
• This causes vasodilation
• Caused by injury or medications that affect
the spinal cord or medulla
• Clinical symptoms may be different
– Hypotensive, bradycardic, vasodilation
Septic Shock
• Occurs when an infectious agent causes
systemic decompensation
• Acute circulatory failure characterized by
persistent hypotension unexplained by
other causes
• 3 principle actions occur with sepsis
– Inflammation
– Coagulation
– Fibrinolysis
Nursing Management
• Prevention
• 2 large bore IVs
• Place patient in modified trendelenburg
position
• Monitor for signs of transfusion reaction
• Monitor for fluid overload and pulmonary
edema
• Monitor VS, especially temperature
• Apply oxygen, administer meds, monitor
labs
• Monitor for skin breakdown, turn q 2 hrs,
and provide skin care
• Watch for DVT
• Monitor ECG
• Wound care
• I&O
• Enteral or parental nutrition
• ROM
• Emotional support for patient and family
• Medications
– Vasopressors
– Inotropes
– Antiemetics & antidiarrheals
– Antibiotics
– Insulin
– Corticosteriods
– Blood thinners and clot busters
– Opiods
– Antianxiety
This is not a complete list of
– Sedation
medications and some listed will not
– rhAPC
be appropriate for all clients
experiencing shock
MODS
• Multiple Organ Dysfunction Syndrome
– End result of severe sepsis
– Triggered by a critical injury or disease
process that initiates a massive systemic
inflammatory response
• Multiple injuries, burns, hypovolemic shock, acute
pancreatitis, ARDS, acute renal failure
• Does not require an infectious trigger
Pathophysiology
• Primary or early MODS
– Hypoperfusion that triggers inflammatory and
stress responses
• Secondary or late MODS
– Excessive inflammation following the initial
insult
– Manifested in organs distant from the original
injury
– Three primary mechanisms: inflammation,
coagulation, and fibrinolysis
Clinical Manifestations & Diagnosis
• Depend on the area or areas affected
• Early MODS is difficult to monitor
• Late MODS follows a specific pattern
– Measured using the SOFA score
– Evolves over 14 days to weeks
• Diagnostic tests are specific to the organ
system(s) that are failing
Treatment
•
•
•
•
•
•
•
•
•
Prevention is key
Antibiotics
Intubation
Fluid resuscitation
Vasopressors
Analgesics
Sedation
Enteral feedings
Glucose monitoring
Nursing Management
•
•
•
•
Hand hygiene and skin care
Monitoring of VS
Positioning
Decrease oxygen demands
– Pain and anxiety meds
– Rest
• Emotional support
• Frequent patient assessments
Resources
• Osborn, Wraa & Watson chapter 61
• YouTube video on shock
– http://www.youtube.com/watch?v=CbM4Uih
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