Chapter 19
Shock
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Definition of Shock
• Inadequate tissue perfusion resulting in
impaired cellular metabolism
• Deprives cells of essential oxygen and nutrients,
forcing cells to rely on anaerobic (without oxygen)
metabolism
• Less energy is produced and lactic acid, a byproduct of anaerobic metabolism, causes
tissue acidosis and subsequent organ
dysfunction
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Hypovolemic Shock
• Inadequate blood volume to maintain the supply of
oxygen and nutrients to body tissues
• Intravascular or circulating volume deficits can occur
from external or internal losses
• Blood volume falls with excessive blood or fluid loss,
inadequate fluid intake, or a shift of plasma from the
blood vessels into body tissues/organs
• Causes of blood/fluid loss: hemorrhage, severe
diarrhea or vomiting, excessive perspiration
• Excessive shift of plasma with pathologic states (burns,
peritonitis, and intestinal obstruction)
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Cardiogenic Shock
• Occurs when heart fails as a pump
• Decreased myocardial contractility causes
decreased cardiac output and impaired tissue
perfusion
• Difficult to treat and usually results when
diseased coronary arteries cannot meet the
demand of the working myocardial cells
• Causes include conditions that result in
ineffective myocardial cell function, such as
dysrhythmias, cardiomyopathy, myocarditis,
valvular disease, and structural disorders
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Distributive Shock
• The problem is not loss of blood, but excessive
dilation of blood vessels or decreased vascular
resistance causing the blood to be improperly
distributed
• Anaphylactic
• Septic
• Neurogenic
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Effects of Shock on
Body Systems and Functions
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Respiratory system
Cardiovascular system
Neuroendocrine system
Immune system
Gastrointestinal system
Renal system
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Early, Reversible, and
Compensatory Stages
• Symptoms
• Mental status
• Irritability, restlessness
• Blood pressure
• Normal or slightly decreased, decreasing pulse pressure,
orthostatic hypotension
• Pulse
• Increased rate; may be thready (as a result of
vasoconstriction) or bounding (caused by vasodilation)
decreased rate (bradycardia) may be present in neurogenic
shock due to loss of sympathetic stimulation
•
Respirations
• Increased rate and depth
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Early, Reversible, and
Compensatory Stages
• Urine output
• Decreased
• Skin
• Cool and pale
• Exception: warm and dry with septic shock
• Abdomen
• Decreased bowel sounds
• Blood glucose
• Increased
• Other
• Thirst
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Intermediate (Progressive) Stage
• Symptoms
• Mental status
• Listlessness, confusion
• Blood pressure
• Decreased; narrow pulse pressure
• Pulse
• Weak and thready, tachycardia, dysrhythmias
• Respirations
• Increased, deep, crackles present on auscultation
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Intermediate (Progressive) Stage
• Temperature
• Subnormal, except with septic shock
• Urine output
• Decreased; possible renal failure
• Skin
• Cold, pale, clammy, slow capillary refill, cyanosis
• Other
• Dry mouth, thirst, sluggish pupillary response,
peripheral edema, and muscle weakness
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Irreversible (Refractory) Stage
• Symptoms
• Mental status
• Loss of consciousness
• Blood pressure
• Systolic continues to fall; diastolic approaches zero
• Pulse
• Progressive slowing, irregular
• Respirations
• Slow, shallow, irregular
• Urine output
• Minimal
• Skin
• Cold, clammy, cyanosis
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Diagnosis
• Based on history and physical examination
• Tests and procedures that help establish type
of shock, stage, and the cause
• Blood and urine studies, measurement of
hemodynamic pressures, chest radiograph, ECG
and continuous cardiac monitoring, pulse oximetry
and arterial blood gases, and urine output
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Oxygenation
• Brain cells begin to die after 4 minutes without
oxygen, and oxygen consumption increases as
delivery decreases in shock: poor prognosis
• Oxygen delivery such as increasing arterial
oxygen saturation, hemoglobin, and cardiac
output
• Supplemental oxygen may be used or
mechanical ventilation may be necessary
• Paralytics, sedatives, and analgesics may be
ordered to decrease oxygen requirements
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Fluid Replacement
• Normal saline is usually administered initially
• Subsequent fluids may include various
crystalloids and colloids depending on situation
• Crystalloids provide replacement water and
electrolytes for all fluid compartments
• Colloids remain in the vascular system and draw
fluid into the bloodstream
• Especially important when large amounts of plasma proteins have
been lost
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Pharmacologic Therapy
• Based on manipulation of the cardiac
dynamics: contractility, preload, afterload, and
heart rate
• No one drug will provide nutrients and oxygen
to the cells; several agents assist in
manipulation of the four circulatory
components
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Figure 19-1
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Figure 19-2
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Assessment
• Continuous monitoring of cardiac rate and
rhythm; blood pressure; body temperature;
hemodynamic values; respiratory rate, rhythm,
and depth; and arterial blood gases
• Observe skin color; palpate for warmth and
moisture
• Note pupil size, equality, and response to light
• Describe patient’s level of consciousness and
response to commands, and assess reflexes
• Auscultate heart, lung, and bowel sounds
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Assessment
• Observe movement of the chest wall with
respirations; inspect and palpate abdomen for
distention
• Palpate for bladder distention, and note the
appearance of urine and the hourly output
• Inspect the extremities for color, and palpate
for peripheral pulses and edema
• Inspect IV infusion sites for pallor, swelling, or
coolness that suggests extravasation
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Nursing Diagnosis
• The primary nursing diagnosis for all patients in
shock is Altered Tissue Perfusion
• May be related to alteration(s) in circulating
blood volume, myocardial contractility, blood
flow, or vascular resistance
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Decreased Cardiac Output
Disturbed Thought Processes and Anxiety
Deficient Fluid Volume
Risk for Injury
Risk for Infection
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Systemic Inflammatory
Response Syndrome (SIRS)
• Generalized inflammation that threatens vital organs
• Conditions that can lead to SIRS are shock, multiple
transfusions, massive tissue injury, burns, and
pancreatitis
• Effects are damage to the endothelium of blood
vessels and a hypermetabolic state
• Hypotension, microemboli, and shunting of blood flow
compromise organ perfusion
• The hypermetabolic state is characterized by increased
serum glucose, which eventually depletes
carbohydrate, fat, and protein stores
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Diagnosis
• Diagnosis of SIRS is made when a patient
manifests two or more of the following:
• Temperature less than 97° F (36° C) or more than
100.4° F (38° C)
• Heart rate more than 90 bpm
• Respiratory rate more than 20/min, or Paco2 less
than 32 mm Hg
• WBC count less than 4000 cells/mm3 or more than
12,000 cells/mm3, or more than 10% immature
(band) neutrophils
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Medical Treatment and
Nursing Interventions
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Prevent and treat infection
Maintain tissue oxygenation
Provide nutritional and metabolic support
Support failing organs
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