Shock
Priority concepts
Objectives
• Perfusion
• Blood Volume
• Cardiac Output
• Systemic Vascular
Resistance
Interrelated
Concepts
• Clotting
• Gas Exchange
• Immunity
Pathophysiology of Shock
Cause of Shock Relative to Perfusion
Inadequate blood
volume
• Total volume vs.
Relative
Inadequate cardiac
output
Inadequate tissue
function
Increased peripheral
vasodilation
Cardiac output and Stroke Volume
Factors that Affect
Blood Flow
• Contractility
• Preload and Afterload
Vital Organ Perfusion
• MAP > 60 mmHg
• Pulse Pressure 40mmHg
• Size and integrity of the vascular bed
Inadequate
perfusion
Effects of shock
are the same regardless of the
cause
Some effects are
due to lack of
oxygen /
nutrients
Other effects are
due to
compensation
The Problem
with Shock
Unknown; it is a
response not a
disease
Recognize
signs
Continued
assessment
Patient
Teaching
Incidence and
Prevalence | Health
Promotion and
Maintenance
Compensatory
Mechanisms
Hypovolemic*
Types of Shock
Cardiogenic*
Distributive*
• Septic*
• Neurogenic
• Anaphylactic
Hypovolemic Shock
Drop in MAP – 5/10
mmHg from baseline
Initial Stage
Increased sympathetic
stimulation
Mild
vasoconstriction/increased
HR
Compensatory Stage
MAP drops further 15 mmHg from baseline
Decreasing pulse pressure
Renin, aldosterone, ADH hormone secretion
Increased vasoconstriction
Urine output decreases
Client may express thirst and anxiety
Mild acidosis/hyperkalemia
Progressive stage
Sustained drop in MAP of >20 mmHg or fluid loss of 35-50%
Compensatory mechanisms still in play but not effective
Body switches from aerobic to anaerobic metabolism creating a further acidotic state
Na+/K+ pump fails causing a shift in fluid into the cell
Acid byproducts cause fluid shift back to interstitial spaces
Refractory
Shock
Class
EBL
Treatment
Classification
of
Hypovolemic
Shock
I
<15% (<750ml)
Fluids
II
15-30% (750-1.5L)
Fluids
III
+ Blood
30-40% (1.5L-2.0L)
IV
>40% (>2.0L)
Fluids + Blood
Fluids
History
• Risk factors
• Illness, trauma, procedures, chronic health
problems
• Urine output
Recognizing
Cues…
Physical Assessment
Signs & Symptoms
• Cardiovascular, respiratory, kidney and urinary,
skin, CNS, and skeletal muscle changes
Psychosocial Assessment
• Determine if behavior and cognition are the same
or different from baseline
Clinical Picture: Early Hypovolemic Shock
All signs of early shock
Oliguria
Clinical
Picture: Late
Hypovolemic
Shock
Rapid, thready pulse – may need a doppler to assess
Hypotension; MAP begins to drop
Restlessness / agitation
Poor capillary refill
Ischemia / cyanosis
3rd spacing
Metabolic acidosis / Lactic acid production
Weakness; DTRs become absent
Laboratory
Assessments
Decreased pH
Decreased PaO2
Increased PaCO2
Increased lactic
acid
Increased or
decreased
hematocrit
Increased or
decreased
hemoglobin
Increased
potassium
Planning and Implementation: Generate
Solutions – Take Action!
Sensorium
HR
Determining
Circulatory
Competence….
BP
Urine output
Skin color
Invasive monitoring
• CVP (Normal 2-6 mmHg)
• PAWP (normal 4-12 mmHg)
• Arterial BP
Cardiogenic
Shock
Clinical Picture:
Cardiogenic Shock
Distended neck veins
Hypotension
Peripheral edema
Hepatomegaly
Dyspnea / Rales
ECG signs of ischemia
Cardiomegaly on chest x-ray
Cardiogenic Shock Management
Oxygen
Laboratory testing/ECG monitoring
Opioids - relieve pain, provide sedation
Diuretics - decrease afterload, alleviate peripheral and pulmonary edema
Inotropic agents - improve cardiac contractility
Pacing
Mechanical support (IABP / LVAD) may be needed
Also known as vasogenic shock
Result is widespread vasodilation and decreased
peripheral vascular resistance
Distributive Shock
There is no change in blood volume
• hypovolemia occurs from fluid shifts from
intravascular space to interstitial space
Septic, neurogenic, and anaphylactic shock are forms
of distributive shock
Septic Shock
Definitions of Sepsis and
Septic Shock
Septic Shock
Early phase
Increased O2 consumption
Tachycardia
Hyperdynamic –
Warm phase
Flushed, warm skin
Low-grade fever (some patients have high fever)
WBCs increasing
Tachypnea
Decreasing urine output
Decreased cardiac output
Massive vasodilation
Hypotension, narrow pulse pressure
Cold clammy skin
Hypodynamic - Cold
Phase
Altered LOC
Hypoperfusion/hypoventilation poor
gas exchange
Oliguria
Microthrombi development
• Progression to DIC (Disseminated
Intravascular Coagulopathy)
Early Detection is
essential!!
Health
Promotion
and
Maintenance
•
•
•
•
•
CAUTI Bundles
CLABSI Bundles
VAP bundles
Wound prevention
Sequential Organ Failure
assessment/qSOFA assessment
• Modified Early Warning System:
MEWS
Prevention is BEST!
History
• Age and risk factors; drugs taken
Physical Assessment: Signs and
Symptoms
Recognize Cues..
•
•
•
•
Cardiovascular
Respiratory
Skin
Kidney/urinary
Psychosocial assessment
• Decreased patience; restless, fidgety
Nonspecific during early phase
Laboratory
Testing
Then…
•
•
•
•
Rising serum procalcitonin level
Increasing serum lactate level
Normal or low total white blood cell (WBC) count
Decreasing segmented neutrophil level with a
rising band neutrophil level
1 hour sepsis bundle
O2 therapy
Antibiotic therapy
Septic Shock:
Management
Low-dose corticosteroids
Unfractionated heparin therapy
Blood replacement therapy: FFP; PRBCs
Antibiotic therapy
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