Shock Flashcards
CONCEPT
Perfusion
Ability of the cardiovascular and pulmonary systems to provide adequate oxygenated blood to the cells and organs of the body and the removal of metabolic waste
Inadequate perfusion will lead to changes that affect all body functioning
Terms to Know
Stroke Volume
amount of blood ejected with each ventricular contraction
Terms to Know
Cardiac Output
amount of blood pumped per minute (CO = HR x SV)
Terms to Know
Mean Arterial Pressure (MAP)
average pressure in the arterial circulation throughout the cardiac cycle
ideal 70-90
Terms to Know
Pulse Pressure
the difference between systolic and diastolic pressures
Types of Shock
Low Blood Flow
HYPOVOLEMIC
- Severe trauma with massive tissue injury
- Hemorrhage
CARDIOGENIC
- Acute MI
- Arrhythmias
- Cardiomyopathy
Maldistribution of Blood Flow
SEPTIC
- Pancreatitis
- Infection →Sepsis
NEUROGENIC
- Spinal Cord Injury
- Narcotic Overdose
ANAPHYLACTIC
- Multiple Transfusion
- Severe Allergic Reaction
Shock
Characterized by decreased tissue perfusion and decreased cellular metabolism
Imbalance in supply/demand
MAP>60 ideal
MAP<50 incompatible with life
confusion, restlessness → ↓BP
normal: 25% o2 used, 1 pass through body
shock: 80% 02 used, 1 pass through body
Hypovolemic Shock
Severe blood +/or fluid loss making the heart unable to pump enough blood to the body
Emergency situation
Loss of 1/5 the normal amount of intravascular volume in the body (~750ml loss)
volume problem
most common form of shock
↓BP, ↓CO
goal: maintain intravascular (fluids, fluids, more fluids)
HYPOVOLEMIC SHOCK
Absolute Hypovolemia
Fluid loss through: Hemorrhage Gastrointestinal loss Fistula drainage Diabetes Insipidus Rapid diuresis Severe dehydration Pregnancy & Childbirth Major Sx
HYPOVOLEMIC SHOCK
Relative Hypovolemia
Fluid loss through: Movement of fluid from Intravascular to Extravascular Space Burns Liver disease (ascites) “Third Spacing” Fluid shifts
HYPOVOLEMIC SHOCK (define)
Size of vascular compartment unchanged
Decreased venous return to heart
Decreased preload, SV and CO
Impaired cellular metabolism
Response to acute volume loss depends upon:
- Age
- Injury
- Health
anaerobic & anaerobic
anaerobic - gives off heat
HYPOVOLEMIC SHOCK
Signs & Symptoms
Anxiety, confusion Agitation Tachycardia Hypotension Pallor Cold & clammy Decreased capillary refill / pulses Decreased urine output (later sign) Decreased or absent bowel sounds (earlier sign)
HYPOVOLEMIC SHOCK
Immediate Treatment
Recognize A-B-C’s and LOC High flow O2 2 large bore IV’s Fluids / blood via warmer Expose the patient (blankets to warm) Medications as warranted
CARDIOGENIC SHOCK
Low Blood Flow Shock
Failure of the heart to act as a pump moving blood forward
Compromised CO & SV
RIGHT SIDE:
Pulmonary circulation compromised
LEFT SIDE:
Impaired ability of the ventricle to fill during diastole
Decreased Stroke Volume
clots
↓↓BP
CARDIOGENIC SHOCK
Causes
MI (#1 cause) Cardiomyopathy Severe Systemic/Pulmonary HTN Blunt Cardiac Injury (MVA. #2) Severe Myocardial Depression from Sepsis Cardiac Tamponade Dysrhythmias
CARDIOGENIC SHOCK (define)
Decreased CO with resultant decreased MAP
Tachycardia compensation stresses the heart
Myocardial ischemia progresses to necrosis
Cardiac failure leads to shock and pulmonary failure
**MAP & urine output
CARDIOGENIC SHOCK
Signs & Symptoms
Tachycardia, thready pulse, JVD Hypotension Narrowed pulse pressure Increased SVR Increased myocardial O2 consumption (Angina) Pale, cold, moist skin Cyanosis
CARDIOGENIC SHOCK
S&S of Peripheral Hypoperfusion
- Renal Blood Flow
- Decreased Urine Output
- Impaired Cerebral Blood Flow
lethargy→coma
CARDIOGENIC SHOCK
Treatments
Cautious use of fluids High flow O2 Medications as indicated Vazoactives (CO & contractility) Beta 1 medications
Starling’s Law: overstretch cardiac muscle to the point it cannot constrict
DISTRIBUTIVE SHOCK (define)
vasogenic shock
An increase in the size of the vascular bed due to massive vasodilatation or peripheral pooling of blood
Normal blood volume that can not adequately fill the increased size of the capillary bed
Types:
NEUROGENIC
SEPTIC
ANAPHYLACTIC
blood vessel problem
massive vasodilation
NEUROGENIC SHOCK (define)
Occurs after spinal cord injury at T5 or above
Results in massive vasodilatation leading to pooling of blood in vessels
Loss or suppression of -sympathetic tone- (↓ sympathetic motor function)
The rarest of all shocks
NEUROGENIC SHOCK
Signs & Symptoms
Hypotension
Bradycardia
–Dry, warm skin initially–
With hypothalamic dysfunction there is temperature dysregulation
Respiratory dysfunction based on level of cord injury
Can begin 30 minutes after injury & last days to weeks
bradycardia→atropine
NEUROGENIC SHOCK
Treatment
Treat the injury
Corticosteroids (anti-inflammatory)
Vasoactive agents (cerebral perfusion pressure = MAP-ICP)
Reduce parasympathetic stimulation
Cannot control ICP, use MAP to counteract ICP
Dopamine, Levafed(?), Epinephrine
ANAPHYLACTIC SHOCK
Pathophysiology
Acute, Life-Threatening Hypersensitivity Reaction
Massive Vasodilatation
Release of Mediators (Histamine, Serotonin, etc.)
Increased Capillary Permeability (capillary leakage)
Loss of Intravascular Volume
Impaired Tissue Perfusion
ANAPHYLACTIC SHOCK
Causes
AntigensFoodsFood AdditivesDiagnostic AgentsBiologic AgentsEnvironmental AgentsDrugsVenoms / Insects Blood reactionsIgE-mediated or non-IgE-mediated
ANAPHYLACTIC SHOCK
Degree of Reaction
Sudden onset of S&S
CUTANEOUS MANIFESTATIONS
Urticaria, rash, erythema, angioedema, puritis, flushing
RESPIRATORY COMPROMISE
Swelling of lips & tongue, SOB, wheezing, stridor, chest pain
NEUROLOGICAL COMPROMISE
Anxiety, confusion, impending doom, ↓ LOC
ANAPHYLACTIC SHOCK
Treatments
Epinephrine
Corticosteroids
High flow O2
Artificial airways
SEPTIC SHOCK (define)
Systemic inflammatory response to infection
Presence of sepsis with hypotension despite fluid resuscitation with abnormal tissue perfusion
Leading cause of death in non-coronary ICU’s
PRIMARY CAUSATIVE ORGANISMS:
Gram-negative & Gram-positive bacteria [↓ outcome gram-neg]
Endotoxins stimulate inflammatory responses
body temperature
heart rate
respiration rate
leukocyte count
SEPTIC SHOCK
Signs & Symptoms
Early Manifestation
↓LOC
Cutaneous Manifestations
Warm, dry, flushed skin
Cardiovascular Manifestations
Hypotension, hyperthermia, ↓SVR, compensatory CO, ↑coagulation, ↓fibrinolysis, ↓urine output
Tachypnea
Fluid resuscitation does NOT work
SEPTIC SHOCK
“Warm” vs “Cool”
“WARM” stage Hypotension Tachycardia Warm, flushed skin Increased core temperature Chills Anxiousness N/V/D
“COLD” stage Hypotension Tachycardia and dysrhythmias Cool, pale edematous skin Lethargy or Coma Oliguria / Anuria Decreased core temperature
longer in cold stage → harder to reverse
SEPTIC SHOCK
Treatments
Antibiotics and IV fluids
Possible ventilator support
Support vital functions
Cultures to identify organism
skin starts weeping d/t fluid overload
STAGES OF SHOCK
Initial Stage
[pt 1]
May not be clinically apparent
May be restless or anxious
Metabolism changes from aerobic to anaerobic (leads to lactic acid accumulation)
Lactic Acid accumulates (sodium bicarb tx)
Must be removed by blood & broken down by the liver
This requires unavailable O2
STAGES OF SHOCK
Initial Stage
[pt 2]
Baroreceptors detect a sustained decrease in the MAP (<10 mmHg)
Decreased circulating blood flow
Natural physiologic responses are activated
Vasoconstriction
Increased cardiac contractions & HR
Reversible at this point
STAGES OF SHOCK
Compensatory Stage
[pt 2]
Attempted homeostasis
MAP < 10-15 mmHg & 25-35% volume loss
Renin-Angiotensin system activated
Impaired GI motility
Cool, clammy skin
Except septic shock where skin is warm & flushed
“fight or flight” activity
still reversible
STAGES OF SHOCK
Compensatory Stage
[pt 2]
Shunting blood from lungs = physiologic dead space
SNS stimulation increases myocardial O2 demand
Decreased blood to kidneys
Reabsorb Na+/H2O, ↓K+
If the deficit is not corrected, the patient enters the PROGRESSIVE STAGE
STAGES OF SHOCK
Progressive Stage
[pt 1]
MAP < 20 mmHg
Begins when compensatory mechanisms fail
Lactic acid accumulation
Requires aggressive interventions to prevent multi-organ dysfunction syndrome (MODS) and death
STAGES OF SHOCK
Progressive Stage
[pt 2]
Decreased cellular perfusion and altered capillary permeability
Movement of fluid from intravasculature to interstitium
Hyperkalemia due to cellular destruction
STAGES OF SHOCK
Progressive Stage
[pt 3]
Fluid movement into alveoli
CO begins to fall
Myocardial Dysfunction
GI system becomes ischemic
Liver fails to metabolize drugs & wastes
Failure of one organ system affects others
cardiac muscle affected by lactic acid
STAGES OF SHOCK
Refractory Stage
Exacerbation of anaerobic metabolism Accumulation of lactic acid (sodium bicarb drips tx) Increased capillary permeability Hypotension & tachycardia worsen Decreased coronary blood flow Cerebral ischemia Hypoxemia
RECOVERY UNLIKELY
COMPARISON OF SHOCK STATES
SHOCKSTATE CVP PWP CO SVR BP Hypovolemic ↓↓↓↓ ↓↓↓↓ ↓↓↓↓ ↑↑↑↑ ↓↓↓↓
Cardiogenic ↓↓↓↓ ↑↑↑↑ ↓↓↓↓ ↑↑↑↑ ↓↓↓↓
Septic ↓↓↓↓ ↓↓↓↓ ↓↓↓↓ ↓↓↓↓ ↓↓↓↓
MEDICAL MANAGEMENT
SUPPORTIVE CARE
Ventilation & Oxygenation
ADEQUATE INTRAVASCULAR VOLUME
Positioning
Volume Replacement
CIRCULATORY SUPPORT
Vasopressors & Positive Inotropes
Vasodilators
Circulatory Assist Devices
NO Ringer’s Lactate
NURSING DIAGNOSES
DECREASED CARDIAC OUTPUT IMPAIRED GAS EXCHANGE FLUID VOLUME DEFICIT ALTERED TISSUE PERFUSION: Cerebral, Renal, GI, Peripheral HYPERTHERMIA / HYPOTHERMIA FEAR / ANXIETY KNOWLEDGE DEFICIT: Patient / Family
[pulse pressure & urinary output - best indicator of tissue perfusion]
COMPLICATIONS
Multiple Organ Dysfunction Syndrome (MODS)
Myocardial Failure
ARDS
Disseminated Intravascular Coagulation (DIC)
GI Bleeding
Hepatic Failure
Death
In which shock state is the client warm, flushed, bradycardia and hypotension?
- Cardiogenic shock
- Septic shock
- Hypovolemic shock
- Neurogenic shock
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