Shock Flashcards
STROKE VOLUME
amount of blood ejected with each ventricular contraction
Three parts to:
afterload
preload
contractility
CARDIAC OUTPUT
amount of blood pumped per minute (CO=HRX SV)
MEAN ARTERIAL PRESSURE (MAP)
average pressure in the arterial circulation throughout the cardiac cycle
(systolic + 2diastolic)/3
PULSE PRESSURE
the difference between systolic and diastolic pressures
TYPES OF SHOCK
- Low blood flow
- Misdistribution of blood flow
LOW BLOOD FLOW
- hypovolemic
- cardiogenic
MALDISTRIBUTION OF BLOOD FLOW
- septic
- neurogenic
- anaphylactic
HYPOVOLEMIC CAUSE
- severe trauma with massive tissue injury
- hemorrhage
CARDIOGENIC CAUSE
- acute MI
- arrhythmias
- cardiomyopathy
SEPTIC CAUSE
- pancreatitis
- infection
- sepsis
NEUROGENIC CAUSE
- spinal cord injury
- narcotic overdose
ANAPHYLACTIC CAUSE
- multiple transfusion
- severe allergic reaction
SHOCK
-characterized by decreased tissue perfusion and decreased cellular metabolism
- imbalance in supply /demand
- not enough oxygen
- aerobic to anaerobic
MAP less than or equal to 60= shock
MAP less than 50= death
MAP 70-90= normal
HYPOVOLEMIC SHOCK
most common
-severe blood and 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
- AFFECTS NEURO STATUS 1ST
ABSOLUTE HYPOVOLEMIA
FLUID LOSS THROUGH
- hemorrhage
- gastrointestinal loss
- fistula drainage
- diabetes insipidus
- rapid diuresis
- severe dehydration
RELATIVE HYPOVOLEMIA
FLUID LOSS THROUGH
- movement of fluid from intravascular space to extravascular space
- burns
- liver disease
- third spacing
HYPOVOLEMIC SHOCK
-size of vascular compartment unchanged
- decreased venous return to heart
- decreased preload, SV and CO
- impaired cellular metabolism
- response to acute voulume loss depends upon
: age, injury, health
SIGNS AND SYMPTOMS OD HYPOVOLEMIC SHOCK
- anxiety , confusion
- agitation
- tachycardia
- hypotension
- pallor
- cold and clammy
- decreased cap refill/pulses
- decreased urine output
- decreased or absent bowel sounds
HYPOVOLEMIC SHOCK IMMEDIATE TREATMENT
- recognize before it happens
- ABC’s and LOC
- high flow O2 95% stat wanted
- 2 large bolus IV
- fluids / blood via warmer
- medications as warranted
- expose pt to find and stop bleeding
CARDIOGENIC SHOCK
LOW BLOOD FLOW SHOCK
- failure of the heart to act as a pump moving blood forward
- compromised CO and SV
- right side - pulmonary circulation compromised
- left side- impaired ability of the ventricle to fill during diastole
- DECREASED STROKE VOLUME
CAUSES OF CARDIOGENIC SHOCK
- MI
- cardiomyopathy
- severe systemic /pulmonary hypertension
- blunt cardiac injury
- severe myocardial depression from sepsis
- cardiac tamponade
- dysrhythmias
CARDIOGENIC SHOCK
- decreased CO with resultant decreased MAP
- tachycardia compensation stresses the heart
- myocardial ischemia progresses to necrosis
- cardiac failure leads to shock and pulmonary failure
SIGNS AND SYMPTOMS OF CARDIOGENIC SHOCK
- tachycardia, thread pulse, JVD
- hypotension
- narrowed pulse pressure
- increased SVR
- increased myocardial O2 consumption (angina)
- pale , cold, moist skin
- cyanosis
signs and symptoms of peripheral hypoperfusion
- RENAL BLOOD FLOW
- DECREASED URINE OUTPUT
- IMPAIRED CEREBRAL BLOOD FLOW
CARDIOGENIC SHOCK TREATMENTS
- cautious use of fluids
- high flow O2
- medications as indicated
- vasoactives
- beta 1 meds (act on the heart)
DISTRIBUTIVE SHOCK
- an increased in the size of the vascular bed due to massive vasodilation or peripheral pooling of blood
- normal blood volume that can not adequately fill the increased size of the capillary bed
TYPES:
neurogenic
anaphylactic
septic
NEUROGENIC SHOCK
- occurs after spinal cord injury at T5 or above
- results in massive vasodilation leading to pooling of blood in vessels
- loss or suppression of sympathetic tone
- the rarest of all shocks
SIGNS AND SYMPTOMS OF NEURGENIC SHOCK
TRIAD
- 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 and last days to weeks
TREATMENTS FOR NEUROGENIC SHOCK
- treat the injury
- corticosteroids
- vasoactive agents
- reduce parasympathetic stimulation
ANAPHYLACTIC SHOCK PATHO
- acute, life threatening hypersensitivity reaction
- massive vasodilation
- release of mediators , (histamine, serotonin, etc)
- loss of intravascular volume
- increased capillary permeadbility
- impaired tissue perfusion
CAUSES OF ANAPHYLACTIC SHOCK
ANTIGENS: BINDS TO ANTIBODIES -foods food additives diagnostic agents biologic agents environmental agents drugs venoms/insects blood reactions
ANAPHYLACTIC SHOCK DEGREE OF REACTION
SUDDEN ONSET OF S AND S
CUTANEOUS MANIFESTATIONS
-utricaria, rash, erythema, angioedema, purirtis, flushing
RESPIRATORY COMPROMISE
- swelling of lips and tongue
- SOB, wheezing stridor, chest pain
NEUROLOGICAL COMPROMISE
-anxiety, confusion, impending doom, decreased LOC
ANAPHYLACTIC SHCOK TREATMENTS
- epinephrine
- corticosteroids
- high flow O2
- artificial airways
SEPTIC SHOCK
- 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 and gram positive bacteria
- endotoxins stimulate inflammatory response
SIGNS AND SYMPTOMS OF SEPTIC SHOCK
early manifestations
-decreased LOC
cutaneous manifestations
-warm, dry , flushed skin only in beginning
Cardiovascular manifestations
- hypotension , hyperthermia, decreased SVR, compensatory CO, increased coagulation , decreased fibrinolytysis, decreased output
Tachypnea
-hyperventilation
SEPTIC SHOCK WARM STAGE
hypotension tachycardia warm,flushed skin increased core temperature chills anxiousness N/V/D
short stage rapid
COLD STAGE SEPTIC SHOCK
hypotension tachycardia and dysrthmias cool pale, edematous skin lethargy or coma oliguria/anuria decreased core temperature
SEPTIC SHOCK TREATMENTS
- anitibiotic and IV fluids
- possible ventilator support
- support vital functions
cultures to identify organism ( pan and urine)
STAGES OF SHOCK : INITIAL STAGE
- may not be clinically apparent
- may be restless or anxious
- metabolism changes from aerobic to anaerobic
- lactic acid accumulates
- must be removed by blood and broken doen by the liver
- this requires O2
INITIAL STAGE
- baroreceptors detect a sustained decrease in the MAP
- decreased circulating blood flow
- natural physiologic responses are activated
- vasoconstriction
- increased cardiac contractions and HR
- reversible at this point
COMPENSATORY STAGE
- attempted homeostaisis
- MAP <10-15 and 25-35% volume loss
- renin angiotensin system activated
- impaired GI motility
- cool skin clammy
- except septic shock where skin is warm and flushed
COMPENSATORY STAGE
- shunting blood from lungs=physiologic dead space
- SNS stimulation increses myocardial O2 demand
- decreased blood to kidneys
PROGRESSIVE STAGE
MAP <20
begins when compensatory mechnisms fail
lactic acid accumulation
requires aggressive interventions to prevent multiorgan dysfunction syndrome and death
-decreased cellular perfusion and altere capillary permeability
- movement of fluid from intravasculature to interstitium
- hyperkalemia due to cellular destruction
PROGRESSIVE STAGE
- fluid movement into alveoli
- CO begins to fall
- myocardial dysfunction
- GI system becomes ischemic
- liver fails to metabolize drugs and wastes
- failure of one organ system affects others
REFRACTORY STAGE
- exacerbation of aneorobic metabolism
- accumulation of lactic acid
- increased capillary permeability
- hypotension and tachycardia worsen
- decreased coronary blood flow
- cerebral ischemia
- hypoxemia
- recovery unlikely
MEDICAL MANAGEMNT
supportive care
- ventilation and oxygenation
adequate intravascular volume
- positioning
- volume replacement
circulatory support
- vasopressors and positive inotropes
- vasodilators
- circulatory assist devices (blood products , plasma, platelets)
NURSING DIAGNOSIS
- decreased cardiac output
- impaired gas exchange
- fluid volume deficit
- altred tissue perfusion
- hyperthermia/hypo
- fear/anxiety
- knowledge deficit
COMPLICATIONS
- MODS
- ARDS
- death
- liver failure
- DIC
- myocardial failure
- Gi bleeds
