Perfusion: Shock Flashcards
Define Shock
a clinical syndrome characterized by a systemic imbalance between oxygen supply and demand
What is needed by the cardiovascular system to keep the body running?
- Sufficient cardiac output
- an uncompromised vascular system, in which the vessels have a diameter sufficient to allow unimpeded blood flow and have good tone
- a volume of blood sufficient to fill the circulatory system, and a BP adequate to maintain blood flow
- Tissues that are able to extract and use the oxygen delivered through the capillaries
What happens in the body when shock occurs?
- one or more cardiovascular components do not function
- inadequate tissue perfusion
- the body attempts to maintain vital organs and to preserve life following a drop in cellular perfusion
- A drop in MAP (decrease in CO or an increase in the size of the vascular bed)
How many classes of shock are there?
4
Describe Class I: Early Shock
- drop in MAP of less than 10 mmHg from normal
- circulating blood volume decreases
- body reacts to a decrease in arterial pressure by increasing HR and signaling SNS response
- SNS response causes peripheral vasoconstriction= increased SVR and a rise in arterial pressure
Describe Class II: Compensatory Shock
- The body tries to make up for the loss of one of the cardiovascular components
- MAP below 10-15 mmHg/blood volume decreases by 15-30%
- Stimulation of SNS: fight or flight hormones, vasoconstriction, decreases perfusion to skin and abdominal viscera, increase heart rate and force= increase in CO and oxygenation
- Renin-angiotensin response: aldosterone stimulated= reabsorb water and sodium, loss potassium; water retention increases blood volume, raises BP
- ADH stimulated: reabsorption of more water
- MAP falling causes decreased capillary hydrostatic pressure= fluid shift from interstitial space into the capillaries= more blood volume
Describe Class III: Decompensated Shock (progressive shock)
- decrease in MAP of 20 mmHg or more below normal levels/ blood volume loss of 30-40%
- Vasoconstriction response limits blood flow to the point that cells become oxygen deficient
- Lactic acid is formed as a byproduct of anaerobic metabolism
- cell damage
- increased hydrostatic pressure= fluid shift back to interstitial space
- perfusion to the skin, skeletal muscles, kidneys, and GI organs decreases
- cells in the heart/brain become hypoxic; other tissues become ischemic and anoxic
Describe Class IV: Refractory Shock (irreversible)
- widespread and generalized anoxia (no treatment can reverse damage)
- Death of cells and tissues
- death of organs
What happens to the respiratory system during shock and what is a potential complication?
- increased respiratory rate
- respiratory acidosis
Potential complication: ARDS
What happens to the urinary system during shock, and what are some potential complications with the urinary system?
- decreased renal perfusion
- decreased GFR
- Late: Oliguria
Potential complications: - acute tubular necrosis
- kidney failure
What happens to the hepatic system during shock, and what is a potential complication with the liver?
- Early: increased glucose production
- Progressive: decreased glucose production= hypoglycemia
- Progressive: decreased lactic acid conversion= metabolic acidosis
Potential complication: destroyed Kupffer cells= systemic bacterial infections
What happens to the GI system during shock, and what is a potential complication?
- Early: decreased GI motility
- Late: paralytic ileus
- Late: ulceration of the GI mucosa
potential complication: bowel necrosis
What happens to the neurologic system during shock?
- decreased cognition
- decreased sympathetic activity
- decreased consciousness
- early: restlessness, apathy
- Progressive: Lethargy
- Late: coma
What happens to the cardiovascular system during shock?
- Early: no change
- Progressive: lightly elevated pulse and slowly rising heart rate
- Progressive: Sinus tachycardia
- Progressive thready pulse
- Late: Map <60 mmHg
- Late: Steadily decreasing BP and Steadily decreasing Cardiac output
- Late: imperceptible pulses
What happens to the integumentary system during shock?
- Pallor (skin, lips, oral mucosa, nail beds, conjunctiva)
- cool, moist skin
- Late: edema
What happens to the metabolic processes in the body during shock?
- decreased temperature
- thirst
- acidosis (metabolic and respiratory)
What is hypovolemic shock?
shock caused by a decrease in intravascular volume of 15% or more (amount of venous blood returning to the heart decreases, and ventricular filling drops)
What things can trigger hypovolemic shock?
- loss of blood volume from hemorrhage
- loss of of intravascular fluid from the skin because of injuries such as burns
- Loss of blood volume from severe dehydration
- Loss of body fluid from the GI system because of persistent and severe vomiting or diarrhea or continuous NG suctioning
- Renal losses of fluid because of diuretic use or endocrine disorders, such as diabetes insipidus
- conditions causing fluid shifts from the intravascular compartment to the interstitial space
- Third spacing because of disorders such as liver diseases with ascites, pleural effusion, or intestinal obstruction
Describe stage 1 of hypovolemic shock?
- loss of blood volume
- decreased Cardiac output= decreased MAP
- compensatory mechanisms (increased stroke volume x increased heart rate= increased cardiac output)
- peripheral vasoconstriction= increased stroke volume
Describe stage 2 of hypovolemic shock
- continued loss of blood volume
Compensatory Mechanisms: - Vasoconstriction: periphery, skin, abdominal organs
- Vasodilation: heart, skeletal muscles, respiratory retention of H2O and Na+
- up SV x up HR= up CO + up SVR= up MAP
Describe stage 3 of hypovolemic shock
- continued loss of blood volume
- decreased CO= Decreased MAP
- decreased tissue perfusion and oxygenation
- Cellular anaerobic metabolism
- Cellular hypoxia and death
Describe stage 4 of hypovolemic shock
Irreversible sock–> Multisystem organ failure–> death
What is cardiogenic shock?
the heart’s pumping ability is compromised to the point that it cannot maintain CO and adequate perfusion
What can cause cardiogenic shock?
- MI/cardiac arrest
- cardiac tamponade
- restrictive pericarditis
- Dysrhythmias such as VF or VT
- pathologic changes in valves
- cardiomyopathies from HTN, alcohol, bacterial or viral infections, or ischemia
- complications of cardiac surgery
- electrolyte imbalances, especially changes in normal potassium and calcium levels
- drugs affecting cardiac muscle contractility
- head injuries causing damage to the cardio regulatory center
Describe what happens in the body with cardiogenic shock
- decrease in MAP
- myocardium depleted of oxygen causing further myocardial ischemia and necrosis
- Cyanosis because of stagnating blood increasing the demand for blood out of the capillaries
- left-ventricular end-diastolic pressure increases
- Possible pulmonary edema
- possible right atrial pressure= JVD
What is obstructive shock?
Shock that is caused by an obstruction in the heart or great vessels that either impedes venous return or prevents effective cardiac pumping action
What things can cause obstructive hock?
- impaired diastolic filling (obstructive shock, pneumothorax)
- increased right ventricular afterload (PE)
- increased left ventricular afterload (aortic stenosis, abdominal distention)
What is distributive shock (vasogenic shock)?
Several types of shock that result from widespread vasodilation and decreased peripheral resistance
What is septic shock (septicemia)?
Altered perfusion resulting from a systemic infection that manifests with hypotension, delayed capillary refill, and inadequate perfusion and oxygen of vital body tissues
What is neurologic shock?
The result of an imbalance between parasympathetic and sympathetic stimulation of vascular smooth muscle
What conditions can cause neurologic shock?
- head injuries
- spinal cord trauma
- insulin reactions (which cause hypoglycemia, decreasing glucose to the medulla)
- Use of CNS depressants
- . Anesthesia
- severe pain
- prolonged exposure to heat
What happens to the body during neurogenic shock?
- bradycardia
- tachycardia when compensatory mechanisms are initiated
- CVP drops as veins dilate
- venous return to the heart decreases
- Stroke volume decreases and MAP falls
- Early stages: extremities are warm and pink
- Shock progressing: skin is pale and cool
What are some ways to prevent cardiogenic shock?
- control BP and avoid HTN
- no smoking
- regular exercise
- maintain a healthy weight
- reduce the intake of cholesterol and saturated fats
What are some ways to prevent hemorrhagic and neurogenic shock?
- avoid risk taking behaviors (driving while under the influence, dangerous sports)
- wear seatbelts, helmets, and other protective gear
3 prevent infection
What is the best way to prevent septic shock?
recognize the signs and prevent infection (good hand hygiene and infection control measures)
What are the general manifestations of shock?
Early: body compensating for hypotension or hypovolemia: 1. tachycardia 2. increased respiratory effort 3. decreased urine output 4. sweating Progressive: 1. systolic BP drops 2. pulse pressure narrows 3. cerebral blood flow reduced (Decreased LOC)
What are the clinical manifestations of the early stage of hypovolemic shock?
- BP: normal- slightly decreased
- Pulse: Slightly increased from baseline
- Respirations: normal (baseline)
- Skin: cool, pale (in periphery), moist
- Mental status: alert and oriented
- Urine output: Slight decrease
- other: thirst, decreased capillary refill time
What are the clinical manifestations of hypovolemic shock during the compensatory and decompensated stages?
- BP: Hypotension
- Pulse: rapid, thready
- Respirations: increased
- Skin: cool, pale; poor turgor with fluid loss, edematous with fluid shift
- Mental Status: restless, anxious, confused, or agitated
- Urine output: oliguria (less than 30 mL/hour)
- Other: marked thirst, acidosis, hyperkalemia, decreased capillary refill time, decreased or absent peripheral pulses
What are the clinical manifestations of hypovolemic shock during the refractory stage?
- BP: severe hypotension (systolic pressure often < 80)
- Pulse: very rapid, weak
- Respirations: Rapid, shallow; crackles and wheezes
- Skin: cool, pale, mottled with cyanosis
- Mental status: disoriented, lethargic, comatose
- Urine output: anuria
- Other: Loss of reflexes, decreased or absent peripheral pulses
What are the clinical therapies for hypovolemic shock?
- take action to control further blood loss
- Administer IV fluid and volume expanders
- administer blood (in severe cases)
- Administer oxygen
- Monitor effectiveness of respiratory effort; mechanical ventilation may be required to meet the body’s oxygen demands
- support vital function until perfusion is restored
- Assess LOC
- Monitor lab data, including hemoglobin, hematocrit, ABG, serum electrolytes, and BUN
- Administer meds as ordered (diuretics, sodium bicarbonate, antidysrhythmic agents, cardiac glycosides)
- Keep patient NPO until GI function returns to normal
What are the clinical manifestations of cardiogenic shock?
- BP: hypotension
- Pulse: rapid, thready; distention of veins of hands and neck
- Respirations: increased, labored; crackles and wheezes; pulmonary edema
- Skin: pale, cyanotic, cold, moist
- Mental status: restless, anxious, lethargic progressing to comatose
- urine output: oliguria to anuria
- Other: dependent edema, Elevated CVP, elevated pulmonary capillary wedge pressure, dysrhythmias
What are the clinical therapies for cardiogenic shock?
- administer IV fluid cautiously to avoid fluid overload, which places more stress on the heart
- Treat underlying cause
- Administer meds as ordered (diuretics, sodium bicarbonate, antidysrhythmic agents, cardiac glycosides)
- Administer O2
- Monitor effectiveness of respiratory effort; mechanical ventilation may be required to meet the body’s oxygen demands
- support vital functions until perfusion is restored
- Monitor lab data, including ABGs, serum electrolytes, BUN, creatinine, cardiac enzymes, CVP, pulmonary wedge pressure, and CO.
- Keep patient NPO until GI function returns to normal
What are the clinical manifestations of obstructive shock?
- pulse: tachycardia
- Respirations: tachypnea
- BP: hypotension
- Urine output: decreased
- Other: delayed capillary refill in extremities, peripheral edema
What are the clinical therapies for obstructive shock?
- Treat underlying cause
- Reduce cardiac workload
- Administer O2
- Monitor effectiveness of respiratory effort; mechanical ventilation may be required to meet the body’s oxygen demands
- Support vital functions until perfusion is restored
- Assess LOC
What are the clinical manifestations of distributive (vasogenic) shock?
- Pulse: tachycardia
- Respirations: Tachypnea
- BP: hypotension
- Urine output: decreased
- Other: delayed cap refill in extremities, peripheral edema, absent or weak peripheral pulses
What are the clinical therapies for distributive shock?
- treat the underlying cause
- Administer IV fluids
- administer O2
- monitor effectiveness of respiratory effort; mechanical ventilation may be required to meet the body’s O2 demands
- Administer vasoconstriction meds as ordered to increase PVR and restore perfusion
What are the early clinical manifestations of septic shock?
- BP: normal to hypotension
- Pulse: increased, thready
- Respirations: Rapid and deep
- Skin: warm, flushed
- Mental Status: Alert, oriented, anxious
- Urine output: normal
- Other: increased body temp; chills; weakness; nausea, vomiting, and diarrhea; decreased CVP
What is another name for early septic shock?
Warm septic shock
What are the late clinical manifestations of septic shock?
- BP: hypotension
- Pulse: tachycardia, arrhythmias
- Respirations: rapid, shallow, dyspneic
- Skin: cool, pale, edematous
- Mental status: lethargic to comatose
- Urine output: oliguria to anuria
- Other: normal to decreased body temperature, decreased CVP
What are the clinical therapies for septic shock?
- treat the underlying cause
- administer antibiotics and IV fluids
- Give O2
- monitor effectiveness of respiratory effort; mechanical ventilation may be required to meet the body’s O2 demands
- Assess for potential DIC
- Support vital functions until perfusion is restored
- assess LOC
- Obtain cultures prior to administration of antibiotics to determine the source of infection and pathogen involved
What are the clinical manifestations of Neurogenic shock?
- BP: hypotension
- Pulse: Slow and bounding
- Respirations: vary
- Skin: warm, dry
- Mental status: anxious, restless, lethargic progressing to comatose
- Urine output: oliguria to anuria
- Other: Lowered body temp
What are the clinical therapies for neurogenic shock?
- treat the underlying cause
- administer fluids
- reduce parasympathetic stimulation or sympathetic under stimulation
- Administer meds as ordered (corticosteroids, vasoconstrictors/vasopressors)
What are the clinical manifestations of anaphylactic shock?
- BP: hypotension
- pulse: increased, dysrhythmias
- Respirations: dyspnea, stridor, wheezes, laryngospasm, bronchospasm, pulmonary edema
- Skin: warm, edematous (lips, eyelids, tongue, hands, feet, genitals)
- Mental status: restless, anxious, lethargic to comatose
- Urine output: oliguria to anuria
- Other: paresthesia, pruritus, abdominal cramps, vomiting, diarrhea
What are the clinical therapies for anaphylactic shock?
- remove allergen (if still present)
- treat underlying cause
- administer meds as ordered (corticosteroids, albuterol and intramuscular epinephrine to treat histamine-induced bronchospasm)
- administer O2
- Monitor BP and respirations
- Insertion of an artificial airway may be required to maintain a functional airway if tracheal edema occurs
What are the main goals for taking care of any type of shock?
- Treat the underlying cause
- increase arterial oxygenation
- improving tissue perfusion
What is another name for Late septic shock?
Cold septic shock
What are some diagnostic tests that may be ordered for shock?
- blood hgb and hematocrit
- ABGs
- serum electrolytes
- BUN, creatinine, urine specific gravity, and osmolality
- blood cultures
- WBC and differential
- serum cardiac enzymes
- Central venous catheterization
What type of shock is most affects hgb and hematocrit?
- Hypovolemic shock.
- When caused by hemorrhage Hgb and hematocrit are usually low
- When caused by intravascular fluid loss, hgb and hematocrit are higher than normal
Why would serum electrolytes be ordered for shock?
It can help determine the severity and progression of shock. As shock progresses, glucose and sodium levels decrease, and potassium levels increase
What happens to BUN, creatinine levels, specific gravity, and osmolality during shock?
Renal function is reduced so BUN, creatinine, urine specific gravity, and osmolality increase.
What happens to serum cardiac enzymes when someone is in cardiogenic shock?
They are increased (lactate dehydrogenase, creatine kinase, and serum glutamic-oxaloacetic transaminase)
Why would central venous catheterization be used when someone is in shock?
It can aid in the differential diagnosis of shock and provide information about the heart’s preload. A pulmonary artery catheter may be inserted to monitor cardiac dynamics, fluid balance, and the effects of vasoconstrictors and vasopressors
What kind of medications may be used to help reverse shock?
- vasopressors (cause vasoconstriction)
- Inotropic drugs (improves cardiac contractility)
- Diuretics
- sodium bicarbonate
- calcium
- antidysrhythmic agents
- broad-spectrum antibiotic
- epinephrine, antihistamines, and inhaled beta2-agonists
- morphine
Why would oxygen therapy be used when someone is in shock?
establishing and maintaining a patent airway and ensuring adequate oxygenation are critical nursing interventions in reversing shock
What does the PaO2 need to be maintained at for the first 4-6 hours of care while someone is in shock?
80 mmHg
What is the most effective treatment for hypovolemic shock?
Administer IV fluids or blood
What are the most common types of crystalloid solution fluids?
- hypertonic 3% saline
- isotonic 0.9% normal saline
- Isotonic lactated ringer’s
- Hypotonic solutions 1/2 normal saline (0.45%) and 5% dextrose in water
What are some common types of colloid solutions?
- 5% albumin
- 25% albumin
- hetastarch
- plasma protein fraction
- dextran
What do colloid solutions do?
They stay in the vascular system and increase the osmotic pressure of the serum. This causes the fluid to move into the vascular compartment from the interstitial space. (increases fluid volume)
If hypovolemic shock is caused by a hemorrhage what may be indicated?
The infusion of blood and blood products
What are the goal levels of hgb and hematocrit for adults in hypovolemic shock due to hemorrhaging?
hematocrit: 30-35%
hemoglobin: 12.5-14.5
What are the most common causes of shock in infants?
hypovolemic shock and hypotension
What are some factors in neonates that can compromise CO?
prolonged very high (greater than 180) or very low (less than 80) heart rate
Hypotension usually indicates what with regard to shock in infants?
late stages of shock
What factors can put neonates at risk for developing shock?
- umbilical cord accident
- fetal or neonatal hemolysis or hemorrhage
- maternal problems such as infection or hypotension
- asphyxia
- neonatal sepsis
What treatments would a neonate that is in shock get?
- vasopressor administration
- possible blood volume expansion
- securing the airway
- O2
- IV access
- colloid or crystalloid solutions or whole blood as appropriate
What are some common causes of hypovolemic shock in children?
- gastroenteritis
- burns
- diabetes insipidus
- heat stroke
- trauma
- surgery
- intestinal obstruction
What are some common causes of distributive shock in children?
- anaphylaxis
- head injuries
- sepsis
What are some common causes of cardiogenic shock in children?
- dysrhythmias
- congenital heart disease
- cardiomyopathies
What are some common causes of obstructive shock in children?
- pneumothorax
- PE
- acute cardiac tamponade
What are the signs and symptoms of shock in children?
- altered mental status
- tachypnea
- tachycardia
- reduced urine output
- delayed cap refill
- temperature instability
- metabolic acidosis
- Late sign: hypotension
What does treatment look like for a child in shock?
- aggressive fluid replacement
- antibiotics for septic shock
- supportive measures
What are some common causes of shock in pregnant women?
- trauma
- antepartum hemorrhage (related to placenta previa, placental abruption, or uterine rupture)
- Septic abortion
- chorioamnionitis and postpartum infection
- valvular disease
- PPCM
- amniotic fluid embolism
What is the first-line vasoactive drug for pregnant women in shock?
ephedrine
What medication should be administered if the cause of shock is postpartum hemorrhage?
oxytocin
What should be monitored which a mother is being treated for shock?
- continuous heart rate monitoring for the fetus
- look for signs of fetal bradycardia (indication of hypoxia)
- ultrasound to assess fetal movement and reactivity; amniotic fluid volume
Why are older adults at a higher risk for developing shock?
- their hearts don’t work as well
- they don’t have great kidneys and some use a lot of diuretics
- can’t fight off infection as well
- falls and other comorbidities
What assessments should be conducted for hypovolemic shock?
- monitor fluid status (daily weight, I&O)
- hemodynamic values
- vital signs
If a patient has neurogenic shock, what should the head of the bed be elevated to and why?
15-20 degrees following spinal anesthesia because elevations of more than 20 degrees can cause headaches
How would a nurse preserve cardiac output when someone is in shock?
- monitor VP, HR, rhythm, pulse ox, peripheral pulses, pulmonary artery pressures, and CVPs
- conduct a baseline assessment to establish the stage of shock
- I&O, make sure urinary output is above 30 mL/hr
- monitor bowel sounds, abdominal distention, and abdominal pain
- monitor the patient for sudden, sharp chest pain or for dyspnea, cyanosis, anxiety, and restlessness (signs of PE)
- Maintain bedrest, and provide a calm, quiet environment
- keep them lying on their back with their legs elevated to about 20 degrees, trunk flat, and head and shoulders elevated higher than the chest (10 degrees) (limits cardiac workload)
Should the position with the legs elevated to 20 degrees be used for cardiogenic shock?
no
What are the nursing interventions for promoting tissue perfusion for shock?
- monitor skin color, temp, turgor, moisture
- monitor cardiopulmonary function (assess BP, rate, depth, lung sounds, pulse ox, JVD, CVP measurements, and peripheral pulses)
- monitor body temp
- monitor urinary output
- assess mental status and LOC
What are the nursing interventions for relieving anxiety in people undergoing shock?
- find out the cause of anxiety, and manipulate the environment to provide rest
- administer pain meds as prescribed
- Provide interventions to increase comfort and reduce restlessness
- provide support for the patient and family
What teaching and care should be given to the patient and family?
- spiritual care
- provide info about temporary housing and meals
- teach the family to reduce stimulation to promote rest and reduce energy consumption
- teach family simple care for the patient (timely position changes, administration of ice chips, and skin care)
- Teach about signs and symptoms that they should tell nursing staff or providers about (change in LOC, SOB< increase in pain, and other signs of distress)