Shock Flashcards
What is shock?
Decreased tissue perfusion and impaired cellular metabolism because perfusion is not adequate to meet cellular needs
Causes an imbalance of oxygen and nutrients of supply and demand
Is shock a disease?
No, it is a clinical syndrome
What are the causes of different types of shock?
Problem with the pump, volume or vessels
What is the common shock among patients in the ICU?
septic shock
Is shock defined by low blood pressure?
Decreased BP is a hallmark sign but it does not define shock
What is CO? What is normal CO? What does CO provide for the body?
CO = SV x HR
Amount of blood ejected by the heat in one minute
Normal: 4-8L/min
Perfusion is supplied by CO
What is SV? What is SV affected by?
Amount of blood ejected with each beat
- Preload
- Afterload
- Contractility
Assessment of preload is done by?
Mainly volume indicator
- Weight (1kg = 1L of fluid)
- I/Os
- UO
- VS
- Edema
Afterload is assessed with? What affects afterload?
- BP
- Skin assessment
- Peripheral pulses (weak or bounding)
Affected by vasoconstriction (cool and clammy) or vasodilation (red and sweating)
What is contractility assessed by?
With an echocardiogram
What happens to the VS when preload (volume) goes down?
BP will decrease and HR will increase
With shock there is decreased __, but the cause of the decrease is ___
CO, difficult to pinpoint
What are some causes of decreased CO? (5)
- Decreased contractility from direct myocardial insult
- Inadequate myocardial stretch from preload being too low
- Overstretched myocardium from preload being too high
- Low after load (vasodilation)
- High after load (vasoconstriction)
What type of shock might cause decrease CO because of decreased contractility from direct myocardial insult?
Caridogenic shock
What type of shock might cause decrease CO because of inadequate myocardial stretch from preload being too low?
Hypovolemic shock
What type of shock might cause decrease CO because of low after load (vasodilation)?
Neurogenic or septic shock
How is organ perfusion measured?
Blood pressure and MAP
What MAP is needed to perfuse vital organs?
> 60 mmHG
An RN may titrate orders based on what MAP and BP?
MAP > 65 mmHG
SBP > 90 mmHG
What is pulse pressure? What is a normal pulse pressure? What indicates vasoconstriction? Vasodilation?
difference between the systolic and the diastolic pressure
Normal = 40
Vasoconstriction <40
Vasodilation >40
What information can a pulse pressure provide?
What the peripheral vessels are doing to maintain BP
Narrowed pulse pressure with an increased HR –> hypovolemia
What is more effective, MAP and BP trends or one time reading?
More effective to follow the trend
Generally pathology of shock
- Decreased CO
- Decreased cellular oxygen supply
- Decreased tissue perfusion
- Impaired metabolism
- End stage of shock (organ failure –> death)
What is cariogenic shock?
Pump failure
Systolic or diastolic dysfunction that leads to decreased SV and decreased CO
What are the causes of cariogenic shock?
- MI ((systolic dysfunction) most common cause and is leading cause of death with acute MI)
- Cardiac tamponade or cardiomyopathy (diastolic)
- Structural issue (valvular disorder)
- Dysrhythmia
What does cardiogenic shock look similar to? How does it manifest?
Similar to decompensated heart failure
- Tachycardia, hypotension, narrow pulse pressure
- Increased systemic vascular resistance
- Increase in pulmonary wedge pressure
- Tachypnea
- Crackles
- Signs of peripheral hypoperfusion (cyanosis, pallor, diaphoresis, weak peripheral pulses, cold/clammy skin)
- Decrease UO
- Anxiety, confusion, agitation
What is hypovolemic shock?
Loss of intravascular fluid volume (d/t any type of fluid loss including dehydration), inadequate circulating volume –> fluid deficit
Decreased intravascular –> decrease venous return –> decreased preload –> decrease SV –> decreased CO
What is absolute hypovolemia?
Loss of fluid d/t hemorrhage, GI, DI, or diuresis
What is relative hypovolemia?
fluid out of intravascular into the extravascular (third spacing) d/t increased capillary permeability like in burn patients
How much fluid loss can the body compensate for? what is this called?
The body can compensate for 15% or 750mL of fluid loss
Called the physiologic reserve
What happens if there is 15-30% fluid loss?
The sympathetic nervous system kick in and increase HR, CO, and RR and decreases SV, CVP, and PAP
If there is more than 15% loss and treatment is provided what happens to the tissues?
Tissue dysfunction is generally reversible
What are the clinical manifestations of hypovolemic shock?
Anxious
Decrease UO
Class 1 of hemorrhagic shock
Up to 15% or less than or equal to 750 mL
Minimal changes
Normal BP, RR, and UO
Increase HR > 100
Anxious
Class 2 of hemorrhagic shock
15-30% or 750-1500 mL
Increased SNS response
Increased CO, HR (100-120), RR (20-25)
Decreased pulse pressure, CVP, PA pressure, UO (20-30mL/hr)
Restless
Class 3 of hemorrhagic shock
30-40% or 1500-2000mL
Significant decrease in BP
HR >120
RR: 25-30
UO: 5-15ml/hr
Class 4 of hemorrhagic shock
Over 40% or over 2000mL
Decreased BP (SBP>90) HR >120 Decrease pulse pressure RR: 30-40 UO: minimal to none Confused, lethargic Loss of auto regulation in microcirculation Irreversible tissue damage
What is the general treatment for class 1 and class 2 hemorrhagic shock?
Fluid replacement with crystalloid
What is the general treatment for class 3 and class 4 hemorrhagic shock?
Fluid replacement with crystalloid and or blood
What is disruptive shock?
Misdistribution of blood flow and volume
What are the 3 subcategories of distributive shock?
Neurogenic shock
Anaphylactic shock
Septic shock
What is neurogenic shock? When does it occur? How long does it last?
Loss of sympathetic nervous system vasoconstrictor –> vasodilation and lypoperfusion
Occurs within 30 minutes of a spinal cord injury and can last up to 6 weeks
What are the causes of neurogenic shock?
- SCI T6 and above (most common)
- Epidural anesthesia
- Drugs (opiods/benzos)
What are the clinical manifestations of neurogenic shock?
- Hypotension
- Bradycardia
- Unable to regulate body temperature
- Warm dry skin d/t pooling blood in extremities
What is anaphylactic shock? What goes on with inside the body?
Sudden hypersensitivity (allergic) reaction to a substance like drug, chemical, food or insect
Massive vasodilation –> increased capillary permeability –> edema –> bronchospasm
** major increase in capillary permeability –> relative hypovolemic state
What are the causes of anaphylactic shock? How can you come in contact with these things?
- Drug, chemical, vaccine, food, insect
venom - Contact, inhalation, ingestion, or injection
How does anaphylactic shock manifest?
- Dizziness
- Chest pain
- INC
- Swelling of lips & tongue
- Wheezing and stridor
- Bronchospasm
- Flushing
- Angioedema (deeper swelling of skin often around the lips and eyes)
What is septic shock?
Systemic inflammatory response to an infection
- Hypotension despite adequate fluid
resuscitation - Inadequate tissue perfusion
- Microorganism enters body –> normal immune response –> immune response
exaggerated –> increased inflammation &
coagulation –> microthormbi
What are the causes of septic shock?
- Unknown organism 50%
- Gram-negative and gram-positive bacteria (most common)
- Parasites, fungi, virus
What are the s/s of septic shock?
- Vasodilation
- Misdistribution of blood flow
- Myocardial depression
- Respiratory failure (common with sepsis)
What does an ABG look like for septic shock?
Initially patient hyperventilates –> respiratory alkalosis –> uncompensated –> respiratory acidosis
What does the volume and ejection fraction look like in septic shock?
- May be euvolemic but d/t vasodilation become hypovolemic and hypotensive
- EF decreased first few days –> ventricles dilate –> maintain stroke volume
What is obstructive shock?
Physical obstruction to the blood flow with decreased CO
What are the causes fo obstructive shock?
Impaired ventricular filling or emptying
Cardiac tamponade, tension pneumothorax,
abdominal compartment syndrome, stenotic
aortic valve, PE, right ventricular thrombi
What are the clinical manifestations of obstructive shock?
Decreased CO
Increased afterload
Jugular distension
Pulsus paradoxus (abnormally large drop in SBP with inspiration (greater than 10mmhg)
What are there stage of shock?
- Initial stage
- Compensatory
- Progressive
- Irreversible (refractory)
What is occurring in the initial stage?
s/s are not clinical but more cellular. Body is experiencing aerobic to anaerobic metabolism causing lactic acid to build up
What occurs in the compensatory stage?
Body attempts to regulate with neural, hormonal, biochemical and compensatory mechanisms to overcome the anaerobic metabolism and maintain homeostasis
During the compensatory stage what does the body do to help with decreased CO?
Decreased CO –> decreased BP and narrowed pulse pressure –> activated SNS –> stimulates vasoconstriction to provide blood flow to vital organs –> increased HR, contractility, and BP –> dilation of coronary vessels because increased HR and contractility increased the demand on the heart
In the compensatory phase, what does the body do in response to decreased BP?
Decrease BP –> activate of SNS –> angiotensin II –> increased water and sodium reabsorption and potassium excretion
In the compensatory phase, what does the body do in response to ventilation perfusion mismatch?
Increases RR and depth of respirations
What occurs in the GI during the compensatory stage?
Impaired mobility –> paralytic ileus
What does the skin feel/look like during the compensatory phase? What about with septic shock?
Cool and clammy
With early septic shock, the skin is warm and flushed d/t hyper dynamic state
How long can compensatory mechanism work?
If compensatory mechanisms are supported patient can stay in this stage for hours without sustaining
permanent damage
What types of patients may have difficulty tolerating compensatory changes?
- HTN
- Elderly
- Children
- Cardiovascular disease
- DM with vascular diseases
What occurs in the progressive stage?
All compensatory mechanisms fail
Massive SNS response that leads to profound vasoconstriction
What are the hallmark s/s for the progressive stage?
- Decreased BP
- Increased RR
- Increased HR
- LOC
- Listless
- Agitated
What occurs to the cardiovascular system during the progressive stage of shock? What are the s/s associated with it?
Complete deterioration of the cardiovascular system
Decreased CO, Decreased BP, altered capillary permeability and anasarca (diffuse profound edema)
What is the first system to display critical dysfunction? What occurs in the system?
Pulmonary d/t altered blood flow to lungs
Pulmonary arteries constrict –> increase pulmonary arterial pressure –> ventilation perfusion mismatch
Fluid from pulmonary vasculature –> interstitial space –> interstitial edema
–> fluid to alveoli –> alveoli edema and decreased surfactant production causing further impaired gas exchange
What are the s/s of pulmonary dysfunction r/t progressive stage?
- Increase RR
- Crackles
- Poor perfusion
- Increased effort the breath
What happens to the cardiovascular in the progressive stage? What are the s/s?
CO drops –> poor perfusion
Altered capillary permeability –> fluid
to interstitial space
1. Anasarca (diffuse profound edema) 2. Weak peripheral pulses 3. Dysrhythmias 4. MI
What happens to the GI/gut in the progressive stage?
Prolonged decreased tissue
perfusion –> mucosal barrier becomes ischemic and unable to absorb nutrients
Ischemia, bleeds and ulcers
What happens to the GI/liver in the progressive stage?
Unable to metabolize drugs/waste products, increased bilirubin, and unable to remove bacteria from GI tract
What happens to the GU in the progressive stage?
Renal tubular ischemia –> ATN, decreased UO, metabolic acidosis
What happens heme in the progressive stage?
Risk for DIC
What is occurs in the body during the refractory stage?
Decrease perfusion d/t vasoconstriction and decreased CO –>
- increase in lactic acid, urea, ammonia and carbon dioxide since there is many organs failing
- fluid leaving the vascular space –> hypotension, tachycardia, and hypoxemia
What are the s/s of the refractory stage? Is recovery likely?
- Unconscious
- Unresponsive
- Decreased BP (DBP=0)
- Arrhythmia
- Respiratory failure
- Ischemia of GI, renal, brain
- Cyanosis
Recover is not likely
What is systemic inflammatory response syndrome (SIRS)? What is the treatment?
Presents like sepsis but cannot isolate the infectious cause
Generalized inflammation not necessarily at specific site
Treatment is same as sepsis, antibiotics and fluids
What is multiple organ dysfunction syndrome?
Failure of 2 or more organ systems
What is occurring in all of the organ systems r/t MODS?
- Neuro: non responsive; coma, Glasgow coma scale
- CV: vasoactive support, hypotension
- Hematology: platelet count decreasing
- Pulmonary: mechanical ventilator
- Renal: CRRT, serum creatinine, UO
- Liver: coagulopathies, hypoalbuminemia,
serum bilirubin - GI: not tolerate TF
- Skin: mottling
What is the overall care of MODS?
- Prevent
- Treat infection if present
- Maintain tissue oxygenation
- Nutritional and metabolic support
- Support individual failing organs
What is the best thing that you can do for shock?
Prevention
Care for shock: fluid resuscitation. What type of shock are the used for? What type of IV is used? What types of fluids are used?
Septic, hypovolemic and anaphylactic shock
Large bore IV or central venous catheter (femoral, jugular, subclavian)
- Crystalloids
- Colloids (albumin)
- Blood products
What type of blood product are given?
- PRBC for hemoglobin less than 7-8 (PRBC do not contain clotting factors so may need to replace clotting factors)
- FFP to increase coag factors by 20%
What are some concern when are amounts of fluids are given?
Hypothermia
Coagulopathy
When do you give medications to improve perfusion?
After adequate fluid resuscitation or for those who don’t respond to fluids
What do sympathomimetic drugs do? What are the drugs?
Cause vasoconstriction and help maintain the goal MAP >65mmhg
NE, dopamine, phenylephrine, vasopressin
Why are vasodilators used in shock? What are some drugs?
Cariogenic shock –> decrease after load
Prevent harmful widespread vasoconstriction
Nitroglycerin, nitroprusside
What do inotropes do? What do positive inotrope do? What do negative inotropes do?
- Medications that either increase or decrease the force of muscular contraction
- Positive inotropes increase contractility –> increase SV and oxygen demand on the heart
- Negative inotropes decrease contractility
What are positive inotrope medications?
- Epinephrine
- Norepinephrine
- Isoproterenol
- Dopamine
- Dobutamine
- Digitalis
- Calcium
What negative inotrope medications?
- Calcium channel blockers
- Beta blockers
- Clinical conditions (acidosis)
What should you do before giving vasoactive medications?
Fluids first!!
If not enough fluids, vasoconstricting the vessel will not help with perfusion
If on high doses, vasoactive will affect the skin by? What patients should you be hyperaware of this with?
Decrease perfusion to skin and fingers or toes
Could be hard on patients with DM or PVD but it is better to safe a life than fingers or toes
What affect will vasoactive medications have on heart? What patient should you be careful with?
Increase after load –> heart has to work harder to push blood out
Careful with patients that have cariogenic shock
Nutrition for a patient with shocks should be
- High protein, high calories
- Enteral nutrition within 24 hours, started slow and advance as tolerated
- Slow continuous parenteral nutrition if unable to meet at least 80% of caloric requirements enterally
Why do you use insulin drips for a patient with shock?
- Insulin drips are used in the ICU to regulate blood sugar and maintain a blood sugar below 180
- Shock will increase glyconeogenesis and gluconeogenisis and the release of catecholamines and glucorticoids –> hyperglycemia and insulin resistance –> placed on insulin drip
Diagnostics for shock
There is not one diagnostic test
Accumulation of data and trends (focus on trends overtime)
Lactic acid –> means anaerobic metabolism –> indicator of shock
Hemodynamic monitoring
What does hemodynamic monitoring measure? What does it assess?
Measure pressure, flow and oxygenation in cardiovascular system
Assesses heart function, fluid balance, effects fo interventions (fluids and meds) on CO
What are invasive hemodynamic monitoring devices?
- Arterial BP
- Arterial pressure cardiac output (APCO)
- Pulmonary artery flow directed catheter
- Enteral venous or right atrial pressure measurement (CVP)
- Venous oxygen saturation (Scvo2)
- Pulmonary arterial wedge pressure (PAWP)
What are non-invasive hemodynamic monitoring devices?
- Pulse ox
- BP
- Physical assessment
What does arterial wedge pressure measure? What about if it is high?
Measures left ventricular end diastolic pressure
If high, worried about left ventricular failure
What does CVP measure? If it is high? If it is low?
Measures the volume of preload through a triple lumen catheter
High: volume overload
Low: volume deficit
What does SVR measure?
Measures after load
When is perfusion indicators like Svo2/scvo2 indicated?
When patients have the potential to develop an imbalance of O2 supply and demand like in sepsis, ARDS, or high risk cardiac surgery
What is Scvo2? What is it measured by? What is the normal value?
Central venous oxygen saturation
Measured with a central venous pressure with oximetric capability
Normal: 70-80% indicating a stable oxygen balance
What is Svo2? What is it measured with? What is normal volume?
Mixed venous oxygen saturation
Measured with pulmonary arterial catheter
Normal: 60-80%
If Svo2 or Scvo2 changes by more than 10% and is maintained for more than 10 minutes, then think about these four factors:
- Arterial oxygen saturation
- Cardiac output
- Hemoglobin
- Oxygen consumption
What could alter the Scvo2/Svo2 in a critically ill patient?
turning, backrub, or getting a patient out of bed.
What is the most effective treatment for cariogenic shock?
Coronary artery reperfusion
How does cardiac catheterization help to treat cardiogenic shock? What are the options for cardiac cath?
Restores blood flow to the myocardium and initial treatment for cariogenic shock
- Angioplasty with stenting
- Valve replacement
- Vascular bypass
What are the circulatory assistive decides? What do they do for cariogenic shock?
- intra-aortic balloon pumping (IABP)
- VAD for people awaiting a heart transplant
Decreases the workload of heart with mechanical support
How does a intra-aortic balloon pumping (IABP) work? Where is the catheter positioned?
Balloon on a catheter is positioned in descending thoracic aorta.
Inflate during diastole to coronary perfusion
Deflates immediately before systole to decrease afterload
Assist with O2 delivery to heart and contractility
If cariogenic shock leads to HF, patient can be treated with…
LVAD
IV rate r/t cariogenic shock
IV fluids should be stricter because they can put more stress on the heart and make cariogenic shock worse
What can be given for cardiac pain r/t cariogenic shock? What does this do to treat it?
Morphine reduces sympathetic stimulation caused by pain and anxiety which decrease cardiac workload and risk associated with catecholamines
How can you decrease the oxygen consumption in a patient with cariogenic shock?
Sedation agents, address pain, calm environment, reduce fever, give blood, more oxygen, improve CO
What medications can be given in cariogenic shock?
- IV nitrates (dilate coronary arteries)
- Diuretics: decreases preload (lasix)
- Vasodilators: decreases afterload (nipride nitroglycerin)
- Betablockers: reduce rate and contractility
- Inotropic agents: increase contractility (Dobutamine, Epi, Milrinone)
- Vasopressors: increase after load
How should you treat hypovolemic shock?
- Stop fluid loss such as bleeding
- Fluids 3:1 (3ml of isotonic crystalloid to 1 ml of loss)
- Blood products like PRBC, FFP, or platelets
- 2 large bore IV and if possible central access
- Give calcium (blood loss leads to calcium loss)
- Vasoactive drugs but give fluids first!!
What is the concern while giving blood products?
Hypothermia –> shivering –> increase oxygen demands on heart
Coagulation issues
What is the care for septic shock?
- Large amounts of fluid replacement
- Vasopressors added
- Corticosteroids if not responding to fluids and vasopressors
- Blood cultures and early antibiotics
- Frequent blood glucose monitoring (<180) IV insulin drip
- Stress ulcers
- Measure lactate
What does QSOFA measure? What are the 3 criteria?
Looks at outcomes or prognosis if patient has sepsis
- Low blood pressure (Hypotension)
- Altered mental status
- Fast respiration rate (tachypnea)
2 or more criteria suggests a greater risk of poor outcome
What is the care for neurogenic shock?
- Stabilize spine
- Vasopressors (phenylephrine)
- Atropine for bradycardia
- Temperature to monitor for hypothermia
How do you care for anaphylactic shock?
- Prevention with thorough history
- IM epinephrine (first choice) - causes vasoconstriction, bronchdilation and opposes histamine
- Adjunct diphenhydramine and ranitidine to block massive release of histamine
- Patent airway with bronchodilators
- Aerosolized Epinephrine for laryngeal edema and intubation
How do you care for obstructive shock?
Depends on the cause
- Mechanical decompression by removing fluid with needle or tubing for pericardial tamponade, tension pneumothorax, and hemopneumonthorax
- Thrombolytic therapy for PE
- Decompressive laparotomy which decompresses and leaves abdomen open for abdominal compartment syndrome
What is the gold standard to monitor BP with shock patients?
Arterial BP