Exam #1: Shock, SIRS And MODS Flashcards
What is shock?
- Syndrome characterized by decreased tissue perfusion and impaired cellular metabolism
- Imbalance in supply/demand for O2 and nutrients
Add stuff that was on the board
*Listen to lecture for more clarification
Low dose of dopamine can cause (<2mcg/min)
Vasodilation
If we give dopamine at 5-10mcg/kg/min, what while happen
It will stimulate beta1 adrenergic receptors -> increases contractility of the heart -> increases CO
If you give dopamine at >10 mcg/kg/min, it will cause
Vasoconstriction
Dobutamine
Causes vasoconstriction.
*may need more info
Nitro/Nitroprusside
Vasodilators
Norepinephrine aka Levophed
Drug of choice.
Listen to lecture for more info.
What are the classifications of shock?
- Cardiogenic Shock
- Hypovolemic
- Distributive
- Obstructive
What is Cardiogenic Shock?
- Systolic (hearts inability to pump the blood forward) or diastolic dysfunction
- Compromised cardiac output (CO)
What can cause cardiogenic shock?
- Myocardial infarction
- Cardiomyopathy
- Blunt cardiac injury
- Severe systemic or pulmonary hypertension
- Cardiac tamponade
- Myocardial depression from metabolic problems
What is the pathophysiology of cardiogenic shock caused by systolic dysfunction?
Slide 6
What is the pathophysiology of cardiogenic shock caused by diastolic dysfunction?
Slide 6
What are early manifestations of cardiogenic shock?
- Tachycardia
- Hypotension (<90)
- Narrowed pulse pressure (diastolic and systolic BP come closer together)
- ↑ Myocardial O2 consumption
- ↑ Pulmonary artery wedge pressure
- Decreased renal perfusion and urinary output
What are physical assessment findings that you would find in a patient with cardiogenic shock?
- Tachypnea, pulmonary congestion
- Pallor and cool, clammy skin
- Decreased capillary refill time
- Anxiety, confusion, agitation (Ativan, morphine could be helpful)
Hypovolemic Shock
- Loss of intravascular fluid volume
- Either absolute or relative hypovolemia
What can cause hypovolemic shock?
- Absolute Hypovolemia:
- Hemorrhage
- GI loss (e.g., vomiting, diarrhea)
- Fistula drainage
- Diabetes insipidus
- Hyperglycemia
- Diuresis - Relative hypovolemia
What is relative hypovolemia?
- Results when fluid volume moves out of the vascular space into extravascular space (e.g., intracavitary space)
- Termed third spacing
Describe the pathophysiology of hypovolemic shock.
Slide 11
Hypovolemic Shock: Response to acute volume loss depends on
- Extent of injury
- Age
- General state of health
What are clinical manifestations of hypovolemic shock?
- Anxiety
- Tachypnea
- *Increase in CO, heart rate
- Decrease in stroke volume, Pulmonary Artery Wedge Pressure, urinary output
Hypovolemic Shock: What is done if loss is >30%?
Compensatory mechanisms may fail and immediate replacement of blood products should be started
What is neurogenic shock?
- Hemodynamic phenomenon
- Can occur within 30 minutes of a spinal cord injury at the fifth thoracic (T5) vertebra or above
- Can last up to 6 weeks
Neurogenic Shock can occur in response to
Spinal cord injury or spinal anesthesia
Neurogenic shock results in
massive vasodilation (d/t loss of SNS vasoconstrictor tone), leading to pooling of blood in vessels, tissue hypoperfusion, ultimately impaired cellular metabolism
What is the pathophysiology of neurogenic shock?
…
What are the types of distributive shocks?
- Neurogenic Shock
- Anaphylactic Shock
- Septic Shock
What are clinical manifestations of neurogenic shock?
- Hypotension and bradycardia
- Inability to regulate body temperature (resulting in heat loss)
- Dry skin
- Poikilothermia- taking on temperature of environment
What is anaphylactic shock?
Acute, life-threatening hypersensitivity (allergic) reaction
What do you give for a patient in anaphylactic shock?**
Epinephrine
Anaphylactic shock can lead to
- Massive vasodilation (in the periphery, the feet, top of head, and in airway)
- Release of vasoactive mediators
- Increased capillary permeability
What are clinical manifestations of anaphylactic shock?
- Anxiety, confusion, dizziness
- Sense of impending doom
- Chest pain
- Incontinence
- Swelling of lips and tongue, angioedema
- Wheezing, stridor due to laryngeal edema
- Flushing, pruritus, urticaria
- Respiratory distress and circulatory failure
What is sepsis?
Systemic inflammatory response to documented or suspected infection
What is severe sepsis?
Sepsis complicated by organ dysfunction
What is septic shock?
- Presence of sepsis with hypotension despite fluid resuscitation
- Presence of inadequate tissue perfusion resulting in hypoxia
What is the pathophysiology of septic shock?
Slide 23
Volume Resuscitation Guidelines
- If you’re not aware of loss: 30-50 mL/kg
2. If you are aware of the loss: use 3:1 rule (3 mL of isotonic crystalloid for every 1 mL of estimated blood loss)
What are clinical manifestations of septic shock?
- ↑ Coagulation and inflammation
- ↓ Fibrinolysis: Formation of microthrombi; Obstruction of microvasculature
- Hyperdynamic state: increased CO and decreased SVR
*Read notes!
What are three major pathophysiologic effects of septic shock?
- Vasodilation
- Maldistribution of blood flow
- Myocardial dysfunction: Decreased ejection fraction and ventricular dilation
*Read notes!
What will findings will you find in a patient with septic shock?
- Tachypnea/hyperventilation: Results in respiratory alkalosis and respiratory failure develops in 85% of patients
- ↓ Urine output
- Altered neurologic status
- GI dysfunction, GI bleeding, paralytic ileus
*Read notes!
What are the stages of shock?
- Initial
- Compensatory
- Progressive
- Refractory
Stages of Shock: Initial
- Usually not clinically apparent
- Metabolism changes at cellular level from aerobic to anaerobic
What happens as metabolism changes at the cellular level from aerobic to anaerobic during the initial stage of shock?
- Lactic acid builds up and must be removed by liver
- Process requires O2, unavailable due to decreased tissue perfusion
Compensatory Stage of Shock: Compensatory Mechanisms include
- Neural
- Hormonal
- Biochemical
Stages of Shock: Compensatory Stage
Attempt to overcome consequences of anaerobic metabolism and maintain homeostasis
What happens during the compensatory stage of shock?
- Baroreceptors in carotid and aortic bodies activate SNS in response to ↓ BP (vasoconstriction while blood to vital organs (brain and heart) are maintained)
- SNS stimulation increases myocardial O2 demands
- Shunting blood from lungs increases physiologic dead space
- Impaired GI motility (risk for paralytic ileus)
- Cool, clammy skin (except in patients who is warm and flushed)
- ↓ Blood to kidneys activates renin–angiotensin system
*Read notes!
Compensatory Stage: What happens when blood is shunted from the lungs increasing physiologic dead space?
- V/Q mismatch
- ↓ Arterial O2 levels
- Increase in rate/depth of respirations
*Read notes on slide 32
Compensatory Stage: What happens when there is a decrease in blood flow to kidneys?
Activates renin-angiotensin system where angiotensin I is converted to angiotensin II. This causes:
- Vasoconstriction
- Increased venous return to heart
- Stimulates the release of aldosterone
- Increased sodium reabsorption stimulates ADH
*Read Notes
Overall Compensatory Stage
- Body is able to compensate for changes in tissue perfusion
- If cause of shock is corrected, patient recovers with little or no residual effects
- If cause of shock is not corrected, patient enters progressive stage
Progressive Stage begins when
- Begins when compensatory mechanisms fail
- Patient moved to ICU for advanced monitoring and treatment
What is the progressive stage of shock?
-Distinguishing features of ↓ cellular perfusion and altered capillary permeability: This causes leakage of protein into interstitial space
and ↑ systemic interstitial edema
What can happen during the progressive stage?
- Anasarca
- Sustained hypoperfusion
- Myocardial dysfunction
- Movement of fluid from pulmonary vasculature to interstitium
- Mucosal barrier of the GI system becomes ischemic
- Fluid moves into the alveoli
- Hypoperfusion can lead to renal tubular ischemia
- Liver fails to metabolize drugs and waste