Shock

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Questions and Answers

What is a major consequence of anaerobic metabolism during shock?

Accumulation of lactic acid (correct)

Increased oxygen delivery to cells

Enhanced aerobic activity

Improved tissue perfusion

At what mean arterial pressure (MAP) is adequate perfusion generally maintained?

60-80 mm Hg

90-120 mm Hg

80-100 mm Hg

70-110 mm Hg (correct)

During the initial stage of hemorrhagic shock, what is a primary compensatory mechanism?

Increase in diastolic pressure

Decrease in heart rate

Increased urine output

Tachycardia (correct)

Which stage of shock involves a sustained decrease in MAP of more than 20 mm Hg?

Progressive stage Signup and view all the answers

What is a potential consequence of not intervening during the progressive stage of shock?

Development of multi-organ dysfunction syndrome Signup and view all the answers

What is the first-line treatment for hypovolemic shock?

Crystalloids Signup and view all the answers

In which stage of shock do vital organs start to show signs of hypoxia?

Progressive stage Signup and view all the answers

What happens if blood loss exceeds 750 cc in the initial stage of shock?

Compensatory mechanisms attempt to sustain blood pressure Signup and view all the answers

Which organ is often first affected in multiple organ dysfunction syndrome (MODS)?

Liver Signup and view all the answers

What is a significant feature of the refractory stage of shock?

Irreversible cell and tissue death Signup and view all the answers

What occurs to urine output during the compensatory stage of shock?

Decreases to less than 30 cc Signup and view all the answers

Which of the following describes hypovolemic shock?

Decreased intravascular volume Signup and view all the answers

What primary treatment goal is essential when managing a patient in shock?

Control the source of blood loss Signup and view all the answers

What can trigger the release of epinephrine and norepinephrine during shock?

Activation of the adrenal medulla Signup and view all the answers

What is the most common cause of direct pump failure in the heart?

Myocardial infarction Signup and view all the answers

What is the normal pressure range on the right side of the heart?

2-5 mmHg Signup and view all the answers

Which medication can be used to increase heart rate and contractility at a moderate dose?

Dobutamine Signup and view all the answers

What is the effect of high doses of dopamine (10 mcg/kg/min)?

Increase vasoconstriction Signup and view all the answers

Which clinical manifestation is associated with cardiogenic shock?

Narrowing pulse pressure Signup and view all the answers

What is a common cause of obstructive shock?

Pulmonary embolism Signup and view all the answers

What is the role of nitroprusside in the treatment of shock?

Decrease afterload Signup and view all the answers

What condition is characterized by pooling of blood due to loss of sympathetic tone?

Distributive shock Signup and view all the answers

What treatment is indicated for cardiac tamponade?

Pericardiocentesis Signup and view all the answers

Which of the following is a treatment for septic shock?

All of the above Signup and view all the answers

What triggers the acute inflammatory response during sepsis?

Cytokines Signup and view all the answers

Anaphylactic shock is primarily caused by which type of reaction?

Antigen-antibody Signup and view all the answers

Which medication is often included in the treatment of neurogenic shock?

All of the above Signup and view all the answers

Study Notes

Week 13 Care of Patients in Shock

Shock: Impaired oxygen delivery to tissues.
Aerobic metabolism uses oxygen.
Anaerobic metabolism occurs without oxygen, leading to lactic acidosis.
Lactic acidosis: Develops when lactate production exceeds its metabolism. This occurs when tissue oxygenation is inadequate.
Shock Causes:
- Blood loss
- History of stroke and on anticoagulants
- History of heart attack and on antiplatelets
- MAP (mean arterial pressure) 70-110 mmHg for adequate perfusion.
- Doppler: Used when diastolic pressure is not obtainable; it provides systolic pressure over Doppler measurement. (RELISTEN!!)
Stages of Shock (Hemorrhagic):
- Initial stage: Loss of 750 cc of blood.

Shock Compensation

Body Compensation:
- Minimal tachycardia (heart rate 110).
- Normal or increased pulse pressure indicates effective heart contraction.
- Measuring pulse pressure (systolic minus diastolic): 40-60 mmHg normal range, if higher, stiffer arteries.
- Atherosclerosis: Shows how well the heart contracts. High blood pressure stiffens vessels requiring greater force for blood pumping.
- Non-progressive (compensatory) stage: MAP decreases by 10-15 mmHg. More than 750-1500 cc of blood loss leads to anxiety and restlessness.
- Loss of oxygen triggers adrenal medulla stimulation. Epinephrine and norepinephrine elevate heart rate and blood pressure. Kidneys try to conserve water (less than 30 cc of urine), and antidiuretic hormone is secreted.

Shock Progression

Sensing Blood Concentration: The body senses concentrated blood and reabsorbs more water, decreasing blood concentration. This process decreases oxygen to non-vital organs.
Shunting Blood Blood is redirected to vital organs (brain, heart, and liver) from non-vital organs during shock. This may not damage non-vital organs.
Anaerobic Effect/Acidosis: Production of lactic acid in the cells. If interventions are not provided, this is reversible.
Progressive Stage: Sustained MAP decrease greater than 20 mmHg (1500-2000 cc blood loss). Heart rate above 120 bpm, diastolic filling time compromised. RR (respiratory rate) 30-40/minute (tachypnea). Narrowed pulse pressure leads to decreased perfusion to vital organs and hypoxia (low oxygen).

Life-Threatening Emergency/Refractory Stage

Emergency: Immediate interventions are needed within one hour of progressive shock.
Refractory Stage: Too little oxygen reaches tissues resulting in too much cell death and damage from blood loss exceeding 2 liters, leading to lethargy and sleepiness.
Severe Hypotension: Cool skin due to body shunting blood to vital organs. Shock continues, inability to respond to interventions.
Multiple Organ Dysfunction Syndrome (MODS): Metabolites released from dead cells; microthrombi throughout the body.
MODS First Occurs in: Liver, heart, brain, and kidney.

Shock Classification/Types

Hypovolemic Shock: Intravascular volume decreased.
Obstructive Shock:
- Problems impairing normal heart muscle function for effective blood pumping.
  - Causes:
    - Pulmonary embolism (blood clot in pulmonary vasculature).
    - Cardiac tamponade (fluid buildup around heart).
Distributive Shock:
- Blood volume not lost but distributed to interstitial space.
- Loss of sympathetic tone, dilated vessels, blood pooling, capillary leakage. -Discoloration of extremities.
  - Septic, anaphylactic, and neurogenic shock - characterized by vasodilation.
    - Shock and WBC low, body cannot fight infections.
    - Organ failure (sepsis).
    - Microthrombi formation, Amplified inflammatory response (body-wide). Anaerobic metabolism continues.
    - Local infection, can become systemic, systemic infection (bacteremia). Caused by gram-negative (E. coli), and gram-positive (staphylococcus).
Cardiogenic Shock:
- Problems with left, right, or both ventricles (actual heart muscle is unhealthy).
- High left ventricular pressure forces fluid from lungs to interstitial space. Myocardial infarction is the leading cause (direct pump failure). Normal pressures (left) are 6-12, and right is 2-5
- Dilated vessels lead to the heart using less oxygen.
- Clinical manifestations: Tachycardia, decreased cardiac output, decreasing blood pressure, narrowing pulse pressure, and crackles.

Treatment Aspects

First-Line Treatment: Isotonic solutions (e.g., normal saline, lactated ringers).
Blood Products: Replaced blood loss; avoid glucose-containing blood products to prevent clots.
Cardiogenic Shock Treatment: Beta adrenergic agonists.
Vasodilators: Decrease workload by decreasing preload and afterload (force heart pumps against) to increase blood flow to the circulatory system.
- Medications: nitroprusside, nitroglycerin.
- Intra-aortic balloon pump (IABP).
Obstructive Shock:
- Pulmonary Embolism: Heparin, Fibrinolytic therapy (streptokinase, alteplase).
- Cardiac Tamponade: Pericardiocentesis.

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Description

This quiz covers the fundamental aspects of patient care in shock, including the types of metabolism affected, causes, and stages of hemorrhagic shock. It emphasizes the body's compensatory mechanisms and the importance of monitoring parameters like MAP and pulse pressure. Test your understanding of these critical concepts for effective patient management.