Nursing Pharmacology: Dopamine Administration

Shock, Sepsis, & Critical Cardio

• Shock is a life-threatening syndrome
• The circulatory system can't supply adequate oxygen to tissues.
• Oxygen delivery (DO2) is the amount of oxygen delivered to tissues
• Oxygen utilization (VO2) reflects the relationship between oxygen delivery and extraction at tissue level.
• CO = Cardiac output - amount of blood ejected every minute
• Preload is blood in ventricles at end of diastole
• Afterload is the resistance to flow that the ventricle must overcome to eject blood.
• Contractility is the force of mechanical contraction.

Learning Objectives

• Explain pathophysiology for perfusion.
• Explore risk factors that contribute to critically ill patients experiencing altered perfusion.
• Describe the impact of altered perfusion on critically ill clients' overall health.
• Differentiate clinical presentations in critically ill clients experiencing altered perfusion.
• Explore roles of nurses caring for critically ill clients experiencing altered perfusion.
• Apply the nursing process while caring for critically ill clients experiencing altered perfusion.

Classification of Shock

• Hypovolemic: Not enough blood volume (burns, significant blood loss)
• Cardiogenic: Inadequate heart pumping.
• Distributive: Disease causes poor vascular tone (sepsis, anaphylaxis).
• Obstructive: Mechanical barrier to ventricular filling (cardiac tamponade, tension pneumothorax, PE).

Assessment

• Central Nervous System: Restlessness, confusion, irritability, lethargy, coma (prolonged).
• Cardiovascular: Hypotension, narrow pulse pressure, tachycardia (then bradycardia, Skin color- cool, mottled, cyanotic (blood shunted), warm, flushed).
• Peripheral pulses: Thready
• Capillary refill: Sluggish
• Respiratory: Tachypnea, ABG's, pulse oximetry
• Renal: Oliguria (first), then anuria, increased creatinine.
• Gastrointestinal: Hypoactive bowel sounds, nausea, vomiting.

Pathophysiology: Distributive Shock

• Decreased SVR & Perfusion
• Septic shock: Inflammatory cytokines damage vessels & initiate clotting.
• Anaphylactic shock: Severe hypersensitivity.
• Neurogenic shock: Autonomic dysregulation caused by spinal cord injury above T6
• Toxic shock: Infection from Staphylococcus aureus causes excessive cytokine activation.

Stages of Shock

• Compensatory: Neural & endocrine compensatory mechanisms.
• Progressive: Failure of compensatory mechanisms, profound hypoperfusion, worsening metabolic acidosis, respiratory acidosis.
• Refractory: Prolonged inadequate blood supply, cell death, multisystem organ failure, death imminent.

Complications: Disseminated Intravascular Coagulation (DIC)

• Blood clots throughout the body, block small blood vessels.
• Risk factors: Pregnancy complications, blood infections, cancer, blood transfusions, liver dysfunction, shock, trauma, burns.
• Clinical presentation: Bleeding, hypovolemia, hypotension, decreased CO & LOC, ecchymosis, hematoma, petechiae, tissue necrosis, dyspnea, epistaxis, conjunctival bleeding.
• Lab diagnostics: Increased PT/PTT, decreased fibrinogen & platelets count.

Complications: Multiple Organ Dysfunction Syndrome (MODS):

• Extreme response to injury, sepsis, or burns.
• Constant release of immune mediators leads to oxidative stress.
• Cellular oxygenation decreased causing anaerobic metabolism & lactic acidosis.
• The increase in metabolic acidosis leads to MODS, causing muscle and vital organ breakdown.
• Risk Factors: Chronic disease, immunosuppressive therapy, extreme age, malnutrition, cancer, trauma, alcoholism, sepsis.
• Clinical Presentation: Respiratory, cardiovascular, hepatic, gastrointestinal, integumentary, & central nervous system issues; often leading to death.

Treatments & Therapies

• Shock: IV fluids (at least 30ml/kg for first three hours), mechanical ventilation, IV antibiotics, norepinephrine (for MAP), blood components, advanced mechanical support (intra-aortic balloon pump, ECMO), nutrition.
• Sepsis/Septic Shock: Aggressive fluid resuscitation, targeted antibiotics within 1 hour, Vasopressors, crystalloids (NS and LR), steroids, antihistamines & early intervention
• DIC: Fresh frozen plasma, platelets, whole blood and anticoagulants, IV fluids (LR/NS), treatment of underlying cause
• MODS: Supportive care, antibiotics, mechanical ventilation, IV fluids, and medications.

Cardiac Tamponade

• Fluid accumulation around the heart.
• 3 Phases: Pericardial fluid builds up, ventricles can't expand fully, CO decreases rapidly.
• Risk factors: central line placement, malignancies, infection, complications from MI, aortic dissection, previous high-risk surgery, aortic aneurysm, hypoparathyroidism.

Cardiac Output

• Blood ejected per minute.
• Influenced by preload, afterload, and contractility.

Other Important Information

• Learning objectives
• Different types of shock (hypovolemic, cardiogenic, distributive, obstructive).
• Stages of shock (compensatory, progressive, refractory)
• Treatment for each type of shock is crucial to preventing further complications.