Cardiogenic shock

Cardiogenic shock

1. Pathophysiology: cardiogenic shock occurs when the heart's ability to contract and pump blood is impaired and the supply of oxygen is inadequate for the heart and tissue. With cardiogenic shock, cardiac output is compromised and when both stroke volume and heart rate are decreased, blood pressure and tissue perfusion is reduced resulting in impaired tissue perfusion leading to decreased blood supply to tissues and organs. Due to impaired tissue perfusion, the heart cannot pump blood effectively during systolic function and cannot fill during diastole, leading to decreased preload and causing fluid accumulation in the lungs from decreased cardiac output. (Overbaugh, J.L.H.K.H.C. K. (2021)

2. Treatments

   • Oxygenation - in early stages of shock, supplemental oxygen via nasal cannula between 2-6 L/min to achieve oxygen saturation above 95%
   • Pain control - IV morphine given to relieve chest pain and dilate the blood vessels to decrease workload of the heart and may decrease the pt's anxiety level
   • Hemodynamic monitoring - arterial line is inserted to monitor continuous blood pressure (typically in ICU), and provides a port to obtain arterial blood samples. A central venous and pulmonary artery catheter may be inserted to measure myocardial filling pressures, cardiac output, pulmonary artery pressures and systemic resistance
   • Fluid therapy - administration of fluids is necessary in treatment of shock but it must be monitored closely to avoid and observe for signs of fluid overload. Fluid boluses are given to maintain optimal filling pressures and improve cardiac output
   • Pharmacological therapy - Nitrates (causes vasodilation of arteries) Diuretics (decrease preload) Vasodilators: Dopamine and Dobutamine (improve cardiac contractility, improve cardiac output) Vasopressors: Norepinephrine, epinephrine (increase blood pressure, MAP)
   • Mechanical assist devices: a intra-aortic balloon pump will provides circulatory assistance to improve cardiac function

3. Nursing Diagnosis

   • Ineffective tissue perfusion
   • Impaired gas exchange
   • Decreased cardiac output
   • Fluid volume overload

4. Complications:

   • Acute respiratory distress
   • Stroke
   • Renal or hepatic failure
   • Ventricular aneurysm
   • Dysrhythmias
   • Acute Kidney Injury

5. Clinical manifestations:

   • hypotension
   • Tachycardia, tachypnea
   • Decreased capillary refill
   • Excessive diaphoresis
   • The lips, nail beds, and skin may become cyanotic, pale, cool, and clammy
   • Oliguria: Urine output decreases, less than 30ml per hr
   • Neurologic changes
   • Orthopnea
   • Pulmonary congestion may be indicated by crackles
   • arterial and systolic blood pressures decrease
   • Narrow pulse pressure and near-normal diastolic blood pressure

6. Diagnostic test

   • Labs
     • ABG
     • Troponin test
     • Hemodynamics
     • Blood glucose
     • BUN and creatinine
   • Cardiac Catheterization
   • Echocardiography
   • Chestradiography