Mr. Patton was admitted due to myocardial infarction. Two hours after the admission, his skin became cool and clammy. Latest BP shows a decrease in the systolic blood pressure. His heart rate and respirations are gradually increasing, and his urine output is decreasing. Mr. Patton is experiencing cardiogenic shock due to myocardial infarction.
What is Cardiogenic Shock?
Cardiogenic shock is also sometimes called “pump failure”.
- Cardiogenic shock is a condition of diminished cardiac output that severely impairs cardiac perfusion.
- It reflects severe left-sided heart failure.
This is what happens in cardiogenic shock:
- Inability to contract. When the myocardium can’t contract sufficiently to maintain adequate cardiac output, stroke volume decreases and the heart can’t eject an adequate volume of blood with each contraction.
- Pulmonary congestion.The blood backs up behind the weakened left ventricle, increasing preload and causing pulmonary congestion.
- Compensation. In addition, to compensate for the drop in stroke volume, the heart rate increases in an attempt to maintain cardiac output.
- Diminished stroke volume.As a result of the diminished stroke volume, coronary artery perfusion and collateral blood flow is decreased.
- Increased workload. All of these mechanisms increase the heart’s workload and enhance left-sided heart failure.
- End result. The result is myocardial hypoxia, further decreased cardiac output, and a triggering of compensatory mechanisms to prevent decompensation and death.
The causes of cardiogenic shock are known as either coronary or non-coronary.
- Coronary. Coronary cardiogenic shock is more common than non coronary cardiogenic shock and is seen most often in patients with acute myocardial infarction.
- Noncoronary. Noncoronary cardiogenic shock is related to conditions that stress the myocardium as well as conditions that result in an ineffective myocardial function.
Statistics and Incidences
Cardiogenic shock could be fatal if left untreated.
- Cardiogenic shock occurs as a serious complication in 5% to 10% of patients hospitalized with acute myocardial infarction.
- Historically, mortality for cardiogenic shock had been 80% to 90%, but recent studies indicate that the rate has dropped to 56% to 67% due to the advent of thrombolytics, improved interventional procedures, and better therapies.
- Incidence of cardiogenic shock is more common in men than in women because of their higher incidence of coronary artery disease.
Cardiogenic shock can result from any condition that causes significant left ventricular dysfunction with reduced cardiac output.
- Myocardial infarction (MI).Regardless of the underlying cause, left ventricular dysfunction sets in motion a series of compensatory mechanisms that attempt to increase cardiac output, but later on leads to deterioration.
- Myocardial ischemia. Compensatory mechanisms may initially stabilize the patient but later on would cause deterioration with the rising demands of oxygen of the already compromised myocardium.
- End-stage cardiomyopathy.The inability of the heart to pump enough blood for the systems causes cardiogenic shock.
Cardiogenic shock produces symptoms of poor tissue perfusion.
- Clammy skin. The patient experiences cool, clammy skin as the blood could not circulate properly to the peripheries.
- Decreased systolic blood pressure.The systolic blood pressure decreases to 30 mmHg below baseline.
- Tachycardia. Tachycardia occurs because the heart pumps faster than normal to compensate for the decreased output all over the body.
- Rapid respirations. The patient experiences rapid, shallow respirations because there is not enough oxygen circulating in the body.
- Oliguria. An output of less than 20ml/hour is indicative of oliguria.
- Mental confusion. Insufficient oxygenated blood in the brain could gradually cause mental confusion and obtundation.
- Cyanosis. Cyanosis occurs because there is insufficient oxygenated blood that is being distributed to all body systems.
Assessment and Diagnostic Findings
Diagnosis of cardiogenic shock may include the following diagnostic tests:
- Auscultation. Auscultation may detect gallop rhythm, faint heart sounds and, possibly, if the shock results from rupture of the ventricular septum or papillary muscles, a holosystolic murmur.
- Pulmonary artery pressure (PAP).PAP monitoring may show increase in PAP, reflecting a rise in left ventricular end-diastolic pressure and increased resistance to the afterload.
- Arterial pressure monitoring. Invasive arterial pressure monitoring may indicate hypotension due to impaired ventricular ejection.
- ABG analysis. Arterial blood gas analysis may show metabolic acidosis and hypoxia.
- Electrocardiography. Electrocardiography may show possible evidence of acute MI, ischemia, or ventricular aneurysm.
- Echocardiography. Echocardiography can determine left ventricular function and reveal valvular abnormalities.
- Enzyme levels. Enzyme levels such as lactic dehydrogenase, creatine kinase. Aspartate aminotransferase and alanine aminotransferase may confirm MI.
The aim of treatment is to enhance cardiovascular status by:
- Oxygen. Oxygen is prescribed to minimize damage to muscles and organs.
- Angioplasty and stenting. A catheter is inserted into the blocked artery to open it up.
- Balloon pump. A balloon pump is inserted into the aorta to help blood flow and reduce workload of the heart.
- Pain control. In a patient that experiences chest pain, IV morphine is administered for pain relief.
- Hemodynamic monitoring.An arterial line is inserted to enable accurate and continuous monitoring of BP and provides a port from which to obtain frequent arterial blood samples.
- Fluid therapy.Administration of fluids must be monitored closely to detect signs of fluid overload.
Drug therapy may include:
- IV dopamine. Dopamine, a vasopressor, increases cardiac output, blood pressure, and renal blood flow.
- IV dobutamine. Dobutamine is an inotropic agent that increase myocardial contractility.
- Norepinephrine. Norepinephrine is a more potent vasoconstrictor that is taken when necessary.
- IV nitroprusside. Nitroprusside is a vasodilator that may be used with a vasopressor to further improve cardiac output by decreasing peripheral vascular resistance and reducing preload.
When the drug therapy and medical procedures don’t work, then the last option is for surgical procedure.
- Intra-aortic balloon pump (IABP).The IABP is a mechanical-assist device that attempts to improve the coronary artery perfusion and decrease cardiac workload through an inflatable balloon pump which is percutaneously or surgically inserted through the femoral artery into the descending thoracic aorta.
Cardiogenic shock needs rapid, accurate nursing management.
The nurse should assess the following:
- Vital signs. Assess the patient’s vital signs, especially the blood pressure.
- Fluid overload.The ventricles of the heart cannot fully eject the volume of blood at systole, so fluid may accumulate in the lungs.
Based on the assessment data, the major nursing diagnoses are:
- Decreased cardiac output related to changes in myocardial contractility/inotropic changes
- Impaired gas exchange related to changes in alveolar-capillary membrane.
- Excess fluid volume related to a decrease in renal organ perfusion, increased sodium and water, hydrostatic pressure increase, or decrease plasma protein.
- Ineffective tissue perfusion related to reduction/cessation of blood flow.
- Acute pain related to ischemic tissues secondary to blockage or narrowing of coronary arteries.
- Activity intolerance related to imbalance between the oxygen supply and needs.
Nursing Care Planning & Goals
Main Article: 5 Cardiogenic Shock Nursing Care Plans
The major goals for the patient are:
- Prevent recurrence of cardiogenic shock.
- Monitor hemodynamic status.
- Administer medications and intravenous fluids.
- Maintain intra-aortic balloon counterpulsation.
The appropriate nursing interventions for a patient with cardiogenic shock includes:
- Prevent recurrence. Identifying at-risk patients early, promoting adequate oxygenation of the heart muscle, and decreasing cardiac workload can prevent cardiogenic shock.
- Hemodynamic status. Arterial lines and ECG monitoring equipment must be well maintained and functioning; changes in hemodynamic, cardiac, and pulmonary status and laboratory values are documented and reported; and adventitious breath sounds, changes in cardiac rhythm, and other abnormal physical assessment findings are reported immediately.
- Fluids. IV infusions must be observed closely because tissue necrosis and sloughing may occur if vasopressor medications infiltrate the tissues, and it is also necessary to monitor the intake and output.
- Intra-aortic balloon counterpulsation. The nurse makes ongoing timing adjustments of the balloon pump to maximize its effectiveness by synchronizing it with the cardiac cycle.
- Enhance safety and comfort. Administering of medication to relieve chest pain, preventing infection at the multiple arterial and venous line insertion sites, protecting the skin, and monitoring respiratory and renal functions help in safeguarding and enhancing the comfort of the patient.
- Arterial blood gas.Monitor ABG values to measure oxygenation and detect acidosis from poor tissue perfusion.
- Positioning. If the patient is on the IABP, reposition him often and perform passive range of motion exercises to prevent skin breakdown, but don’t flex the patient’s “ballooned” leg at the hip because this may displace or fracture the catheter.
Expected outcomes include:
- Prevented recurrence of cardiogenic shock.
- Monitored hemodynamic status.
- Administered medications and intravenous fluids.
- Maintained intra-aortic balloon counterpulsation.
Discharge and Home Care Guidelines
Lifestyle changes must be made to avoid the recurrence of cardiogenic shock.
- Control hypertension. Exercise, manage stress, maintain a healthy weight, and limit salt and alcohol intake.
- Avoid smoking. The risk of stroke is the same for smokers and nonsmokers years after you stop smoking
- Maintain a healthy weight.Losing those extra pounds would be helpful in lowering the cholesterol and blood pressure.
- Diet. Eat less saturated fat and cholesterol to reduce heart disease.
- Exercise. Exercise daily to lower blood pressure, increase high-density lipoproteins, and improve the overall health of the blood vessels and the heart.
The focus of documentation include:
- Baseline and subsequent findings and individual hemodynamic parameters, heart and breath sounds, ECG pattern, presence/strength of peripheral pulses, skin/tissue status, renal output, and mentation.
- Respiratory rate, character of breath sounds, frequency, amount, and appearance of secretions, presence of cyanosis, laboratory findings, and mentation level.
- Conditions that may interfere with oxygen supply.
- Conditions contributing to the degree of fluid retention.
- I&O, fluid balance.
- Pulses and BP.
- Client’s description of response to pain.
- Acceptable level of pain.
- Specifics of pain inventory.
- Prior medication use.
- Plan of care.
- Teaching plan.
- Client’s responses to interventions, teaching, and actions performed.
- Status and disposition at discharge.
- Attainment or progress toward desired outcomes.
- Modifications to plan of care.
Practice Quiz: Cardiogenic Shock
1. A person comes into your ER room with a very weak pulse after a suffering a heart attack. You suspect:
A. The weak pulse has nothing to do with shock or the heart attack, so send him home.
B. A late stage (decompensated) shock, the least life-threatening stage of shock.
C. A very early stage (compensated) shock, the most life-threatening stage of shock.
D. A late stage (decompensated) shock, the most life-threatening stage of shock.
1. Answer: D. A late stage (decompensated) shock, the most life-threatening stage of shock.
- D: A very weak pulse shows that the heart is slowly ceasing to function as a result of pumping too hard.
- A: The patient should not be sent home; close observation is necessary.
- B: This stage is a life-threatening stage as the heart could tire itself out and stop functioning.
- C: An early stage of shock shows a rapid, bounding pulse.
2. Which of the following would make the most sense as a more specific diagnostic test of shock?
A. A CSF (spinal) tap to check for meningitis.
B. A brainstem auditory evoked response test to see if the person can hear ok.
C. A pupillary light reflex test to check how well the eyes are working.
D. The measurement of serum lactate, elevated levels of which are an indicator of shock.
2. Answer: D. The measurement of serum lactate, elevated levels of which are an indicator of shock.
- D: Serum lactate is one of the enzymes that can indicate the occurrence of shock.
- A: Checking for meningitis is different from the identification cardiogenic shock.
- B: Auditory sense have nothing to do with shock.
- C: The eyes could not determine the diagnosis of cardiogenic shock.
3. What are characteristics of the irreversible stage of shock?
A. The worsening of tissue hypoperfusion and the onset of worsening circulatory and metabolic imbalances, including acidosis.
B. The body tries to initiate compensatory mechanisms.
C. Nothing can correct the hemodynamic defect.
D. Tissue and cell damage are too great tissue and necrosis of the tissue will occur even if the underlying hemodynamic defect is corrected.
3. Answer: D. Tissue and cell damage are too great tissue and necrosis of the tissue will occur even if the underlying hemodynamic defect is corrected.
- D: Irreversible symptoms already occur despite treating the underlying cause.
- A: Options A, B, and C are not symptoms of cardiogenic shock.
4. Cardiogenic shock occurs as a result of:
A. Excessive vasodilation and possibly increased capillary permeability.
B. Severe central nervous system trauma that causes a rapid loss in sympathetic stimulation.
C. Reduction in intravascular fluid volume.
D. Myocardial dysfunction.
4. Answer: D. Myocardial dysfunction.
- D: Myocardial infarction can lead to cardiogenic shock.
- A: Option A is anaphylactic shock.
- B: Option B is neurogenic shock.
- C: Option C is hypovolemic shock.
5. Which characteristic often distinguishes cardiogenic shock from hypovolemic shock?
B. Increased respiratory rate.
C. Narrow pulse pressure.
5. Answer: C. Narrow pulse pressure.
- C: Cardiogenic shock has a narrow pulse pressure while hypovolemic shock has a widened pulse pressure.
- A: Options A, B, and D are all similar characteristics of hypovolemic and cardiogenic shock.
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