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Decreased Cardiac Output Pathophysiology
Decreased cardiac output occurs when the heart cannot pump enough blood to meet the body’s needs. This can result in decreased oxygenation to the tissues and organs, leading to potential organ damage or failure.
Cardiac output (CO), expressed in L/min, is the blood volume in the heart pump in one minute, depending on the heart’s rate, contractility, preload, and afterload. The heart rate and stroke volume directly influence cardiac output. Regulation of cardiac output includes the autonomic nervous system, endocrine and paracrine signaling.
Cells, tissues, and organs rely on the heart pumping the blood to deliver nutrients. Decreased cardiac output may result in insufficient blood supply and compromise vital reactions.
This can result in a transition towards anaerobic metabolic pathways, which leads to lactic acid production, reduced cellular pH, enzyme denaturation, and altered membrane potential. Decreased cardiac output can lead to tissue and organ damage if not addressed. The most common diagnosis associated with decreased cardiac output is heart failure.
Heart failure (HF) is defined as failure of either the left and/or right chambers of the heart resulting in insufficient output to meet tissue needs resulting in pulmonary and systemic vascular congestion. In addition, blood pooling in the ventricles can increase the risk of stroke and pulmonary embolism.
Decreased cardiac output nursing care plans and nursing interventions for decreased cardiac output are crucial steps to prevent possible life-threatening complications.
Decreased Cardiac Output Causes
- Arrhythmias
- Cardiomyopathy
- Valvular heart disease
- Myocardial infarction
- Fluid overload
- Coronary disease
- Hypertension
- Congenital problems
- Tamponade
- Medications (such as vasopressors and calcium channel blockers)
- Pericardial effusions
- Emboli
- Congestive heart failure
- Shock
- Cardiac arrhythmias/dysrhythmias
- Genetic diseases
- Structural abnormalities
- Myocardial ischemia and myocardial infarction
Decreased Cardiac Output Symptoms
The symptoms of decreased cardiac output can vary depending on the severity and underlying cause:
- Shortness of breath
- Fatigue
- Weakness
- Dizziness
- Chest pain
- Palpitations
- Swelling in the legs and ankles
Subjective Data (Client Reports)
- Difficulty breathing
- Fatigue
- Chest pain or discomfort
- Palpitations
- Swelling in the legs
- Fatigue
- Exhaustion progressing throughout the day
- Exercise intolerance
- Insomnia
- Chest pain/pressure with activity
- Dyspnea at rest or with exertion
Objective Data
- Weak or irregular pulse
- Elevated blood pressure or heart rate
- Crackles in the lungs
- Fluid accumulation in the legs
- Increased heart rate
- Altered myocardial contractility
- Inotropic changes
- Diagnosis for Atrial Fibrillation
- History of decreased cardiac output nursing diagnosis
- Irregular heart rate
- Changes in rhythm and electrical conduction
- Cardiac dysrhythmia
- Structural heart changes
- Valvular defects
- Ventricular aneurysm
- Jugular vein distention
- Extra heart sounds
- Decreased urine output
- Diminished peripheral pulses
- Cool, ashy skin; diaphoresis
- Wheezes
- Tachypnea
- Nail beds pale or cyanotic, with slow capillary refill
- Orthopnea
- Crackles
- Liver engorgement
- Edema
- Lower extremity swelling
- Mental status change
- Cough
- Dry/hacking/nonproductive
- gurgling with/without sputum
- Restlessness, anxiety
- Lethargy
- Vital signs change with activity
- Diminished breath sounds (bibasilar crackles)
Decreased Cardiac Output Risk Factors
- History of heart disease or heart failure
- Smoking
- Obesity
- Diabetes
- High blood pressure
- History of hypertension
- Recent/acute MI
- Previous episodes of HF
- Valvular heart disease, cardiac surgery
- Endocarditis
- Systemic lupus erythematosus (SLE)
- Anemia
- Septic shock
- Swelling of feet, legs, abdomen,
- A diet high in salt, processed foods, fat, sugar, and/or caffeine
- Smoking
Decreased Cardiac Output Nursing Assessment
During the nursing assessment, evaluating the client’s cardiac, respiratory, neurologic, and sensory functions is important.
Cardiac Function
- Assess the client’s heart rate, rhythm, and blood pressure.
- Listen to heart sounds for any murmurs or irregularities.
- Evaluate peripheral pulses and capillary refill.
- Increased HR
- Altered myocardial contractility
- Diagnosis for Atrial Fibrillation
- Structural changes
- Jugular vein distention
- Extra heart sounds
- Diminished peripheral pulses
Respiratory Function
- Assess the client’s respiratory rate, rhythm, and depth.
- Listen to lung sounds for any crackles or wheezes.
- An alteration in oxygen saturation is one of the earliest signs of reduced cardiac output.
- Breath sounds
- Wheezing
- Cough
- Tachypnea
- Orthopnea
Neurologic Function
- Assess the client’s level of consciousness, orientation, and cognition.
- Evaluate for any signs of confusion or disorientation, as decreased oxygen saturation can cause the client to have altered mental status.
- Mental status change
- Restlessness
- Anxiety
- Lethargy
Sensory Function
- Assess the client’s vision, hearing, touch, and proprioception.
Labs for Decreased Cardiac Output (Evaluate and Report)
Labs to evaluate may include: electrolytes, blood glucose levels, renal function tests, liver function tests, and cardiac enzymes. Report any abnormalities to the health care provider (HCP).
Decreased Cardiac Output Nursing Diagnosis
Diagnostic test | Rationale |
ECG | Ventricular or atrial hypertrophy, axis deviation, ischemia, and damage patterns may be present. Dysrhythmias, e.g.,tachycardia, atrial fibrillation, conduction delays, especially left bundle branch block, frequent premature ventricular con-tractions (PVCs) may be present. Persistent ST-T segment abnormalities and decreased QRS amplitude may be present. |
Chest X-ray | May show enlarged cardiac shadow, reflecting chamber dilation/hypertrophy, or changes in blood vessels, reflecting increased pulmonary pressure. Abnormal contour, e.g., bulging of left cardiac border, may suggest ventricular aneurysm. |
Sonograms echocardiogram
Doppler and transesophageal echocardiogram | May reveal enlarged chamber dimensions, alterations in valvular function/structure, the degrees of ventricular dilation and dysfunction. |
Heart scan | Measures cardiac volume during both systole and diastole, measures ejection fraction, and estimates wall motion. |
Exercise or pharmacological stress myocardial perfusion | Determines presence of myocardial ischemia and wall motion abnormalities.
Positron emission tomography (PET) scan. Sensitive test for evaluation of myocardial ischemia/detecting viable myocardium. |
Cardiac catheterization | Abnormal pressures are indicative and help differentiate right- versus left-sided heart failure, as well as valve stenosis or insufficiency. Also assesses patency of coronary arteries. Contrast injected into the ventricles reveals ab-normal size and ejection fraction/altered contractility. Transvenous endomyocardial biopsy may be useful in some clients to determine the underlying disorder, such as myocarditis or amyloidosis. |
Liver enzymes | Elevated in liver congestion/failure |
Digoxin and other cardiac drug levels | Determine therapeutic range and correlate with client response. |
Bleeding and clotting times | May be altered because of fluid shifts/decreased renal function, diuretic therapy. |
Electrolytes: | May be altered because of fluid shifts/decreased renal function, diuretic therapy |
Pulse oximetry | Oxygen saturation may be low, especially when acute HF is imposed on chronic obstructive pulmonary disease (COPD) or chronic HF. |
Arterial blood gases (ABGs) | Left ventricular failure is characterized by mild respiratory alkalosis (early) or hypoxemia with an increased PCO2(late). |
BUN/creatinine | Elevated BUN suggests decreased renal perfusion. Elevation of both BUN and creatinine is indicative of renal failure. |
Serum albumin/transferrin: | May be decreased as a result of reduced protein intake or reduced protein synthesis in congested liver. |
Thyroid studies | Increased thyroid activity suggests thyroid hyperactivity as precipitator of HF. |
Complete blood count (CBC) | May reveal anemia, polycythemia, or dilutional changes indicating water retention. Levels of white blood cells (WBCs) may be elevated, reflecting recent/acute MI, pericarditis, or other inflammatory or infectious states. |
ESR: | May be elevated, indicating acute inflammatory reaction |
Nursing Interventions for Decreased Cardiac Output
Perform |
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Provide |
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Administer |
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Monitor |
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Encourage |
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Decreased Cardiac Output Goals and Outcomes
The nurse should monitor the client’s progress toward these goals and adjust interventions as needed:
- Improved oxygenation and circulation
- Decreased fluid overload
- Relief of symptoms
- Cardiac output adequate for individual needs
- Complications prevented/resolved
- Optimum level of activity/functioning attained
- Dysrhythmia controlled or absent
- Pulse oximetry within an acceptable range/free of signs of respiratory distress
Decreased Cardiac Output Client Case
A client presents to the ER with the chief complaint of fatigue and shortness of breath when engaging in mild physical activity. They’ve also noticed a recent weight gain and swelling in ankles. The client’s current blood pressure is 146/80, and heartbeat is 70 bpm. They have a history of atrial fibrillation, hypertension, dyslipidemia, and type 2 diabetes.
Decreased Cardiac Output NCLEX Questions
Based on the client case, what are the symptoms predictive of heart failure?
Answer: shortness of breath, fatigue, edema
Changes in what lab value is indicative of renal failure in clients with decreased cardiac output?
a. AST
b. BUN
c. Troponin
d. VHDL
Answer: b. BUN
What chronic medications should be generally avoided in clients with known diagnosis of heart failure?
a. ACE inhibitors
b. Beta blockers
c. Calcium channel blocker
d. morphine
Answer: c. Calcium channel blocker
Which exam can measure cardiac volume during systole and diastole?
a. Chest X-ray
b. ECG
c. Heart scan
d. Sonogram
Answer: c. Heart scan
Units that represent Cardiac Output are:
a. L
b. L/min
c. m3
d. Min
Answer: b. L/min
References
Vincent JL. Understanding cardiac output. Crit Care. 2008;12(4):174. doi:10.1186/cc6975
King J, Lowery DR. Physiology, Cardiac Output. In: StatPearls. Treasure Island (FL): StatPearls Publishing; September 15, 2020.