Cardiac output is a critical hemodynamic parameter representing the volume of blood the heart pumps per minute, measured in liters per minute (L/min). It is the product of stroke volume (the amount of blood ejected from the left ventricle with each heartbeat) and heart rate. Optimal cardiac output ensures adequate oxygen and nutrient delivery to meet the body’s metabolic demands. Several factors influence cardiac output, including preload, afterload, and contractility. Decreased cardiac output (DCO) occurs when the heart fails to pump sufficient blood to satisfy the body’s needs, leading to a cascade of physiological and psychological effects.
In this guide, we will delve into the nursing diagnosis of decreased cardiac output, exploring its causes, signs and symptoms, expected outcomes, nursing assessments, interventions, and care plans to provide comprehensive support for patients experiencing this condition.
Causes of Decreased Cardiac Output
A multitude of factors can lead to decreased cardiac output. Understanding these underlying causes is crucial for effective nursing management. Here are some potential causes:
- Hypertension: Chronic hypertension can lead to left ventricular hypertrophy and diastolic dysfunction, ultimately impairing cardiac output.
- Coronary Artery Disease (CAD): CAD reduces blood flow to the myocardium, causing ischemia and potentially infarction, which weakens the heart muscle and reduces its pumping efficiency.
- Genetic Cardiac Disease: Inherited conditions like hypertrophic cardiomyopathy or dilated cardiomyopathy can directly affect the heart’s structure and function, leading to decreased cardiac output.
- Myocardial Ischemia/Infarction (MI): Ischemia and infarction damage myocardial tissue, reducing contractility and stroke volume, thereby decreasing cardiac output.
- Congestive Heart Failure (CHF): Heart failure is a syndrome where the heart cannot pump enough blood to meet the body’s needs. It is a primary cause of decreased cardiac output, often resulting from various underlying cardiac conditions.
- Shock: Different types of shock (hypovolemic, cardiogenic, septic, anaphylactic, neurogenic) can all lead to decreased cardiac output through various mechanisms such as reduced preload, impaired contractility, or increased afterload.
- Arrhythmias: Both bradyarrhythmias (slow heart rates) and tachyarrhythmias (fast heart rates) can compromise cardiac output. Bradycardia reduces the frequency of ventricular ejection, while tachycardia can reduce ventricular filling time and stroke volume.
- Cardiac Structural Abnormalities: Valvular heart disease (stenosis or regurgitation), congenital heart defects, and other structural issues can impede blood flow and reduce cardiac output.
- Pericardial Effusions: Fluid accumulation in the pericardial space can compress the heart, limiting its ability to fill and pump effectively.
- Cardiac Tamponade: A severe form of pericardial effusion where rapid fluid accumulation critically impairs ventricular filling and drastically reduces cardiac output.
It’s important to note that this list is not exhaustive, and various combinations of these factors can contribute to decreased cardiac output. Furthermore, the clinical manifestations of DCO may not be immediately apparent as the body may initially compensate for reduced cardiac output. Nurses must be vigilant in recognizing subtle signs and symptoms and understand how various cardiac and systemic conditions can impact cardiac function.
Signs and Symptoms of Decreased Cardiac Output
The signs and symptoms of decreased cardiac output are diverse and can manifest both physiologically and psychologically. Recognizing these manifestations is crucial for prompt intervention.
Physiological Signs and Symptoms:
- Hypotension: Reduced cardiac output often leads to decreased systemic blood pressure as less blood is being pumped into the arterial system.
- Hypercapnia: In severe cases, poor tissue perfusion and circulatory failure can lead to carbon dioxide retention and hypercapnia.
- Cardiac Arrhythmias: Decreased cardiac output can be both a cause and a consequence of arrhythmias. The heart may develop abnormal rhythms in an attempt to compensate or due to underlying cardiac dysfunction.
- Chest Pain: Myocardial ischemia, a common cause of decreased cardiac output, can manifest as angina or chest pain due to insufficient oxygen supply to the heart muscle.
- Poor Tissue Perfusion (Diminished Pulses): Reduced cardiac output means less blood reaches peripheral tissues, leading to weak or diminished peripheral pulses.
- Clammy, Cool Skin: Peripheral vasoconstriction, a compensatory mechanism in low cardiac output states, results in reduced blood flow to the skin, causing it to become cool and clammy.
- Dizziness/Lightheadedness/Syncope: Reduced cerebral blood flow due to decreased cardiac output can cause dizziness, lightheadedness, and even syncope (fainting).
- Fatigue: Inadequate oxygen delivery to tissues results in generalized fatigue and weakness as the body struggles to meet energy demands.
- Weakness: Muscle weakness is another consequence of poor tissue perfusion and insufficient oxygen supply.
- Edema: Fluid retention, often seen in heart failure, can occur as the kidneys attempt to compensate for reduced cardiac output, leading to peripheral edema.
- Decreased Urine Output: Reduced renal perfusion due to decreased cardiac output can result in oliguria (decreased urine output) as the kidneys try to conserve fluid.
- Altered Mental Status: Cerebral hypoperfusion can lead to confusion, disorientation, restlessness, and other changes in mental status.
Psychological Signs and Symptoms:
- Restlessness: Anxiety and discomfort from physiological changes can manifest as restlessness.
- Anxiety: The sensation of breathlessness, chest discomfort, and overall physiological distress can trigger anxiety.
- Altered Mental Status/Confusion: As mentioned before, reduced cerebral blood flow impacts cognitive function, leading to altered mental status and confusion.
It is essential to consider both physiological and psychological manifestations when assessing patients for decreased cardiac output. A holistic approach ensures comprehensive care.
Expected Outcomes for Decreased Cardiac Output
Nursing care planning for decreased cardiac output focuses on achieving specific, measurable, achievable, relevant, and time-bound (SMART) expected outcomes. These outcomes guide interventions and provide a framework for evaluating patient progress. Common expected outcomes include:
- Adequate Cardiac Output: The patient will demonstrate adequate cardiac output as evidenced by:
- Blood pressure within normal limits (e.g., systolic 90-130 mmHg, diastolic 60-90 mmHg).
- Heart rate and rhythm within normal limits (e.g., heart rate 60-100 bpm, regular sinus rhythm).
- Strong peripheral pulses.
- Warm and dry skin.
- Urine output within normal limits (e.g., >30 mL/hr).
- Absence of chest pain, dyspnea, or edema.
- Stable mental status.
- Return to Baseline Activity Level: The patient will gradually return to their pre-illness activity level without experiencing undue fatigue or symptoms of decreased cardiac output.
- Adequate Breathing: The patient will exhibit adequate breathing patterns as evidenced by:
- Oxygen saturation (SpO2) within the prescribed range (e.g., >95% on room air or supplemental oxygen as ordered).
- Absence of adventitious breath sounds (e.g., crackles, wheezes).
- Respiratory rate within normal limits (e.g., 12-20 breaths per minute).
- Absence of dyspnea at rest and with activity (within limitations).
- Verbalizes Self-Care Strategies: The patient will be able to verbalize and demonstrate understanding of future self-care activities to promote cardiac health and prevent recurrence or worsening of decreased cardiac output. This includes medication management, dietary modifications (e.g., sodium restriction), activity recommendations, and recognition of warning signs and symptoms.
These expected outcomes provide a clear direction for nursing interventions and serve as benchmarks for evaluating the effectiveness of care.
Nursing Assessment for Decreased Cardiac Output
A thorough nursing assessment is the cornerstone of effective care for patients with decreased cardiac output. It involves gathering both subjective and objective data to identify the underlying issues and guide interventions.
1. Monitor Heart Rate and Blood Pressure:
Low cardiac output triggers the sympathetic nervous system to compensate by increasing heart rate and initially, blood pressure. This is a physiological response to maintain perfusion. However, prolonged decreased cardiac output can lead to exhaustion of compensatory mechanisms, resulting in hypotension. Regular monitoring of heart rate and blood pressure trends is crucial.
2. Monitor Breath Sounds, Respiratory Rate and Pattern, and Oxygen Saturation:
Decreased cardiac output often leads to pulmonary congestion as blood backs up into the pulmonary circulation. This can manifest as shortness of breath (dyspnea), increased respiratory rate, and abnormal breathing patterns. Auscultation of breath sounds may reveal adventitious sounds like crackles (rales) indicative of fluid in the lungs. Pulse oximetry provides objective data on oxygen saturation levels.
3. Monitor Heart Rhythm:
Decreased cardiac output can both cause and be caused by cardiac arrhythmias. Conditions that reduce cardiac output can disrupt the heart’s electrical activity. Conversely, arrhythmias themselves can impair cardiac output. Electrocardiogram (ECG) monitoring is essential to detect and identify arrhythmias, with atrial fibrillation being a common arrhythmia associated with decreased cardiac output. Ventricular tachycardia and ventricular fibrillation are life-threatening arrhythmias requiring immediate intervention.
4. Monitor Heart Sounds:
Normal heart sounds (S1 and S2) may be diminished in patients with poor heart function. The presence of abnormal heart sounds such as S3 and S4 gallops can indicate heart failure and reduced cardiac output. Auscultation of heart sounds provides valuable information about cardiac function.
5. Assess Peripheral Pulses:
Decreased cardiac output results in reduced blood flow to peripheral tissues, leading to weak, thready, or diminished peripheral pulses. Palpating and comparing pulses in different locations (radial, pedal, etc.) provides an assessment of peripheral perfusion.
6. Assess Skin Color and Temperature:
Poor tissue perfusion due to decreased cardiac output leads to peripheral vasoconstriction and reduced oxygen delivery to the skin. This can manifest as pale, cool, and clammy skin. Assessing skin color and temperature provides a visual indicator of circulatory status.
7. Assess the Patient’s Mental Status:
Reduced cerebral blood flow from decreased cardiac output can cause altered mental status, ranging from mild confusion to disorientation and lethargy. Assessing the patient’s level of consciousness, orientation, and cognitive function is critical for detecting cerebral hypoperfusion.
8. Assess Lab Values and Imaging Studies:
Laboratory tests (e.g., electrolytes, renal function, cardiac enzymes, B-type natriuretic peptide – BNP) and imaging studies (e.g., echocardiogram, chest X-ray) can help identify underlying causes of decreased cardiac output and provide objective data on cardiac function and related conditions.
9. Monitor Weight Closely:
Fluid retention is a common consequence of decreased cardiac output, especially in heart failure. Daily weight monitoring helps detect fluid accumulation, which can worsen symptoms and indicate worsening cardiac status.
10. Monitor Intake and Output Closely:
Monitoring fluid intake and urine output provides crucial information about fluid balance. Decreased urine output can be an early sign of reduced renal perfusion secondary to decreased cardiac output. Accurate intake and output monitoring is essential for guiding fluid management.
11. Monitor Patient’s Activity Level:
Patients with decreased cardiac output often experience fatigue and reduced exercise tolerance. Monitoring activity levels and assessing for fatigue with minimal exertion helps gauge the severity of cardiac compromise and the patient’s functional capacity.
Nursing Interventions for Decreased Cardiac Output
Nursing interventions for decreased cardiac output aim to improve cardiac function, reduce workload on the heart, optimize tissue perfusion, and alleviate symptoms.
1. Administer Supplemental Oxygen as Needed:
Hypoxemia is common in patients with decreased cardiac output due to pulmonary congestion and poor gas exchange. Supplemental oxygen administration, guided by pulse oximetry and arterial blood gas analysis, helps maintain adequate oxygen saturation and improve oxygen delivery to tissues.
2. Administer Prescribed Medications as Ordered:
Various medications are used to manage decreased cardiac output depending on the underlying cause and specific patient needs. These may include:
- ACE inhibitors and ARBs: Reduce afterload and preload, promote vasodilation, and decrease fluid retention.
- Beta-blockers: Reduce heart rate and myocardial contractility, decreasing myocardial oxygen demand and improving diastolic filling.
- Diuretics: Reduce fluid overload and preload by promoting sodium and water excretion.
- Inotropes (e.g., digoxin, dobutamine): Enhance myocardial contractility and improve cardiac output (used cautiously and often in acute settings).
- Vasodilators (e.g., nitrates): Reduce preload and afterload by dilating blood vessels.
- Antiarrhythmics: Manage arrhythmias that may be contributing to or resulting from decreased cardiac output.
Nurses play a crucial role in medication administration, monitoring for therapeutic effects and side effects, and patient education regarding medication regimens.
3. Elevate the Head of the Bed:
Elevating the head of the bed (semi-Fowler’s or high-Fowler’s position) promotes lung expansion, reduces venous return (preload), and eases breathing, especially in patients with dyspnea and pulmonary congestion.
4. Maintain Fluid Restriction and/or Sodium Restriction:
Fluid and sodium retention exacerbate heart failure and decreased cardiac output. Fluid restriction and sodium-restricted diets help minimize fluid overload, reduce preload, and alleviate symptoms like edema and dyspnea. Nurses educate patients and families about dietary modifications and fluid management.
5. Bed Rest and Gradual Activity Progression:
During the acute phase of decreased cardiac output, bed rest reduces myocardial oxygen demand and conserves energy. As the patient’s condition stabilizes, a gradual increase in activity is essential to prevent deconditioning and promote functional recovery. Activity progression should be tailored to the patient’s tolerance and monitored closely for signs of decompensation.
6. Educate the Patient on Home Self-Care:
Patient education is paramount for long-term management of decreased cardiac output. Nurses provide comprehensive education on:
- Medication management: Importance of adherence, dosage, timing, and potential side effects.
- Dietary modifications: Sodium restriction, fluid management, heart-healthy diet.
- Activity recommendations: Gradual exercise program, pacing activities, recognizing limitations.
- Symptom recognition: Early signs and symptoms of worsening cardiac output and when to seek medical attention.
- Lifestyle modifications: Smoking cessation, weight management, stress reduction.
Empowering patients with knowledge and self-care strategies promotes adherence to treatment plans and improves long-term outcomes.
7. Place the Patient on a Cardiac Monitor:
Continuous cardiac monitoring is essential to detect and manage arrhythmias in patients with decreased cardiac output. Early detection and prompt treatment of arrhythmias can prevent further hemodynamic compromise.
8. Educate Patient to Avoid Valsalva Maneuvers:
Valsalva maneuvers (straining during bowel movements, holding breath during exertion) increase intrathoracic pressure, reduce venous return, and can worsen decreased cardiac output. Patients should be educated on techniques to avoid Valsalva maneuvers, such as using stool softeners and breathing properly during activities.
9. Implement a Rehabilitation Plan (PT and/or Cardiac Rehab):
Cardiac rehabilitation programs provide structured exercise, education, and support for patients with cardiac conditions, including decreased cardiac output. These programs improve functional capacity, quality of life, and reduce mortality. Physical therapy (PT) can address specific mobility and strength deficits.
10. Anticipate Potential for Deterioration:
Patients with decreased cardiac output are at risk for cardiac arrest and other life-threatening complications. Nurses must be vigilant in monitoring for deteriorating vital signs, changes in level of consciousness, increasing anxiety, and other signs of clinical worsening. Prompt communication with the medical team and anticipation of potential resuscitation needs are critical in managing acutely decompensating patients.
Nursing Care Plans for Decreased Cardiac Output
Nursing care plans provide a structured framework for organizing and delivering individualized care. Here are examples of nursing care plans for decreased cardiac output, focusing on different underlying causes and associated manifestations.
Care Plan #1
Diagnostic Statement: Decreased cardiac output related to altered heart rate secondary to bundle branch block as evidenced by ECG changes and chest pain.
Expected Outcomes:
- Patient will demonstrate adequate cardiac output as evidenced by:
- Heart rate 60-100 bpm.
- Blood pressure 90-130/60-90 mmHg.
- Regular sinus rhythm.
- Absence of chest pain.
- Absence of dyspnea.
- Patient will not manifest a decrease in the level of consciousness.
Assessment:
- Monitor chest pain: Assess characteristics (precipitating/relieving factors, quality, radiation, severity, timing, location, associated symptoms). Chest pain may indicate myocardial ischemia contributing to decreased cardiac output. Untreated DCO can lead to end-organ damage.
- Monitor ECG findings: Bundle branch block (BBB) may be an incidental finding or indicate underlying myocardial degeneration, especially with cardiac symptoms. BBB with symptoms suggests worsening myocardial dysfunction.
Interventions:
- Instruct the patient to relax during chest pain episodes: Relaxation reduces myocardial oxygen demand and helps restore oxygen supply-demand balance.
- Administer sublingual nitroglycerin as ordered: Nitroglycerin relieves acute chest pain by dilating cardiac arteries and veins, improving myocardial perfusion. Administer every 5 minutes for up to three doses until pain relief.
- Administer oxygen as indicated: Supplemental oxygen increases arterial oxygen saturation and oxygen delivery to the heart.
- Educate the patient on avoiding angina-provoking factors: Heavy meals, excessive exertion, extreme temperatures, emotional stress, and stimulants can trigger angina. Patient education promotes self-management and compliance.
- Refer to cardiac rehabilitation: Cardiac rehabilitation programs offer education and monitored exercise, improving quality of life, functional capacity, and reducing mortality for patients with decreased cardiac output.
Care Plan #2
Diagnostic Statement: Decreased cardiac output related to altered rhythm secondary to atrial fibrillation as evidenced by irregular pulse and dizziness.
Expected Outcomes:
- Patient will demonstrate adequate cardiac output as evidenced by:
- Regular sinus rhythm.
- Strong regular peripheral pulses.
- Heart rate 60-100 bpm.
- Blood pressure 90-130/60-90 mmHg.
- Patient will not experience falls or injuries from dizziness.
Assessment:
- Hook to ECG monitor: Atrial fibrillation increases the risk of thromboembolism, stroke, and premature death. Continuous cardiac monitoring is essential for assessing heart rate and rhythm and guiding prompt management.
- Monitor hemodynamic parameters: In hemodynamically unstable patients, central monitoring (pulmonary wedge pressure, systemic vascular resistance, stroke volume, cardiac output) may be necessary to detect cardiogenic shock, a severe complication of atrial fibrillation.
- Identify the underlying cause of atrial fibrillation: For stable patients, assess for triggers and contributing factors: timing and frequency of episodes, previous episodes, cardiovascular history, and current medications.
Interventions:
- Position patient in semi- to high-Fowler’s and administer oxygen: These measures promote adequate ventilation and perfusion.
- Anticipate cardioversion if hemodynamically unstable: Cardioversion (chemical or electrical) aims to restore sinus rhythm in unstable patients.
- Administer medications as ordered: Calcium channel blockers or beta-blockers control heart rate and rhythm. Anticoagulants may be prescribed to reduce thromboembolic risk.
- Educate the patient about lifestyle modifications:
- Medications: Emphasize medication adherence and bleeding risks with anticoagulants.
- Diet: For warfarin users, educate about Vitamin K-rich foods and their effect on anticoagulation.
- Avoid alcohol and caffeine: These substances can trigger atrial fibrillation.
- Smoking cessation: Nicotine is a cardiac stimulant that can worsen dysrhythmias.
- Caution with OTC medications: Avoid cold remedies and nasal sprays containing cardiac stimulants.
- Stress management: Relaxation techniques can help prevent atrial fibrillation triggered by stress.
- Refer to community resources: Connect patients with programs for education, support, and guided activity to improve quality of life and disease management.
Care Plan #3
Diagnostic Statement: Decreased cardiac output related to altered preload as evidenced by anxiety and altered blood pressure.
Expected Outcomes:
- Patient will demonstrate adequate cardiac output as evidenced by:
- Stable blood pressure, pulse rate, and rhythm.
- Strong peripheral pulses.
- No deterioration in the level of mentation.
- No chest pain and dyspnea.
- Adequate urinary output.
- Patient will explain actions and precautions to prevent primary or secondary cardiac disease.
Assessment:
- Monitor and report symptoms: Assess for dyspnea (rest/exertion), orthopnea, paroxysmal nocturnal dyspnea, nocturnal cough, abdominal distention, fatigue, and weakness, which are consistent with heart failure and decreased cardiac output.
- Monitor vital signs and level of consciousness: Frequent assessments are crucial for patients with acute changes in blood pressure and anxiety, escalating care if decompensation occurs.
- Monitor intake and output (I&O): Hourly urine output monitoring in acute conditions to detect oliguria or anuria, indicating decreased renal perfusion and treatment response.
Interventions:
- Position patient in semi- to high-Fowler’s with legs dependent: This position may reduce the work of breathing and venous return (preload).
- Obtain ECG and stat blood work if acute cardiac event suspected: If decompensation is suspected, prompt medical evaluation and intervention are critical. Call code blue if patient is rapidly deteriorating.
- Provide a restful environment: Minimize stressors and unnecessary disturbances to reduce cardiac workload and oxygen demand.
- Teach about worsening heart failure symptoms: Educate patients and families about recognizing emergency symptoms, when to contact healthcare providers, and when to seek urgent care.
References
- Ackley, B.J., Ladwig, G.B.,& Makic, M.B.F. (2017). Nursing diagnosis handbook: An evidence-based guide to planning care (11th ed.). Elsevier.
- Bauldoff, G., Gubrud, P., & Carno, M. (2020). LeMone and Burke’s Medical-Surgical Nursing: Clinical Reasoning in Patient Care (7th ed). Pearson
- Bruss, Z. & Raja, A. (2021). Physiology, stroke volume. https://www.ncbi.nlm.nih.gov/books/NBK547686/
- Carpenito, L.J. (2013). Nursing diagnosis: Application to clinical practice (14th ed.). Lippincott Williams & Wilkins.
- Doenges, M.E., Moorhouse, M.F., & Murr, A.C. (2019). Nursing care plans: Guidelines for individualizing client care across the life span (10th ed.). F.A. Davis Company.
- Gulanick, M. & Myers, J.L. (2014). Nursing care plans: Diagnoses, interventions, and outcomes (8th ed.). Elsevier.
- Harkness, W.T.& Hicks, M. (2022). Right bundle branch block. StatPearls. https://www.ncbi.nlm.nih.gov/books/NBK507872/
- Kim, et al. (2022). Nitroglycerin. StatPearls. https://www.ncbi.nlm.nih.gov/books/NBK482382/
- King, J. & Lowery, D. (2021). Physiology, cardiac output. https://www.ncbi.nlm.nih.gov/books/NBK470455/
- Nesheiwat, Z., Goyal, A.,& Jagtap, M. (2022). Atrial fibrillation. StatPearls. https://www.ncbi.nlm.nih.gov/books/NBK526072/
- RegisteredNursing.org (2021). Hemodynamics: NCLEX-RN https://www.registerednursing.org/nclex/hemodynamics/
- Vincent, JL. Understanding cardiac output. Crit Care 12, 174 (2008). https://doi.org/10.1186/cc6975
