Oxygenation & Cardiac Fundamentals

Oxygenation & Cardiac Fundamentals: NUR 204

Introduction

• Presented by: Morgan Chojnacki, DNP, APRN, CPNP, with permission from Kent Brouwer, DNP, APRN, ACNP.

Course Coverage

Pre-Class Topics

• Pulmonary

  • Normal ventilation and perfusion.

  • Recall of key terms from Quizzlet.

  • Conduct a respiratory assessment.

  • Define hypoxia and outline nursing interventions for hypoxia.

• Cardiac

  • Recall of key terms from Quizzlet.

  • Telemetry lead placement and emergency interventions.

  • Prevention, screening, diagnosis, nursing interventions, and evaluation of hypertension.

In-Class Topics

• Pulmonary

  • Detailed explanation of gas exchange in the lungs (Diffusion).

  • Factors influencing oxygenation.

  • Common nursing diagnoses related to pulmonary issues.

• Cardiac

  • Recall important terms from Quizzlet.

  • Review the blood flow process.

  • Concepts of preload, afterload, cardiac output, left and right-sided heart failure.

  • Discuss impaired myocardial perfusion.

  • Engage in a clicker review.

Key Concepts on Oxygenation

• Oxygen as Essential Resource

  • Required to sustain life, supplied by the cardiac and respiratory systems.

  • Exchange of respiratory gases occurs between the environment and the blood.

• Respiration Definition

  • The process of exchanging oxygen and carbon dioxide during cellular metabolism.

• Regulation of Respiration

  • Controlled by neural and chemical regulators that respond to changing tissue oxygen demands.

Cardiopulmonary Connection

• Lungs and Heart

  • Direct connection via the pulmonary artery and veins; any inefficiency in blood pumping affects oxygenation.

Definitions and Conditions Related to Oxygenation

• Apnea: Cessation of breathing.

• Arterial Blood Gas: A test measuring the levels of oxygen and carbon dioxide in blood.

• Atelectasis: Collapse of lung tissue preventing gas exchange.

• Bradypnea: Abnormally slow breathing.

• Cheyne-Stokes Respiration: Abnormal pattern of breathing characterized by periods of deep breathing followed by periods of apnea.

• Clubbing: Enlargement of the distal phalanges of the fingers or toes, often associated with chronic hypoxia.

• Crackles or Rales: Abnormal lung sounds typically indicative of fluid in the lungs.

• Cyanosis: Bluish discoloration indicating low oxygen saturation.

• Diaphragmatic Breathing: Breathing technique focusing on using the diaphragm.

• Diffusion/Gas Exchange: Process of gases moving from areas of high to low concentration in the alveoli and capillaries.

• Dyspnea: Shortness of breath.

• Endotracheal Tube (ET Tube): A tube placed into the trachea to maintain an open airway.

• Expiration: Expelling air out of the lungs.

• Face Mask (Simple): A device to deliver oxygen at a moderate concentration.

• Hyperventilation: Increased ventilation causing excessive loss of CO2.

• Hypoventilation: Decreased ventilation leading to increased CO2 levels.

• Hypoxia: Inadequate oxygen supply to tissue.

• Incentive Spirometry: Device encouraging deep breathing to prevent atelectasis.

• Kussmaul Breathing: Deep, labored breathing pattern, typically associated with metabolic acidosis.

• Nasal Cannula: Device delivering oxygen through the nostrils.

• Nebulization: Administration of medication in mist form directly into the airways.

• Non-Rebreather Mask: A mask providing high concentrations of oxygen to patients.

• Orthopnea: Difficulty breathing while lying flat.

• Paroxysmal Nocturnal Dyspnea (PND): Sudden shortness of breath occurring at night.

• Pleural Friction Rub: A grating sound caused by inflamed pleurae rubbing together.

• Postural Drainage: Technique used to drain secretions from the lungs.

• Pulse Oximetry: Non-invasive method to measure hemoglobin saturated with oxygen.

• Pursed-lip Breathing: Technique to slow breathing and promote CO2 elimination.

• Rhonchi: Continuous low-pitched sounds indicating obstructed airways.

• Stridor: High-pitched inspiratory sound resulting from airway obstruction.

• Tachypnea: Abnormally rapid breathing.

• Trach Collar: Device providing oxygen through a tracheostomy.

• Tracheostomy: Surgical procedure to create an opening in the trachea.

• Ventilation: Process of air flowing in and out of the lungs.

• Venturi Mask: Device delivering oxygen at a controlled concentration.

• Wheezing: High-pitched sound caused by narrowed airways.

Steps in Oxygenation

• Ventilation: The physical movement of gases from the outside environment into the lungs.

  • Example: Taking a breath.

• Diffusion: The exchange of respiratory gases in the alveoli and capillaries.

• Perfusion: The cardiovascular system's ability to pump oxygenated blood to the tissues and return deoxygenated blood to the lungs.

Regulation of Respiration

Neural Regulation

• Central nervous system (CNS) controls respiratory rate, depth, and rhythm.

• The cerebral cortex manages voluntary control of respiration.

Chemical Regulation

• Maintains the rate and depth of respiration based on blood concentrations of CO2, O2, and hydrogen ions (pH).

• Chemoreceptors detect chemical changes and stimulate neural regulators for adjustment.

Chronic Obstructive Pulmonary Disease (COPD) Considerations

• Patients often adapt to higher levels of CO2.

• Dysfunction in chemoreceptors affects their breathing stimulus; they respond to low oxygen levels.

• Excessive oxygen delivery may inhibit their natural drive to breathe, leading to respiratory distress.

Factors Influencing Oxygenation

Physiological Factors

• Decreased oxygen-carrying capacity (e.g., anemia).

• Hypovolemia, decreased inspired oxygen concentration, increased metabolic rate.

• Conditions affecting chest wall movement (e.g., musculoskeletal disorders).

• Influence of chronic lung diseases.

Developmental Factors in Adults & Older Adults

• Smoking: Impairs oxygenation.

• Changes in mental status can indicate respiratory distress, often manifesting as forgetfulness or irritability.

• Patients may not express dyspnea until it hinders daily living activities (ADLs).

• Altered cough mechanisms may lead to retained pulmonary secretions and atelectasis, especially with cough suppressants.

• Immunodeficiency increases susceptibility to infections.

• Decreased respiratory muscle strength disrupts chest expansion.

Lifestyle Risk Factors

• Directly linked to heart disease, COPD, and lung cancer.

• Smokers have a 10x greater risk of developing lung cancer compared to non-smokers.

• Excessive alcohol and drug use can diminish tissue oxygenation.

• Stress increases metabolic rate and oxygen consumption; manage through deep-breathing techniques.

Environmental Factors

• Occupational exposure may heighten risk for pulmonary diseases (e.g., farmers with coccidioidomycosis).

• Asbestosis from historic exposure to asbestos in construction materials; while mostly banned, still present in some sectors.

• Pulmonary diseases are notably more prevalent in urban, smog-laden environments compared to rural locations.

Assessment of Respiratory Health

History

• Comprehensive evaluation of patient’s pulmonary history, including past impairments, present respiratory function, and oxygenation optimization strategies.

• Medication and allergy reviews essential.

Nursing History

• Common Symptoms

  • Chest pain, dyspnea, wheezing, smoking habits, respiratory infections, allergies, health risks, medications, environmental/geographical exposures.

Physical Examination

1. Inspection: Evaluate skin and mucous membranes, level of consciousness, breathing patterns, and chest wall movement.

2. Auscultation: Listen for normal/abnormal heart and lung sounds.

3. Palpation: Assess chest, feet, legs, and pulses.

4. Percussion: Check for presence of fluid or air; evaluate diaphragmatic excursion.

   • Normal: Resonance.

   • Abnormal: Hyperresonance indicating hyper-inflated lungs (e.g., COPD).

Look, Listen, Count Metrics

• Rate: Monitor breathing rate.

• Volume: Assess shallow vs. deep breathing.

• Rhythm: Regular vs. irregular.

• Effort: Determine ease of breathing.

• AP:LAT Diameter: Should be 1:2.

• Cough Assessment: Classify as nonproductive or productive, and evaluate amount, color, consistency, and odor of sputum.

Adventitious Breath Sounds

• Crackles/Rales: Short, discrete sounds indicating fluid in airways.

• Rhonchi/Gurgles: Low-pitched rattling sounds from fluid-filled airways.

• Wheezes: High-pitched sounds from narrowed airways.

• Stridor: High-pitched sound from obstruction; inspiratory phase may last longer than the expiratory phase.

• Pleural Friction Rub: Creaking sound from inflamed pleurae.

• Absent/Diminished Sounds: May indicate conditions such as pneumothorax or atelectasis.

Sample Documentation

• Example: "RR 30/min, labored; using anterior scalene muscles; nasal flaring noted; bilateral crackles in posterior lower lobes and scattered inspiratory wheeze noted. J. Wilson, RN."

Alterations in Oxygenation

Hypoxia/Hypoxemia Definitions

• Hypoxia: Inadequate tissue oxygenation at the cellular level.

• Hypoxemia: Low arterial blood oxygen levels.

Evaluation for Hypoxia/Hypoxemia

• Pulse Oximetry: Non-invasive measure of O2 saturation; normal range is 95-100%.

• Arterial Blood Gases (ABGs): Invasive measure assessing the partial pressure of oxygen (pO2); normal range is 80-100 mmHg.

• Clinical Presentation: Observational symptoms denoting hypoxia/hypoxemia.

Nursing Interventions for Promoting Oxygenation

• Prioritization: Starting with least invasive interventions and escalating as needed.

  • Hydration: Essential for thinning secretions; aim for 1500-2500 mL/day.

  • Positioning: Encouraging effective lung expansion through various positions.

  • Breathing Techniques: Teach patients effective coughing, pursed lip breathing, diaphragmatic breathing, etc.

  • Chest Physiotherapy: Aids in mobilizing secretions.

  • Oxygen Therapy: Administer through non-invasive devices, nebulizers, or IV as needed.

  • Suctioning: Clear secretions from airways when patients cannot do so autonomously.

Chest Physiotherapy Components

1. Chest Percussion: Helps loosen secretions.

2. Vibration: Another method to dislodge secretions.

3. Postural Drainage: Uses gravity to assist in drainage from lobes of the lungs.

Coughing and Deep Breathing Techniques

• Diaphragmatic Breathing: Increases air to lower lungs; involves abdominal movement.

• Coughing: Recommended every 2 hours while awake or more frequently for those with excessive secretions.

Pursed Lip Breathing Process

• Aids in preventing alveolar collapse; involves deep inhalation followed by prolonged exhalation through pursed lips. Useful in managing COPD and anxiety.

Maintenance and Promotion of Lung Expansion

• Ambulation: Early and regular mobilization prevents atelectasis.

• Positioning: Frequent adjustments to maximize respiratory function, ideally maintaining a 45-degree semi-Fowler’s position for optimal lung expansion.

Incentive Spirometer Usage

• Encourages deep breathing with visual feedback to prevent atelectasis.

• Teach splinting technique for post-op patients for comfort during usage.

Oxygen Delivery Devices

Non-Invasive Ventilation Methods

• Continuous Positive Airway Pressure (CPAP): Provides positive pressure to keep airway open, often for sleep apnea.

• Bi-level Positive Airway Pressure (BiPAP): Offers both inspiratory and expiratory positive pressures; assists in avoiding intubation for patients with respiratory complications.

Oxygen Therapy Methods

• Room Air: Typically 21% oxygen concentration.

• Oxygen Masks:

  • Simple Face Mask: Delivers 35-50% O2 at 5-8 L/min.

  • Partial Rebreather Mask: Delivers 40-70% O2; reservoir bag collects exhaled air.

  • Non-Rebreather Mask: Delivers 60-80% O2; prevents room air from entering.

  • Venturi Mask: Delivers specific concentrations based on flow rates; highly precise for COPD patients.

Humidification of Oxygen

• Purpose: Prevents drying of airways and enhances clearance of secretions; essential in dry environments.

Medications for Promoting Oxygenation

• Requires orders from a medical provider; may include expectorants, bronchodilators, anti-inflammatories, and mucolytics. Nurses ensure medications are administered as prescribed.

Complications of Oxygen Therapy

• Potential adverse effects include dryness of mucosa, oxygen toxicity, combustion risks, skin breakdown, and hypoxic drive impairment in certain patients (particularly those with COPD).

Suctioning Techniques

When to Perform

• Necessary when patients cannot clear secretions independently.

Types of Suctioning

• Oropharyngeal and Nasopharyngeal: For patients who can cough.

• Orotracheal and Nasotracheal: For patients unable to manage secretions through coughing.

• Tracheal Suctioning: Conducted via artificial airways (ET or tracheostomy).

Artificial Airways

Types of Airways

1. Oral Airway: Prevents obstruction by repositioning the tongue.

2. Endotracheal Tube: Used for temporary venting and secretion clearance.

3. Tracheostomy: Long-term airway management.

Potential Complications from Suctioning

• Risks include hypoxia, arrhythmias, airway trauma, infections, and anxiety.

Evaluation of Interventions

• Assess degree of breathlessness and distance ambulated.

• Rate interventions effectiveness on a scale from 0-10 for dyspnea.

• Monitor respiratory rate and sputum characteristics pre- and post-activity

• Auscultate for improvements in breath sounds.

Cardiac Concepts

Cardiovascular Physiology

• Blood flow from the right heart to lungs for oxygenation and back to the left heart for distribution to tissues.

Important Cardiac Terms

• Stroke Volume: Amount of blood pumped with each heartbeat.

• Systole: Phase of contraction in the heart.

• Diastole: Phase of relaxation in the heart.

• Cardiac Output: Volume of blood the heart pumps per minute.

• Preload: Volume of blood in the ventricles at the end of diastole.

• Afterload: Resistance the heart must overcome to eject blood.

• SA Node: The heart’s natural pacemaker, controlling heart rhythm.

Telemetry Basics

• 5-lead telemetry is standard for monitoring patients.

• Lead Placement Mnemonic: "White is always right, Smoke over fire, and Chocolate next to my heart."

Diagnostic Tests

• ECG/EKG: A 12-lead electrocardiogram illustrating the electrical activity of the heart.

Telemetry Monitoring Duties

• Continuous monitoring of electrical activity, recognizing rhythm abnormalities, and documenting findings.

• Communicate with telemetry teams and correlate findings with physical assessments.

Assessment for Cardiac Problems

Inspection

• Observe skin color and signs of perfusion.

• JVD (Jugular Venous Distension) indicates fluid overload.

Auscultation

• Listen for normal (S1, S2) and abnormal heart sounds (murmurs, rubs).

• Assess for irregular rhythms and pulse characteristics.

Special Assessment Techniques

• Telemetry monitoring, EKG interpretation, Holter monitors, echocardiograms.

Assessment for Cardiac Output Problems

• Evaluate symptoms like tachycardia, bradycardia, dysrhythmias, and their implications on CO.

Cardiovascular Auscultation Order

• Mnemonic: "APE To Man" for heart sounds (Aortic, Pulmonic, Erb’s, Tricuspid, Mitral).

• Heart Sound Characteristics: S3 and S4 sounds indicate heart failure and diastolic dysfunction respectively.

Orthostatic Vital Signs

• Process to assess postural changes in blood pressure and pulse; performed after a period of laying down, standing, and retaking measurements at specified intervals.

• Abnormal drop: SBP >20 mmHg or DBP >10 mmHg indicates possible orthostatic hypotension.

Electrical System of the Heart

• Overview of cardiac conduction pathways, including the SA node, AV node, and bundle branches, emphasizing the importance in maintaining rhythm.

Disturbances in Conduction

• Classification of dysrhythmias based on heart rate response and origin site.

  • Types include tachycardias, bradycardias, and life-threatening ventricular arrhythmias (e.g., V-tach, V-fib).

  • Emergency Response: Immediate CPR and AED usage for suspected cardiac arrest.

Hypertension Overview

• Blood Pressure Categories: Established by the American Heart Association, ranging from normal to hypertensive crisis levels.

• Blood Pressure Measurement Guidelines: Importance of rest, proper position, and ideal cuff size for accurate readings.

Complications of Uncontrolled Hypertension

• Potential impact on various organs, including heart failure, stroke, renal failure, visual impairment, and urogenital dysfunction (e.g., erectile dysfunction).

Nursing Assessment for Hypertension

• Recognized as a “silent killer” with symptoms like headaches, blurry vision, and dizziness.

Nursing Interventions for Hypertension

• Essential assessment strategies: blood pressure measurement, family history evaluation, dietary analysis, and encouraging lifestyle changes (DASH diet, reducing sodium intake, smoking cessation, and exercise).