Oxygenation

OXYGENATION NUR 1119 Study Notes

OBJECTIVES

  • Examine the structure and function of the cardiopulmonary system.

  • Explain the interrelationship among ventilation, perfusion, and exchange of gases.

  • Identify physical manifestations that occur with alterations in oxygenation.

  • Discuss clinical outcomes resulting from altered respiratory and cardiac function.

  • Apply the CJMM/nursing process to develop a plan of care for a patient with altered oxygenation.

  • Determine nursing responsibilities and implications of various procedures used for diagnosing respiratory function.

  • Identify goals of oxygen therapy, including safety precautions and methods of delivery.

  • Demonstrate application of oxygen-delivery devices.

  • Discuss how a patient's level of health, age, lifestyle, and environment affect oxygenation.

  • Explain how clinical judgment is used to identify potential clinical problems and interventions that promote oxygenation across different healthcare settings.

RESPIRATORY PHYSIOLOGY

Key Components of the Respiratory System

  • Pulmonary vein to left heart

  • Pulmonary artery from right heart

  • Capillary plexus

  • Alveoli

  • Right main stem bronchus

  • Right lobes of the lungs

  • Trachea

  • Left main stem bronchus

  • Bronchi

  • Bronchioles

  • Left lobes

  • Pleura

  • Pleural fluid

ELEMENTS OF RESPIRATORY PHYSIOLOGY

  1. Ventilation:

    • Process of moving air in and out of lungs (includes inspiration and expiration).

  2. Perfusion:

    • Blood flow through capillaries surrounding organs or tissues.

    • Pulmonary perfusion refers specifically to blood flow through pulmonary capillaries around the alveoli.

  3. Diffusion:

    • Movement of molecules from an area of higher concentration to lower concentration.

    • Example: Oxygen diffuses into the blood, carbon dioxide diffuses out of the blood.

  4. Work of Breathing:

    • Involves factors such as inspiration, expiration, surfactant secretion, accessory muscle use, compliance, and airway resistance.

VENTILATION/PERFUSION MISMATCH

Symptoms

  • Dyspnea: Shortness of breath.

  • Cyanosis: Bluish tint to skin.

  • Tachycardia: Increased heart rate.

  • Tachypnea: Rapid breathing.

  • Confusion/AMS: Altered mental status.

  • Chest Pain (CP): Discomfort in the chest.

  • Palpitations: Noticeable heartbeats.

  • Wheezing/Coughing: Increased respiratory effort.

Treatment Options

  • Supplemental oxygen

  • Bronchodilators

  • Inhaled steroids

  • Anticoagulation

  • Diuretics

  • Positive pressure ventilation (e.g., PEEP)

  • Antibiotics

  • Treatment of underlying cardiac conditions

  • Pulmonary vasodilators

CAUSES OF VENTILATION/PERFUSION MISMATCH

  • Obstructed Airways

  • Obstructed Blood Vessels

  • Chronic Lung Diseases: COPD, Asthma, Bronchitis, Pulmonary Edema, Obstructive Sleep Apnea (OSA)

  • Acute Lung Impairments: Pneumonia, Airway Obstruction, Pulmonary Embolism (PE)

CARDIOVASCULAR PHYSIOLOGY

Components Inside a Healthy Heart

  • Right Atrium

  • Left Atrium

  • Right Ventricle

  • Left Ventricle

FACTORS AFFECTING OXYGENATION

  1. Physiological:

    • Includes respiratory and cardiac function.

  2. Developmental:

    • Age-related factors affecting lung development and function.

  3. Lifestyle:

    • Physical activity, diet, and habits (e.g., smoking).

  4. Environmental:

    • Air quality, pollution, allergens.

Decreased Oxygen-Carrying Capacity Causes

  • Anemia

  • Inhalation of toxic substances (e.g., carbon monoxide)

  • Hypovolemia due to reduced circulating volume or shock

Decreased Inspired Oxygen Concentration Causes

  • Airway obstructions

  • High altitudes

  • Opiate overdose leading to hypoventilation

  • Increased metabolic rate due to fever, exercise, wound healing, or pregnancy

CONDITIONS AFFECTING CHEST WALL MOVEMENT (DECREASED VENTILATION)

  • Pregnancy

  • Obesity

  • Musculoskeletal abnormalities

  • Trauma

  • Neuromuscular diseases

  • Central nervous system alterations

  • Chronic lung diseases

ALTERATIONS IN RESPIRATORY FUNCTIONING

  • Hypoventilation:

    • Inadequate ventilation to meet oxygen demand or eliminate carbon dioxide.

    • Risks with excessive oxygen administration in COPD patients.

  • Hyperventilation:

    • Removal of carbon dioxide faster than produced.

  • Hypoxia:

    • Inadequate tissue oxygenation at the cellular level.

Signs & Symptoms of Altered Breathing

  1. Hypoventilation:

    • Altered mental status (AMS)

    • Dysrhythmias

    • Risk of cardiac arrest

    • Rapid decline in patient status

    • Seizures

    • Loss of consciousness (LOC)

    • Potential for death

  2. Hyperventilation:

    • Rapid respirations

    • Sighing breaths

    • Numbness/tingling in hands and feet

    • Light-headedness

    • Loss of consciousness (LOC)

ALTERATIONS IN CARDIAC FUNCTIONING

  • Affects:

    • Cardiac rhythm

    • Strength of heart pump

    • Blood flow and peripheral circulation

RIGHT-SIDED HEART FAILURE

  • Symptoms:

    • Fatigue

    • Increased peripheral venous pressure

    • Ascites

    • Enlarged liver and spleen (Cor Pulmonale)

    • Distended jugular veins

    • Anorexia and gastrointestinal distress

    • Weight gain

    • Dependent edema

FACTORS INFLUENCING OXYGENATION

  1. Developmental Factors:

    • Infants and toddlers: Increased infection risk between 3-6 months.

    • School-age and adolescents: Risk from cigarette use, drugs, obesity, inactivity, excess caffeine.

    • Young/middle adults: Effects of lifestyle choices (unhealthy diets, stress).

    • Older adults: Physiological changes like calcified heart valves, cognitive decline, etc.

  2. Lifestyle Factors:

    • Nutrition, hydration, exercise, smoking, substance abuse, stress.

  3. Environmental Factors:

    • Pollution and allergens.

ASSESSMENT: RECOGNIZING CUES (NURSING HISTORY)

  • Health risks and medical history (e.g., TB, family history)

  • Pain assessment (cardiac, pleuritic, musculoskeletal origins)

  • Subjective fatigue assessment (sudden, gradual, better, worse)

  • Dyspnea evaluation (activity levels vs. rest)

  • Cough analysis (acute vs. chronic)

  • Environmental exposure history (smog, dust, allergies)

  • Smoking history (pack/year or secondhand exposure)

  • Respiratory infections history (e.g., URI, HIV, Covid)

  • Allergy history (foods, drugs, etc.)

  • Medication use (including OTC and illegal substances)

  • Assessment of presenting condition vs. patient’s baseline.

ABNORMAL BREATHING PATTERNS

  1. Cheyne-Stokes Respiration:

    • Pattern: Deep breaths followed by shallow breaths and periods of apnea.

    • Commonly seen in: Stroke, brain injury, congestive heart failure.

  2. Kussmaul's Respiration:

    • Pattern: Deep, rapid, regular breathing.

    • Commonly seen in: Diabetic ketoacidosis (DKA), metabolic acidosis.

  3. Agonal Breathing:

    • Ineffective breathing pattern.

ASSESSMENT: RECOGNIZING CUES (PHYSICAL EXAM)

Inspection

  • Chest wall movement

  • Chest wall shape

  • Respiratory rate and patterns

  • Use of accessory muscles

  • Clubbed nails

  • Nasal flaring

  • Cyanosis or skin coloration

  • General appearance and level of consciousness (LOC)

Palpation

  • Areas of tenderness

  • Pulses (graded 0-4+; with 4+ being full/bounding and 1+ weak/thready)

  • Capillary refill time

  • Edema assessment (1+-4+)

Auscultation

  • Normal lung sounds: Vesicular, bronchial, bronchovesicular

  • Adventitious sounds: Wheezes, crackles, rhonchi, pleural rub

ASSESSMENT: RECOGNIZING CUES (DIAGNOSTIC STUDIES)

  • Pulse oximetry

  • Capnography

  • Complete blood count (CBC)

  • Chest x-ray

  • Sputum specimens

  • Arterial blood gases (ABGs)

  • Tuberculosis (TB) skin test

  • Pulmonary function tests

  • Bronchoscopy

  • Lung scan (e.g., for PE)

  • Thoracentesis

ARTERIAL BLOOD GAS ANALYSIS

  • pH Levels: Normal range 7.35-7.45.

  • HCO3 Levels: Normal range 21-28 mEq/L.

  • PaCO2 Levels: Normal range 35-45 mmHg.

  • PaO2 Levels: Normal range 80-100 mmHg.

  • SaO2 Levels: Normal >95%.

PLANNING: ANALYZING CUES

  • Identifying clinical issues and priorities:

    • Activity intolerance

    • Decreased cardiac output

    • Fatigue

    • Impaired gas exchange

    • Impaired spontaneous ventilation

    • Impaired verbal communication

    • Ineffective airway clearance

    • Ineffective breathing pattern

    • Risk for aspiration

    • Risk for infection

PLANNING: PRIORITIZING HYPOTHESES

  • Identify top goals/outcomes.

  • Establish priorities and required collaborations (e.g., physical therapy, nutrition, respiratory therapy).

  • Develop a realistic, measurable, specific plan of care. Examples of targets:

    • Respiratory Rate (RR) 12-20 breaths per minute.

    • Bilateral lung expansion.

    • Absence of accessory muscle use.

IMPLEMENTATION: GENERATE SOLUTIONS

Health Promotion

  • Introduce vaccines targeting flu, pneumonia, COVID, especially for at-risk groups including infants, older adults, and chronic illness patients.

  • Promote healthy lifestyles to reduce risk factors.

Dyspnea Management

  • Monitor signs and symptoms: Shortness of breath (SOB), exaggerated respiratory effort, increased respiratory rate, use of accessory muscles, nasal flaring.

  • Interventions include:

    • Pharmacologic agents (e.g., bronchodilators)

    • Oxygen therapy

    • Physical techniques (e.g., repositioning, breathing exercises)

    • Psychosocial techniques (e.g., relaxation).

Airway Maintenance

  • Focus on adequate hydration (1500-2500mL/day).

  • Ensure humidification for oxygen patients (O2 > 4L/min).

  • Employ nebulization techniques to deliver medications and moisture.

  • Mobilize pulmonary secretions through coughing techniques, chest physiotherapy.

Maintenance of Patent Airway

  • Utilize artificial airways as needed (oral airway, endotracheal tube, tracheostomy).

  • Perform suctioning using open or closed methods depending on patient need.

SPECIAL CONSIDERATIONS

Chest Tube Management

  • Keep chest tubes closed and below the chest level.

  • Mark drainage amounts and changes; monitor for bubbling and tidaling.

  • Address the potential for life-threatening events associated with improper tube management, such as clamping.

MAINTENANCE OF OXYGENATION

  • Mobilize secretions and maintain airway patency.

  • Administer oxygen therapy carefully:

    • Monitor oxygen supply closely.

    • Adhere to safety precautions when delivering oxygen (e.g., keep away from flames).

Methods of Oxygen Delivery

  1. Low-Flow Delivery Devices:

    • Nasal Cannula: 1-6 L/min.

    • Simple Face Mask: 6-12 L/min.

    • Partial Rebreather Mask: 10-15 L/min.

    • Non-Rebreather Mask: 10-15 L/min.

  2. High-Flow Delivery Devices:

    • Venturi Mask: 24-50% precise oxygen concentration.

    • High-Flow Nasal Cannula: Adjustable up to 60 L/min.

RESTORATION OF CARDIOPULMONARY FUNCTIONING

  • Cardiopulmonary Resuscitation (CPR)

  • Maintain focus on circulation, airway, and breathing during emergency resuscitation.

  • Employ defibrillation techniques for arrhythmias like ventricular fibrillation or pulseless v-tach.

RESTORATIVE AND CONTINUING CARE

  • Cardiopulmonary rehabilitation programs aimed at rebuilding lung function post-injury or illness.

  • Facilitate breathing exercises such as pursed-lip and diaphragmatic breathing to improve function.

  • Explore options for home oxygen therapy where necessary.

ASSESSMENT CONTINUED

  • Continuously monitor the degree of breathlessness experienced by patients and their ambulation without fatigue.

  • Rate breathlessness on a scale from 0-10 and observe which interventions most effectively relieve dyspnea.

  • Keep track of cough patterns and sputum production; auscultate lungs for improvements in abnormal sounds.