Lungs

Overview

• Speaker: Sarah, registered nurse, presenting on lung oscillation, highlighting:
    - Auscultation sites.
    - Normal vs. abnormal breath sounds.

Objectives of the Lecture

1. Lung Anatomy
      - Importance of understanding anatomy for auscultation.

2. Specific Auscultation Sites
      - Landmarks for easing auscultation practice.

3. Normal Breath Sounds
      - Audio clips for identifying normal sounds.

4. Abnormal Breath Sounds
      - Comparing and contrasting with normal sounds.

Lung Anatomy

• Auscultation Areas
    - Anterior Chest: Predominantly upper lobes of lungs.
    - Posterior Chest: Predominantly lower lobes of lungs.

Anterior View of the Chest

• Right Lung:
    - Comprised of three lobes:
      1. Right upper lobe.
      2. Right middle lobe.
      3. Right lower lobe.
    - Divided by:
      - Horizontal fissure (separates upper from middle).
      - Oblique fissure (separates middle from lower).

• Left Lung:
    - Comprised of two lobes:
      1. Left upper lobe.
      2. Left lower lobe.

• Trachea branches into:
    - Bronchi, which further divide into bronchioles and alveolar sacs (site of gas exchange).

Posterior View of the Chest

• Essential to identify:
    - The position of clavicle and scapula.
    - The right and left lung orientations (flipped compared to the anterior view).

• Important Landmarks: C7 to T10 for correct stethoscope placement.

Tips for Effective Auscultation

• Direct Contact:
    - Place diaphragm of stethoscope directly on skin, avoiding clothing to prevent interference from rustling sounds.

• Female Patients:
    - Recommend patients to raise their breast to ensure clear access to lung sounds, as breast tissue can muffle sounds.

• Listening Process:
    - Note full cycles of inspiration and expiration.
    - Factors to Assess:
      - Pitch (high, medium, low).
      - Sound quality.
      - Duration of inspiration vs expiration (equal, longer, or shorter).
      - Any adventitious sounds present.

• Patient Positioning:
    - Ideally seated to avoid blockage by the scapula.
    - Have the patient breathe in and out slowly through the mouth.
    - Monitor for signs of hyperventilation or dizziness in respiratory-challenged patients.

Auscultation Sites

Anterior Chest Assessment

1. Apex of Lungs:
      - Find the clavicle, place diaphragm slightly above it.
      - Listen for inspiration and expiration.

2. Second Intercostal Space:
      - Midclavicular line, assess right and left upper lobes.

3. Third to Fifth Intercostal Spaces:
      - Continue assessing upper lobes of both lungs.

4. Sixth Intercostal Space (Midaxillary):
      - Assess lower lobes, then compare sides.

5. Seventh Intercostal Space:
      - Continue assessing lower lobes up to the base.

Posterior Chest Assessment

1. Start Above Scapula:
      - Ensure patient separates shoulder blades for clear access.

2. Upper Lobes (C7 to T3):
      - Assess in between scapulae.

3. Lower Lobes (T3 to T10):
      - Continue downward, staying between scapulae and spine, ensuring sound clarity.

Normal Breath Sounds

• Types of Normal Breath Sounds:
    1. Bronchial Sounds:
       - Location: Anteriorly over trachea.
       - Characteristics: High-pitched, loud; inspiration shorter than expiration.
    2. Bronchovesicular Sounds:
       - Location: Anteriorly (1st and 2nd intercostal spaces), posteriorly (between scapulae).
       - Characteristics: Medium pitch; equal-length inspiration and expiration.
    3. Vesicular Sounds:
       - Location: Throughout peripheral lung fields.
       - Characteristics: Low-pitched, soft; inspiration longer than expiration.

Listening Tip

• Utilize a stethoscope to familiarize with both personal and others' breath sounds for clearer understanding.

Abnormal Breath Sounds

• Classifications
    - Continuous Sounds: Lasting more than 2 seconds during a full respiration cycle.
      1. High-pitched Polyphonic Wheeze:
         - Mainly heard in expiration; characterized by high-pitched musical sound with multiple tones.
      2. Low-pitched Monophonic Wheeze:
         - Mostly during expiration; lower-pitched whistle sound.
      3. Stridor:
         - High-pitched whistling or gasping sound during inspiration; indicative of airway obstruction.
    - Discontinuous Sounds: Lasting less than 2 seconds.
      1. Coarse Crackles (Rales):
         - Low-pitched bubbling sound, mostly during inspiration, can extend into expiration.
      2. Fine Crackles:
         - High-pitched crackling sound during inspiration; does not clear with coughing.
      3. Pleural Friction Rub:
         - Low-pitched harsh grading sound both in inspiration and expiration, results from pleura rubbing without adequate lubrication.

Distinguishing Pleural Friction Rub from Cardiac Friction Rub

• Have patient hold their breath; if sound persists, it’s likely cardiac in origin, not pulmonary.

Conclusion

• Encouraged to take the associated quiz and review additional supportive materials.

• Appreciation for viewer engagement and invitation for subscriptions.

Overview of Adventitious Lung Sounds

• Adventitious lung sounds are abnormal sounds detected during auscultation in the lungs.

• Recognizing these sounds is crucial in respiratory assessments.

• Five main types of adventitious lung sounds:
    - Crackles (also known as rales)
    - Wheezes
    - Rhonchi
    - Stridor
    - Pleural friction rub

Key Questions for Identifying Lung Sounds

• When auscultating for abnormal lung sounds, consider the following:
    - Timing:
        - Is the sound heard mainly during inspiration or expiration, or both?
    - Pitch:
        - Is the sound high-pitched or low-pitched?
    - Nature of Sound:
        - Is the sound considered discontinuous or continuous?
          - Discontinuous: Sounds are distinguishable individually and occur in succession, lasting less than 250 milliseconds.
          - Continuous: Sounds are more constant in nature, generally lasting longer than 250 milliseconds.
    - Location:
        - Where are these sounds primarily located? Large airways (trachea, bronchi) or small airways (alveoli, bronchioles)?
    - Defining Characteristics:
        - Is there a specific sound quality that stands out, such as a harsh grading noise, squeaky noise, musical whistling, snoring, etc.?

Types of Adventitious Lung Sounds

1. Crackles

• Definition: Abnormal lung sounds that can be divided into fine and coarse crackles.

• Fine Crackles (Rails):
    - Timing: Heard towards the end of inspiration.
    - Pitch: High-pitched.
    - Nature: Discontinuous; distinguishable individual pops or crackling sounds.
    - Location: Small airways (bronchioles).
    - Characteristics: Similar to light crackling of a fire; sounds cannot be cleared with coughing.
    - Causes:
        - Presence of air entering collapsed or deflated small airways, causing them to crackle open.
        - Associated conditions: Congestive heart failure, atelectasis, pneumonia, pulmonary fibrosis.

• Coarse Crackles:
    - Timing: Occur at the beginning of inspiration and may extend into expiration.
    - Pitch: Low.
    - Nature: Discontinuous; longer duration than fine crackles.
    - Location: Large airways (bronchi).
    - Characteristics: Gurgling or bubbling sound; not cleared with coughing.
    - Causes:
        - Breathing air into partially blocked airways filled with fluid or thick mucus.
        - Associated conditions: Heart failure due to pulmonary edema, pneumonia, bronchiectasis.

2. Wheezes

• Definition: Continuous sounds produced due to narrowed airways.

• Timing: Mainly heard on expiration, but can also be noted on inspiration.

• Pitch: High.

• Nature: Continuous; may be loudest during expiration.

• Location: Throughout the respiratory system.

• Characteristics: Squeaky, musical whistling noise; may be audible without a stethoscope, especially during an asthma attack.

• Causes:
      - Narrowed airways due to conditions such as asthma, Chronic Obstructive Pulmonary Disease (COPD), or viral respiratory infections.

3. Rhonchi

• Definition: Continuous low-pitched sounds, often resembling snoring.

• Timing: Mainly heard on expiration but can also be heard on inspiration.

• Pitch: Low.

• Nature: Continuous.

• Location: Large airways (trachea and bronchus).

• Characteristics: Snoring or snorting sound; sound can decrease or resolve with coughing or suctioning.

• Causes:
      - Created when air flows over secretions in the large airways.
      - Associated conditions: Bronchitis, pneumonia, COPD.

• Literature Note: Rhonchi may be classified as either a type of coarse crackle or wheeze; follow institutional guidelines for classification.

4. Stridor

• Definition: A high-pitched sound indicating upper airway obstruction.

• Timing: Can be heard during both inspiration and expiration but is often louder during one.

• Pitch: High.

• Nature: Continuous.

• Location: Mainly in the upper respiratory system (trachea, throat).

• Characteristics: Screeching or squawking noise coming from the throat area; very distinctive sound that is hard to ignore.

• Causes:
      - Narrowing of the larynx and trachea due to swelling from infection or obstruction (e.g., foreign object).
      - Can be life-threatening if complete airway obstruction occurs.
      - Associated conditions: Epiglottitis, croup (barking cough in children), anaphylaxis, foreign body obstruction.

5. Pleural Friction Rub

• Definition: A sound made by inflamed pleural layers rubbing together.

• Timing: Can occur during both inspiration and expiration.

• Pitch: Low.

• Nature: Can be discontinuous or continuous, depending on severity.

• Location: Pleura layer surrounding the lungs (visceral pleura and parietal pleura).

• Characteristics: Harsh, grating sound; patients may experience pain, especially during deep breaths or coughing.

• Causes:
      - Inflammation of pleural layers leading to decreased space between them, causing them to rub together.
      - Associated conditions: Pleurisy, pneumonia, pulmonary embolism, tuberculosis, lung cancer.