Respiratory Assessment and Clinical Skills

Essential Formulas and Clinical Concepts

• Oxygen Carrying Capacity and Dissolved Oxygen: A specific formula concerning the body's capacity to carry oxygen and the amount of oxygen dissolved in the blood was emphasized as crucial for clinical practice and case studies. This formula is a "must-know." Its understanding aids in assessing the basic model of alveoli with the capillary membrane.
• Alveolar Air Equation: This equation is considered a "must-know" for respiratory professionals, even if specific tricks are required to deduce its components from given formulas and fractions.

Clinical Assessment: Dyspnea, Absent Breath Sounds, and Tracheal Deviation

Understanding Tracheal Deviation

• Assessment: To assess for tracheal deviation, place a finger in the center of the trachea. If deviated, the trachea will be shifted to one side, meaning the finger will not sit centrally.
• Physiological Impact: Tracheal deviation indicates significant pressure shifts within the chest. When deviated, it compresses vital organs, particularly the heart.
  • Cardiac Compression: Compression of the heart impairs blood contractility, leading to reduced pumping efficiency.
  • Blood Pooling and Clots: If the heart cannot pump effectively, blood pools, increasing the risk of clot formation.
  • Cardiac Tamponade: Severe compression can lead to cardiac tamponade, a life-threatening condition where pressure on the heart prevents it from filling properly.
  • Blood Pressure Drop: Compression also leads to a significant drop in blood pressure due to the inability to maintain a necessary pressure gradient for circulation.

Case Study Example: Patient Presentation

• Symptoms: A patient presents with sudden severe dyspnea, absent breath sounds on the right side, and tracheal deviation to the left.

Differential Diagnoses Explained

• Absent Breath Sounds: Indicates an issue with air conduction or presence. Air is a poor conductor of sound. If there's an extra barrier (like fluid or air in the pleural space) between the sound generation (inside the lung) and the stethoscope, breath sounds will be diminished or absent.
  • Bilateral Listening: Always listen bilaterally to compare. If one side is significantly quieter, it's a critical indicator.
• Tracheal Deviation Direction: The side to which the trachea deviates is critical for diagnosis.

Analyzing the Options:

1. Right-sided Pleural Effusion: While it causes absent breath sounds due to fluid outside the lung, a right-sided pleural effusion would cause the trachea to shift away from the affected side (to the left in this case) due to the fluid pushing.
   • Breath Sounds in Pleural Effusion: Sounds would be diminished because fluid acts as a barrier, not amplifying or creating sound. However, a "pool of rub" (pleural rub) could potentially be louder than tracheal sounds.
2. Right-sided Tension Pneumothorax (Correct Answer):
   • Mechanism: A tension pneumothorax on the right side involves a buildup of air in the pleural space, which collapses the lung and exerts pressure, pushing structures away from the affected side.
   • Tracheal Shift: A right-sided problem would push the trachea to the left (non-affected side), matching the case study.
   • Absent Breath Sounds: Excess air in the pleural space is a very poor conductor of sound, leading to absent breath sounds on the affected (right) side.
   • Urgency: This is an emergency condition requiring rapid intervention (e.g., needle decompression).
3. Left-sided Atelectasis: Atelectasis (lung collapse) causes a shift towards the affected side because the reduced lung volume pulls the trachea. If it were left-sided, the trachea would shift to the left, which contradicts the case (right-sided absent breath sounds and deviation to the left).
4. Left-sided Pulmonary Fibrosis: This involves scarring of the lungs. While it affects lung function, it typically does not cause acute, dramatic tracheal shifts or unilateral absent breath sounds as described in this scenario.

Additional Assessment Notes

• Tactile Fremitus: This is the vibration felt on the chest wall when a patient speaks (vocalizes sound), not just when breathing. It helps assess the transmission of sound through lung tissue.
• Pulmonary Pain: Chest pain that occurs with every breath or is associated with chronic coughing is often indicative of a pulmonary issue, particularly conditions affecting the pleural space.

Laboratory Activities and Equipment Familiarization

Required Equipment for Lab Stations

• Pulse Oximeters (2-3 per group): Used to measure oxygen saturation. Students will practice setting values.
• Flow Meters: Students will practice attaching and using flow meters.
• Oxygen Delivery Devices: Students will practice with various O2 delivery devices.
• Bubble Humidifiers: These are needed at specific stations for practice.

Pulse Oximeter Settings and Interpretation

• Normal Oxygen Saturation: 95\% - 100\%.
• COPD Patient Oxygen Saturation Target: 88\% - 92\% to prevent suppressing their hypoxic drive.
• Documented Hypoxemia: Defined as an oxygen saturation less than 90\% or an arterial partial pressure of oxygen (PO_2) less than 90 mmHg.

Lab Roles

• Students will alternate roles between observer and active participant at each station, setting up and practicing with the specified devices, using provided worksheets.