Management of Dyspnea, Airway Obstruction, and Tracheal Collapse

Instructor Information

• Matthew W. Beal, DVMDiplomate ACVECC Professor; Emergency & Critical Care Medicine & Interventional RadiologyCollege of Veterinary Medicine, Michigan State University

Localization of Respiratory Distress

• Use anatomy for localization:

  • Nose/Nasopharynx

  • Pharynx

  • Larynx

  • Trachea and large airways

  • Small airways

  • Alveoli

  • Pleural space

  • Chest wall/diaphragm

Major Body Systems (MBS) Assessment

• MBS Components:

  • Respiratory:

    • Respiratory Rate

    • Respiratory Effort

  • Central Nervous System (CNS):

    • Level of Consciousness (LOC)

    • Consider immobilization ASAP (in cases of trauma)

Physical Examination

• Cardiovascular:

  • Murmur

  • Arrhythmia

  • Jugular distention

• Perform a full physical examination on all patients.

KEY Physical Examination

Oxygenation Assessment

• Oxygenation:

  • Methods for assessment:

    • Ohmeda Biox 3740 Pulse Oximeter

    • SpO2 Pulse Display

Consequences of Hypoxemia

• Shock:

  • Definition and types of shock

  • Consequences of hypoxemia

Focus of Treatment for Dyspnea

• Optimize oxygen saturation (SpO2)

Oxygenation Re-Assessment / Goals

• Pulse Oximetry:

  • SpO2 > 92% with FiO2 < 0.6 (60%)

• Arterial Blood Gas Analysis:

  • PaO2 > 60mmHg with FiO2 < 60%

  • PaCO2 < 60mmHg (soft cutoff)

• Assess respiratory effort

Sedation

• Sedation can reduce stress in patients with airway obstruction (after performing a physical examination)

Physical Examination of the Respiratory System

• Palpation Techniques:

  • Importance of observation

  • Oral examination

  • Pharyngeal/retropharyngeal palpation

  • Laryngeal palpation

  • Tracheal palpation

  • Chest wall for mass, defects, and fractures

Signs and Symptoms in Respiratory System

• Oral Cavity Exam

• Hemoptysis:

  • Definition

• Expiratory dyspnea:

  • Causes

• Stridor:

  • Distinction between inspiratory vs. both inspiratory and expiratory

• Stertor

• Paradoxical abdominal movement:

  • Indicates specific respiratory distress

Airway Obstruction

• Common Causes:

  • Think neuro-anatomically

• Acid-base Disorder:

  • Occurs with airway obstruction

Case Example

• Presenting a 6mo F DSH:

  • PC: Respiratory distress

  • LN: 1 hour prior

  • RR/RE: Markedly increased with stridor (inspiratory and expiratory)

  • Triage back to ICU

Key Reminders and Questions

• Stress can exacerbate airway obstruction in animals.

• Methods to stabilize patients with airway obstruction.

Case Study: Cat with Upper Airway Obstruction

• Radiographs show mineral density foreign body in the trachea.

• Discuss removal options with pros and cons.

Tracheostomy

• Indications:

  • Rarely considered a true emergency

  • Controlled settings require general anesthesia and intubation

  • Proper positioning considerations for procedure

Emergency Tracheostomy

• Critical steps and protocols for managing urgent airway obstructions.

Progression of Stabilization and Airway Obstruction Workup

1. Oxygen

2. Examination

3. Sedation

4. Airway examination

5. Radiographs (neck and chest)

6. +/- Fluoroscopy

7. +/- Scope

Successful Management of Respiratory Distress

• Critical Factors:

  • Early identification of problems

  • Physical examination reliance

  • Attention to stress management

  • Optimize oxygenation

  • Follow logical diagnostic progression

  • Specific disease-focused treatment

Overview of Tracheal Collapse and Interventional Radiology

• Tracheal Collapse:

  • Definition, causes, and problems impacting the patient

Fixed vs. Dynamic Obstruction

• Obstruction Classification:

  • Fixed: Inspiratory AND expiratory stridor

  • Dynamic: Inspiratory OR expiratory

  • Tracheal collapse can exhibit characteristics of both types.

Localization of Tracheal Collapse Symptoms

• Inspiratory Stridor: Indicates dynamic extrathoracic obstruction.

• Inspiratory and Expiratory Stridor: Suggests fixed extrathoracic airway obstruction.

• Cough: Indicates potential intrathoracic airway obstruction.

Phenotypes of Tracheal Collapse

• Classification based on symptoms and severity:

  • Cervical and inlet collapse or rings malformation

  • Diffuse collapse

  • Intrathoracic collapse

Evaluation Process for Tracheal Collapse

• History, physical examination, and imaging options dictate treatment decisions.

Fluoroscopic Evaluation

• Utilizes fluoroscopy to assess anatomic extent of tracheal collapse.

Tracheoscopy

• Pros and cons of performing tracheoscopy in diagnosing collapse characteristics and laryngeal examination.

Treatment Strategies for Tracheal Collapse

• Approach to treatment will vary based on type of collapse and symptoms presented.

Case Selection and Management

• Not all dogs require intervention; assess clinical signs and quality of life.

Medical Management for Population 3 (Intrathoracic Collapse)

• Considerations:

  • Mild signs impacting quality of life.

  • Medications include antibiotics and anti-inflammatories.

Indications for Surgical Intervention

• Key indicators for proceeding with intervention for airway obstruction.

Technical Skills Required for Treatment Procedures

• Prosthetic rings: Requires significant time and skill

• Tracheal stent: Less intensive, rapid and reliable deployment.

Emergency Situations with Tracheal Collapse

• Critical timeline and steps for managing emergencies effectively in patients with tracheal collapse.

Potential Complications

• Acknowledge and educate on risks related to different intervention techniques.

Chronic Complications and Long-term Management

• Discuss potential chronic issues following interventions and overall patient outcomes.

Conclusions

• All surgical procedures are primarily palliative, highlighting the importance of a multifaceted approach to care.