Respiratory Distress Management Case Study

Respiratory Distress Approach

• Case Study: A 58-year-old woman, brought in by EMS, is experiencing acute respiratory distress. Symptoms include increasing difficulty breathing, diaphoresis, use of accessory muscles, tachypnea (45 breaths per minute), and low oxygen saturation (82%).

Approach to Undifferentiated Respiratory Distress

• First 10 Minutes: Focus on rapid identification of appropriate therapy, not necessarily a definitive diagnosis.
• Limited Therapies: A limited number of treatments are available, so quickly choose the best options from the following:
  • Airway management
  • Oxygen (including high-flow humidified nasal oxygen)
  • Positive end expiratory pressure (PEEP)
  • Positive pressure ventilation
  • Chest decompression
  • Bronchodilators (and steroids)
  • Epinephrine
  • Nitroglycerin
  • Cardioversion
  • Thrombolytics/PCI
  • Pericardiocentesis

Patient Positioning

• Sitting Position: Most dyspneic patients benefit from a sitting position. Raise the head of the bed or allow the patient to assume a position of maximal comfort.

Airway Assessment

• Rapid Assessment: Assess airway patency quickly. Key questions: Can the patient speak? Is the patient alert? Is there stridor or gurgling? Is there respiratory effort without air movement? Look into the mouth and feel the anterior neck.
• Airway Maneuvers: Start with basic airway maneuvers.
• RSI (Rapid Sequence Intubation): Consider RSI if basic maneuvers are insufficient. Ask if the patient is ready for RSI.

Respiratory Assessment

• Oxygenation and Ventilation: Separate processes. Consider together initially.
• Normal Oxygen Saturation: Increased work of breathing can occur even with normal oxygen saturation.
• Hypoxia: If hypoxic, administer oxygen (start at high concentration, then titrate down).
• High Flow Oxygen: Avoid routine high-flow oxygen if not hypoxic. It can be harmful. This is based on data from multiple trials and should therefore be avoided in the absence of hypoxia.
• Persistent Hypoxia: Hypoxia despite face mask oxygen suggests potential shunt physiology or alveolar diffusion issues. Rule out airway obstruction and apnea.
• PEEP (Positive End Expiratory Pressure): Used to treat persistent hypoxia. Use a 2-hand seal on a bag-valve mask with PEEP valve, CPAP, or intubation and PEEP.

Air Movement

• Respiratory Rate, Tidal Volume, Work of Breathing: Evaluate respiratory rate, tidal volume, and work of breathing.
• Apnea: Apnea requires bag valve mask ventilation and empiric naloxone.
• Poor Ventilatory Effort: Treat poor ventilatory effort with BiPAP or assist breathing using a bag valve mask.
• Adequate Tidal Volume with Significant Work of Breathing: Non-invasive positive pressure ventilation is warranted if tidal volume is adequate but the patient is working hard.
• Agitation: Agitation from dyspnea, hypoxia, or hypercarbia can hinder oxygen delivery. Use small boluses of ketamine for sedation (delayed sequence intubation).

Vital Signs Assessment

• Monitor and Vital Signs: Place the patient on a monitor, obtain a full set of vital signs, and initiate vascular access.
• Life Threats: Address obvious life threats (cardiac arrhythmias, shock, apnea) before proceeding.

Initial Examination

• Focused Exam: Perform a quick exam, focusing on breath sounds, breathing pattern, heart sounds, and skin.
• History: In general, history is more valuable than a physical exam, especially with significant dyspnea. However, obtain history if the patient is able to communicate.
• Non-Communicating Patients: If the patient can't speak, prioritize empiric therapy and proceed to adjunctive tests like ultrasound.

Initial Therapy

• Empiric Therapies: Begin empiric therapies based on available clues, prioritizing treatment over definitive diagnosis.
• Flexibility: Be ready to adjust treatment strategies as more information becomes available.
• Example: Treat wheezing patients with salbutamol even if the initial diagnosis is suspected to be a different pulmonary condition.

Targeted Therapies Based on Findings

• Wheeze: Salbutamol, ipratropium, steroids
• Crackles with Normal/High Blood Pressure: Nitroglycerin, CPAP
• Unilateral Decreased Breath Sounds: Finger thoracostomy (usually after ultrasound/x-ray confirmation).
• Hives: Intramuscular epinephrine

Additional Diagnostic Tests

• Bedside Tests: Three standard bedside tests are ECG, chest X-ray, and bedside ultrasound.
• ECG: Quickly rule out STEMI and arrhythmias.
• Chest X-ray: Valuable, but bedside ultrasound may be more critical now.
• Ultrasound: Rapid lung ultrasound rules out pneumothorax and large pleural effusions. Evaluate for diffuse B-lines, A-lines, or focal disease in the lung. Examine the heart for pericardial effusion, left heart function, and right ventricle size.

Reassessment

• Rare Definitive Diagnosis: A definitive diagnosis is rare in the initial minutes of resuscitation.
• Empiric Therapy First: Empiric therapy is often initiated without a definitive diagnosis.
• Reassessment: Reassessment is crucial for adjusting treatment and obtaining the correct diagnosis. This process is essential in all resuscitation situations.

Definitive Testing and Disposition

• Unclear Diagnosis: If diagnosis remains ambiguous, consider additional tests.
• Blood Work: Blood work is often automatically initiated.
• CT: CT scans are helpful for suspected pulmonary embolism, atypical infections, inflammatory conditions, or neoplasms.
• Echocardiogram: Urgent echocardiogram may be required for heart murmur or suspected acute valvular disorder.
• ICU/Transfer: Contact the ICU or relevant team to transfer the patient.

Key Blood Tests

(Tests to look for in patients with respiratory distress)

• ABG (Arterial Blood Gas): Assess oxygenation, ventilation, acid-base status.
• PaO2: Hypoxemia (<60 mmHg).
• PaCO2: Hypercapnia (>45 mmHg).
• pH: Acidosis or alkalosis.
• CBC (Complete Blood Count): Look for anemia, infection, or other systemic issues.
• Leukocytosis/Leukopenia: Suggest infection or sepsis (increased or decreased white blood cells).
• Anemia: Reduced oxygen carrying capacity.
• Platelets: Coagulopathy or hemorrhage risk.
• D-Dimer: Rules out pulmonary embolism (PE).
• Cardiac Markers: (Troponin/BNP) Assess cardiac causes of dyspnea.
• Troponin: Myocardial infarction (heart attack) possible.
• BNP: Elevated in heart failure.
• Electrolytes (Na, K, Ca, Mg): Assess for electrolyte imbalances.
• Renal Function (BUN/Creatinine): Assess kidney function/perfusion.
• Lactate: Indicates tissue hypoxia or sepsis.

X-Ray and CT Scan of the Chest

(Imaging findings in respiratory distress)

• CXR (Chest X-Ray): Rapid, non-invasive imaging.
• Pneumonia: Consolidation or infiltrates.
• Pneumothorax: Loss of lung markings, visible pleural line.
• Pulmonary Edema: Kerley B lines, bilateral infiltrates, pleural effusion.
• Pleural Effusion: Blunted costophrenic angles.
• Cardiomegaly: Enlarged cardiac silhouette (heart failure).
• CT Chest: High-resolution imaging for detailed evaluation (e.g., suspected PE, complex lung pathology).
• PE (Pulmonary Embolism): CT pulmonary angiography (CTPA) is the gold standard for diagnosis.
• Interstitial Lung Disease: Ground glass opacities, honeycombing.
• Mass/Neoplasms: Identify lung tumors or metastases.
• Trauma: Rib fractures, hemothorax, pneumothorax.

Checklist Review

• After initial interventions and empiric therapy, review a checklist to avoid missing important diagnoses.

Common Causes of Respiratory Distress

• (Categorized for easier recall)*
• Upper Airway: Foreign body, blood/vomit, allergy, trauma, mass, laryngospasm, epiglottitis/infections.
• Lungs: Pneumothorax, pneumonia, pulmonary embolism (PE), bronchospasm (asthma, COPD, anaphylaxis), pleural effusion, fibrosis, tumors
• Heart: Myocardial infarction (MI), cardiac tamponade, acute pulmonary edema, arrhythmias
• Others: Acidosis, carbon monoxide poisoning, methemoglobinemia, anemia, muscular weakness, chest wall issues, abdominal pressure, anxiety, other drugs (opioids).