Chapter 2-03: Approaches and Chief Complaints in Pulmonology

KEY TERMS AND DEFINITIONS

• Dyspnea: Subjective experience of breathing discomfort, must be self-reported

• Respiratory distress: Presence of increased work of breathing, which signals approaching respiratory collapse; physical exam may reveal high respiratory rate, use of accessory muscles, evidence of acute obstruction (e.g., wheezing, stridor), and/or cyanosis

• Hypoxia: Insufficient delivery of oxygen to tissues/organs, which can result from anemia, hypoxemia, circulatory dysfunction, hypermetabolic states, and/or the presence of histotoxins (e.g., cyanide)

• Hypoxemia: Insufficient oxygenation of arterial blood; directly measured by blood gas

DYSPNEA

• Pathophysiology: 1) Increased effort in setting of respiratory muscle fatigue. 2) Acute hypercapnia > acute hypoxemia. 3) Bronchoconstriction. 4) Dynamic airway compression. 5) Afferent mismatch.

• Differential diagnosis: Etiologies may be pulmonary, cardiac, metabolic, hematologic, acid–base, and psychiatric; the dyspnea pyramid (Figure 2.10) can be helpful for remembering how common each etiology is for dyspnea (i.e., base of pyramid most common, top of pyramid least common)

• Physical exam:

  • - Vital signs: HR, RR, SpO₂

  • - General: Distress, mental status

  • - HEENT: Airway exam

  • - Volume: JVD, rales, edema, S3 (→ CHF)

  • - Pulm: Wheeze, pursed lips, increased I/E, stridor (→ COPD/asthma, anaphylaxis, angioedema), rhonchi/crackles, egophony (→ PNA), distant/absent breath sounds, dull to percussion (→ pleural effusion), absent breath sounds, resonant to percussion (→ pneumothorax)

  • - CV: Distant heart sounds, pulsus paradoxus (→ pericardial effusion, tamponade), palpitations/irregular rhythm

  • - Neuro: GCS <8 (→ early intubation), strength/sensation

  • - Abd: Ascites or distention

• Differential diagnosis by system: (Figure 2.10)

  • - Cardiac: ACS, CHF, cardiomyopathy, valvular disease, arrhythmia, tamponade

  • - Pulm: Infection (pneumonia), PE, pneumothorax, asthma, COPD, ARDS, aspiration, hemorrhage, effusion, tumor

  • - HEENT: Angioedema, anaphylaxis, pharyngeal infection, foreign body, neck trauma

  • - Chest wall: Rib fracture, flail chest

  • - Neuro: CVA, neuromuscular disease (myasthenia gravis, muscular dystrophy)

  • - Toxic/metabolic: CO poisoning, methemoglobinemia, sepsis, DKA, anemia, narcotic overdose

  • - Psych: Anxiety

  • - Other: Pneumomediastinum, ascites, obesity

• Workup: CBC with differential, BMP, LFTs (evaluate for congestion), CXR, ECG, A/VBG; additional testing to consider: BNP, troponin, cardiac/IVC POCUS, TTE; pulmonary POCUS; CT chest/CT-PE/HRCT chest

• Management: If “respiratory distress” is present, see next section; otherwise, treat suspected underlying cause

RESPIRATORY DISTRESS

• Ask for help: Call your team and consider rapid response

• Confirm code status

• Provide respiratory support: Oxygen via nasal canula, non-rebreather, or high-flow nasal canula. Consider non-invasive positive pressure ventilation (NIPPV) if not contraindicated or intubation if needed.

• Perform physical exam: See physical exam under dyspnea above

• First-pass diagnostics: STAT ABG, CBC with differential, CXR, ECG. Consider BMP, BNP, troponin, VBG with lactate, cardiac and/or pulmonary POCUS, CT chest/CTPE (based on stability)

• Differential diagnosis: Consider differential diagnosis based on patient characteristics (Table ...