Key Takeaways
- Normal adult respiratory rate is 12-20 breaths/min; rates outside this range indicate respiratory distress
- Asthma involves bronchospasm and inflammation -- EMTs can assist with prescribed MDI (metered-dose inhaler)
- COPD patients may have a hypoxic drive -- administer O2 to maintain SpO2 of 94% but do not withhold oxygen in emergencies
- Pulse oximetry target for most patients is 94-99%; for COPD patients, target 88-92%
- Pulmonary embolism presents with sudden dyspnea, pleuritic chest pain, tachycardia, and a history of immobility or DVT
- Adventitious lung sounds include wheezing (narrowed airways), crackles/rales (fluid), and rhonchi (mucus in large airways)
- Capnography measures end-tidal CO2 (ETCO2) -- normal is 35-45 mmHg; values >45 suggest hypoventilation
Respiratory Emergencies
Respiratory emergencies account for a significant portion of 911 calls and represent some of the most time-sensitive conditions EMTs encounter. The ability to rapidly assess breathing adequacy, identify the underlying cause, and deliver appropriate interventions can mean the difference between life and death.
Anatomy and Physiology Review
The respiratory system consists of the upper airway (nose, mouth, pharynx, larynx) and lower airway (trachea, bronchi, bronchioles, alveoli). Gas exchange occurs at the alveolar-capillary membrane, where oxygen diffuses into the blood and carbon dioxide diffuses out.
Normal Respiratory Parameters:
- Adult respiratory rate: 12-20 breaths/min
- Tidal volume: approximately 500 mL per breath
- Minute ventilation = rate x tidal volume (approximately 6,000-10,000 mL/min)
Asthma
Asthma is a chronic inflammatory condition causing reversible bronchospasm. During an acute attack:
- Smooth muscle around the bronchioles constricts
- Mucous membranes swell (inflammation)
- Excess mucus production further narrows the airway
Signs and Symptoms
- Wheezing (high-pitched whistling, often on expiration)
- Dyspnea and tachypnea
- Use of accessory muscles (neck, intercostals, abdominal)
- Difficulty speaking in full sentences
- Tripod positioning
- Absence of wheezing in severe attack -- may indicate inadequate air movement (ominous sign)
EMT Treatment
- Place patient in position of comfort (usually sitting upright)
- Administer high-flow oxygen via nonrebreather mask (15 L/min)
- Assist with prescribed MDI (metered-dose inhaler) -- typically albuterol
- MDI administration: shake inhaler, have patient exhale fully, press canister while patient inhales slowly, hold breath for 10 seconds
- Reassess after each treatment
- Transport to hospital
COPD (Chronic Obstructive Pulmonary Disease)
COPD encompasses two related conditions:
| Feature | Chronic Bronchitis | Emphysema |
|---|---|---|
| Primary problem | Chronic inflammation and mucus production in bronchi | Destruction of alveolar walls |
| Classic presentation | "Blue bloater" -- cyanotic, overweight, productive cough | "Pink puffer" -- thin, barrel chest, pursed-lip breathing |
| Sputum | Copious, often purulent | Minimal |
| Primary symptom | Chronic productive cough | Progressive dyspnea |
Oxygen Management in COPD
- Some COPD patients rely on a hypoxic drive to breathe (low O2 levels stimulate breathing rather than high CO2)
- Target SpO2 of 88-92% for known COPD patients
- NEVER withhold oxygen from a patient in respiratory distress -- if a COPD patient needs oxygen, give it
- Monitor closely and be prepared to assist ventilations with a BVM if respiratory rate drops
Pneumonia
Pneumonia is an infection of the lung parenchyma (alveoli) causing inflammation and fluid accumulation.
Signs and Symptoms
- Productive cough (often with colored/purulent sputum)
- Fever and chills
- Crackles/rales on auscultation
- Pleuritic chest pain (sharp, worse with breathing)
- Tachypnea, tachycardia
- Decreased SpO2
EMT Treatment
- High-flow oxygen as needed
- Position of comfort
- Monitor vitals and SpO2
- Transport -- antibiotics are definitive treatment
Pulmonary Embolism (PE)
A pulmonary embolism occurs when a blood clot (usually from a deep vein thrombosis in the legs) travels to the pulmonary arteries, blocking blood flow to a portion of the lung.
Risk Factors
- Recent surgery or prolonged immobility
- Long travel (flights, car rides)
- Oral contraceptive use
- History of DVT or PE
- Cancer, obesity, pregnancy
Signs and Symptoms
- Sudden onset dyspnea (most common symptom)
- Pleuritic chest pain
- Tachycardia, tachypnea
- Anxiety, sense of impending doom
- Decreased SpO2 despite high-flow O2
- Hemoptysis (coughing blood -- less common)
EMT Treatment
- High-flow oxygen (15 L/min via NRB)
- Position of comfort
- Rapid transport -- this is a true emergency
- Monitor for cardiac arrest (PE is a reversible cause)
Hyperventilation Syndrome
Hyperventilation may be anxiety-driven but can also indicate a serious underlying condition. Never assume hyperventilation is "just anxiety."
- Respiratory rate >20 with deep breathing
- Tingling/numbness in extremities and around the mouth (from respiratory alkalosis)
- Dizziness, lightheadedness
- Carpopedal spasm (hands clamp into claw position)
Do NOT have the patient breathe into a paper bag -- this is outdated and dangerous. Instead, coach calm breathing and assess for underlying causes.
Pulse Oximetry and Capnography
Pulse Oximetry (SpO2)
- Measures percentage of hemoglobin saturated with oxygen
- Normal: 94-99%
- Below 94%: administer supplemental oxygen
- Limitations: unreliable with carbon monoxide poisoning, severe anemia, hypothermia, poor perfusion, nail polish
Capnography (ETCO2)
- Measures end-tidal carbon dioxide
- Normal: 35-45 mmHg
- High ETCO2 (>45): hypoventilation, COPD exacerbation
- Low ETCO2 (<35): hyperventilation, pulmonary embolism, cardiac arrest with poor perfusion
- Waveform provides real-time feedback on ventilation quality
A 45-year-old patient with a history of asthma is found sitting upright, using accessory muscles, and has audible wheezing. SpO2 is 88%. After placing the patient on high-flow oxygen, what should the EMT do next?
A COPD patient on home oxygen at 2 L/min is found in severe respiratory distress with SpO2 of 82%. What is the MOST appropriate oxygen administration for this patient?
Which lung sound is MOST associated with fluid in the alveoli, as seen in pneumonia?
A 28-year-old woman who recently returned from an overseas flight presents with sudden-onset dyspnea, tachycardia, and pleuritic chest pain. SpO2 is 91%. What condition should the EMT suspect?
An asthma patient who was previously wheezing now has silent lung fields, is becoming drowsy, and has a respiratory rate of 8. What does this indicate?
Normal end-tidal CO2 (ETCO2) as measured by capnography is:
When assisting a patient with an MDI, the correct technique includes:
Pulse oximetry may give falsely elevated (inaccurate high) readings in which situation?
Match each respiratory condition to its classic presentation:
Match each item on the left with the correct item on the right