Prehospital Academy Lesson 15.4
Respiratory Emergencies: Infectious and Environmental Diseases of the Lower Airway
This lesson focuses on infectious and environmental diseases affecting the lower airway, expanding on the EMT's understanding of respiratory emergencies. Unlike obstructive diseases that primarily involve airflow issues, these conditions are caused by pathogens or external irritants that can lead to inflammation, fluid accumulation, and impaired gas exchange. Effective management requires not only treatment of the patient's symptoms but also considerations for provider safety and infection control.
Infection Control and Provider Safety
When dealing with any infectious process, particularly respiratory ones, strict adherence to infection control protocols is paramount.
Body Substance Isolation (BSI) and Personal Protective Equipment (PPE): Always assume infectious risk and utilize appropriate PPE, including gloves, masks, and eye protection. Aerosol-generating procedures (e.g., nebulizer treatments, suctioning) increase the risk of transmission.
Hand Hygiene: Frequent and thorough hand washing or use of alcohol-based hand rub is essential.
Situational Awareness: Be mindful of complacency. Respiratory infectious diseases pose a significant risk of exposure to providers and bystanders through aerosolization of infectious agents.
Infectious Diseases of the Lower Airway
Pneumonia
Pneumonia is an infection that inflames the air sacs in one or both lungs, which may fill with fluid or pus.
Bacterial Pneumonia: Typically has a rapid onset and presents with a high fever.
Viral Pneumonia: Tends to develop more gradually and is often less severe.
Signs and Symptoms: Respiratory distress, dyspnea, productive cough (sputum may be green, yellow, or rusty), fever, chills, chest pain (pleuritic, sharp pain with breathing), tachypnea, tachycardia. Patients may appear acutely ill, especially those who are immunocompromised or chronically ill.
Assessment: Assess temperature, lung sounds (crackles, rhonchi), oxygen saturation, and work of breathing.
Management: Supportive care focusing on airway, breathing, and circulation (ABCs). Administer supplemental oxygen to maintain adequate SpO2, assist ventilations if needed, and transport to a definitive care facility. Prehospital treatment aims to stabilize the patient and ensure transport.
Bronchitis (Acute)
Acute bronchitis is an inflammation of the lining of your bronchial tubes, which carry air to and from your lungs. It's usually caused by a viral infection.
Signs and Symptoms: Persistent cough (may be productive), chest discomfort, fatigue, low-grade fever, wheezing.
Management: Primarily supportive care, including rest, fluids, and symptomatic relief. Oxygen may be indicated if the patient is hypoxic.
Environmental Diseases of the Lower Airway
Toxic Gas Exposure (e.g., Carbon Monoxide, Chlorine, Ammonia)
Exposure to toxic gases can cause significant irritation, inflammation, and damage to the lower airways and lung tissue.
Pathophysiology: Gases can displace oxygen, interfere with cellular respiration, or directly damage lung tissue, leading to pulmonary edema, bronchospasm, and ARDS (Acute Respiratory Distress Syndrome).
Signs and Symptoms: Depend on the gas and exposure level, but can include dyspnea, cough, chest tightness, wheezing, altered mental status, nausea, vomiting. Carbon monoxide poisoning is particularly insidious due to its odorless, colorless nature, and can cause flu-like symptoms, headache, and cherry-red skin (a late sign).
Management:
Primary Step: Remove Patient from Source: Ensure provider safety before entering the scene.
Airway Management: Secure and maintain a patent airway.
High-Flow Oxygen: Essential for all toxic inhalation patients, especially carbon monoxide (100% non-rebreather or BVM).
Supportive Care: Monitor vital signs, manage symptoms, and rapid transport.
Allergic Reactions (Severe, Respiratory Manifestations)
While anaphylaxis has upper airway components, severe allergic reactions can also cause lower airway issues.
Signs: Bronchospasm (wheezing), pulmonary edema.
Management: Treat as anaphylaxis with epinephrine, oxygen, and ventilatory support if necessary.
Critical Thinking Questions
You are called to a patient with a productive cough, fever, and crackles in the lower lung fields. What are your immediate concerns regarding infection control and personal protective equipment, and why?
Distinguish between bacterial and viral pneumonia in terms of onset, severity, and typical prehospital management.
You arrive on the scene of a suspected carbon monoxide poisoning. What are the key assessment findings you would look for, and what is the definitive prehospital treatment for this condition?
A patient who was exposed to an unknown chemical fume is now experiencing severe dyspnea and wheezing. What assessment findings would indicate impending respiratory failure, and what advanced airway interventions might be considered (if within your scope of practice/medical direction)?
Discuss the importance of a detailed history in identifying environmental exposures that may lead to lower airway diseases. What specific questions would you ask, and why are these crucial for patient care?