Respiratory System Concepts

Key Concepts

• Gas Exchange is the central focus.
• Interrelated concepts: Perfusion, Inflammation, Cellular Regulation.

Respiratory System Overview

• Upper Airway: Comprises nares, pharynx, and larynx (housing vocal cords).
• Lower Airway: Includes trachea, bronchi, bronchioles, and alveoli (site of gas exchange).

Pediatric vs. Adult Respiratory System

• Infants have less surfactant and smaller, undeveloped airways.
• Infants are obligatory nose breathers and exhibit poorly developed intercostal muscles.
• Newborns often experience brief apnea.
• Faster respiratory rate and metabolic needs in pediatrics.
• Eustachian tubes are relatively horizontal, increasing risk for ear infections.
• Enlarged tonsillar tissue and a more flexible larynx, prone to spasms.
• Children tend to be abdominal breathers.

Asthma: Incidence and Prevalence

• Asthma can develop at any age, peaking between 10-17 years.
• It's a leading cause of acute/chronic illness in children, prevalent in 8.3% of U.S. children.
• Higher incidence in African American and urban populations.

Asthma Pathophysiology

• Characterized as a chronic, intermittent disease with genetic and environmental influences.
• Leads to airway inflammation and hypersensitivity.
• Immediate Reaction: Allergen activation of IgE receptors causes bronchoconstriction through histamines and leukotrienes.
• Late Reaction: Involves eosinophils and neutrophils which contribute to prolonged bronchoconstriction and hyperresponsive airways.

Asthma Assessment: History

• Consider risk factors: family history, previous wheezing episodes, and respiratory infections.
• Note symptoms like coughing (especially at night or post-exercise), shortness of breath (SOB), and allergies.

Asthma Triggers

• Cold air, smoke, allergens (pollen, mold), respiratory infections, stress, exercise, environmental pollutants, specific foods, and medications can provoke symptoms.

Asthma Signs and Symptoms

• Monitor vital signs (heart rate, respiratory rate), check for wheezing, stridor, and chest tightness.
• Observe for use of accessory muscles during respiratory distress and symptoms of anxiety or restlessness.
• Symptoms may worsen at night and lead to difficulty with talking or eating.

Asthma Diagnostics

• Laboratory assessments include pulse oximetry, end-tidal CO2 monitoring, and arterial blood gases (ABGs).
• Use of a peak flow meter for daily monitoring is recommended.
• Diagnostic pulmonary function tests show decreased FVC and FEV1.

Classification of Asthma

• Intermittent, Mild Persistent, Moderate Persistent, and Severe Persistent classifications exist for management strategies.

Therapeutic Management of Asthma

• Aim to improve airflow and gas exchange through swift recognition of symptoms, adherence to action plans, trigger avoidance, medication administration, and education.

Asthma Medications

• Rescue Drugs: SABA (short-acting beta-agonists), bronchodilators like Albuterol, Ipratropium bromide.
• Control Therapy: Long-term anti-inflammatory agents (e.g., Budesonide), LABAs (e.g., Salmeterol), leukotriene inhibitors (Montelukast), and anti-IgE treatments (Omalizumab).

Emergency Indicators for Asthma

• Symptoms necessitating emergency treatment include worsening cough/wheeze, lack of response to bronchodilators, difficulty breathing, or listlessness.
• Signs of insufficient aeration or cyanosis indicate a critical state needing immediate intervention.

Status Asthmaticus

• A severe, potentially life-threatening asthma episode that may not respond to standard treatment.
• Requires urgent IV fluids, systemic bronchodilators, steroids, epinephrine, and oxygen.

Asthma Action Plan

• Recommendations and resources for managing asthma episodes effectively.

Environmental Modifications

• Implement changes to reduce exposure to Pollen and Dust, such as regular washing of bedding, avoiding certain materials, using air filters, and maintaining household humidity levels.