AH

Inhaled Medications

Inhaled Medications

Respiratory Assessment

  • Key Components of Assessment:

    • History

    • Lung Sounds

    • Respiratory Effort

    • Respiratory Rate

    • Pulse Oximetry

    • Arterial Blood Gas (ABG) Analysis

    • Diagnostics (Bronchoscopy, X-ray, CT, MRI, Biopsy)

Lung Problems

  • Pneumonia: Fluid buildup and infection (can be bacterial or viral)

  • Pulmonary Edema: Fluid in the alveoli; often a result of heart failure, treated with medications such as Lasix, Morphine, and Nitrates.

  • Pleural Effusion: Fluid in pleural spaces, reduces lung volume, leads to shortness of breath (shob), may occur due to infection; treated with chest tubes or catheter for fluid removal.

  • Pulmonary Embolus: Blood clot in the lungs, typically from DVT in legs or arms that gets dislodged; treatment includes Heparin drip and oxygen; can be difficult to treat once lodged in the lung.

  • Asthma: Constricted airways and airway inflammation, consolidated lung spaces, decreases air movement and gas exchange in the lungs.

  • COPD: Involves chronic bronchitis (airway inflammation) and emphysema (consolidated lung space).

Gas Movement and Gas Exchange

  • Key Structures Involved:

    • Airways (Trachea, Bronchial tubes)

    • Alveoli (Oxygen exchange occurs here)

    • Impact of excess mucus compared to healthy bronchiole and alveoli.

Inhaled Drugs

  • Two Basic Classes:

    • Bronchodilators

    • Anti-inflammatory Agents

Bronchodilators

  • Xanthines (Older Class): Caffeine, Theophylline

  • Sympathomimetics and Anticholinergics (Most Common):

    • Uses: Class of choice for acute shortness of breath, dilates bronchial passages, increases respiratory rate (RR) and depth, opens up the airways.

    • Examples:

      • Albuterol (first option, sympathetic agonist, intended for lighter short-term use)

      • Epinephrine (non-selective, used in emergent situations)

        • Relaxes the airway and helps the patient move air adequately

        • affects beta one (heart) and alpha one receptors

More Examples of Bronchodilators

  • Long-Acting Beta Agonists (LABA): Salmeterol, Formoterol

  • Short-Acting Beta Agonist (SABA): Levalbuterol

    • Affects Beta 1 (heart) and Beta 2 (lungs) receptors

Effects of Sympathomimetics

  • Physiological Responses:

    • Sympathetic stimulation

    • Increased heart rate

    • Increased blood pressure

    • Decreased renal and GI perfusion

    • Bronchodilation

    • Increased RR

    • Sweating

    • By using an inhaler, you limit the systemic side effects

Other Bronchodilators: Anticholinergics

  • Ipratropium: Less effective than Albuterol, commonly used with it for chronic conditions, does not cause sympathetic stimulation.

    • Parasympathetic Antagonist

    • Commonly used in conjunction with albuterol for chronic use

    • Counteracts parasympathetic nervous system for bronchodilation

    • No Sympathetic Stimulation

    • Disrupts vagus enervation

  • Mechanism: Disrupts vagal enervation, acts as a parasympathetic antagonist for bronchial dilation.

Anticholinergic Effects

  • Reduced systemic effects when using inhalers:

    • Smooth muscle dilation of bronchi

    • Side effects: Dry mouth, urinary retention

Anti-Inflammatories

  • Glucocorticoids:

    • Budesonide: for long-term prophylaxis.

    • Inhalation decreases systemic side effects; all steroids must be weaned off especially after prolonged use.

    • Inhaled steroids for long term use and daily maintenance to avoid systemic side effects.

Anti-Inflammatory Use

  • To note: Not for acute exacerbations; takes 2-3 weeks to reach effective levels.

  • Post-use recommendation: Rinse mouth with water post inhalation to avoid development of thrush.

Steroid Side Effects

  • Common Side Effects:

    • Hyperglycemia

    • Thrush

    • Osteoporosis

    • Immunocompromise

    • Increased risk of glaucoma (particularly with long-term use).

    • Effects are more likely to happen with systemic use and are less likely with inhaled medications.

Inhaling Advantages

  • Three Key Advantages:

    • Increased therapeutic effect at the site of action.

    • Decreased systemic side effects.

    • Rapid onset of action; works quickly.

Metered Dose Inhalers (MDI)

  • Administration Tips:

    • Requires coordination: inhale before activation.

    • Only 10% reaches the lungs; spacers can increase this to about 20%, allowing more medication to reach the lungs.

    • Steps for MDI Use:

      • Prime 4 times before first use.

      • Shake inhaler.

      • Inhale deeply before activation, hold breath, and rinse mouth after use.

      • Ensure to wait 1-5 minuted between each dose.

Dry Powder Inhalers (DPI)

  • Advantages:

    • Less coordination needed, activated by inhalation.

    • Approximately 20% of medication reaches the lungs; do not breathe it back out.

    • The quality of inspiration affects the drug delivery

Nebulizers

  • How It Works: Drug is mistified and inhaled over several minutes, very simple, and uses equipment.

  • Benefit: More drug reaches the lungs compared to other forms of inhalation.