Chapter 03: Administration of Aerosolized Agents

Chapter 03: Administration of Aerosolized Agents

Complete Chapter Questions With Answers

Sample Questions Are Posted Below

MULTIPLE CHOICE

1. A 2-year-old child is seen in the emergency department of a local hospital, and croup is diagnosed. The physician orders a dose of racemic epinephrine via a small volume nebulizer to help reduce the subglottic swelling. What size aerosol particle is most likely to deposit in this region, providing the greatest therapeutic benefit to the patient?

ANS:  B

The upper airway (nose and mouth) is efficient in filtering particulate matter, so generally there is 100% deposition in the nose and mouth of particles larger than 10 µm and 15 µm. Particle sizes 5 to 10 µm tend to deposit out in the upper airways and the early airway generations, whereas particles 1 to 5 µm have a greater probability of reaching the lower respiratory tract from the trachea to the lung periphery. Larger or coarser aerosol particles (>5 µm) may be useful for treating the upper airway (nasopharynx and oropharynx).

REF:   p. 34

2. The main uses of aerosol therapy in respiratory care include the following:
3. Humidification of dry gases
4. Improved mobilization and clearance of secretions
5. Delivery of aerosol drugs to the respiratory tract
6. Delivery of nutrients for patients unable to chew food

ANS:  B

At the present time, there are three main uses of aerosol therapy in respiratory care, as follows:

Humidifying dry inspired gases, using bland aerosols

Improving mobilization and clearance of respiratory secretions, including sputum induction, using bland aerosols of water and hypertonic or hypotonic saline

Delivering aerosolized drugs to the respiratory tract

REF:   p. 32

3. What is the particle size range for pulmonary diagnostic and therapeutic applications?

ANS:  B

For pulmonary diagnostic and therapeutic applications, the particle size range of interest is 1 to 10 µm. This size range is small enough to exist as a suspension and enter the lung and large enough to deposit and contain the required amount of an agent. Larger particles deposit mostly in the nasopharynx or oropharynx, and smaller particles may be too fine to leave suspension and could be exhaled.

REF:   p. 32

4. Two hypothetical small volume nebulizers, A and B, have the following specifications from the manufacturer:

Which nebulizer would be best to use to treat the lower respiratory tract?

ANS:  A

Although nebulizer B has a smaller CMD than nebulizer A, nebulizer A produces particles whose mass centers within a lower range and so would be the better nebulizer with which to treat the lower respiratory tract. A major factor in lung penetration by aerosols is particle size, which is best characterized by the mass median aerodynamic diameter (MMAD) for inhaled drugs, because particle mass is a function of the third power of the particle radius. Nebulizer A produces particles whose mass centers within a lower size range (1 to 5 µm), and would be the better nebulizer for treatment of the lower respiratory tract.

REF:   p. 33