aerosol therapy

Question 1

what is an aerosol ?

Answer 1

solid or liquid particles suspended in gas. An ideal particle size for medical aerosols is btw 1 and 10 microns
-effect of gravity limits its actions

Question 2

median diameter for parenchyma (alveoli)

Answer 2

0.8-2 microns

less than one can get exhaled due to its stability

Question 3

median diameter for lower airway (bronchi-bronchioles)

Answer 3

2-5 microns

Question 4

median diameter for upper airway (mouth, nose and trachea)

Answer 4

> 5 microns

gets filtered

Question 5

define stability

Answer 5

tendency of aerosol particles to remain in suspension
directly relates to the usefulness of an aerosol particle- affected by size(smaller the better) and RH ( high RH may cause powders to clump together and drop out of suspension)

Question 6

define concentration

Answer 6

greater the concentration, the greater the possibility that particles come together onto larger particles and rain out.
optimum concentration is 100-1000 particles per cubic centimeter.

Question 7

define penetration

Answer 7

depth within the respiratory tract that an aerosol reaches

Question 8

define deposition

Answer 8

rain out of particles within the respiratory tract

Question 9

what are the factors affecting penetration and deposition

Answer 9

gravity 
kinetic energy 
intertial impaction 
physical nature of the particle 
ventilatory pattern 
airway resistance 
water content 
clearance

Question 10

gravity

Answer 10

as diameter gets bigger the forces of gravity increases- rein put
as gas flow slows down, larger particles tend to rain out due to gravity and inertia
example could be powder aerosol therapy.

Question 11

kinetic energy

Answer 11

particles with increased kinetic energy will deposit before particles with less kinetic energy- this is due to collision

Question 12

inertial impaction

Answer 12

the larger the particle, the more likely it is to travel a straight course
the smaller the airway= the greater the tendency for deposition

Question 13

physical nature of the substance

Answer 13

temp= increase means more KN
electrical charge- opposite charged particles attract
tonicity- hypertonic, isotonic, hypotonic

Question 14

ventilatory pattern

Answer 14

inspiratory flow- patient should take a slow breath
RR- high rates reduce deposition so patient should hold breath at the end of inspiration.
mouth brathing is encourage, nose filters too much

Question 15

airway resistance

Answer 15

smaller airway diameter increase in deposition

Question 16

water content

Answer 16

density of aerosol mist affects deposition and penetration *the less dense=lower change of deposition

Question 17

clearance

Answer 17

describes a particles removal from the pulm tree- removal happens during exhalation.

Question 18

hypertonic fluid

Answer 18

absorbs (grows larger and rains out) = increase deposition

Question 19

hypotonic fluid

Answer 19

lose fluids (grow smaller and travel further in the airway)