3d. Pneumatic (Jet) Nebulizer

Question 1

What are most nebulizers powered by?

Answer 1

•High-pressure oxygen or air provided by portable compressor •Compressed gas cylinder •50-psi wall outlet to aerosolize liquid medication

Question 2

What patients often use Pneumatic (Jet) Nebulizer?

Answer 2

•Infants •Patients with ARDS •Patients who have slow breathing and may not obtain an inspiratory pause

Question 3

What’s a Baffle and what’s its purpose?

Answer 3

A surface in which large particle impact and fall out of suspension, and produce small particles ‣ Decreases MMAD (size) and GSD (range of sizes)

Question 4

What’s a Capillary Tube?

Answer 4

Where the liquid flows up the tube

Question 5

What’s a Jet and what’s its purpose?

Answer 5

…

Question 6

How does a Pneumatic (Jet) Nebulizer generate aerosol?

Answer 6

‣ External source of compressed gas goes through a narrow orifice inside the reservoir cup ‣ Creates a localized negative pressure and draws drug solution up capillary/feeder tubes ‣ When liquid enters the gas stream, droplets form from gas turbulence and impaction from baffles ‣ Smaller particles size emitted after baffling process, and larger particles recirculated back to reservoir

Question 7

What causes Drug Reconcentration, and how much does the concentration increase from the original solution?

Answer 7

‣Evaporation and constant recirculation, drug becomes increasingly concentrated 150-300%

Question 8

What are the factors affecting Nebulizer Performance? (5)

Answer 8

‣Nebulizer Design ‣Gas Pressure and Flow ‣Gas Density ‣Medication Characteristics ‣Humidity and Temperature

Question 9

How does Gas Pressure and Flow affect Nebulizer perfomance?

Answer 9

‣ Affects particle size distribution and output ‣ The Greater Pressure and Flow ➔ the smaller the particle size, greater output, and shorter treatment time

Question 10

What’s the relationship between Gas Flow to the Droplet Size and Nebulization time?

Answer 10

‣ Inversely proportional The higher flow of gas to nebulizer ➔ the smaller particles and shorter time required for nebulization

Question 11

How does Gas Density affect Nebulization performance?

Answer 11

‣ Affects aerosol generation and delivery to the lungs The lower the Density ➔ less aerosol impaction as gas passes through airways, and greater deposition

Question 12

How does Humidity and Temperature affect Nebulization performance?

Answer 12

‣ Affects particle size and concentration of drug remaining in the nebulizer ‣ Aerosol particle entrained into a warm and fully saturated gas stream increases in size ‣ Reduction of temperature from evaporation to 10 C less than ambient may increase solution viscosity, and reduce nebulizer output while decreasing particle MMAD

Question 13

What’s the range size of aerosol droplets when its dispersed?

Answer 13

0.1-500 um

Question 14

What are 4 types of Small Volume Nebulizers?

Answer 14

◦ Small Volume Nebulizer with Simple Reservoir ◦ Continuous Nebulizer with Collection Reservoir Bag ◦ Breathe Enhanced ◦ Breath Actuated Nebulizer (BAN)

Question 15

Small Volume Nebulizer with Simple Reservoir: How much can the inhaled dose be increased?

Answer 15

‣ May increase inhaled dose by 5-10%, or from 10 to 11% with 6-inch piece of reservoir tube

Question 16

Continuous Nebulizer with Collection Reservoir Bag: What’s the bag for?

Answer 16

‣ Bag reservoirs hold aerosol generated during exhalation ‣ Allows small particles to remain in suspension for inhalation with next breath while larger particles rain out ‣ Inhaled aerosol in the bag ➔ increases total dose efficiency

Question 17

Continuous Nebulizer with Collection Reservoir Bag: How much can the inhaled dose be increased?

Answer 17

‣ Attributed to 30-50% increase in inhaled dose

Question 18

Continuous Nebulizer with Collection Reservoir Bag: How does it work?

Answer 18

• Patient inhales aerosol from the reservoir through a one way valve and exhales to the atmosphere through an exhalation port between valve and mouthpiece

Question 19

Breath Enhanced: How does it work?

Answer 19

• Air from the compressor breaks the liquid medication into small breathable particles which form a mist (aerosol). • As the patient breathes in, the valve at the top opens, letting air in and speeding up the mist generation. • When the patient breathes out, the top valve closes, slowing down the mist and the mouth piece flap opens letting the patient’s breath out.

Question 20

Breath Enhanced: What’s the one way valves for?

Answer 20

To prevent the medication from escaping until the patient takes another breath

Question 21

Breath Actuated Nebulizer: What is it designed to do?

Answer 21

‣ Designed to increase aerosol drug delivery by generating aerosol only during active inspiration

Question 22

Breath Actuated Nebulizer: How much can the inhaled dose be increased?

Answer 22

‣ Can increase inhaled aerosol mass by 3-4 fold over conventional continuous nebulization

Question 23

What are two types of Breath Actuated Nebulizers?

Answer 23

Manual Breath-Actuated and Mechanical Breath-Actuated

Question 24

Manual Breath Actuated Nebulizer: How does it work?

Answer 24

• Uses thumb to control and regulate aerosol production during insp. and exp. • Blocking the thumb port directs gas to the nebulizer only during inspiration. Releasing thumb pauses the nebulization

Question 25

Manual Breath Actuated Nebulizer: What’s an advantage and disadvantage?

Answer 25

Advantage: Less wasted medication Disadvantage: Increases treatment time and required hand-breath coordination

Question 26

Mechanical Breath-Actuated: How does it work and whats a Brand for it?

Answer 26

AeroEclipse • Breath-actuated valve that triggers aerosol generation only during active inspiration

Question 27

Mechanical Breath-Actuated: What’s an advantage and disadvantage/limitation?

Answer 27

Advantage: Eliminates need for storage bag or reservoir Limitation: Patient must be able to generate sufficient inspiratory flow to trigger nebulizer

Question 28

What’s the main technique to optimize SVN aerosol deposition?

Answer 28

Slow inspiratory flow

Question 29

What are delivery methods for SVNs?

Answer 29

Mask or Mouthpiece. Encourage mouthpiece unless they are not able to have a good seal in their mouth

Question 30

What’s the Technique Step by Step to use an SVN?

Answer 30

• Assess the patient for need (clinical signs and symptoms, breath sounds, peak flow, %FEV1). • Select mask or mouthpiece delivery (nose clips may be needed with mouthpiece). • Use conserving system (thumb port, breath actuator or reservoir) if indicated. • Place drug in the nebulizer. If using a multidose vial, add saline to approved dose volume (per drug label). • Set gas flow to nebulizer at 6 to 10 L/min (per manufacturer label). • Coach patient to breathe slowly through the mouth at normal VT. • Continue treatment until nebulizer begins to sputter. • Rinse the nebulizer with sterile water and air dry, or discard, between treatments. • Monitor patient for adverse response. • Assess outcome (change in peak flow, %FEV1). hO

Question 31

What can happen when you fail to clean an SVN?

Answer 31

‣ Failure to clean ➔ degradation of performance ➔ clogging of jet orifice, reducing output flow, and buildup of electrostatic change in the device

Question 32

Advantages of SVNs (5)

Answer 32

‣ Less patient coordination required

‣ High doses possible (even continuous)

‣ Effective with low inspiratory flows or volumes

‣ Normal breathing pattern can be used

‣ Drug concentrations and dose can be modified if desired

Question 33

Disadvantages of SVNs (6)

Answer 33

‣ Wasteful ‣ Drug preparation required ‣ Contamination possible ‣ Pressurized gas source required ‣ Long treatment times ‣ Not all medications available

Question 34

Large Jet Nebulizers: What is it used for (compared to SVNs)?

Answer 34

◦ Used to delivery aerosolized drugs to lungs or deliver bland aerosol ◦ Patients who need continuous bronchodilators several hours without having to refill every 15 min. ◦ And when SVNs aren’t affective

Question 35

What are 4 types of Large Jet Nebulizers?

Answer 35

‣ HEART ‣ Westmed ‣ HOPE ‣ Small-particle aerosol generator (SPAG)

Question 36

Small-Particle Aerosol Generator: What medication is used and for what disease?

Answer 36

• Medication: Ribavirin (Virazole) ➔ Disease: RSV

Question 37

Small-Particle Aerosol Generator: Precautions to take when administering

Answer 37

• Administer SPAG in negative pressure room and use PPE, due to environmental contamination

Question 38

Small-Particle Aerosol Generator: What’s the Drying Chamber for?

Answer 38

It’s to dehydrate the large particles and decrease the MMAD of particles

Question 39

What’s Sputtering and where does is begin around?

Answer 39

Sputter is a noise when the nebulizer stopped with the onset of inconsistent nebulization. That’s when it’s best to end the treatment. It begins to sputter when there’s 2.5 mL volume remaining

Question 40

Large Jet Nebulizers: What’s the MMAD particle size?

Answer 40

1.2-1.4 um