This document provides an overview of aerosol therapy. It discusses that aerosols are suspensions of fine liquid or solid particles in a gas, and that only 10% of drugs are deposited in the lungs. It describes different aerosol delivery systems including metered dose inhalers (MDIs), dry powder inhalers (DPIs), and nebulizers. MDIs are most widely used but have disadvantages like requiring coordination. Spacers can help with MDI use. DPIs do not require coordination but need high inspiratory flow. Nebulizers can deliver high doses and combinations of drugs and are useful for certain patients. The document outlines factors influencing aerosol deposition and characteristics of therapeutic

1. AEROSOL THERAPY
BY;KAPOOR SINGH

2. AEROSOL
A suspension of very fine liquid or solid
particles in a gas.
; Only 10% drugs deposited in LUNGS
• Size of Particle
• <5 MICRONS -- BEST TO NEGOTIATE
<1 MICRONS -- DON’T HAVE
ENOUGH TIME TO SETTLE

3. AEROSOL THERAPY
• Deliver a therapeutic dose of the selected
agents to the desired site of action.
• In clinical settings, medical aerosols are
generated with atomizer, nebulizer or inhalers
devices that physically disperse matter into
small particles & suspend them into a gas.

4. MECHANISM OF AEROSOL
DEPOSITION

6. AEROSOL DELIVERY SYSTEMS
The three principle types of devices widely
used are :
1.MDI-metered dose inhalers
2.DPI-dry powder inhalers
3.Nebulizers

7. METERED DOSE INHALERS
• Most widely used
• Aerosol flow rate 30
m/s or 100 km/h

8. ADVANTAGES OF MDI
• Inexpensive
• Light, compact
• Quick delivery of drugs
• Precise and consistent doses

9. DISADVANTAGES OF MDI
• Difficulty in coordination of activation &
inspiration
• Time consuming to teach
• Contains CFC
• Cannot be used in children & elderly
• Cannot be used in seriously ill patients
• Cannot be used in mechanically ventilated
patients

11. SPACERS

12. SPACERS
• Holding chambers or reservoirs
• Attachment to a MDI
• Advantages :
1.No need to activate coordination
With inspiration
2.Increases drug deposition in lung
3.Reduces drug deposition in mouth
4.Used in children with face mask
5.Decreases incidence of oral
thrush

13. DRY POWDER INHALERS
• Introduced in 1960’s
• No propellants
• Requires patient’s own Inspiratory effort
to form aerosol
• Powder is delivered only when patient
inhales

14. ADVANTAGES OF DryPowder Inhaler
• Light weight
• No hand breath coordination
• Quick delivery of drugs
• Useful in children above 5 yrs of age
Disadvantages of DPI
• Require high inspiration flow >28 l/min

15. COMPARISION BETWEEN MDI &DPI
• High velocity aerosols
• Requires coordination
• Time consuming to
teach
• Requires slow & deep
breathing only
• Aerosol velocity
depends on inspiratory
flow rate
• No coordination
needed
• Easy to teach
• Requires high insp
flow >28 l/min

16. CHARACTERISTICS OF THERAPEUTIC
AEROSOLS
• Effective use of aerosols requires an
understanding of characteristics of the
aerosols.
• Aerosol output (wt /minute)
• Emitted dose
This tells little about the amount of
drug reaching the targeted site of action.

17. • A substantial proportion of particles that leave
a nebulizer may never reach the lungs.
• Effectiveness of medical aerosols depends on
amount of aerosol particles deposition to the
lower respiratory tract & deposition of aerosol
influenced by many other factors.

18. PATIENT DEPOSITION FACTORS
Age
Inspiratory flow rate,volume
Breathing pattern
Breath holding
Nasal vs mouth breathing
Upper and lower airway pathology

19. FACTORS INFLUENCING DEPOSITION
• Physical & chemical properties of
aerosols
• Anatomy of the respiratory tract
• Physiological factors

20. PHYSICAL & CHEMICAL PROPERTIES
OF AEROSOLS
GRAVITY
• Aerosol size must be >1 microns because at this
mass gravity loses its influence on particles.
• Gravity influence is in direct relation with particle
mass
• Greater mass—tendency to undergo proximal
airway deposition

21. INERTIAL IMPACTION
Water particles
Gas molecules

22. PARTICLE SIZE
• Aerosol particle size depends upon :
-- nebulizer chosen
--Method used to generate aerosol
• It is not possible to visually determine whether a
nebulizer is producing an optimal size
particles…
• Aerosols traverse tubular strs in which turbulent
flow is the rule…
• >Particle size---- gravity influence

23. TONICITY OF THE FLUID
• Hypertonic fluid tend to absorb water.
• Hypotonic aerosols may evaporate
• Normally, mucous membrane is neutral in
relation to electrical charges

24. ANATOMY OF THE RESPIRATORY TRACT
• Diameter
Infants and children have small diameter of an
airway suggest that having low level of drug
deposition , even that is adequate when
considered in terms of body weight (mg of
drug deposited per kg of BW ).
• Length
• Branching angles of airway segments

25. PHYSIOLOGICAL FACTORS
• Airflow
Increasing flow 6,8,10 L / min increased the
mass output of particles in the respirable
range of 1-5 microns.
• Breathing pattern
Deposition of particles are directly related
to inhaled volume & inversely related to
ventilatory rate.
• Inspiratory hold

26. NEBULIZER

27. Nebulizer as an adjunct to chest
physiotherapy
• Nebulized NS enhances mucociliary clearance ,
given thrice in a day before chest
physiotherapy & also salbutamol before NS to
prevent bronchoconstriction
; With the patient resting in an upright position;
chest physiotherapy, by the forced expiration
technique with postural drainage; and chest
physiotherapy following five minutes' inhalation
of either nebulized normal saline or nebulized
terbutaline 5 mg

28. • Use of both nebulized saline and nebulized
terbutaline immediately before chest
physiotherapy gave a significantly greater yield
of sputum than did physiotherapy alone, and
terbutaline.
• In mechanically ventilated patients , those
having low lung volume chest PNF technique
should be used to improve lung volume & thus
maximum aerosols can be administered.
• Lung segment which is to be drained out
require to positioned up so that aerosols reach
to upper area.

29. INDICATIONS FOR NEBULIZER
• Useful in children ,
Handicapped person ,
Seriously ill patients
• Ventilated patients
• Elderly individuals
• High doses can be given
• Combination drugs can be given

30. • Enhancement of secretion clearance
• Sputum induction
• Humidification of respired gases
• Prevent dehydration
• Prevent or relieve bronchospasm

31. HAZARDS OF NEBULIZER
• Bronchospasm
• Over hydration
• Delivery of contaminated aerosols
• Tubing condensation
• Swelling of retained secretions

32. JET NEBULIZER

34. ULTRASONIC NEBULIZER

37. DRUGS FOR NEBULIZATION
• Distilled water or normal saline
• Mucolytics : mesna , acetylcysteine
• Beta 2 agonists : salbutamol , terbutalin ,
fometerol , salmeterol
• Antimuscarinic : ipratropium bromide
• Steroids : budesonide
• Antibiotics
• Antifungal

38. Distilled water/NS
• Cheapest / very economical
• Easily available
• Effective Mucolytic
• Free of ions (distilled water)
• Routinely used in practice

39. Mucolytic agents
• Mucomyst
• Drug action
• Side effects
• How to counteract

40. Beta-2 agonists
• Mechanism of action
beta receptor stimulation
adenylcyclase
IC ATP
IC cAMP
smooth muscle relaxation

41. salbutamol
• Short acting
• Selective beta 2 agonist
• Peak of action
• Long term use effects
• Side effects

42. Epinephrine
• Classic catecholamine
• Strong alpha & beta-1 beta-2 action
• Available 1:100 solution
• 0.25 to 0.5 ml in 4ml NS
• Lasting effect , side effects

43. Anticholinergic agent
• Ipratropium bromide
• Site of action
• Usually given through mouthpiece

44. Thank YOU