Bronchodilators delivered by inhalation are commonly used to treat mechanically ventilated patients. Short-acting inhaled beta-2 agonists like salbutamol are effective for reducing airway resistance in patients with conditions like asthma or COPD. Inhaled corticosteroids like budesonide are used to treat underlying lung inflammation. Nebulizers, metered dose inhalers, and dry powder inhalers can be used for inhalation therapy in ventilated patients, though special techniques are needed to optimize drug delivery. Monitoring lung function parameters can help guide bronchodilator use in the ICU.
2. Why and why not?
Advantages:
- Less systemic toxicity
- More rapid onset of medication
- Delivery to target of action
- Higher concentrations available in the lung
Disadvantages:
- Time and effort consuming
- Limitation of delivery device
3. What are the Inhalant drugs?
Antiallergic agents
Budesonide
Cromolyn sodium
Bronchodilators
Ventolin nebules (βagonist)
Bricanyl solution (βagonist)
Atrovert nebulizer solution (anti-
cholinergic)
6. Inhalant drugs
Anesthetics
Opioids
Other
Granulocyte-Macrophage Colony-Stimulating Factor
Surfactant
Interleukin II
Gene therapy vectors
7. Respiratory tract characteristics
Large surface area, good vascularization,
immense capacity for solute exchange, ultra-
thinness of the pulmonary epithelium
Conducting region :
Nasal cavity, nasopharynx, bronchi,
bronchioles (first 16 generations)
Respiratory region :
respiratory bronchioles, alveolar ducts and sacs
(17-23 generations)
8. Particle Size
MMAD: mass median aerodynamic
diameter
MMAD <1μm: exhaled
MMAD 1~5μm: target
MMAD >5μm: oropharynx
Strict control of MMAD of the particles
ensures the reproducibility of aerosol
deposition and retention.
10. Device for Inhalation Therapy
Selections of device include :
– 1.Nebulizer( 霧化器 ): small volume,
large volume, ultrasonic, pneumatic…
– 2.Metered dose inhaler, MDI ( 定量吸入器 )
– 3.Dry powder inhaler, DPI ( 粉末型吸入器 )
11. Metered-dose inhalers
A liquid propellant
A metering valve that dispenses a constant
volume of a solution or suspension of the drug in
the propellant.
Inhalation technique is critical for optimal drug
delivery – Actuating a MDI out of synchrony
may cause negligible lower airway delivery
Mainly oropharyngeal deposition
Protein denaturation
13. Dry powder inhalers
No propellant
Breath-activated, and patient coordination
is not as important an issue.
The drug is formulated in a filler and
contained in a capsule that is placed in the
device and punctured to release the
powder.
Proteins and macromolecules are more
stable in dry powder form, this approach
has been preferred for delivery of these
compounds by the inhalational route
14. Nebulizers
Patient cooperation and coordination is
not as critical
Commercially available nebulizers
deliver 12% to 20% of the nebulized dose
into the bronchial tree.
Heterogeneous drops
Protein denaturation
21. General Indications
Bronchodilator aerosol administration
and evaluation of response is indicated
whenever bronchoconstriction or
increased airway resistance is
documented or suspected in patients
during mechanical ventilation
- AARC Clinical Practice Guideline
22. Criteria
Presence of one or more of the following
criteria:
Previous demonstrated response of bronchodilator
Presence of auto-PEEP not eliminated by reduced
rate, increased inspiratory flow, or decreased
inspiratory to expiratory time ratio
Increased airway resistance evidenced by:
• Increased peak inspiratory pressure and plateau pressure
difference
• Wheezing or decreased breathing sound
• Intercostal or sternal retraction
• Patient – ventilator dyssynchrony
23. Some Evidence Based Facts
from American Journal of
Respiratory Critical Care Medicine
24. Mechanically Ventilated Patients (1)
Bronchodilator therapy is commonly used in the
intensive care unit, although the indications for
its use are not well defined
Patients with COPD demonstrate a significant
decrease in airway resistance after administration
of bronchodilators
Bronchodilators have been successfully used to
treat acute bronchial spasm in the operating
room, and they are widely used in mechanically
ventilated patients with severe asthma
Inhaled Bronchodilator Therapy in Mechanically Ventilated Patients
Am J Respir Crit Care Med Vol. 156. pp. 3-10, 1997
25. Mechanically Ventilated Patients (2)
A heterogeneous group of mechanically
ventilated patients, including some patients
without a previous diagnosis of airway
obstruction, have shown improvement in their
expiratory airflow after bronchodilator
administration
Although ARDS is primarily a disease affecting
the alveoli, nebulized metaproterenol sulfate
produced a decrease in airway resistance in
patients with this disorder
Inhaled Bronchodilator Therapy in Mechanically Ventilated Patients
Am J Respir Crit Care Med Vol. 156. pp. 3-10, 1997
26. Mechanically Ventilated Neonates
and Infants (1)
Pressure-limited, time-cycled modes of
mechanical ventilation are widely used in
neonates and infants
Several investigators have reported that the small
diameter of the endotracheal tubes and ventilator
tubing and the low tidal volumes used for
ventilating neonates and infants decrease aerosol
delivery to the respiratory tract
Inhaled Bronchodilator Therapy in Mechanically Ventilated Patients
Am J Respir Crit Care Med Vol. 156. pp. 3-10, 1997
27. Mechanically Ventilated Neonates
and Infants (2)
The lung deposition to be as low as 0.98 ±
0.2% and 0.22 ± 0.1% with an MDI and
spacer or a jet nebulizer, respectively
Even such low levels of drug deposition
are adequate when considered in terms of
the body weight of the patient (mg of drug
deposited per kg body weight)
Inhaled Bronchodilator Therapy in Mechanically Ventilated Patients
Am J Respir Crit Care Med Vol. 156. pp. 3-10, 1997
28. Mechanically Ventilated Neonates
and Infants (3)
Inhaled beta-adrenergic and anticholinergic drugs
are effective in ventilator-supported neonates and
infants with acute, subacute, and chronic lung
disease
The use of inhaled corticosteroids has also been
advocated in infants with bronchopulmonary
dysplasia
Inhaled Bronchodilator Therapy in Mechanically Ventilated Patients
Am J Respir Crit Care Med Vol. 156. pp. 3-10, 1997
29. Current Guideline of Bronchodilator
Usage in NTUH SICU
Ventoline: first choice as Bronchodilator to
reduce airway resistance in mechanically
ventilated patients
Atrovent: recommended to given patient with
Asthma & COPD history, as a combination
with Bronchodilator. Old age, long-term use,
might be an indication of this combination also.
Pulmicort: first line to treat pulmonary
inflammatory disease.
Give Ventoline before Pulmicort.
30. Indication for Bronchodilator (1)
Short-acting inhaled Beta-2 Agonist
Bronchodilators
– Acute asthma for quickly relieving symptoms
– AECOPD, maybe can combine inhaled Anti-
cholinergics
– Stable COPD combine inhaled Anti-cholinergics
for short term use seems more effective than
either alone
– In mechanically ventilated patients which present
auto-PEEP or evidently increased airway
resistance
31. Indication for Bronchodilator (2)
Inhaled Anti-cholinergics
– AECOPD can be used or be added to short-acting
inhaled beta-2 agonist bronchodilators
– Stable COPD combine short-acting inhaled beta-2
agonist bronchodilators for short term use seems
more effective than either alone
– In mechanically ventilated patients which present
auto-PEEP or evidently increased airway
resistance
32. AARC Recommendation I
Ventilator setting:
- tidal volume > 500
- Addition of inspiratory pulse (in case the
inspiratory flow demands of the patient are
met)
- Spontaneous breath should not be
suppressed
33. AARC Recommendation II
Humidifier use:
- reduce aerosol delivery by 40%
- Humidified gas should still be used for
dry gas associated risk
- Increase dose for compensation
34. AARC Recommendation III
Metered Dose Inhaler
- Delivered dose significantly reduced due
to failure to actuate the inhaler with the
onset of inspiration
- Actuate the inhaler manually for
synchronizing the inspiration
35. AARC Recommendation IV
Nebulizer Use:
- Change nebulizer every 24 hours
- Leave it 30 cm proximal to endotracheal
tube if possible
- It may be necessary to add a filter in the
expiratory limb of the circuit to maintain
expiratory flow-sensor accuracy
36. AARC Recommendation V
Patient monitoring:
- Volume ventilation: peak inspiratory pressure
and the difference between peak and plateau
pressure
- Pressure ventilation: tidal volume
- Auto-PEEP
- Peak Expiratory Flow and Flow-Volume Loop
- Breath Sound