By Adem Lewis / in , , , /

While the information contained within this video was considered correct by Intersurgical at the time of production, it in no way qualifies anyone to undertake any medical activity.
Intersurgical can accept no responsibility for the medical practices of persons who directly or indirectly reference this programme. Intersurgical Presents Nebuliser Therapy Nebuliser Therapy Introduction The European Respiratory Society
publication ‘The European Lung White Book’ states that; “Respiratory diseases are
among the leading causes of death worldwide. Lung infections (mostly
pneumonia and tuberculosis) lung cancer and chronic obstructive pulmonary
disease (COPD) together accounted for nine point five million deaths worldwide
during 2008, one sixth of the global total.” The diversity of respiratory
disease is often not appreciated by those who do not work in the specialty
in many countries around the world chest physicians treat everything from
tuberculosis and the pulmonary complications of HIV to asthma, chronic
obstructive pulmonary disease, cystic fibrosis, lung cancer and many others.
Lung diseases are not just smoking related – there are a wide variety of
other causes ranging from genetic influences to nutritional, environmental
and poverty related factors. Many respiratory diseases require careful
nebuliser therapy to improve the day-to-day lives of sufferers. This
therapy allows delivery of aerosolised respiratory drugs directly to the
therapeutic site, the lungs. There are several classes of respiratory
Pharmaceuticals used to treat different respiratory conditions: Bronchodilators
and anti-inflammatories which are used to treat airway obstructions. Antibiotics
which are used to treat infections. Mucolytics which are used to treat
abnormal secretions and opioids and analgesics which are used for pain
relief. Nebuliser therapy can be used to deliver all these drugs to the patient.
This video looks at how a jet nebuliser works, nebuliser delivery systems, nebuliser performance factors, and where
nebulisers are used. We can now look at how a nebuliser works a nebulisation
system comprises four main components a driving force, the tubing, the nebuliser
itself and the delivery system. The driving force is a supply of pressurised
gas which can be either air or oxygen although oxygen should not be used if
there are concerns about CO2 retention. Oxygen is readily available from the
hospital pipeline systems or pressurised cylinders. Air is most often supplied
from a small portable, electrically driven compressor. The function of the
tubing is to convey the compressed gas from source to the nebuliser. A nebuliser
is a device that can convert a liquid solution or suspension into aerosol
droplets suitable for patient inhalation. The chamber of the nebuliser unit is
filled with a drug. The flow of gas is driven up a tube through the center of
the chamber, creating an area of low pressure, which draws the drug up to the
top of the chamber itself. The aerosol produced is then forced at very high
speed against the baffle which recycles the large particles, returning them to
the nebuliser cup. This results in a mist of appropriately sized particles of the
drug, which flow out of the chamber. The delivery system can be either; a
mouthpiece, a face mask or a T-Piece. A mouthpiece is the ideal administration
device as there is no leakage and no deposition in the nasal passage or on
the face. This results in an efficient delivery of the drug. A face mask is easy
for the patient to use and is necessary when patients are unable to use a
mouthpiece. The disadvantage of using a face mask is that drug can be deposited
in the nasal passage or on the face. Care needs to be taken to ensure that the
mask is a good fit, particularly around knows to prevent drug from getting into
the eyes. The new generation of Intersurgical EcoLite™ masks feature a soft
anatomical seal that provides a greatly improved fit compared to earlier mask designs. This minimizes the potential of drug leaking into the eyes. A face
mask should be avoided if a nebulized steroid is administered, to avoid
deposition on the skin and eyes. A face mask should also be avoided if
anticholinergenic agents are to be administered to glaucoma patients. If
delivering antibiotics the immediate environment, staff and other patients
must be protected this can be achieved by either using an anti-pollution kit or
by adding a breathing filter to the exhalation side of the mouthpiece. A T-Piece is used for ventilated patients and is suitable for adults, children and
neonates. The nebulizer and T-Piece is positioned in the inspiratory limb of
the ventilator breathing system. Use of a self-sealing T-Piece enables a nebuliser
to be attached and detached from the ventilator breathing system without
interfering with patient ventilation or inadvertently activating any alarms. We
can now look at the factors that influence the performance of a nebuliser.
Firstly it is important to understand the three main factors which determine
where in the respiratory tract a nebulised drug droplet is deposited, these are: the aerosol droplet size, the breath pattern during inhalation and
the age and condition of the lung. The easiest parameter to control is the
droplet size, this is also the main factor which determines where the
nebulised drug is deposited and so is a key parameter to consider in the design
of a nebuliser. In order to maximize drug deposition in the targeted area of the
lung, there are however other factors to consider which determine nebulizer
performance. These are the nebuliser: efficiency, mass output, respirable output,
nebulisation time, residual volume and mass median diameter. The efficiency of a
nebuliser is measured by the aerosol output at varying particle sizes and is
expressed as the percentage of particles at optimum size. The optimum particle
sizes are; two to five microns per tracheobronchial deposition and nought
point 5 to 2 microns for alveolar deposition. Particles larger than 5
microns may be deposited in the nose and mouth. Resulting in the drug being
swallowed. Mass output is defined as the total weight of drug particles produced
by the nebuliser and is expressed in grams per minute. Respirable output is
the weight of drug particles produced by the nebuliser of the optimum particle
size and this is also expressed in grams per minute. Residual volume is the volume
of drug remaining at the end of the nebulisation procedure. This may be
minimised by tapping the cup when the nebuliser begins to splutter. Probably
the most simple and useful single measure of droplet size is the mass
median diameter usually abbreviated to MMD. This is defined as half of the “mass” of
nebuliser aerosol is contained in droplets, which are larger than the MMD,
and the other half are smaller. Intersurgical offers two nebulisers which
produce particles for tracheobronchial deposition, the Cirrus 2, and the high performance Hot Top 2. Lets look at these two options in detail. The Cirrus 2 is a conventional, closed jet nebuliser which produces the majority of
particles between 2 and 5 microns in diameter. This versatile nebuliser can be used in all applications. It can be used for adults and children, with a mouthpiece or a mask and because it is a closed system
it can also be used for ventilated patients. The calibrated nebuliser cup only requires a quarter turn, for fast, accurate filling. And a quarter turn closes the cup with a positive click to indicate the cup has sealed. The high performance Hot Top 2 also produces the majority of particles between 2 and 5 microns in diameter,
however it has an open vent design which uses the venturi effect to increase gas
flow through the nebuliser. This increases the output and therefore
greatly reduces the nebulisation time. It is suitable for use with compressors,
which typically have lower output flows because Hot Top 2 performance and
gas flows of 6 liters per minute approximates to a conventional closed
nebuliser at 8 liters per minute. Hot Top 2 nebuliser can also be used with
a Sure-loc tube which provides a secure connection, preventing accidental
disconnections. An adapter is attached to the flow meter
which enables the Sure-loc tube to be attached to the flow meter and the other
end of the Sure-loc tube is attached to the nebuliser. Sure-loc tubing can
however also be used on a standard nebuliser spigot and on standard tubing.
Hot Top 2 is suitable for adults and children, and could be used with a
mouthpiece or a mask, but is not suitable for ventilated patients due to the open
vent design. Closed nebulisers of the Cirrus 2 type should be used in this
application. The use of nebulisers for respiratory therapy is widespread. Their
importance and practical use can be seen in pre-hospital emergency care, in
hospitals and by patients at home. The European respiratory society guidelines on the use of nebulisers felt that it was appropriate for ambulance staff and
paramedics to institute bronchodilator treatment as early as possible in acute
asthma using nebulised bronchodilator therapy driven by oxygen. Nebulisers are
also used in accident and emergency to deliver Salbutamol to asthma patients
and ipratropium bromide to CODP patients. Some patients who are in
Intensive Care Units and who are ventilated, require Inhalation Therapy.
The required volume of drug is put into the nebuliser. The nebuliser
and a T-Piece is then placed into the inspiratory limb of the ventilator
breathing system ideally 30 to 45 centimeters from the Y-Piece. If a heat and moisture exchanger is fitted this must be removed and an
alternative source of humidification must be provided. Consideration should be
given to placing a filter in the expiratory and inspiratory limbs of the
breathing system to protect the ventilator from contamination. Resistance
to flow should also be monitored. The gas flow to the nebulizer should be set at 8 Liters per minute. Nebulisers can be used to deliver aerosol therapy for patients
requiring Intermittent Positive Pressure Breathing (IPPB) physiotherapy. The aims of IPPB are to: increase lung volume, decrease the work of breathing, mobilize
secretions and increase collateral ventilation. A nebuliser can add humidity
to the dry gases coming from the ventilator in which case 0.9% saline would be used or it can administer a bronchodilator to
patients with acute severe asthma. Nebulisers are used extensively in
hospital wards. For patients who do not need oxygen, air is advisable as the
driving force. Select a mouthpiece if possible, unless patient preference or
excessive breathlessness precludes this. Nose breathing filters the drug and
reduces drug deposition by 1/4 and aerosol escaping from a mask can affect
the eyes. If possible, have the patient sitting upright in a chair or side-lying
to maximize basal deposition. Ensure breathless patients have support for
their elbows. Filled between 2.5 and 10 milliliters depending on the nebuliser.
Dilute with normal saline if appropriate, this will reduce the amount of wasted
drug. Set the flow rate to 8 liters per minute, unless a compressor is used, which has a preset flow rate. Advise the patient: to mouth breathe if possible, to intersperse tidal breaths with and deep breaths and some end-
inspiratory holds to improve deposition, not to obstruct the exhalation port if
using a mouthpiece or the inlet ports if using an open vent nebulizer such as the
HOT Top 2, and to allow adequate time for completion. Patients at home use
nebulisers extensively. This means that the treatment received by the patient in
hospital can be continued in the patients home releasing valuable bed
space. This treatment is supervised by nurses of the Acute Respiratory Team. To summarise, we have looked at: how a nebuliser works, nebuliser delivery
systems, nebuliser performance factors, and where nebulisers are used and we hope that this will help understanding in this discipline.

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