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.