Evaluation of an on-demand humidifier in neuromuscular patients on chronic ventilatory support; a pilot study.

Mechanically ventilated patients require the inspired air to be humidified when
the upper airway is bypassed by a tracheotomy. Patients being ventilated
non-invasively for almost 24 hours need this humidification as well. The
conventional heated humidifier generates water vapor near the ventilator. The
water vapor and air mixture travel up the tube to the patient*s interface.
Movement of the patient or the patient circuits often move the water condensate
to the tracheal interface. This poses a serious health risk since the
condensate inside the tubing is not sterile, and can re-enter the airway. The
conventional heated humidifier method is also not practical for portable
mechanical ventilators such as the Philips Respironics trilogy. The required
battery for 8 hours of heated humidification would weigh about 12 pounds.
Therefore, an on-demand humidification system has been built that delivers
along nebulization only humidification when the patients breathes in. As the
nebulizer systems have a low power consumption it opens the way to a portable
humidification system. These nebulizers deliver also the humidification at room
temperature in small quantities and therefore will reduce the risk of high
amount of condensate that collects in the tubes and might enter the patient*s
lungs.

The primary hypothesis is that the perception and preference of the optimal
amount of humidification provided by the on-demand humidification for subjects
requiring mechanical ventilation will be better when compared to humidification
supplied by their presently used humidifier or no humidification.

Primary objective: To evaluate the optimum comfortable on-demand humidification
doses for neuromuscular patients requiring chronic mechanical ventilation using
subjective as well as objective measurements of the optimum comfort.

In the pilot study, trained clinicians will set up participants, who already
use a Trilogy Ventilator, with the on-demand humidification.
Prior to patient arrival, the system is cleaned according to the cleaning
procedure (appendix 2) by Philips representatives, and prepared according to
the manual.

At their arrival, the patient*s subjective well-being will be assessed using
the hospital anxiety and depression scale(HADS) . Explicitly, the kind of
humidification used by the subject on the way to the hospital (HME, for
example) and the subjective perception of the quality of this humidification
will be asked for.
Before the test, the settings of the patients* Trilogy ventilator will be
copied into the hospitals Trilogy ventilator by the clinician responsible for
the test. Subsequently, the patient is disconnected from their Trilogy
ventilator, and is connected to the hospital Trilogy ventilator.

The subjects will use the on-demand humidifier 2 X 2 hours. They start with the
low dose for 2 hours. If the dose of humidification is to low, we stop directly
and their conventional humidification being used while they are mobile, will be
used 30 minutes. Finally the highest dose starts for 2 hours. If the dose of
humidification is to low we stop directly and restart the conventional
humidification and the pilot stops. The total time of participation has a
maximum of 4,5 hours.

During this first phase of the study, objective measures of ventilator data,
heart rate, breathing rate, SpO2, transcutaneous CO2, as well as the number of
mucus clearance events will be collected. Also the FLIR E40bx Handheld
infrared camera, used for optional thermogram of nose and mouth. will be used.
Records images on local storage medium (SD card).
After each cycle the patient will be asked on his comfort level. At the end of
the first phase the patient will be asked which humidification dose was most
comfortable.

The study starts with the recruitment, including explanation of the trial and
signing the informed consent form, and testing the on-demand humidification
devices in 10 neuromuscular patients requiring home mechanical ventilation. It
starts with the first phase in the evaluation of the on-demand humidification
amount that is optimum in the perception of the patient. After this optimum
humidification amount has been identified, the patient will test this on-demand
humidification quantity for 2 X 2 hours.

Nature and extent of the burden and risks associated with participation,
benefit and group relatedness:

Anticipated clinical benefits
The benefit of the device under investigation is that the patient will have
humidification while being mobile. The low power method of humidification makes
it easier for the patient to be mobile and have active humidification at the
same time.
Anticipated adverse device effects:
- Coughing due to airway irritation or excess mucus production.
- Transient lower oxygen saturation
- Transient increased carbon dioxide
- Transient Increased work of breathing
- Shortness of breath
- Anxiety.
Residual risks associated with investigational device [as identified in risk
analysis report]
- Too much fluid nebulized. This is part of the investigation which means the
staff should be alert on symptoms indicating this. For instance more frequent
coughing of the patient.

Risks associated with participation in clinical investigation No additional
device risks.
Burden associated with participation in clinical investigation -Single day-long
hospital visit
-Potential mild discomfort during test (dry and/or cold air, coughing)
Possible interactions with concomitant medical treatments There are no
interactions with concomitant medical treatments