Clinical Trial Details
— Status: Completed
Administrative data
| NCT number |
NCT01143961 |
| Other study ID # |
09/MRE09/54 |
| Secondary ID |
|
| Status |
Completed |
| Phase |
N/A
|
| First received |
|
| Last updated |
|
| Start date |
June 2010 |
| Est. completion date |
January 2011 |
Study information
| Verified date |
February 2010 |
| Source |
Cardiff and Vale University Health Board |
| Contact |
n/a |
| Is FDA regulated |
No |
| Health authority |
|
| Study type |
Interventional
|
Clinical Trial Summary
Surveillance of the lungs for bacteria is routinely undertaken in artificially ventilated
patients as these individuals are at high risk of developing pneumonia. Knowledge of the
types of bacteria present allows the rapid treatment with the correct antibiotics if a
pneumonia develops. Surveillance is undertaken using a technique called non-directed
bronchoalveolar lavage (NBL), which can be performed by the bedside nurse. This involves
suctioning some of the lung secretions into a sample pot and sending it to the microbiology
laboratory to identify any bacteria present. When this procedure is performed there is some
collapse of the lung due to escaping gas. The purpose of this study is:
1. To use a non-invasive imaging technique known as electrical impedance tomography (EIT)
to measure the amount of lung collapse during an NBL. Half of the patients in the study
will have a one-way adapter valve connected to the breathing circuit. This adapter is
designed to make the insertion of a suction catheter easier and prevent the loss of gas.
2. Look at which region of the lung the sample is being collected from as the suction tube
used to take the samples may pass into either the left or right lung.
EIT is a simple non-invasive technique which has been in use for many years. It uses pairs of
electrodes around the chest through which imperceptible currents are passed. A computer shows
an image of which parts of the lungs have the most or least air in them. This has the
advantage over other imaging techniques in critical care that it does not use radiation and
gives a real time picture at the bedside of the variations in ventilation throughout the
lungs.
Description:
This study has two objectives. The first is to measure changes in lung ventilation using EIT
during the performance of an NBL with and without a one-way adapter valve attached to the
catheter mount. This will be done by randomising half of the patients to having the one-way
adapter valve attached to the catheter mount. Assignment will be by randomisation.
The second objective of the study is to locate the placement of catheter tips during the
performance of NBLs, using electrical impedance tomography.
Equipment: A sixteen-electrode single frequency electrical impedance tomography device with
on-line image analysis (CareFusion). One-way adapter valves which attach to the catheter
mount (CareFusion).
Study Population: Critically ill adult patients admitted to the intensive care unit at the
University Hospital of Wales Cardiff in whom NBLs are performed as part of their routine
care.
Recruitment: All patients satisfying inclusion and exclusion criteria, admitted to the adult
ICU at the University Hospital of Wales from the start date of the study will be considered
eligible for recruitment. Patients identified by the duty consultant will be notified to the
research team. Patients will be randomly allocated to have NBLs performed with or without the
one-way valve attached to the catheter mount.
Since this is an observational pilot study a minimum of fifty patients will be identified.
Interventions: The second cohort of patients will have NBLs performed with the one-way
adapter connected to the catheter mount, otherwise there will be no change will be made to
the normal standard of care.
Method: Following cleaning of the skin with alcohol wipes sixteen ECG electrodes will be
placed equidistantly from one another midway between sternum and umbilicus. A reference
electrode will be placed on the right hand side of the chest. NBLs will be undertaken
according to routine standards of care. In brief, this involves pre-oxygenating the patient,
and inserting a suction catheter attached to a 20ml saline filled syringe through the
catheter mount (25 patients) or adapter with one-way valve connected to the catheter mount
(25 patients) until resistance is met. The saline is instilled and then slowly withdrawn to
obtain a sample. Since saline is conductive, instillation results in a change in local
impedance which is detected by the array of electrodes. The image obtained will identify into
which region of the lung the catheter is placed. Any changes in the gas content of lung (due
to loss of PEEP) will be manifest as changes in lung impedance and reflects a change in
regional ventilation. NBLs are undertaken when clinically indicated and patients may have
more than one recoding undertaken up to a maximum of three times.
Collection of other data: Baseline demographics of patients will be recorded, including age,
sex, APACHE II score, co-morbidities, diagnosis, days from hospital admission. Ventilator
settings - mode, inspired oxygen fraction, tidal and minute ventilation, compliance, PEEP and
mean airway pressure will be recorded.
