Plain English Summary
Background and aims
Lung collapse occurs when the positive pressure drops in mechanically ventilated patients with acute respiratory failure. The aim in this study is to investigate whether a short, routine disconnection to change the bacterial filter in a mechanical ventilator circle would affect lung function.
Who can participate?
Critically ill and mechanical ventilated patients who are admitted to an intensive care unit and are above 18 years of age.
What does the study involve?
All participants will receive the same treatment. Before a routine filter change, blood pressure and pulse rate will be registered and a blood sample will be drawn. One hour and fifteen minutes after the filter change the same measurements will be repeated.
What are the possible benefits and risks of participating?
Since this study examines the effect of a routine procedure, no risk (more than in the normal routine care) exists. There are no direct benefits, but participation in the study could lead to gained knowledge in the field of respiratory care. It is also possible that the gained knowledge could help future intensive care patients.
Where is the study run from?
Uppsala Academic Hospital, Sweden
When is the study starting and how long is it expected to run for?
The study will be open to participants from approximately February 2011 until January 2013.
Who is funding the study?
Local hospital grants
Who is the main contact?
Mr Joakim Engström
Routinely ventilator disconnection on critically ill patients - effect on oxygenation and lung function. A clinical observational study in the intensive care unit at Uppsala University Hospital
Even a short disconnection from a ventilator during a daily change of a High-Efficiency Particulate Air (HEPA) filter may cause deterioration of lung function in critically ill patients.
To test this hypothesis with the primary end-point of lung function expressed by oxygenation and compliance in a clinical prospective observational study in an intensive care unit (ICU) at Uppsala University Hospital.
Regional Ethical Review Board in Uppsala [Regionala etikprövningsnämnden i Uppsala], 09/12/2010, ref: 2010/317
Single-centre prospective observational study with consecutive inclusion
Primary study design
Secondary study design
Cross sectional study
Patient information sheet
Critically ill patients with an acute respiratory failure treated with mechanically ventilation.
Twenty patients admitted to the intensive care unit will be consecutively enrolled in this clinical prospective observational study. The study is approved by the Regional Ethical Review Board in Uppsala, Sweden. Informed consent will be obtained from the next in kin before measurements is made.
Before the routinely filter change tidal volume [Vt], respiratory rate, end-inspiratory plateau pressure [EIP] and PEEP (Positive End Expiratory Pressure, will be registered. Compliance of the respiratory system (Crs) will be calculated as VT/(EIP-PEEP). Both EIP and PEEP is measured after a prolonged pause of 10 seconds. A decrease of Crs could suggest that lung collapse has occurred. The fraction of inspired oxygen [FiO2], blood pressure and pulse rate will be registered and an arterial blood gas sample for determination of PaO2, PaCO2, pH and BE will be drawn from the patient. A decrease in PaO2 could also suggest that lung collapse has occurred. Fifteen minutes and one hours after the filter change the same measurements will be repeated.
Primary outcome measure
The difference in PaO2 (kPa) between baseline, 15 minutes and 60 minutes after the HEPA filter change.
Secondary outcome measures
The difference in pulmonary compliance between baseline, 15 minutes and 60 minutes after the HEPA filter change.
Overall trial start date
Overall trial end date
Reason abandoned (if study stopped)
Participant inclusion criteria
1. Patients with respiratory failure treated in the ICU with controlled mechanical ventilatory support
2. Need for fraction of inspired oxygen ≥ 0.5 and positive end expiratory pressure ≥ 10 cmH2O
Target number of participants
The aim is to include 20 patients
Participant exclusion criteria
1. Patients with spontaneous mechanical ventilatory treatment, patients without an arterial access, 2. Patients without an informed consent from next of kin
3. Pregnant patients
4. Patients under the age of 18
5. Patients that do not meet the inclusion criteria
Recruitment start date
Recruitment end date
Countries of recruitment
Trial participating centre
Uppsala University Hospital (Sweden)
Uppsala University Hospital - Akademiska Sjukhuset (Sweden)
Funding Body Type
Funding Body Subtype
Results and Publications
Publication and dissemination plan
Not provided at time of registration
Intention to publish date
Participant level data
Not provided at time of registration
Basic results (scientific)
2014 results in: http://www.ncbi.nlm.nih.gov/pubmed/24282318