Routine ventilator disconnection on critically ill patients - how bad is it? A clinical observational study in the intensive care unit at Uppsala University Hospital

ISRCTN	ISRCTN76631800
DOI	https://doi.org/10.1186/ISRCTN76631800
Protocol serial number	N/A
Sponsor	Uppsala University Hospital (Sweden)
Funder	Uppsala University Hospital - Akademiska Sjukhuset (Sweden)

Submission date: 15/03/2012
Registration date: 29/03/2012
Last edited: 12/08/2015

Recruitment status: No longer recruiting
Overall study status: Completed
Condition category: Respiratory

Prospectively registered

Protocol

Statistical analysis plan

Results

Individual participant data

Plain English summary of protocol

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
joakim.engstorm@akademiska.se

Contact information

Prof Anders Larsson
Scientific

Department of Anesthesiology and Intensive Care Medicine
Uppsala University
Akademiska sjukhuset
ANIVA Ing70, 1 tr
Uppsala
75185
Sweden

Study information

Primary study design	Observational
Study design	Single-centre prospective observational study with consecutive inclusion
Secondary study design	Cross sectional study
Study type	Participant information sheet
Scientific title	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
Study objectives	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. Aim: 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.
Ethics approval(s)	Regional Ethical Review Board in Uppsala [Regionala etikprövningsnämnden i Uppsala], 09/12/2010, ref: 2010/317
Health condition(s) or problem(s) studied	Critically ill patients with an acute respiratory failure treated with mechanically ventilation.
Intervention	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.
Intervention type	Other
Primary outcome measure(s)	The difference in PaO2 (kPa) between baseline, 15 minutes and 60 minutes after the HEPA filter change.
Key secondary outcome measure(s)	The difference in pulmonary compliance between baseline, 15 minutes and 60 minutes after the HEPA filter change.
Completion date	01/01/2013

Eligibility

Participant type(s)	Patient
Age group	Adult
Sex	All
Target sample size at registration	20
Key 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
Key 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
Date of first enrolment	14/02/2011
Date of final enrolment	01/01/2013

Locations

Countries of recruitment

Sweden

Study participating centre

Uppsala University

Uppsala
75185
Sweden

Results and Publications

Individual participant data (IPD) Intention to share	No
IPD sharing plan summary	Not provided at time of registration
IPD sharing plan

Study outputs

Output type	Details	Date created	Date added	Peer reviewed?	Patient-facing?
Results article	results	01/08/2014		Yes	No
Participant information sheet	Participant information sheet	11/11/2025	11/11/2025	No	Yes