Helium-oxygen reduces the work of breathing during weaning from mechanical ventilation

ISRCTN	ISRCTN56470948
DOI	https://doi.org/10.1186/ISRCTN56470948
Clinical Trials Information System (CTIS)	2005-003612-30
Protocol serial number	REC ref: 05/Q0605/150
Sponsor	Barts and The London NHS Trust (UK)
Funder	Barts and the London NHS Trust (UK)

Submission date: 02/01/2009
Registration date: 30/01/2009
Last edited: 04/07/2011

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

Not provided at time of registration

Contact information

Dr Gordon Flynn
Scientific

Intensive Care Unit
Prince of Wales Hospital
Sydney
2031
Australia

Email	docgordonflynn@yahoo.co.uk

Study information

Primary study design	Interventional
Study design	Prospective randomised controlled cross-over single-centre trial
Secondary study design	Randomised controlled trial
Scientific title	A comparison of a helium-oxygen mixture (Heliox) with an oxygen air mixture in reducing the work of breathing during weaning from mechanical ventilation
Study objectives	There is evidence in patients with chronic obstructive pulmonary disease (COPD) that around the period of extubation helium-oxygen leads to a reduction in the work of breathing. In a small physiological study in patients without airways disease, breathing helium-oxygen during weaning decreased the work of breathing. If so, could there be a use for helium in the weaning of patients from mechanical ventilation?
Ethics approval(s)	East London & The City HA Local Research Ethics Committee 3, approved on 09/11/2005 (ref: 05/Q0605/150)
Health condition(s) or problem(s) studied	Work of breathing during weaning from mechanical ventilation
Intervention	This is a single-centre trial carried out at The Royal London Hospital. Intervention: Helium inhaled at a concentration no less than 60%. Patients received 2 hours of continuous positive airway pressure (CPAP) ventilation (positive end-expiratory pressure [PEEP] setting remained unchanged and pressure support set to zero) with helium-oxygen or air-oxygen via an eVent ventilator. This ventilator was calibrated for the helium oxygen mixture on an individual patient basis. Patients were returned to their pre-study ventilator settings for 2 hours, before being given the alternative gas mixture for 2 hours. The level of CPAP support and FiO2 were unchanged for individual patients throughout the trial period.
Intervention type	Other
Primary outcome measure(s)	Work of breathing measured by carbon dioxide production. Measurements were taken continuously but presented before starting CPAP and helium then 1 hour later then at 2 hours, patient then returned to pre-CPAP ventilator settings for 2 hours then back on CPAP with alternate gas mixture with readings taken continuously but presented at 1 and 2 hours.
Key secondary outcome measure(s)	1. Respiratory rate 2. Pulse oximetry (SpO2) 3. Alveolar minute ventilation 4. Alveolar tidal volume 5. CO2 production 6. End tidal CO2 7. Alveolar dead space (Vd/Vt) Above measurements were taken continuously but presented before starting CPAP and helium then 1 hour later then at 2 hours, patient then returned to pre-CPAP ventilator settings for 2 hours then back on CPAP with alternate gas mixture with readings taken continuously but presented at 1 and 2 hours.
Completion date	01/01/2008

Eligibility

Participant type(s)	Patient
Age group	Adult
Lower age limit	18 Years
Upper age limit	80 Years
Sex	All
Target sample size at registration	24
Key inclusion criteria	1. General adult intensive care unit (ICU) patients 2. Both males and females, aged between 18 and 80 3. The underlying cause of respiratory failure was improving 4. Pressure support ventilation of less than 10 cm H2O 5. No continuous intravenous sedation or inotropes 6. FiO2 less than or equal to 0.4 and requiring less than 10 cm H2O positive end expiratory pressure 7. Written informed consent from the patient or assent from their next of kin was obtained
Key exclusion criteria	1. Failure to meet inclusion criteria 2. Inadequate analgesia 3. Pregnancy 4. Participation in other intervention trials in the past 30 days 5. Refusal of consent from the patient or assent from the next of kin
Date of first enrolment	01/01/2006
Date of final enrolment	01/01/2008

Locations

Countries of recruitment

United Kingdom
Australia

Study participating centre

Intensive Care Unit

Sydney
2031
Australia

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	26/08/2010		Yes	No