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Trial registered on ANZCTR


Registration number
ACTRN12622001235796
Ethics application status
Approved
Date submitted
9/09/2022
Date registered
13/09/2022
Date last updated
13/09/2022
Date data sharing statement initially provided
13/09/2022
Type of registration
Prospectively registered

Titles & IDs
Public title
The protective versus conventional ventilation during laparoscopic surgery trial
Scientific title
A pragmatic, randomized, multi-centre trial of protective versus conventional ventilation on the incidence of acute respiratory failure in adults patients undergoing major laparoscopic surgery
Secondary ID [1] 307564 0
Nil known
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Post-operative pulmonary complications 327010 0
Major laparoscopic surgery 327615 0
Condition category
Condition code
Anaesthesiology 324190 324190 0 0
Other anaesthesiology
Surgery 324704 324704 0 0
Other surgery

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
Low tidal volume and high positive end-expiratory pressure (6 ml/kg of predicted body weight and 12 cmH2O of positive end-expiratory pressure) will be delivered via a mechanical ventilatory during major laparoscopic surgery with an expected during of more than two hours. It is anticipated minimum and maximum duration that the ventilation will be applied will be 2.5 hours to 6 hours, depending on the length of the procedure. The intervention will be administered and monitored by the treating anaesthetist. Adherence to the allocation intervention arm will be via an audit of operation reports.
Intervention code [1] 324022 0
Prevention
Comparator / control treatment
Conventional tidal volumes and high positive end-expiratory pressure (10 ml/kg of predicted body weight and 5 cmH2O of positive end-expiratory pressure) will be delivered via a mechanical ventilatory during major laparoscopic surgery with an expected during of more than two hours. It is anticipated minimum and maximum duration that the ventilation will be applied will be 2.5 hours to 6 hours, depending on the length of the procedure. The intervention will be administered and monitored by the treating anaesthetist. Adherence to the allocation intervention arm will be via an audit of operation reports.
Control group
Active

Outcomes
Primary outcome [1] 332003 0
Acute respiratory failure (defined as a postoperative PaO2 < 60 mmHg on room air, a PaO2 to FiO2 ratio of less than 300 mmHg or arterial oxyhaemoglobin saturation measured with pulse oximetry less than 90% and requiring oxygen therapy during the first 7 in-hospital post-operative days.
Timepoint [1] 332003 0
A review of hospital records will be performed to determine the onset of acute respiratory failure as documented in the patient's electronic medical record for a period of 7 days after the laparoscopic surgery was performed.
Secondary outcome [1] 411881 0
Pneumonia (defined as need of antibiotics for a suspected respiratory infection and one or more of the following criteria: new or changed sputum, new or changed lung opacities, fever and/or white blood cell count greater than 12x10^9/Litre during the first 7 in-hospital post-operative days.
Timepoint [1] 411881 0
A review of hospital records will be performed to determine the onset of pneumonia as documented in the patient's electronic medical record for a period of 7 days after the laparoscopic surgery was performed.
Secondary outcome [2] 411884 0
Bronchospasm (defined as newly detected expiratory wheeze treated with bronchodilators) during the first 7 in-hospital post-operative days.
Timepoint [2] 411884 0
A review of hospital records will be performed to determine the onset of bronchospasm as documented in the patient's electronic medical record for a period of 7 days after the laparoscopic surgery was performed.
Secondary outcome [3] 411885 0
Atelectasis (defined as lung opacification with a shift of the mediastinum, hilum or hemidiaphragm toward the affected area, and compensatory over-inflation in the adjacent non-atelectatic lung) during the first 7 in-hospital post-operative days.
Timepoint [3] 411885 0
A review of hospital records will be performed to determine the onset of atelectasis as documented in the patient's electronic medical record for a period of 7 days after the laparoscopic surgery was performed.
Secondary outcome [4] 411886 0
Acute respiratory distress syndrome as per the Berlin definition during the first 7 in-hospital post-operative days.
Timepoint [4] 411886 0
A review of hospital records will be performed to determine the onset of acute respiratory distress syndrome as documented in the patient's electronic medical record for a period of 7 days after the laparoscopic surgery was performed.
Secondary outcome [5] 411887 0
Pulmonary congestion (defined as clinical signs of congestion, including dyspnoea, oedema, rales, and jugular venous distention, with or without chest x-ray demonstrating increase in vascular markings and diffuse alveolar interstitial infiltrates) during the first 7 in-hospital post-operative days.
Timepoint [5] 411887 0
A review of hospital records will be performed to determine the onset of pulmonary congestion as documented in the patient's electronic medical record for a period of 7 days after the laparoscopic surgery was performed.
Secondary outcome [6] 411888 0
Pleural effusion (defined as chest radiograph demonstrating blunting of the costophrenic angle, loss of sharp silhouette of the ipsilateral hemidiaphragm in upright position, evidence of displacement of adjacent anatomical structures or [in supine position] a hazy opacity in one hemithorax with preserved vascular shadows) during the first 7 in-hospital post-operative days.
Timepoint [6] 411888 0
A review of hospital records will be performed to determine the onset of pleural effusion as documented in the patient's electronic medical record for a period of 7 days after the laparoscopic surgery was performed.
Secondary outcome [7] 411889 0
Pneumothorax (defined as air in the pleural space with no vascular bed surrounding the visceral pleura) during the first 7 in-hospital post-operative days.
Timepoint [7] 411889 0
A review of hospital records will be performed to determine the onset of pneumothorax as documented in the patient's electronic medical record for a period of 7 days after the laparoscopic surgery was performed.
Secondary outcome [8] 411890 0
Requirement for unplanned invasive mechanical ventilation during the first 7 in-hospital post-operative days.
Timepoint [8] 411890 0
A review of hospital records will be performed to determine the requirement for unplanned need of invasive ventilation as documented in the patient's electronic medical record for a period of 7 days after the laparoscopic surgery was performed.
Secondary outcome [9] 413814 0
Requirement for non-invasive mechanical ventilation during the first 7 in-hospital post-operative days.
Timepoint [9] 413814 0
A review of hospital records will be performed to determine the requirement for unplanned need of non-invasive ventilation as documented in the patient's electronic medical record for a period of 7 days after the laparoscopic surgery was performed.

Eligibility
Key inclusion criteria
Equal to or greater than 40 years
Scheduled to have major laparoscopic surgery (including robotic surgery) with an expected duration of more than two hours
Expected to have invasive arterial pressure monitoring as part of their routine care
Minimum age
40 Years
Maximum age
No limit
Sex
Both males and females
Can healthy volunteers participate?
No
Key exclusion criteria
Pregnancy
Scheduled to have cardiac, thoracic, or intracranial neurological surgery
Need of nitrous oxide administration
Previously had lung surgery
Planned reintubation after surgery (e.g., planned re-operations)
Received invasive ventilation for longer than 12 hours within the last 30 days prior to surgery
Any other contra-indication to hypercapnia
Previous randomization into this clinical trial

Study design
Purpose of the study
Prevention
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Allocation concealment is via central randomisation by computer
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Simple randomisation will be used a randomisation table created by computer software and will include stratification by centre, body mass index (equal to or less than 35 or greater than 35 kilograms per metre squared) and age (equal to or less than 65 years and greater than 65 years).
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?



The people analysing the results/data
Intervention assignment
Parallel
Other design features
Phase
Not Applicable
Type of endpoint/s
Safety/efficacy
Statistical methods / analysis
A detailed statistical analysis plan will be prepared before patient enrolment, and it will be published or made available electronically. All analyses will be conducted according to the intention-to-treat principle. No or minimal losses to follow–up for the primary and secondary outcomes are anticipated. Complete–case analysis will be carried out for all the outcomes, that is, excluding patients with missing data. However, if more than 1% of missing data were found for the primary outcome, a sensitivity analysis using multiple imputations and estimating–equation methods will be carried out.

The effect of protective versus conventional arm on the primary outcome will be assessed will be assessed using absolute differences with 95% confidence interval calculated from mixed-effect generalized linear model with binomial distribution and identity link. For the binary secondary and tertiary outcomes, the same strategy will be employed. ICU and hospital length of stay will be compared using Fine-Gray competing risk models and reported as subdistribution hazard ratio with 95% confidence interval.

The effect of the intervention on the primary outcome will be assessed in the following pre-specified subgroups:
Aged less than 65 years vs. greater than 65 years
Body mass index of equal to or less than 35 kg/metre s vs. greater than 35 kg/metre squared
Non-emergency vs. emergency surgery
ARISCAT equal to or less than 26 vs. greater than 26; and
Non-robotic vs. robotic surgery.

The effect on subgroups will be evaluated according to the interaction effects between each subgroup and the study arms in the proposed model and presented in a forest plot.

As additional analyses, the effect of the interventions on the primary outcome will be re-estimated using models with adjustment for the following covariates at baseline: age, ARISCAT Risk calculator for postoperative pulmonary complications, and the American Society of Anesthesiologists (ASA). In all analyses, centres will be as random effects.

Recruitment
Recruitment status
Not yet recruiting
Date of first participant enrolment
Anticipated
3/10/2022
Actual
Date of last participant enrolment
Anticipated
Actual
Date of last data collection
Anticipated
Actual
Sample size
Target
1750
Accrual to date
Final
Recruitment in Australia
Recruitment state(s)
VIC
Recruitment hospital [1] 22816 0
Austin Health - Austin Hospital - Heidelberg
Recruitment postcode(s) [1] 38105 0
3084 - Heidelberg

Funding & Sponsors
Funding source category [1] 311838 0
Hospital
Name [1] 311838 0
Austin Health
Country [1] 311838 0
Australia
Primary sponsor type
Hospital
Name
Austin Health
Address
145 Studley Road
Heidelberg
Victoria 3084
Country
Australia
Secondary sponsor category [1] 313314 0
Individual
Name [1] 313314 0
Dr Heidi Gaulke
Address [1] 313314 0
Austin Health
Austin Hospital,
145 Studley Road
Heidelberg
Victoria 3084
Country [1] 313314 0
Australia

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 311280 0
Austin Health Human Research Ethics Committee
Ethics committee address [1] 311280 0
145 Studley Road
Heidelberg VIC 3084
Ethics committee country [1] 311280 0
Australia
Date submitted for ethics approval [1] 311280 0
24/11/2021
Approval date [1] 311280 0
22/04/2022
Ethics approval number [1] 311280 0
HREC/81399/Austin-2021

Summary
Brief summary
Many patients are admitted to hospital each year for a laparoscopic surgical procedure. At times, the procedure requires general anaesthesia and mechanical ventilation. General anaesthesia means that you will be unaware of the procedure as it is happening and mechanical ventilation involves the placement of a breathing tube into the upper airway to support breathing and oxygenation.

Two key components of mechanical ventilation are tidal volume (volume of air breathed and positive-end expiratory pressure (PEEP)(pressure in the lungs after breathing out). Traditionally, for patients having laparoscopic surgery conventional tidal volumes (10 to 15 ml per kilogram of predicted body weight) are used as a means to prevent low-blood oxygen or lung tissue collapse. However, studies involving people suggests that high tidal volumes are injurious to healthy lungs and can cause localised inflammation. Similarly, accumulating data from observational and small randomized controlled human studies have found that high tidal volumes can damage the lungs. Conversely, using low tidal volumes (6 ml per kilogram of predicated body weight) during mechanical ventilation has been shown to be beneficial in patients suffering from acute respiratory distress syndrome. Indeed, low tidal volume ventilation has been adopted for the management of critically ill patients at risk of respiratory distress syndrome.

At the present time it is unclear whether a higher tidal volume strategy – conventional ventilation, or a lower tidal volume strategy – known as protective ventilation, during mechanical ventilation for patients having laparoscopic surgery requiring general anaesthesia.

We believe that the information obtained from this study will help anaesthetists to better manage the ventilator management for patients who are having a laparoscopic surgical procedure that requires general anaesthesia.

This study will involve 1750 patients admitted to hospital to have laparoscopic surgery under general anaesthesia. The research has been initiated by the researchers at the Austin Hospital (Melbourne) and is anticipated it will take two years to complete.
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 120554 0
Dr Dharshi Karalapillai
Address 120554 0
Department of Intensive Care
Austin Hospital
145 Studley Road
Heidelberg VIC 3084
Country 120554 0
Australia
Phone 120554 0
+61394964835
Fax 120554 0
+61394963932
Email 120554 0
dharshi.karalapillai@austin.org.au
Contact person for public queries
Name 120555 0
Dr Dharshi Karalapillai
Address 120555 0
Department of Intensive Care
Austin Hospital
145 Studley Road
Heidelberg VIC 3084
Country 120555 0
Australia
Phone 120555 0
+61394964835
Fax 120555 0
+61394963932
Email 120555 0
dharshi.karalapillai@austin.org.au
Contact person for scientific queries
Name 120556 0
Dr Dharshi Karalapillai
Address 120556 0
Department of Intensive Care
Austin Hospital
145 Studley Road
Heidelberg VIC 3084
Country 120556 0
Australia
Phone 120556 0
+61394964835
Fax 120556 0
+61394963932
Email 120556 0
dharshi.karalapillai@austin.org.au

Data sharing statement
Will individual participant data (IPD) for this trial be available (including data dictionaries)?
No
No/undecided IPD sharing reason/comment
This is a small sample sized, pragmatic trial in which we do not plan on making de-identified individual participant data available unless approached in the future with a specific research question and a plan to obtain human ethical committee approval in advance of data sharing.


What supporting documents are/will be available?

Doc. No.TypeCitationLinkEmailOther DetailsAttachment
16617Study protocol  dharshi.karalapillai@austin.org.au The PROtective versus CONventional Ventilation dur... [More Details]



Results publications and other study-related documents

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Documents added automatically
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