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Trial registered on ANZCTR


Registration number
ACTRN12623000726651
Ethics application status
Approved
Date submitted
1/06/2023
Date registered
5/07/2023
Date last updated
5/07/2023
Date data sharing statement initially provided
5/07/2023
Date results information initially provided
5/07/2023
Type of registration
Retrospectively registered

Titles & IDs
Public title
Assessing the impact of blood pressure targets and surgical approach (laparoscopic or open) on continuous urinary oxygenation in patients undergoing general surgical procedures
Scientific title
Assessing renal blood flow, as measured by urinary oxygenation, acute kidney injury (AKI) and biomarkers of AKI (Nephrocheck) in patients undergoing Laparoscopic and Open General Surgery
Secondary ID [1] 309804 0
Nil known
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Surgery requiring general anaesthesia 330216 0
Condition category
Condition code
Surgery 327083 327083 0 0
Other surgery

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
Mean arterial blood pressure target to be within 10% of the patient's pre-operative baseline or above 75 mmHg, whichever was the greater number and to be targeted by the anaesthesiology team using noradreanline and metaraminol vasopressor drugs at doses they deem clinically necessary achieve the targeted blood pressure number after induction and for the duration of the surgical procedure.
Intervention code [1] 326234 0
Treatment: Drugs
Comparator / control treatment
Mean arterial pressure target of between 65 and 75 mmHg to be targeted by the anaesthesiology team using noradreanline and metaraminol vasopressor drugs at doses they deem clinically necessary achieve the targeted blood pressure number after induction and for the duration of the surgical procedure.
Control group
Active

Outcomes
Primary outcome [1] 334950 0
Mean urinary oxygen level throughout the first 150 minutes after incision.
Timepoint [1] 334950 0
Urine oxygen values as measured by sterile fibre optic luminescence optode, measuring urinary oxygen levels every 0.6 seconds from induction and throughout the entire duration of of the surgical procedure according to allocated blood pressure target group.
Secondary outcome [1] 422526 0
Difference in mean urinary oxygen level throughout the first 150 minutes after incision for patients who undergo an open surgical procedure compared with those who undergo a laparoscopic surgical technique
Timepoint [1] 422526 0
Urine oxygen values as measured by sterile fibre optic luminescence optode, measuring urinary oxygen levels every 0.6 seconds from induction and throughout the entire duration of of the surgical procedure.
Secondary outcome [2] 423771 0
Mean arterial blood pressure during surgery
Timepoint [2] 423771 0
Difference in mean arterial blood pressure levels assessed via intra-arterial pressure monitoring throughout the first 150 minutes after incision for patients who undergo an open surgical procedure compared with those who undergo a laparoscopic surgical technique
Secondary outcome [3] 423772 0
Incidence of acute kidney injury
Timepoint [3] 423772 0
Incidence of acute kidney injury defined as either Stage 2 or Stage 3 of the Kidney Disease Improving Global Outcomes (KDIGO) criteria occurring during the first 72-hours after the end of the surgical procedure.
Secondary outcome [4] 423773 0
Neutrophil gelatinase-associated lipocalin assessed biomarker of acute kidney injury.
Timepoint [4] 423773 0
Evaluation of change in the urinary sample derived acute kidney injury biomarker levels of neutrophil gelatinase-associated lipocalin taken prior to surgery, at the end of the surgical procedural and at 24 hours (the following day post-surgery).

Eligibility
Key inclusion criteria
Adult patients aged equal to or greater than 18 years of age.
Schedule to have either a laparoscopic or open general surgery
Require placement of a urinary catheter as a part of routine clinical care
Participant provides own consent
Minimum age
18 Years
Maximum age
No limit
Sex
Both males and females
Can healthy volunteers participate?
No
Key exclusion criteria
Baseline serum creatinine greater than 200µmol.L-1 or an estimated glomerular filtration rate according to the CKD-EPI method below 30ml.min-1.1.73m-2
Patients with acute kidney injury as defined by the KDIGO consensus criteria,
pregnant women
Pre-anaesthetics mean arterial pressure greater than 100mmHg or lower than 65mmHg

Study design
Purpose of the study
Treatment
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
The treatment allocation was placed in an opaque, sealed envelope by an independent party not involved in collecting or analysing the data and given to the clinical anaesthetist.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Group allocation was determined by fixed block randomisation of four with a 1:1 allocation generated by a web-based computer random sequence generator (https://www.sealedenvelope.com). The randomisation was stratified according to the laparoscopic or open surgery group.
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?


The people assessing the outcomes
Intervention assignment
Parallel
Other design features
Phase
Phase 2
Type of endpoint/s
Safety/efficacy
Statistical methods / analysis
Descriptive statistics to summarise patient characteristics for each group.
Continuous variables were reported as median with interquartile range (IQR) or mean ± SD as appropriate and categorical variables as proportions.
Linear mixed-effect models to investigate the slope and mean PuO2 differences between the groups.
Models to include random intercepts for both time and patients to account for the repeated measures nature of the data.
Evaluate the first 150 minutes after incision, to represent the mean surgery duration.
Exploratory analyses was divided by the time scale, if necessary, for descriptive purposes.
Difference in arterial blood pressure among the groups assessed by linear mixed models with the same random intercepts.
The model assumptions, including linearity and normality of the residuals, were checked using diagnostics plots.
Sensitivity analysis to estimate the difference in area under the curves (AUC) for PuO2 levels between the groups by a non-parametric bootstrapping procedure.
Statistical analyses were performed using R version 4.2.2 (R Foundation for Statistical Computing).

Recruitment
Recruitment status
Completed
Date of first participant enrolment
Anticipated
Actual
19/10/2020
Date of last participant enrolment
Anticipated
Actual
5/10/2022
Date of last data collection
Anticipated
Actual
30/03/2023
Sample size
Target
40
Accrual to date
Final
43
Recruitment in Australia
Recruitment state(s)
VIC
Recruitment hospital [1] 24824 0
Austin Health - Austin Hospital - Heidelberg
Recruitment postcode(s) [1] 40473 0
3084 - Heidelberg

Funding & Sponsors
Funding source category [1] 313988 0
Hospital
Name [1] 313988 0
Austin Health
Country [1] 313988 0
Australia
Primary sponsor type
Hospital
Name
Austin Health
Address
Austin Hospital
145 Studley Road
Heidelberg
Victoria 3084
Country
Australia
Secondary sponsor category [1] 315870 0
Individual
Name [1] 315870 0
Professor Rinaldo Bellomo
Address [1] 315870 0
Austin Hospital
145 Studley Road
Heidelberg
Victoria 3084
Country [1] 315870 0
Australia

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 313124 0
Austin Health Human Research Ethics Committee
Ethics committee address [1] 313124 0
145 Studley Road
Heidelberg
Victoria 3084
Ethics committee country [1] 313124 0
Australia
Date submitted for ethics approval [1] 313124 0
Approval date [1] 313124 0
19/03/2020
Ethics approval number [1] 313124 0
HREC/59893/Austin-2019

Summary
Brief summary
The impact of blood pressure targets and surgical approach (laparoscopic or open) on continuous urinary oxygenation (PuO2), a validated surrogate of renal medullary PO2, during general surgery is unclear. We aimed to assess the effects of different blood pressure targets and surgical procedures on PuO2. In this pilot, single centre, randomised controlled physiological study, patients were allocated to usual mean arterial pressure target management or a slightly higher mean arterial blood pressure target as managed by the treating anesthetists during the operation. The primary outcome was the mean urinary oxygen value during the operation. In doing so, our trial has explored the complex relationship between blood pressure targets, surgical procedures, and renal oxygenation and guide future investigations aiming to personalise renal protective perioperative management stratagies.
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 127082 0
Prof Rinaldo Bellomo
Address 127082 0
Director, Department of Intensive Care
Austin Hospital
145 Studley Road
Heidelberg
VIC 3084
Country 127082 0
Australia
Phone 127082 0
+61 394965992
Fax 127082 0
+61394963932
Email 127082 0
[email protected]
Contact person for public queries
Name 127083 0
Rinaldo Bellomo
Address 127083 0
Director, Department of Intensive Care
Austin Hospital
145 Studley Road
Heidelberg
VIC 3084
Country 127083 0
Australia
Phone 127083 0
+61394965992
Fax 127083 0
+61394963932
Email 127083 0
[email protected]
Contact person for scientific queries
Name 127084 0
Rinaldo Bellomo
Address 127084 0
Director, Department of Intensive Care
Austin Hospital
145 Studley Road
Heidelberg
VIC 3084
Country 127084 0
Australia
Phone 127084 0
+61394965992
Fax 127084 0
+61394963932
Email 127084 0
[email protected]

Data sharing statement
Will individual participant data (IPD) for this trial be available (including data dictionaries)?
No
No/undecided IPD sharing reason/comment
Pilot investigation and findings will be considered hypothesis-generating.


What supporting documents are/will be available?

No Supporting Document Provided



Results publications and other study-related documents

Documents added manually
No documents have been uploaded by study researchers.

Documents added automatically
No additional documents have been identified.