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Trial registered on ANZCTR


Trial ID
ACTRN12614001196639
Ethics application status
Approved
Date submitted
3/11/2014
Date registered
13/11/2014
Date last updated
20/01/2016
Type of registration
Prospectively registered

Titles & IDs
Public title
Apprehending micro-organisms injected during anaesthesia: the 'Zbugs' randomised controlled trial to reduce surgical site infection
Scientific title
Does the injection of anaesthetic drugs through a 0.2micron filter unit in the intravenous line of surgical patients reduce infection?
Secondary ID [1] 285312 0
Nil known
Universal Trial Number (UTN)
U1111-1161-0573
Trial acronym
Zbugs
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Surgical site infection due to microbiological contamination of intravenous drugs administered during anaesthesia 293027 0
Condition category
Condition code
Anaesthesiology 293297 293297 0 0
Other anaesthesiology
Infection 293744 293744 0 0
Studies of infection and infectious agents

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
We propose to incorporate a 0.2micron filter unit into the intravenous lines of patients undergoing anaesthesia for hip or knee replacement or cardiothoracic surgery, and a request that participant anaesthetists inject all drugs except propofol (due to its pharmaceutical characteristics) and infusions through this. The filter unit will be inserted into the patients IV administration line at the beginning of the case (just after the patient has been transported into theatre) and removed at the end of the patients stay in the post anaesthesia care unit or cardiac operating room. This involves a small change in current practice which we believe is benign and was the basis for our previous study "Investigating the microbiological contamination of drugs administered for anaesthesia in the operating theatre" ACTRN12613000040763. In the current study we will recruit participating anaesthetists managing patients under their care until the required number of cases (11,000 in total) has been included.
Intervention code [1] 290225 0
Prevention
Intervention code [2] 290569 0
Treatment: Devices
Comparator / control treatment
The standard group of patients will be managed according to participating anaesthetists’ usual practices.
Control group
Active

Outcomes
Primary outcome [1] 293132 0
All surgical site infection (SSI) in patients remaining in hospital or requiring readmission to hospital, including (a) superficial incisional SSI; (b) deep incisional SSI; and (c) organ/space SSI derived from the national surveillance programme. This programme has recently been established to track SSI for total hip and total knee replacement surgery. It already provides robust data on the overall mean rate of SSI for these two conditions (the national average is currently 1.4%). The programme substantially simplifies the problem of collecting postoperative data on SSI. Surveillance for cardiac surgical operations is expected to be in place later this year and a somewhat higher rate of SSI is expected in this group (in 2013 the rate of deep SSI in cardiac patients was 2%; for superficial SSI it was 7% (unpublished data on 100 patients)).
Timepoint [1] 293132 0
90 days post surgery
Secondary outcome [1] 310423 0
All-cause mortality
Timepoint [1] 310423 0
90 days post surgery

Eligibility
Key inclusion criteria
The participants are anaesthetic specialists, trainees and other medical officers willing to take part in the study, who will undertake 11,000 cases (a case is defined as one patient undergoing general or regional anaesthesia on one occasion). The cases are elective or acute hip or knee arthroplasty, or elective cardiothoracic surgery under general anaesthesia with or without regional anaesthesia, or under regional anaesthesia with sedation in adult patients (i.e. 16 years of age or over). We shall attempt to include all eligible cases started during normal working hours on Mondays to Fridays when the researchers and the participant anaesthetist are both available.
Minimum age
25 Years
Maximum age
70 Years
Gender
Both males and females
Can healthy volunteers participate?
Yes
Key exclusion criteria
Procedures other than hip or knee arthroplasty or elective cardiac surgery will be excluded. Participating anaesthetists will be able to exclude cases if any clinical reasons to do so emerge, including any request by a patient to opt out of the study

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)
We plan to include six of the busiest district health boards, which manage hip and knee arthroplasty surgery in NZ, and all the cardiothoracic surgery. At each of six study centres we will randomly allocate “months” (actually 28 day periods) to be “filter unit months” or “standard care months” so that there is a 1:1 ratio over clusters of 6 months. Within those clusters the allocations will be in random order. For example, a sequence could be filter-filter-standard-filter-standard-standard. Thus, in each hospital over a 24-week period (6 x 4 weeks), there will be 12 weeks in which filter units will be used and 12 weeks of standard care. Allocation will be carried out by the study statistician but is not concealed. Allocation and data collection will only apply to hip and knee arthroplasties and cardiac operations.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
At each of six study centres we will randomly allocate “months” (actually 28 day periods) to be “filter unit months” or “standard care months” so that there is a 1:1 ratio over clusters of 6 months. Within those clusters the allocations will be in random order. For example, a sequence could be filter-filter-standard-filter-standard-standard. Thus, in each hospital over a 24-week period (6 x 4 weeks), there will be 12 weeks in which filter units will be used and 12 weeks of standard care.
Masking / blinding
Open (masking not used)
Who is / are masked / blinded?



Intervention assignment
Other
Other design features
The study participants are the anaesthetists. We will be randomly allocating “months” (actually 28 day periods) to be “filter unit months” or “standard care months” so that there is a 1:1 ratio over clusters of 6 months. Within those clusters the allocations will be in random order. For example, a sequence could be filter-filter-standard-filter-standard-standard. Thus, in each hospital over a 24-week period (6 x 4 weeks), there will be 12 weeks in which filter units will be used and 12 weeks of standard care.
Phase
Not Applicable
Type of endpoint(s)
Efficacy
Statistical methods / analysis
We assume that the relationship between injected micro-organisms and SSI is not independent but rather, that micro-organism injection occurs in a higher proportion of those patients that develop an SSI. Consider 1000 patients: micro-organisms will be injected in 60 (6% from unpublished data – collection completed June 2014). If just one in 10 of these patients develops a related SSI that otherwise would not have occurred, this will be 6 infections per 1000 (0.6%) patients. Eliminating these infections would reduce SSIs from 14 (1.4%) to 8 (0.8%). A decision to change practice would only be justified by a reduction in the rate of infection; if there was either no difference or (very improbably) the filter unit increased the rate of infection, no change in practice would be justified. It follows that to show a reduction from 1.4% to 0.8% with 90% power (beta=0.10) as statistically significant (1-tailed alpha=0.05) 5503 patients per group (11006 in total – rounded to 11000, or 5500 per group) are required (estimated with MedCalc (MedCalc Software, Ostend, Belgium)). These power calculations assume that the intra-class correlation within site blocks is 0.0. This assumption will be tested with the blinded interim analysis (with no analysis of outcomes) and if necessary the sample size amended.

Recruitment
Recruitment status
Not yet recruiting
Date of first participant enrolment
Anticipated
Actual
Date of last participant enrolment
Anticipated
Actual
Date of last data collection
Anticipated
Actual
Sample size
Target
Accrual to date
Final
Recruitment outside Australia
Country [1] 6346 0
New Zealand
State/province [1] 6346 0
Waitemata District Health Board
Country [2] 6457 0
New Zealand
State/province [2] 6457 0
Auckland District Health Board
Country [3] 6458 0
New Zealand
State/province [3] 6458 0
Counties Manukau District Health Board
Country [4] 6459 0
New Zealand
State/province [4] 6459 0
Waikato District Health Board
Country [5] 6460 0
New Zealand
State/province [5] 6460 0
Capital and Coast District Health Board
Country [6] 6461 0
New Zealand
State/province [6] 6461 0
Canterbury District Health Board

Funding & Sponsors
Funding source category [1] 289934 0
Self funded/Unfunded
Name [1] 289934 0
Address [1] 289934 0
Country [1] 289934 0
Primary sponsor type
University
Name
the University of Auckland
Address
Private Bag 92019
Grafton
Auckland 1142
Country
New Zealand
Secondary sponsor category [1] 288625 0
Individual
Name [1] 288625 0
Professor Alan Merry
Address [1] 288625 0
Department of Medicine
the University of Auckland
85 Park Road
Grafton
Auckland 1142
Country [1] 288625 0
New Zealand

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 291650 0
Northern B Health and Disabilities Ethics Committee
Ethics committee address [1] 291650 0
Ministry of Health
No 1 The Terrace
PO Box 5013
Wellington 1601
Ethics committee country [1] 291650 0
New Zealand
Date submitted for ethics approval [1] 291650 0
20/11/2014
Approval date [1] 291650 0
21/01/2015
Ethics approval number [1] 291650 0
14/NTB/196

Summary
Brief summary
This study follows on from previous simulation-based research where we found bacterial growth in 13.1% (n=5/38) of empty sterile IV bags used to collect all administered medications from ten surgical scenarios. These findings were confirmed in our recently completed clinical study (data collection completed June 2014) ACTRN12613000040763. In the current study we will test the primary hypothesis that the rate of SSI will be reduced by asking anaesthetists to inject all drugs except propofol and infusions through a 0.2micron filter unit to reduce the number of micro-organisms inadvertently injected into patients' bloodstreams. Our secondary hypothesis is that the rates of all SSI are higher in Maori and Pacific than non-Maori and non-Pacific Peoples in New Zealand.
Trial website
To be confirmed
Trial related presentations / publications
“Anaesthetic drug administration as a potential contributor to healthcare-associated infections: a prospective simulation-based evaluation of aseptic techniques in the administration of anaesthetic drugs“[Gargiulo et al, BMJ Quality & Safety, 2012 DOI: 10.1136/bmjqs-2012-000814 ].
Public notes
We will recruit anaesthetists who will manage patients under their care until the required number of cases (11,000) have been included in the study. We therefore may recruit more or less than 200 anaesthetists.

Contacts
Principal investigator
Name 51338 0
Prof Alan Merry
Address 51338 0
School of Medicine
the University of Auckland
Private Bag 92019
Grafton
Auckland 1142
Country 51338 0
New Zealand
Phone 51338 0
+64 9 3737599 ext 89301
Fax 51338 0
Email 51338 0
a.merry@auckland.ac.nz
Contact person for public queries
Name 51339 0
Prof Alan Merry
Address 51339 0
School of Medicine
the University of Auckland
Private Bag 92019
Grafton
Auckland 1142
Country 51339 0
New Zealand
Phone 51339 0
+64 9 3737599 ext 89301
Fax 51339 0
Email 51339 0
a.merry@auckland.ac.nz
Contact person for scientific queries
Name 51340 0
Mrs Derryn Gargiulo
Address 51340 0
Department of Anaesthesiology
the University of Auckland
Private Bag 92019
Grafton
Auckland 1142
Country 51340 0
New Zealand
Phone 51340 0
+64 9 3737599 ext 89321
Fax 51340 0
Email 51340 0
d.gargiulo@auckland.ac.nz