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Trial registered on ANZCTR


Registration number
ACTRN12619000315112
Ethics application status
Approved
Date submitted
26/02/2019
Date registered
28/02/2019
Date last updated
8/10/2019
Date data sharing statement initially provided
28/02/2019
Date results information initially provided
8/10/2019
Type of registration
Prospectively registered

Titles & IDs
Public title
Assessing hypercoagulability after total hip arthroplasty
Scientific title
A retrospective evaluation of hypercoagulability detected by thromboelastography (TEG) in patients undergoing elective total hip arthroplasty who received a TEG as part of standard care.
Secondary ID [1] 297534 0
None
Universal Trial Number (UTN)
U1111-1229-2715
Trial acronym
None
Linked study record
Not applicable

Health condition
Health condition(s) or problem(s) studied:
Orthopaedic surgery 311745 0
Total hip arthroplasty 311746 0
Condition category
Condition code
Surgery 310370 310370 0 0
Other surgery
Anaesthesiology 310371 310371 0 0
Anaesthetics
Blood 310372 310372 0 0
Clotting disorders

Intervention/exposure
Study type
Observational
Patient registry
False
Target follow-up duration
Target follow-up type
Description of intervention(s) / exposure
This retrospective observational study will include the records of patients who have undergone elective total hip arthroplasty under general and spinal anaesthesia who have had a thromboelastograph done as part of routine clinical care. We aim to review thromboelastograph from the time of surgery until patient discharge. As this is a retrospective audit of the medical records, no patient involvement is required. Patients will not be contacted in any way, and all information extracted from the records will be de-identified and aligned with hospital governance processes for clinical audit and retrospective data collection.
Intervention code [1] 313770 0
Early Detection / Screening
Comparator / control treatment
For patients who have undergone elective total hip arthroplasty who have had a thromboelastograph done as part of routine care, we will compare the thromboelastograph in patients who have had their surgery performed under general anaesthesia to those who have had their surgery performed under spinal anaesthesia.
Control group
Active

Outcomes
Primary outcome [1] 319248 0
The development of a hypercoagulable state as evident by the maximum amplitude (measured in millimeters). This information will be obtained by reviewing the medical records. There is no patient contact at any point.
Timepoint [1] 319248 0
From the time of surgery to hospital discharge.
Secondary outcome [1] 367433 0
The development of a hypercoagulable state as evident by the R-time (measured in minutes) on the thromboelastograph. This information will be obtained by reviewing the medical records. There is no patient contact at any point.
Timepoint [1] 367433 0
From the time of surgery to hospital discharge.
Secondary outcome [2] 367434 0
The development of a hypercoagulable state as evident by the K-Time (measured in minutes) on the thromboelastograph. This information will be obtained by reviewing the medical records. There is no patient contact at any point.
Timepoint [2] 367434 0
From the time of surgery to hospital discharge.
Secondary outcome [3] 367435 0
The development of a hypercoagulable state as evident by the Alpha Angle (measured in degrees) on the thromboelastograph. This information will be obtained by reviewing the medical records. There is no patient contact at any point.
Timepoint [3] 367435 0
From the time of surgery to hospital discharge.
Secondary outcome [4] 367436 0
The development of a hypercoagulable state as evident by the clot lysis at 30 minutes on the thromboelastograph. This is measure by the amplitude of the thromboelastograph at this time point. This information will be obtained by reviewing the medical records. There is no patient contact at any point.
Timepoint [4] 367436 0
From the time of surgery to hospital discharge.

Eligibility
Key inclusion criteria
Adult patients (age greater 18 years), undegoing elective primary total hip arthoplasty under a general or spinal anaesthetic
Minimum age
18 Years
Maximum age
No limit
Gender
Both males and females
Can healthy volunteers participate?
No
Key exclusion criteria
Emergency hip arthroplasty
Patients who have not had a thromboelastogram performed as part of routine clinical care

Study design
Purpose
Natural history
Duration
Longitudinal
Selection
Defined population
Timing
Retrospective
Statistical methods / analysis
Given that this is a retrospective audit, simple descriptive statistics will be performed. For non-normally distributed data we will use non-parametric statistical analysis (Friedman’s test) followed by the Wilcoxon signed rank test with Bonferroni correction to evaluate changes in TEG over time in each group. We will use the Mann-Whitney U test to compare data between patients having general anaesthesia and patients having spinal anaesthesia at any given sampling time point. Data will be enteredas medians with quartiles. A p < 0.05 will be considered statistically significant.

Recruitment
Recruitment status
Completed
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 in Australia
Recruitment state(s)
VIC
Recruitment hospital [1] 13260 0
Austin Health - Austin Hospital - Heidelberg
Recruitment hospital [2] 13261 0
Austin Health - Heidelberg Repatriation Hospital - Heidelberg West
Recruitment postcode(s) [1] 25824 0
3084 - Heidelberg

Funding & Sponsors
Funding source category [1] 302093 0
Hospital
Name [1] 302093 0
Austin Health
Address [1] 302093 0
145 Studley Road, Heidlelberg, 3084, Victoria, Australia
Country [1] 302093 0
Australia
Primary sponsor type
Hospital
Name
Austin Health
Address
145 Studley Road, Heidlelberg, 3084, Victoria, Australia
Country
Australia
Secondary sponsor category [1] 301914 0
None
Name [1] 301914 0
Address [1] 301914 0
Country [1] 301914 0

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 302772 0
Austin Health Research Ethics Commitee
Ethics committee address [1] 302772 0
145 Studley Road, Austin Health, Heidlelberg, 3084, Victoria, Australia
Ethics committee country [1] 302772 0
Australia
Date submitted for ethics approval [1] 302772 0
25/02/2019
Approval date [1] 302772 0
05/04/2019
Ethics approval number [1] 302772 0
LNR/19/Austin/21

Summary
Brief summary
This retrospective observational study will be conducted by the Department of anaesthesia.

Total hip arthroplasty (THA) can result in a significant surgical stress, which in turn can trigger a hypercoagulable state. These patients are at significant risk for the development of thromboembolic complications. Despite venous thromboembolism (VTE) chemoprophylaxis being administered to all patients who undergo THA at Austin Health, VTE remains a common cause of preventable death and a well recognised complication after total THA. Despite combining extended VTE chemoprophylaxis with early mobilization, compression stockings and intermittent pneumatic compression devices, many patients at Austin Health who undergo THA remain at high risk for VTE because of advanced age, extensive surgical procedures, and greater medical comorbidities. Furthermore, a large multicenter study showed that most VTE’s occur due to prophylaxis failure rather than failure to provide prophylaxis. Although several agents have been shown to reduce the risk of thromboembolic disease, there is no clear preference for thromboembolic chemoprophylaxis for patients undergoing elective total hip arthroplasty.

Thromboelastography (TEG) measures whole blood coagulation and fibrinolysis providing a global view of the interaction between all components of clot formation, retraction and lysis. TEG is one of the most sensitive methods currently available for the assessment of a perioperative hypercoagulable state with numerous reports in surgical patients demonstrating an association between TEG measured variables, anaesthetic techniques, and postoperative thrombotic events. Studies have demonstrated that major joint arthroplasty is associated with activation of coagulation (hypercoagulable state) as measured by TEG, however there have been few comparisons of the effects of general and regional anaesthesia techniques on coagulation.

Therefore, we propose to perform a retrospective audit of patients who underwent THA at Austin Health, who received a TEG as part of routine care.

The primary aims of this retrospective review are to determine if VTE chemoprophylaxis with low molecular weight heparin prevents hypercoagulability after THA (as assessed by TEG) and if general or spinal anaesthesia had similar effects on perioperative coagulability as measured by TEG.

Notably, there will be NO CLINICAL or patient contact at any point. All data collected has already been collected as part of routine clinical care according to standard anaesthesia and surgical processes. No new data will be collected.

Trial website
Not applicable
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 91346 0
A/Prof Laurence Weinberg
Address 91346 0
Department of Anaesthesia, Austin Health, Studley Road, Heidelberg, Victoria, Australia, 3084
Country 91346 0
Australia
Phone 91346 0
+61 394965000
Fax 91346 0
+61 394966421
Email 91346 0
laurence.weinberg@austin.org.au
Contact person for public queries
Name 91347 0
A/Prof Laurence Weinberg
Address 91347 0
Department of Anaesthesia, Austin Health, Studley Road, Heidelberg, Victoria, Australia, 3084
Country 91347 0
Australia
Phone 91347 0
+61 394965000
Fax 91347 0
+61 394966421
Email 91347 0
laurence.weinberg@austin.org.au
Contact person for scientific queries
Name 91348 0
A/Prof Laurence Weinberg
Address 91348 0
Department of Anaesthesia, Austin Health, Studley Road, Heidelberg, Victoria, Australia, 3084
Country 91348 0
Australia
Phone 91348 0
+61 394965000
Fax 91348 0
+61 394966421
Email 91348 0
laurence.weinberg@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 retrospective study and a non international study
What supporting documents are/will be available?
No other documents available
Summary results
Have study results been published in a peer-reviewed journal?
No
Other publications
Have study results been made publicly available in another format?
Results – basic reporting
Results – plain English summary