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Trial registered on ANZCTR


Registration number
ACTRN12617001263381
Ethics application status
Approved
Date submitted
25/08/2017
Date registered
1/09/2017
Date last updated
13/12/2018
Date data sharing statement initially provided
13/12/2018
Date results information initially provided
13/12/2018
Type of registration
Prospectively registered

Titles & IDs
Public title
Magnesium after cardiac surgery practice change audit
Scientific title
An audit of a change in the intensive care unit magnesium administration protocol in patients following cardiac surgery: effect on occurrence of atrial fibrillation
Secondary ID [1] 292733 0
Nil Known
Universal Trial Number (UTN)
Trial acronym
MAGIC IV
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Electrolyte disturbance 304499 0
Cardiovascular disease 304500 0
CARDIAC SURGERY 304564 0
Condition category
Condition code
Cardiovascular 303837 303837 0 0
Coronary heart disease
Surgery 303890 303890 0 0
Other surgery

Intervention/exposure
Study type
Observational
Patient registry
False
Target follow-up duration
Target follow-up type
Description of intervention(s) / exposure
From 1st October 2017 until 31st March 2018, for all cardiac surgical patients at admission to the ICU following surgery, a loading dose of 10 mmol of magnesium sulphate diluted in 100 mL of saline will be administered intravenously over the period of 1 hour. After the end of the loading dose, a continuous infusion of magnesium sulphate will be commenced at a rate of 3 mmol/h (total extrapolated dose over 24 hours of 82 mmol). The continuous infusion will be maintained during the first 96 hours of ICU stay or until ICU discharge, whichever occurs first; and we will aim a serum magnesium concentration between 1.5 and 2.0 mmol/L with magnesium level monitoring twice daily.
Intervention code [1] 298979 0
Not applicable
Comparator / control treatment
From 1st October 2016 until the 31st March 2017, for all cardiac surgical patients admitted to the ICU we will retrospectively collected data for their medical record
Control group
Historical

Outcomes
Primary outcome [1] 303200 0
Occurrence of atrial fibrillation - hospital stay
Timepoint [1] 303200 0
As documented in the patient's medical record as assessed from the time of admission to the intensive care unit through to discharge from the hospital
Primary outcome [2] 303201 0
Occurrence of atrial fibrillation - Intensive care unit admission
Timepoint [2] 303201 0
As documented in the patient's medical record as assessed from the time of admission to the intensive care unit through to discharge from the intensive care unit
Secondary outcome [1] 338222 0
Duration of intensive care unit admisison
Timepoint [1] 338222 0
Number of days that patient is admitted to the intensive care unit following cardiac surgery.
Secondary outcome [2] 338223 0
Duration of hospital admission
Timepoint [2] 338223 0
Number of days that patient is admitted to the hospital following cardiac surgery.
Secondary outcome [3] 338224 0
Duration of mechanical ventilation
Timepoint [3] 338224 0
The total number of hours of mechanical ventilation in the intensive care unit following cardiac surgery.
Secondary outcome [4] 338225 0
Mean serum magnesium concentration
Timepoint [4] 338225 0
Mean serum magnesium concentration of the routine morning formal blood test during admission to intensive care
Secondary outcome [5] 338226 0
Dose of magnesium sulphate administered
Timepoint [5] 338226 0
Total amount in mmol/L of magnesium sulphate administered to post-cardiac surgery patients during the intensive care admission

Eligibility
Key inclusion criteria
Adult (aged 18 years or older) patients who are admitted to the intensive care unit following cardiac surgery.
Minimum age
18 Years
Maximum age
No limit
Gender
Both males and females
Can healthy volunteers participate?
No
Key exclusion criteria
- known renal impairment
- treating intensive care unit consultant feels that it is not in the patient's best interest to be treated with the new magnesium supplementation protocol

Study design
Purpose
Natural history
Duration
Cross-sectional
Selection
Convenience sample
Timing
Both
Statistical methods / analysis
We will apply descriptive and inferential statistical procedures to the data collected for the purposes of this audit. Baseline comparisons will be performed using Fisher’s exact tests and reported as n (%). Continuous normally distributed variables will be compared using Student t-tests and reported as means (standard deviation), while non-normally distributed data will be compared using Wilcoxon rank-sum tests and reported as medians [interquartile range]. Changes over time will be determined using repeated measures mixed linear modeling with each patient treated as a random effect, and therapy group, time and the interaction of therapy group and time as effect fixed effects.

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] 8869 0
Austin Health - Austin Hospital - Heidelberg
Recruitment postcode(s) [1] 17119 0
3084 - Heidelberg

Funding & Sponsors
Funding source category [1] 297370 0
Hospital
Name [1] 297370 0
Austin Hospital
Address [1] 297370 0
145 Studley Road
Heidelberg VIC 3084
Country [1] 297370 0
Australia
Primary sponsor type
Hospital
Name
Austin Health
Address
145 Studley Road
Heidelberg VIC 3084
Country
Australia
Secondary sponsor category [1] 296348 0
Individual
Name [1] 296348 0
Professor Rinaldo Bellomo
Address [1] 296348 0
Director, Intensive Care Research
Department of Intensive Care
Austin Hospital
145 Studley Road
Heidelberg, VIC 3084
Country [1] 296348 0
Australia

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 298474 0
Austin Health Human Research Ethics Committee
Ethics committee address [1] 298474 0
Austin Hospital
145 Studley Road
Heidelberg VIC 3084
Ethics committee country [1] 298474 0
Australia
Date submitted for ethics approval [1] 298474 0
16/08/2017
Approval date [1] 298474 0
22/08/2017
Ethics approval number [1] 298474 0
LNR/17/Austin/416

Summary
Brief summary
Atrial fibrillation (AF) is the most common complication after cardiac surgery, with an incidence ranging from 20 to 50%. It represents a potential cause of thromboembolic events, hemodynamic instability and prolonged Intensive Care Unit (ICU) stay. Maintaining a normal blood magnesium concentration may help prevent the onset of atrial fibrillation after cardiac surgery.

Previously we performed an assessment of the pharmacokinetics of magnesium administration after cardiothoracic surgery from August, 2016 to April, 2017: “Assessment of Blood and Urine Magnesium Levels in Patients Admitted to the Intensive Care Unit” (HREC: LNR/15/Austin/306). We included 60 patients: 30 patients in the before period who received a bolus of 20 mmol of magnesium sulphate over 1 hour; and 30 patients in the after period who received a bolus of 10 mmol of magnesium sulphate followed by a continuous infusion at 3 mmol/h over 12 hours. In the before period, we found that the loading dose of 20 mmol increased both serum and urinary magnesium concentrations, however the serum concentration returned to pre-intervention levels within 12 hours of observation and the urinary excretion remained elevated. In the after period, the intervention of a loading dose of 10 mmol of magnesium sulphate followed by a continuous infusion was associated with an increase of both the serum and urinary concentrations of magnesium over time. The after-period protocol allowed us to achieve a sustained, safe, and moderately elevated serum magnesium concentration at twice to three times the lowest total magnesium concentration in our laboratory (1.4 to 2.0 mmol/L), which might be expected to deliver a greater chance of AF prevention. As such the management practices associated with magnesium administration in our intensive care unit has changed. The purpose of this project is to evaluate the effect of the new protocol on the incidence of atrial fibrillation in patients who undergo cardiac surgery and are admitted to the intensive care unit. Using a medical record audit design we will evaluate patients treated with the new magnesium protocol with that of a historical control.
Trial website
Trial related presentations / publications
Public notes
Attachments [1] 1994 1994 0 0

Contacts
Principal investigator
Name 77194 0
Prof Rinaldo Bellomo
Address 77194 0
Department of Intensive Care
Austin Hospital
145 Studley Road
Heidelberg VIC 3084
Country 77194 0
Australia
Phone 77194 0
+61 3 9496 5992
Fax 77194 0
+61 3 9496 3932
Email 77194 0
rinaldo.bellomo@austin.org.au
Contact person for public queries
Name 77195 0
Dr Glenn Eastwood
Address 77195 0
Department of Intensive Care
Austin Hospital
145 Studley Road
Heidelberg VIC 3084
Country 77195 0
Australia
Phone 77195 0
+61 3 9496 4835
Fax 77195 0
+61 3 9496 3932
Email 77195 0
glenn.eastwood@austin.org.au
Contact person for scientific queries
Name 77196 0
Prof Rinaldo Bellomo
Address 77196 0
Department of Intensive Care
Austin Hospital
145 Studley Road
Heidelberg VIC 3084
Country 77196 0
Australia
Phone 77196 0
+61 3 9496 4835
Fax 77196 0
+61 3 9496 3932
Email 77196 0
rinaldo.bellomo@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
pilot single centre investigation with the aim of providing preliminary safety data and only be hypothesis generating.
What supporting documents are/will be available?
No other documents available
Summary results
Have study results been published in a peer-reviewed journal?
Yes
Journal publication details
Publication date and citation/details [1] 764 0
Critical Care and Resuscitation • Volume 20 Number 3 • September 2018
Attachments [1] 764 0
Other publications
Have study results been made publicly available in another format?
Results – basic reporting
Results – plain English summary
The strategy of a 10 mmol magnesium bolus followed by a continuous infusion over 12 hours achieved a more sustained and moderately elevated magnesium concentration in comparison to a single 20 mmol bolus, despite increased urinary losses of magnesium. Further studies are required.