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Trial registered on ANZCTR

Registration number
Ethics application status
Date submitted
Date registered
Date last updated
Type of registration
Retrospectively registered

Titles & IDs
Public title
Value of the Analgesia Nociception Index (ANI) to intraoperatively predict changes in blood pressure and heart rate
Scientific title
Intraoperative patients: value of the Analgesia Nociception Index to predict changes in heart rate and blood pressure.
Secondary ID [1] 281992 0
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Heart rate and systolic blood pressure in anaesthetized patients 288427 0
Nociception (by means of the analgesia nociception index) 288428 0
Condition category
Condition code
Anaesthesiology 288778 288778 0 0
Neurological 288799 288799 0 0
Studies of the normal brain and nervous system

Study type
Patient registry
Target follow-up duration
Target follow-up type
Description of intervention(s) / exposure
Observation (continuous monitoring) of the analgesia nociception index (ANI) during anaesthesia for elective surgery. Simulataneously monitoring of systolic blood pressure, heart rate and bispectral index.
ANI will be monitored over the entire period of anaesthesia (hence varying times between patients) by means of 2 sticky electrodes applied to the patient's chest. The sampled electrogrardiographic data is then used to calculate cardiac poarasympathetic activity, and finally displayed as a 0-100 score (high numbers mean more comfortable patient).
Intervention code [1] 286563 0
Not applicable
Comparator / control treatment
Control group

Primary outcome [1] 288914 0
Predictive value of ANI for changes of systolic blood pressure or heart rate within a 5-minute interval (5 minutes from ANI change) in patients undergoing non-emergency surgery
Timepoint [1] 288914 0
intraoperatively. Multiple events possible. ANI changes > 20% from baseline are named "ANI event". A period of 5 minutes after such event is observed for changes in HR or blood pressure (> 10%)
Secondary outcome [1] 301321 0
Changes in ANI after (within 5 minutes) changes in heart rate or blood pressure ("changes" of HR and BP defined as > 15% from baseline)
Timepoint [1] 301321 0
intraoperatively. Observation of ANI for 5 minutes after changes in heart rate of blood pressure (> + 15% from baseline)

Key inclusion criteria
Patients scheduled for non-emergency surgery planned to be anaesthetized using sevoflurane and fentanyl.
Minimum age
18 Years
Maximum age
No limit
Both males and females
Can healthy volunteers participate?
Key exclusion criteria
Patients on medication with beta-receptorblockers, clonidine, ketamine, continuous infusion of vasoactive substances, neostigmine, glycopyrrolate or atropine. Patients with incapacity to consent, < 18 years or patients who not wish to participate. Patients with an allergy to sticky ecg electrodes as well as patients with a pacemaker. Patients whose surgery will include use of a tourniquet will also be excluded.

Study design
Statistical methods / analysis

Recruitment status
Date of first participant enrolment
Date of last participant enrolment
Date of last data collection
Sample size
Accrual to date
Recruitment in Australia
Recruitment state(s)
Recruitment postcode(s) [1] 6366 0
6000 - Perth

Funding & Sponsors
Funding source category [1] 286771 0
Commercial sector/Industry
Name [1] 286771 0
Becor Medical Solutions, Perth, WA provided the ANI monitor and electrodes free of charge
Address [1] 286771 0
3/6 Norton St
South Perth , WA 6161
Country [1] 286771 0
Funding source category [2] 286772 0
Self funded/Unfunded
Name [2] 286772 0
Thomas Ledowski
Address [2] 286772 0
Dept. of Anaesthesia
Royal Perth Hospital
Wellington St
Perth WA 6000
Country [2] 286772 0
Primary sponsor type
Thomas Ledowski
Dept. of Anaesthesia
Royal Perth Hospital
Wellington St
Perth WA 6000
Secondary sponsor category [1] 285551 0
Name [1] 285551 0
Address [1] 285551 0
Country [1] 285551 0

Ethics approval
Ethics application status
Ethics committee name [1] 288836 0
Royal Perth Hospital
Ethics committee address [1] 288836 0
Royal Perth Hospital
Level 5 Colonial House
Wellington Street
Perth WA 6000
Ethics committee country [1] 288836 0
Date submitted for ethics approval [1] 288836 0
Approval date [1] 288836 0
Ethics approval number [1] 288836 0
EC 12/191

Brief summary
The Analgesia nociception index (ANI) is a novel score aiming to enable anaesthetists to estimate pain perception in anaesthetized patients. It work via 2 sticky (single use) electrodes applied to the chest (like ECG electrodes) from which it derives ECG data. This is then transformed into an index from 0-100, the ANI which will be larger in states of comfort and smaller in states of more pain. Although non-invasive and risk free, very few data exist to show the association of ANI with standard measures of nociception/pain in unconscious subjects: changes in blood pressure, heart rate or patient movement. We aim to do an observational trial on 30 patients in which we attach ANI monitoring to anaesthetized patients, record the ANI score continuously and match these records with other patient data obtained at the same time (blood pressure, heart rate, patient movement). This should enable us to get a better idea about the predictive value of ANI changes to preempt changes in above mentioned standart observations.
Trial website
Trial related presentations / publications
Public notes

Principal investigator
Name 38010 0
Prof Thomas Ledowski
Address 38010 0
Dept. of Anaesthesia
Royal Perth Hospital
Wellington Street Campus
Perth WA 6000
Country 38010 0
Phone 38010 0
+61 8 9224 0201
Fax 38010 0
Email 38010 0
Contact person for public queries
Name 38011 0
Prof Thomas Ledowski
Address 38011 0
Dept. of Anaesthesia
Royal Perth Hospital
Wellington Street Campus
Perth WA 6000
Country 38011 0
Phone 38011 0
+61 8 9224 0201
Fax 38011 0
Email 38011 0
Contact person for scientific queries
Name 38012 0
Prof Thomas Ledowski
Address 38012 0
Dept. of Anaesthesia
Royal Perth Hospital
Wellington Street Campus
Perth WA 6000
Country 38012 0
Phone 38012 0
+61 8 9224 0201
Fax 38012 0
Email 38012 0

No information has been provided regarding IPD availability
Summary results
Have study results been published in a peer-reviewed journal?
Other publications
Have study results been made publicly available in another format?
Results – basic reporting
Results – plain English summary