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Trial registered on ANZCTR

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

Titles & IDs
Public title
Can Heart Rate Variability analysis reduce analgesic requirements after laparoscopic cholecystectomy?
Scientific title
A randomised controlled pilot trial comparing the effectiveness of intraoperative Acute Nociception Index (ANI) monitoring on reducing moderate-severe pain in the Postanaesthesia Care Unit (PACU) in patients having elective cholecystectomy.
Secondary ID [1] 281101 0
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
cholecystectomy 287259 0
Condition category
Condition code
Anaesthesiology 287676 287676 0 0
Pain management

Study type
Description of intervention(s) / exposure
Dose of intraoperative intravenous analgesia administration (morphine or fentanyl) based on measurement of autonomic tone using the Acute Nociception Index (ANI) monitor. The ANI monitor is a modified ECG monitor that uses a software algorthim to measure variation in the ECG R-R interval to generate an index for the patients autonomic tone. Dose ranges MORPHINE 3-5mg (give 5mg if ANI < 30), max cumulative dose 40mg (age<50), 30mg (age<75) OR FENTANYL 30-50mcg (give 50mcg if ANI < 30), max cumulative dose 400mcg (age<50), 300mcg (age<75)
Review ANI after 5 minutes and repeat bolus as above if ANI score remains below 50. Repeat after every 5 minutes until ANI score >50 (maximum morphine dose permitted 40mg if age<50, 30 mg if age 50-75- or fentanyl equivalent)
Intervention code [1] 285555 0
Treatment: Devices
Intervention code [2] 285623 0
Treatment: Drugs
Comparator / control treatment
Intervention group:, ANI score below 50:
a. MORPHINE 3-5mg (give 5mg if ANI < 30), max cumulative dose 40mg (age<50), 30mg (age<75)
b. FENTANYL 30-50mcg (give 50mcg if ANI < 30), max cumulative dose 400mcg (age<50), 300mcg (age<75)
Review ANI every 5 minutes and bolus as per above.
Comparator group: usual practice. i.e. Intraoperative analgesia administration (morphine of fentanyl) in doses based on clinician experience and training, based on usual clinical practice (e.g. increase heart rate,increased blood pressure, etc). There are no protocols to guide this. Maximum doses as above.
Control group

Primary outcome [1] 287848 0
Proportion with severe pain (Visual Analogue Scale >5 ) in PACU
Timepoint [1] 287848 0
1 hour
Secondary outcome [1] 298931 0
Sum of pain scores (Visual Analogue Scale) at 15, 30, 45 and 60 minutes in recovery room
Timepoint [1] 298931 0
1 hour
Secondary outcome [2] 298932 0
Total amount of rescue Morphine/Fentanyl protocol in PACU in mg. PACU opioid pain protocol is based on clinical assessment of patients pain i.e VAS score 3-5 give morphine 1mg, reassess after 5 minutes, VAS pain score >5 give 3mg morphine, reassess after 5 minutes.
Timepoint [2] 298932 0
1 hour

Key inclusion criteria
Elective laparoscopic cholecystectomy
Minimum age
18 Years
Maximum age
74 Years
Both males and females
Can healthy volunteers participate?
Key exclusion criteria
Inability to obtain informed consent from patient
Cognitively impaired patients
Emergency cholecystectomy
Non-sinus rhythmn cardiac status
Known impairment of the autonomic nervous system

Study design
Purpose of the study
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Eligible participant will be identified from the elective surgical operating list. Informed written consent will be sought from the patient on the day of surgery by an investigator, or by the anaesthetist / anaesthetic registrar.
Randomisation to a treatment group will be determined in advance (blocked random allocation) and concealed by means of sealed, opaque and tamper-proof envelopes.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Blocked random allocation by the trial statistician
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?

Intervention assignment
Other design features
Phase 4
Type of endpoint(s)
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)

Funding & Sponsors
Funding source category [1] 285887 0
Name [1] 285887 0
Peninsula Health
Address [1] 285887 0
Hastings Rd
Frankston. VIC 3199
Country [1] 285887 0
Primary sponsor type
Peninsula Health (Frankston Hospital)
Hastings Rd
Frankston VIC 3199
Secondary sponsor category [1] 284712 0
Name [1] 284712 0
Address [1] 284712 0
Country [1] 284712 0

Ethics approval
Ethics application status
Ethics committee name [1] 287917 0
Peninsula Health HREC
Ethics committee address [1] 287917 0
PO Box 52
Frankston VIC 3199
Ethics committee country [1] 287917 0
Date submitted for ethics approval [1] 287917 0
Approval date [1] 287917 0
Ethics approval number [1] 287917 0

Brief summary
This study investigates whether using a new pain monitoring device, the ANI monitor, can better predict how much pain-killing medication patients having keyhole gallbladder surgery need. During gallbladder removal patients are asleep and unaware but still need pain-killing medication such as morphine or fentanyl to make sure they are not in severe pain when you wake up.

Anaesthetist currently estimate how much pain-killing medication is needed based on factors including patient age, body weight, thepatients response to the surgery judged by blood pressure/heart rate monitoring and the anaesthetists clinical experience. Using these methods, patients sometimes wake up after surgery with severe pain because the prediction of dose for pain-killing medicine during surgery was incorrect.

In this study, we will be testing a new pain monitor which may be able to more accurately predict a patients analgesia requirements during surgery. This monitor requires two gel electrodes to be placed on your chest, alongside the gel electrodes that are put on by the anaesthetist for standard heart monitoring. It records heart rate with great accuracy and using complex mathematical formulas, generates a number (the acute nociception index) which may better predict the pain levels while the patient is anaesthetized.
This study compares the comfort of patients waking up after gallbladder surgery when the monitor is used compared with standard care.
Trial website
Trial related presentations / publications
J. A. Szental, A. Webb, C. Weeraratne, A. Campbell, H. Sivakumar, and S. Leong
Postoperative pain after laparoscopic cholecystectomy is not reduced by intraoperative analgesia guided by analgesia nociception index (ANI®) monitoring: a randomized clinical trial
Br. J. Anaesth. (2015) 114 (4): 640-645 first published online December 23, 2014 doi:10.1093/bja/aeu411
Public notes

Principal investigator
Name 34627 0
Dr Joshua Szental
Address 34627 0
Department of Anaesthesia
Peninsula Health
Frankston VIC 3199
Country 34627 0
Phone 34627 0
Fax 34627 0
Email 34627 0
Contact person for public queries
Name 17874 0
Dr Dr Ashley Webb
Address 17874 0
Department of Anaesthesia
Peninsula Health
Hastings Rd
Frankston VIC 3199
Country 17874 0
Phone 17874 0
Fax 17874 0
Email 17874 0
Contact person for scientific queries
Name 8802 0
Dr Dr Ashley Webb
Address 8802 0
Department of Anaesthesia
Peninsula Health
Hastings Rd
Frankston VIC 3199
Country 8802 0
Phone 8802 0
Fax 8802 0
Email 8802 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