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NCT Number: NCT03978819

ANI Parasympathetic Monitoring in Neurosurgery

Surgery of large cerebellopontine angle (CPA) tumors (>2 x 2 cm diameter), with compression of the pons exposes the patient to inadvertent parasympathetic nerve stimulation (IPNS) leading to bradycardia and asystole.

The analgesia nociception index (ANI) monitor assesses the balance between analgesia and nociception through the detection of parasympathetic tone. ANI >80 generally denotes excessive analgesia (EA). The main objective of this study was to determine whether ANI values for IPNS are different or the same as ANI values for EA. This study also aims at calculating the number of patients with IPNS and EA during surgery of large CPA tumours.

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Key information

Conditions

Bradycardia Arrhythmias, Cardiac Cardiovascular Diseases Heart Diseases Pathologic Processes Pathological Conditions, Signs and Symptoms

Age range

18 year and older

Sex eligibility

All sexes

Study type

Observational

Primary location

CHU Bordeaux University Hospital

Bordeaux, 33076, France

About this study

Bradycardia and asystole are potential life threatning complications during surgery of large cerebellopontine angle (CPA) tumors (>2 x 2 cm diameter), with compression of the pons.The incidence of such complications are unknown. One of the plausible mechanisms is inadvertent parasympathetic nerve stimulation (IPNS) due to the proximity of this cranial nerve to the CPA tumor. Monitoring parasympathetic nerve activity may provide further insight to the implication of this cranial nerve in the cardiac complications observed during surgery of large CPA tumors. The analgesia nociception index (ANI) monitor assesses the balance between analgesia and nociception through the detection of parasympathetic tone. Despite the abundant clinical reports about this index, to the knowledge of the investigators, only a few studies have been published in the neurological setting. Moreover, there are no data reporting the parasympathetic profile (measured by the ANI monitor) in situations of IPNS and EA. Are these profiles the same or different? Such is the main question this study thrives to answer. Understanding the behavior of parasympathetic nerve activity in this context could help provide the appropriate management strategy.

In order to answer this question, participants undergoing elective large CPA tumor surgery were included in this prospective observational study. Standard cardiorespiratory monitoring including heart rate (HR) was done. Target-controlled anesthesia with Propofol and Remifentanil was guided by a bispectral index of 30-40 and an ANI of 50-70 respectively. Data was continuously recorded with event markers at the onset of bradycardia (HR < 45 bpm), asystole and the coincidence of ANI > 80 with Remifentanil site effect > 6 ng.ml-1 (defined as excessive analgesia).

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • patients undergoing elective surgery of large cerebellopontine angle tumors

Exclusion criteria

  • age below 18yr
  • arrhythmia
  • preoperative use of vagolytics, β-blockers and clonidine.

Treatment and study plan

ANI

Device

ANI profiles during IPNS (bradycardia/asystole) or excessive analgesia.

During surgery continuous monitoring of ANI, HR and Remifentanil effect site concentration was done and recorded. Event markers were placed at the onset of bradycardia, asystole and the coincidence of ANI>80 + Remifentanil >6ng/mL). ANI values of 1 min before and 1 min after the event were used for analysis.

Primary outcomes

  1. Differences in instantaneous ANI (ANIi) values during bradycardia versus ANIi values when Remifentanil effect size concentration >6ng/mL

    Time frame: ANIi values recorded at Day 1 only during surgery (duration: 4-6 hours)

    ANI, HR and Remifentanil effect site concentration were continuously recorded with event markers on the ANI monitor at the onset of bradycardia (HR<45 bpm) or Remifentanil effect site concentration>6ng/mL

  2. Differences in the area under the ROC curves between ANI values for IPNS and EA analgesia

    Time frame: ANIi values recorded at Day 1 only during surgery (duration: 4-6 hours)

    ROC curves were built at different ANIi for IPNS or EA

Secondary outcomes

  1. Percentages of IPNS and EA cases

    Time frame: Cases observed at Day 1 only during surgery (duration: 4-6 hours)

    The percentages of IPNS or EA cases on the overall study population were calculated.

Sponsors and collaborators

Lead sponsor

Association de Developpement de la Neuroanesthesie Reanimation

Other

Collaborators

  • University of Bordeaux

Registry information

Official study title

Ability of the Analgesia Nociception Index Monitor to Distinguish Between Excessive Analgesia and Inadvertent Parasympathetic Nerve Stimulation During Surgery of Large Cerebellopontine Angle Tumours

Acronym: ANI

Important dates

Study start
2015
Primary completion
2017
Study completion
2017
First posted
Jun 7, 2019
Registry last updated
Jun 7, 2019

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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