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ANI Parasympathetic Monitoring in Neurosurgery

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

Status
Completed
Phases
Unknown
Study type
Observational
Source
ClinicalTrials.gov
Registry ID
NCT03978819
Acronym
ANI
Enrollment
100
Registered
2019-06-07
Start date
2015-11-30
Completion date
2017-11-30
Last updated
2019-06-07

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Bradycardia

Keywords

Analgesia nociception index, Parasympathetic nerve stimulation, Excessive analgesia

Brief summary

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.

Detailed description

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).

Interventions

DEVICEANI

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.

Sponsors

Association de Developpement de la Neuroanesthesie Reanimation
Lead SponsorOTHER
University of Bordeaux
CollaboratorOTHER

Study design

Observational model
COHORT
Time perspective
PROSPECTIVE

Eligibility

Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No

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.

Design outcomes

Primary

MeasureTime frameDescription
Differences in instantaneous ANI (ANIi) values during bradycardia versus ANIi values when Remifentanil effect size concentration >6ng/mLANIi 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
Differences in the area under the ROC curves between ANI values for IPNS and EA analgesiaANIi values recorded at Day 1 only during surgery (duration: 4-6 hours)ROC curves were built at different ANIi for IPNS or EA

Secondary

MeasureTime frameDescription
Percentages of IPNS and EA casesCases 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.

Countries

France

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026