NOL Index in Response to Pacemaker Stimulation

NOL Index in Response to Pacemaker Stimulation in Open-heart Surgery

The Nociception Level Index (NOL Index) utilizes various signals to assess the balance of nociception and antinociception during anesthesia. Its correlation with nociceptive stimuli and opioids is known, but its response to isolated heart rate changes remains uncertain. The aim is to investigate how cardiac pacing affects the NOL Index.

Study Overview

• Status: Completed
• Conditions: Nociceptive Pain
• Intervention / Treatment: Procedure: Pacemaker stimulation

Detailed Description

The Nociception Level Index (NOL Index) represents an innovative approach to monitoring nociception during general anesthesia, utilizing a combination of signals from photoplethysmography, accelerometry, thermometry, and skin conductance to assess the balance between nociceptive and antinociceptive states. Research has already established how the NOL Index correlates with both nociceptive stimuli and opioid levels, providing valuable insights into patient responses. However, the impact of changes in heart rate, specifically through isolated cardiac pacing, on the NOL Index is not yet clear. The primary goal of this study is to explore and understand how cardiac pacing might influence the readings of the NOL Index, potentially offering a new dimension to managing anesthesia effectively.

• Study Type: Observational
• Enrollment (Actual): 20

Contacts and Locations

Study Locations

• Romania
  • Bucharest, Romania, 022328
    • "Prof CC Iliescu" Emergency Institue for Cardiovascular Diseases

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Probability Sample

Study Population

Mechanically ventilated postoperative adult patients, admitted to the ICU within 6 hours after elective cardiac surgery.

Description

Inclusion Criteria:

• Informed consent
• Preoperative and postoperative sinus rhythm (50-90 bpm)
• Norepinephrine support < 100 ng/kg/min

Exclusion Criteria:

• Redo or emergent surgery
• History of any cardiac arrhythmia
• Any cardiocirculatory support other than norepinephrine
• Perioperative treatment with beta-blockers, calcium-channel blockers or ivabradine

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort

Intervention / Treatment

Pacemaker; Mechanically ventilated postoperative adult patients, admitted to the intensive care unit (ICU) within 6 hours after elective cardiac surgery, undergo pacemaker stimulation at various rates to observe how this influences the NOL Index.

Procedure: Pacemaker stimulation; We deactivate the pacemaker to establish baseline measurements of NOL, bispectral index (BIS), mean arterial pressure (MAP), and heart rate (HR), recorded every minute for 5 minutes. We then adjust the pacemaker to 90 bpm and 110 bpm in subsequent 5-minute phases to assess the physiological responses. After deactivating the pacemaker to analyze washout effects, we reactivate it at 110 bpm to observe any changes. A temporary disconnection of the NOL monitor for 1 minute tests system reliability, followed by continued monitoring at the same rate for an additional 5 minutes. Each measurement phase averages data from the last 10 seconds each minute to ensure accuracy and reduce artifacts.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
NOL index	The Nociception Level Index (NOL Index) quantitatively evaluates the balance between nociception and antinociception in mechanically ventilated postoperative adult patients after elective cardiac surgery, utilizing a multiparametric approach that includes photoplethysmography, accelerometry, thermometry, and skin conductance.	Every minute during seven 5-minute intervals under various pacemaker settings, totaling 35 minutes of monitoring.

Collaborators and Investigators

• Sponsor: Institutul de Urgenţă pentru Boli Cardiovasculare Prof.Dr. C.C. Iliescu
• Investigators: Study Chair: Serban-Ion Bubenek-Turconi, Professor, CC Iliescu Cardiovascular Institute

Study record dates

Study Major Dates

• Study Start (Actual): November 18, 2024
• Primary Completion (Actual): June 1, 2025
• Study Completion (Actual): July 1, 2025

Study Registration Dates

• First Submitted: November 17, 2024
• First Submitted That Met QC Criteria: November 17, 2024
• First Posted (Actual): November 20, 2024

Study Record Updates

• Last Update Posted (Actual): August 11, 2025
• Last Update Submitted That Met QC Criteria: August 7, 2025
• Last Verified: August 1, 2025

More Information

Terms related to this study

• Keywords: cardiac surgery; NOL index; pacemaker; nociception
• Additional Relevant MeSH Terms: Pain; Neurologic Manifestations; Nociceptive Pain
• Other Study ID Numbers: 33964

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No