NOL-Guided vs Conventional Intraoperative Opioid Infusion on Outcomes in Geriatric Patients

Effect of NOL-Guided vs Conventional Intraoperative Opioid Infusion on Outcomes in Geriatric Patients Undergoing Lumbar Stabilization Surgery

The aim of this study is to compare the effects of conventional methods and goal-directed therapy guided by pain monitoring on total remifentanil dosage, wake-up time, and complications in geriatric patients undergoing lumbar stabilization surgery.

Study Overview

• Status: Not yet recruiting
• Conditions: Pain; Opioid Use; Geriatric Anesthesia
• Intervention / Treatment: Device: nociceptive level

Detailed Description

With the aging population, the number of geriatric patients undergoing surgery is increasing daily. One of the anesthesiologists' main responsibilities is to prevent intraoperative pain and related complications. Opioids have been known for thousands of years as valuable tools for pain management and remain the cornerstone of perioperative analgesia today (1). Remifentanil is currently the most commonly used opioid during the intraoperative period due to its potent analgesic properties, short duration of action, and metabolism by plasma enzymes. While it may improve hemodynamic stability, remifentanil can also cause hypotension and bradycardia. Prolonged remifentanil use may lead to hyperalgesia, increasing the need for postoperative opioid analgesics and consequently leading to opioid-related side effects. In elderly patients, changes in body composition, drug sensitivity, and hepatic/renal metabolism require more cautious opioid administration.

Optimizing remifentanil infusion dosing during surgery may reduce total opioid consumption and thus decrease side effects such as wake-up time, postoperative pain, and nausea.

In conventional use, remifentanil is administered as a continuous infusion, and dosage adjustments are made based on heart rate and blood pressure changes to estimate pain levels. However, with goal-directed therapy guided by pain monitoring, more effective analgesia can be achieved. These applications are selected based on the clinician's experience and preferences. While some publications report that total remifentanil use decreases in patients with dose adjustments guided by pain monitoring, evidence is lacking regarding which method is superior in terms of patient outcomes in elderly populations.The aim of this study is to compare the effects of conventional methods and goal-directed therapy guided by pain monitoring on total remifentanil dosage, wake-up time, and complications in geriatric patients undergoing lumbar stabilization surgery.

After obtaining informed consent, a total of 80 geriatric patients undergoing lumbar stabilization surgery will be included. Once on the operating table, all patients will receive standard monitoring including peripheral oxygen saturation, non-invasive blood pressure, ECG, and anesthesia depth. All patients will receive intravenous 2-2.5 mg/kg propofol under Sedline guidance, and remifentanil via target-controlled infusion at an effect-site concentration of 4 ng/ml. After anesthesia depth falls below 50, 0.6 mg/kg rocuronium will be administered. Maintenance anesthesia will be with 1-2% sevoflurane in 40/60% oxygen/air mixture at 2 L flow. The method of remifentanil administration will be determined by the attending anesthesiologist.

Demographic data (age, height, weight, gender, comorbidities, ASA score) will be recorded. Hemodynamic parameters (blood pressure, heart rate, oxygen saturation, end-tidal CO₂), remifentanil dosage, and NOL levels (for Group 2) will be recorded every 15 minutes during the surgery. At the end of surgery, the following will be documented:

Total remifentanil dosage Blood loss and transfusion volume Number of hypotensive events (MAP <55) Wake-up time Total surgical time NRS (Numerical Rating Scale) pain scores Nausea-vomiting scores

In the post-anesthesia care unit (PACU), pain and nausea-vomiting scores will be evaluated at the 10th, 20th, and 30th minutes, along with duration of PACU stay. During ward follow-up, pain scores, nausea-vomiting scores, administered medications, and length of postoperative hospital stay will be recorded at 1, 3, 6, and 24 hours.

Nausea-vomiting will be assessed using a 4-point scale:

0: none

1. nausea without vomiting
2. nausea with vomiting
3. vomiting more than twice

Pain will be assessed using the NRS scale.

• Study Type: Observational
• Enrollment (Estimated): 80

Contacts and Locations

• Study Contact: Name: Süheyla Abitağaoğlu; Phone Number: 05325267656; Email: suheylaatay81@gmail.com

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Older Adult
• Accepts Healthy Volunteers: N/A

• Sampling Method: Probability Sample

Study Population

A total of 80 geriatric patients undergoing lumbar stabilization surgery

Description

Inclusion Criteria:

• Patients undergoing lumbar stabilization surgery

Exclusion Criteria:

• Chronic opioid use
• Severe congestive heart failıure
• Severe arrhythmia
• Uncontrolled hypertension

Study Plan

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Conservative; Our clinic's standard anesthesia induction and maintenance method will be applied to all patients. Patients will receive standard monitoring including peripheral oxygen saturation, non-invasive blood pressure, ECG, and anesthesia depth. All patients will receive intravenous 2-2.5 mg/kg propofol under Sedline guidance, and remifentanil via target-controlled infusion at an effect-site concentration of 4 ng/ml. After anesthesia depth falls below 50, 0.6 mg/kg rocuronium will be administered. Maintenance anesthesia will be with 1-2% sevoflurane in 40/60% oxygen/air mixture at 2 L flow.Remifentanil is administered as a continuous infusion in conservative approach;dosage adjustments are made based on heart rate and blood pressure changes to estimate pain levels.
Nociceptive level; Our clinic's standard anesthesia induction and maintenance method will be applied to all patients. Patients will receive standard monitoring including peripheral oxygen saturation, non-invasive blood pressure, ECG, and anesthesia depth. All patients will receive intravenous 2-2.5 mg/kg propofol under Sedline guidance, and remifentanil via target-controlled infusion at an effect-site concentration of 4 ng/ml. After anesthesia depth falls below 50, 0.6 mg/kg rocuronium will be administered. Maintenance anesthesia will be with 1-2% sevoflurane in 40/60% oxygen/air mixture at 2 L flow.Remifentanil is administered as a continuous infusion by using Nociceptive level guidance	Device: nociceptive level; remifentanil infusion dose adjustment according to the changes of nociceptive level

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Total dose	Total dose of remifentanil used in operation	operation duration

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
postoperative pain	pain evaluation during postoperative 24 hour, 11 point Numeric Rating Scale (NRS) will be used to measure pain level (0-10) 0: No pain, 10: Worst possible pain	postoperative 10th, 20th, and 30th minutes, 1, 3, 6, and 24 hours
nausea and vomiting	postoperative nausea and vomiting Nausea-vomiting will be assessed using a 4-point scale: 0: none; nausea without vomiting; nausea with vomiting; vomiting more than twice	postoperative 10th, 20th, and 30th minutes, 1, 3, 6, and 24 hours

Collaborators and Investigators

• Sponsor: Saglik Bilimleri Universitesi
• Investigators: Principal Investigator: Süheyla Abitağaoğlu, University of Health Sciences

Publications and helpful links

General Publications

• Gazelka HM, Leal JC, Lapid MI, Rummans TA. Opioids in Older Adults: Indications, Prescribing, Complications, and Alternative Therapies for Primary Care. Mayo Clin Proc. 2020 Apr;95(4):793-800. doi: 10.1016/j.mayocp.2020.02.002.
• Hwang W, Lee J, Park J, Joo J. Dexmedetomidine versus remifentanil in postoperative pain control after spinal surgery: a randomized controlled study. BMC Anesthesiol. 2015 Feb 24;15:21. doi: 10.1186/s12871-015-0004-1. eCollection 2015.
• Mercadante S. Influence of aging on opioid dosing for perioperative pain management: a focus on pharmacokinetics. J Anesth Analg Crit Care. 2024 Aug 1;4(1):51. doi: 10.1186/s44158-024-00182-2.

Study record dates

Study Major Dates

• Study Start (Estimated): July 1, 2025
• Primary Completion (Estimated): September 1, 2025
• Study Completion (Estimated): October 1, 2025

Study Registration Dates

• First Submitted: July 1, 2025
• First Submitted That Met QC Criteria: July 10, 2025
• First Posted (Actual): July 20, 2025

Study Record Updates

• Last Update Posted (Actual): July 20, 2025
• Last Update Submitted That Met QC Criteria: July 10, 2025
• Last Verified: July 1, 2025

More Information

Terms related to this study

• Other Study ID Numbers: sabitagaoglu

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No