Intraoperative PainNOLNCT07002541
PECS-II vs ESP in Nociception Level Index Guided Breast Surgery
A study testing PECS II block and ESP block in people with Intraoperative Pain and Postoperative Pain, run by Koç University at 1 site in Turkey (Türkiye).
Trial summary
Background: Breast surgery is often associated with significant perioperative pain. While systemic opioids are commonly used, their side effects (nausea, vomiting, respiratory depression, delayed recovery) have encouraged the adoption of regional anesthesia techniques for better analgesia and reduced opioid… Read more about this study
- Who is it for?
- Ages 18 to 80 years, women only
- Conditions the study is for
- Intraoperative Pain, Postoperative Pain
- What is being tested?
- PECS II block and ESP block
- Type of treatment
- Surgery or procedure
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 90 participants
- Where
- 1 siteTurkey (Türkiye)
- Study dates
- 1 Dec 2024to 30 Jun 2025
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 80 years
- Women only
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Female patients aged 18 to 80 years ASA Physical Status Classification I-III
- Scheduled for elective unilateral or bilateral breast surgery, including one or more of the following:
- Lumpectomy with axillary lymph node biopsy or dissection Breast reconstruction Breast reduction Mastopexy Implant expander removal or placement
Who cannot join
- Morbid obesity (BMI > 40 kg/m²) Presence of non-sinus cardiac rhythm Chronic opioid use (defined as daily use for >2 weeks in the last month or total use >4 weeks) History of opioid abuse or dependence Comorbidities causing moderate to severe functional limitation Inability to communicate with study personnel or follow instructions Pregnancy or breastfeeding Known allergy or hypersensitivity to bupivacaine or any study-related medication
- -
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Turkey (Türkiye)1 site, 1 recruiting
- Recruiting
Koc University
Istanbul
Omur Ercelen, Professor, +905325105014, oercelen@kochealthcare.org
About this study
Official title: NOL-Guided Intraoperative Remifentanil Consumption With PECS-II and Erector Spinae Plane Blocks in Breast Surgery: A Randomized Controlled Trial
Background:
Breast surgery is often associated with significant perioperative pain. While systemic opioids are commonly used, their side effects (nausea, vomiting, respiratory depression, delayed recovery) have encouraged the adoption of regional anesthesia techniques for better analgesia and reduced opioid requirements. PECS-II and Erector Spinae Plane (ESP) blocks are two effective regional techniques frequently utilized in breast surgery. However, comparative data on their impact on intraoperative opioid consumption under nociception-guided anesthesia remains limited.
Read more
The Nociception Level Index (NOL) is an objective monitoring tool that integrates multiple physiological signals (e.g., heart rate variability, skin conductance, pulse amplitude) to assess nociceptive responses in real-time. When used intraoperatively, it enables more precise opioid titration, potentially optimizing analgesia while minimizing opioid exposure.
Objective:
To compare the efficacy of PECS-II and ESP blocks in reducing intraoperative remifentanil consumption during breast surgery under general anesthesia guided by NOL monitoring.
Methods:
This prospective, randomized controlled trial was conducted at Koç University Hospital following ethical approval. Ninety female patients aged 18-80 years, classified as ASA I-III and scheduled for elective mastectomy or other breast surgeries, were randomly assigned into three groups (n=30 each):
Group 1 (PECS-II Block) Group 2 (ESP Block) Group 3 (Control - no block) Regional blocks were performed before surgery with ultrasound guidance. PECS-II block was administered at the 3rd to 5th rib levels in the mid-axillary line using 30 mL of 0.3% bupivacaine. ESP block was applied at T2-T5 levels with a total of 20 mL 0.5% bupivacaine.
All patients received standardized general anesthesia, including propofol, fentanyl, rocuronium, and desflurane maintenance. Remifentanil infusion (0.05-0.1 μg/kg/min) was titrated based on NOL values every 5 minutes: increased by 0.03 μg/kg/min if NOL >25, and decreased by 0.03 μg/kg/min if NOL <10.
Data collected included:
Total intraoperative remifentanil consumption (primary outcome) NOL scores every 5 minutes Postoperative pain scores (NRS) at 1st, 6th, 12th, and 24th hours (at rest and with arm abduction) Total opioid consumption (morphine, tramadol) in the first 24 hours Opioid-related side effects (nausea, vomiting, pruritus) Length of hospital stay Blinding was applied to data collectors (pain nurses and anesthesia technicians), but due to the nature of the procedures, surgeons and anesthesiologists were not blinded.
Statistical Analysis:
Data were analyzed using SPSS v26. Continuous variables were tested for normality (Shapiro-Wilk), and analyzed with t-tests or Mann-Whitney U as appropriate. Categorical variables were compared using Chi-square tests. Significance was set at p<0.05.
Expected Outcomes and Contribution:
It is hypothesized that both PECS-II and ESP blocks will significantly reduce intraoperative remifentanil consumption compared to the control group. Furthermore, these blocks may improve postoperative pain control, reduce opioid-related side effects, and shorten recovery time.
This study aims to clarify the relative efficacy of two widely used regional blocks in the context of objective, nociception-guided anesthesia. The findings are expected to support evidence-based use of regional techniques in breast surgery and contribute to the growing body of literature emphasizing opioid-sparing strategies in perioperative care.
- Conditions
- Intraoperative Pain, Postoperative Pain
- Being tested
- PECS II block, ESP block
- Medical subject headings
- Pain, Postoperative
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
PECS II blockProcedure or surgery
The PECS-II block is an ultrasound-guided interfascial plane block designed to provide analgesia for surgeries involving the anterolateral chest wall, particularly breast surgery. It is an extension of the PECS-I block, which targets the medial and lateral pectoral nerves. In the PECS-II technique, a high-frequency linear ultrasound probe is used to identify the fascial planes. A 22G, 50 mm regional block needle is advanced in-plane under sterile conditions. A total of 30 mL of 0.25% bupivacaine is administered: 10 mL is injected between the pectoralis major and minor muscles (targeting the pectoral nerves), and 20 mL between the pectoralis minor and serratus anterior muscles (to block the lateral branches of intercostal nerves and intercostobrachial nerve).
ESP blockProcedure or surgery
The erector spinae plane (ESP) block is a fascial plane block performed under ultrasound guidance to provide multimodal analgesia for thoracic and abdominal surgeries, including breast procedures. In this technique, a high-frequency linear ultrasound probe is used to visualize the transverse process of the thoracic vertebra, typically at the T4-T5 level. With the patient in a seated position and under standard sterile conditions, a 22G, 50 mm regional block needle is inserted in-plane until the tip reaches the fascial plane between the erector spinae muscle and the transverse process. After negative aspiration, 1-2 mL of test dose is injected to confirm correct needle placement by observing separation of fascial layers. Then, 20 mL of 0.25% bupivacaine is injected incrementally.
| Study group | Role | What they receive |
|---|---|---|
| PECS-II group | Active comparator | Not described Receives: Procedure: PECS II block |
| ESP group | Active comparator | Not described Receives: Procedure: ESP block |
| Control group | No intervention | Not described |
What is being measured
The primary outcome is the main question the study is designed to answer.
intraoperative remifentanyl consumption
Measured: The time frame for intraoperative remifentanil consumption refers to the entire duration of the surgical procedure, starting from skin incision to the end of surgery (skin closure).
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted3 Jun 2025
- Study start1 Dec 2024
- Primary completion1 Jun 2025 (estimated)
- Study completion30 Jun 2025 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Intraoperative PainStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Triple blind
- Who is masked
- Participant, Care provider, Outcomes assessor
- Enrolment
- 90 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Koç University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Kamil Darcin, Koç University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07002541
- Sponsor's protocol ID
- 2024.424.IRB1.047
- Acronym
- NOL
- Status last verified
- May 2025
- First submitted
- 7 May 2025
- Last updated
- 3 Jun 2025
- Results posted
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Yes
Study at a glance
From the registry record, last updated by the sponsor on 3 Jun 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- NOL-Guided Intraoperative Remifentanil Consumption With PECS-II and Erector Spinae Plane Blocks in Breast Surgery: A Randomized Controlled Trial
- ClinicalTrials.gov ID
- NCT07002541
- Acronym / sponsor ID
- NOL / 2024.424.IRB1.047
- Conditions
- Intraoperative Pain, Postoperative Pain
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 90 participants (estimated)
- Lead sponsor
- Koç UniversityUniversity, hospital or other
- Study start
- 1 Dec 2024 (actual)
- Primary completion
- 1 Jun 2025 (estimated)
- Study completion
- 30 Jun 2025 (estimated)
- First posted
- 3 Jun 2025 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Background:
Breast surgery is often associated with significant perioperative pain. While systemic opioids are commonly used, their side effects (nausea, vomiting, respiratory depression, delayed recovery) have encouraged the adoption of regional anesthesia techniques for better analgesia and reduced opioid requirements. PECS-II and Erector Spinae Plane (ESP) blocks are two effective regional techniques frequently utilized in breast surgery. However, comparative data on their impact on intraoperative opioid consumption under nociception-guided anesthesia remains limited.
The Nociception Level Index (NOL) is an objective monitoring tool that integrates multiple physiological signals (e.g., heart rate variability, skin conductance, pulse amplitude) to assess nociceptive responses in real-time. When used intraoperatively, it enables more precise opioid titration, potentially optimizing analgesia while minimizing opioid exposure.
Objective:
To compare the efficacy of PECS-II and ESP blocks in reducing intraoperative remifentanil consumption during breast surgery under general anesthesia guided by NOL monitoring.
Methods:
This prospective, randomized controlled trial was conducted at Koç University Hospital following ethical approval. Ninety female patients aged 18-80 years, classified as ASA I-III and scheduled for elective mastectomy or other breast surgeries, were randomly assigned into three groups (n=30 each):
Group 1 (PECS-II Block) Group 2 (ESP Block) Group 3 (Control - no block) Regional blocks were performed before surgery with ultrasound guidance. PECS-II block was administered at the 3rd to 5th rib levels in the mid-axillary line using 30 mL of 0.3% bupivacaine. ESP block was applied at T2-T5 levels with a total of 20 mL 0.5% bupivacaine.
All patients received standardized general anesthesia, including propofol, fentanyl, rocuronium, and desflurane maintenance. Remifentanil infusion (0.05-0.1 μg/kg/min) was titrated based on NOL values every 5 minutes: increased by 0.03 μg/kg/min if NOL >25, and decreased by 0.03 μg/kg/min if NOL <10.
Data collected included:
Total intraoperative remifentanil consumption (primary outcome) NOL scores every 5 minutes Postoperative pain scores (NRS) at 1st, 6th, 12th, and 24th hours (at rest and with arm abduction) Total opioid consumption (morphine, tramadol) in the first 24 hours Opioid-related side effects (nausea, vomiting, pruritus) Length of hospital stay Blinding was applied to data collectors (pain nurses and anesthesia technicians), but due to the nature of the procedures, surgeons and anesthesiologists were not blinded.
Statistical Analysis:
Data were analyzed using SPSS v26. Continuous variables were tested for normality (Shapiro-Wilk), and analyzed with t-tests or Mann-Whitney U as appropriate. Categorical variables were compared using Chi-square tests. Significance was set at p<0.05.
Expected Outcomes and Contribution:
It is hypothesized that both PECS-II and ESP blocks will significantly reduce intraoperative remifentanil consumption compared to the control group. Furthermore, these blocks may improve postoperative pain control, reduce opioid-related side effects, and shorten recovery time.
This study aims to clarify the relative efficacy of two widely used regional blocks in the context of objective, nociception-guided anesthesia. The findings are expected to support evidence-based use of regional techniques in breast surgery and contribute to the growing body of literature emphasizing opioid-sparing strategies in perioperative care.
Study design
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Triple blind (participant, care provider, outcomes assessor)
- Number of arms
- 3
| Arm | Type | Receives |
|---|---|---|
| PECS-II group | Active comparator | Procedure: PECS II block |
| ESP group | Active comparator | Procedure: ESP block |
| Control group | No intervention | – |
Who may qualify
- Ages
- 18 to 80 years
- Sex
- Female only
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (3 listed)
- Female patients aged 18 to 80 years ASA Physical Status Classification I-III
- Scheduled for elective unilateral or bilateral breast surgery, including one or more of the following:
- Lumpectomy with axillary lymph node biopsy or dissection Breast reconstruction Breast reduction Mastopexy Implant expander removal or placement
Key exclusion criteria (2 listed)
- Morbid obesity (BMI > 40 kg/m²) Presence of non-sinus cardiac rhythm Chronic opioid use (defined as daily use for >2 weeks in the last month or total use >4 weeks) History of opioid abuse or dependence Comorbidities causing moderate to severe functional limitation Inability to communicate with study personnel or follow instructions Pregnancy or breastfeeding Known allergy or hypersensitivity to bupivacaine or any study-related medication
- -
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| PECS II blockThe PECS-II block is an ultrasound-guided interfascial plane block designed to provide analgesia for surgeries involving the anterolateral chest wall, particularly breast surgery. It is an extension of the PECS-I block, which targets the medial and lateral pectoral nerves. In the PECS-II technique, a high-frequency linear ultrasound probe is used to identify the fascial planes. A 22G, 50 mm regional block needle is advanced in-plane under sterile conditions. A total of 30 mL of 0.25% bupivacaine is administered: 10 mL is injected between the pectoralis major and minor muscles (targeting the pectoral nerves), and 20 mL between the pectoralis minor and serratus anterior muscles (to block the lateral branches of intercostal nerves and intercostobrachial nerve). | Procedure or surgery | PECS-II group |
| ESP blockThe erector spinae plane (ESP) block is a fascial plane block performed under ultrasound guidance to provide multimodal analgesia for thoracic and abdominal surgeries, including breast procedures. In this technique, a high-frequency linear ultrasound probe is used to visualize the transverse process of the thoracic vertebra, typically at the T4-T5 level. With the patient in a seated position and under standard sterile conditions, a 22G, 50 mm regional block needle is inserted in-plane until the tip reaches the fascial plane between the erector spinae muscle and the transverse process. After negative aspiration, 1-2 mL of test dose is injected to confirm correct needle placement by observing separation of fascial layers. Then, 20 mL of 0.25% bupivacaine is injected incrementally. | Procedure or surgery | ESP group |
Primary outcome
intraoperative remifentanyl consumption
Time frame: The time frame for intraoperative remifentanil consumption refers to the entire duration of the surgical procedure, starting from skin incision to the end of surgery (skin closure).
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 3 Jun 2025.
- Individual participant dataSharing planned: Yes
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing PECS II block and ESP block in people with Intraoperative Pain and Postoperative Pain, run by Koç University at 1 site in Turkey (Türkiye).
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 3 inclusion and 2 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 3 Jun 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Turkey (Türkiye). Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Ilayda Kalyoncu Karahan, MD (+905325105014, ilaydaakalyoncu@gmail.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
intraoperative remifentanyl consumption (time frame: The time frame for intraoperative remifentanil consumption refers to the entire duration of the surgical procedure, starting from skin incision to the end of surgery (skin closure).). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 3 Jun 2025.