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NCT Number: NCT07079436

EIT Evaluation of Pulmonary Ventilation With Different Ropivacaine Concentrations in Intercostal Nerve Blockade

This study aims to find out how different strengths of the anesthetic drug ropivacaine affect lung breathing function when used in intercostal nerve block (a type of local anesthesia) for breast quadrantectomy surgery. Researchers will use a non-invasive imaging technique called electrical impedance tomography (EIT) to monitor lung ventilation in real time.

Why is this study being done? Intercostal nerve block is a common anesthesia method for breast surgeries, but the ideal strength of ropivacaine that balances effective pain relief with safety for lung function is not fully clear. EIT can help measure how each drug strength affects breathing by showing changes in lung airflow.

What will happen in the study? Participants: 72 adults scheduled for breast quadrantectomy, aged 18-80, will be randomly assigned to receive one of three ropivacaine strengths (0.25%, 0.375%, or 0.5%) during intercostal nerve block.

Procedures: After anesthesia, EIT will monitor lung ventilation before and after the block. Researchers will measure:

How much each lung side contributes to breathing during quiet and deep breaths. How quickly the anesthesia works, pain levels during surgery, and any side effects (like difficulty breathing or allergic reactions).

Who can join? Adults having elective breast quadrantectomy. ASA physical status I-II (generally healthy to mildly ill). BMI <35 kg/m². No history of nerve block allergies, breathing problems, or certain lung diseases.

What are the possible benefits? The study may help doctors choose the best ropivacaine strength to ensure good pain control while minimizing risks to lung function, especially for same-day surgery patients.

What are the risks? Potential risks include rare side effects from the anesthetic (like allergic reactions or low blood pressure) or temporary breathing changes, which will be closely monitored.

How is the study designed? This is a double-blind, randomized trial (neither patients nor doctors know which drug strength is used) at Fudan University Shanghai Cancer Center.

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Key information

Conditions

Intercostal Nerve Block Anesthesia, Local Breast Diseases Breast Neoplasms Neoplasms Neoplasms by Site Pulmonary Ventilation Skin Diseases Skin and Connective Tissue Diseases Surgical Procedures, Operative

Age range

18 year–80 year

Sex eligibility

Female

Study type

Interventional

Phase

Not applicable

About this study

The purpose of this study is to explore the impact of different concentrations of ropivacaine on pulmonary ventilation function and anesthetic efficacy during intercostal nerve block, so as to provide a reference for clinical medication selection.

This is a single-center, prospective, randomized controlled trial, with the research subjects being patients scheduled to undergo breast quadrant resection under intercostal nerve block anesthesia. Eligible patients will be randomly assigned to three groups, receiving 0.25%, 0.375%, or 0.5% ropivacaine for intercostal nerve block respectively (4ml injected into each intercostal space, blocking the 2nd to 6th intercostal nerves). The procedure will be performed by experienced anesthesiologists under ultrasound guidance, with a double-blind design where neither the anesthesiologists nor the patients are aware of the grouping and drug concentration information.

In the study, Electrical Impedance Tomography (EIT) will be used for real-time, non-invasive monitoring of changes in patients' pulmonary ventilation function before and after the block. Meanwhile, indicators related to anesthetic efficacy such as the onset time of anesthesia and block success rate will be evaluated. The entire research process includes preoperative screening, intraoperative intervention, and postoperative follow-up, aiming to clarify the relationship between ropivacaine concentration, its impact on pulmonary ventilation function, and anesthetic efficacy, so as to provide a basis for optimizing the clinical application of ropivacaine in intercostal nerve block.

Who can participate

Healthy volunteers accepted: No

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

Inclusion criteria

  • Patients scheduled for elective breast quadrantectomy;
  • Aged 18-80 years;
  • American Society of Anesthesiologists (ASA) physical status I-II;
  • Body mass index (BMI) <35 kg/m².

Exclusion criteria

  • Contraindications for nerve block: infection at the puncture site, local anesthetic allergy, coagulation dysfunction or bleeding risk;
  • Patients with unilateral diaphragmatic paralysis;
  • Patients with severe ventilatory or gas exchange dysfunction;
  • Complicated with acute or chronic pulmonary and bronchial diseases, sleep apnea syndrome;
  • Mental disorders;
  • Patients who refuse to participate;
  • Patients whom the researchers consider unsuitable for the clinical trial, with reasons to be specified.

Treatment and study plan

0.25% ropivacaine

Drug

During breast quadrantectomy, intercostal nerve block is performed at the 2nd to 6th intercostal spaces along the posterior axillary line using an in-plane technique. 4ml of 0.25% ropivacaine (prepared from Naropin, 10ml:75mg) is injected into each intercostal space. Under ultrasound guidance, the needle tip is ensured to reach the space between the internal intercostal muscle (intercostal endomysium) and the innermost intercostal muscle below the rib margin. After aspiration shows no blood, the drug is injected, and anechoic fluid can be seen diffusing below the internal intercostal muscle, with the local parietal pleura gradually descending as the injected fluid volume increases.

Other names: Ropivacaine Hydrochloride Injection , Naropin , AstraZeneca AB, Sweden

0.375% Ropivacaine

Drug

During breast quadrantectomy, intercostal nerve block is performed at the 2nd to 6th intercostal spaces along the posterior axillary line using an in-plane technique. 4ml of 0.375% ropivacaine (prepared from Naropin, 10ml:75mg) is injected into each intercostal space. Under ultrasound guidance, the needle tip is ensured to reach the space between the internal intercostal muscle (intercostal endomysium) and the innermost intercostal muscle below the rib margin. After aspiration shows no blood, the drug is injected, and anechoic fluid can be seen diffusing below the internal intercostal muscle, with the local parietal pleura gradually descending as the injected fluid volume increases.

Other names: Ropivacaine Hydrochloride Injection , Naropin , AstraZeneca AB, Sweden

0.5% ropivacaine

Drug

During breast quadrantectomy, intercostal nerve block is performed at the 2nd to 6th intercostal spaces along the posterior axillary line using an in-plane technique. 4ml of 0.5% ropivacaine (prepared from Naropin, 10ml:75mg) is injected into each intercostal space. Under ultrasound guidance, the needle tip is ensured to reach the space between the internal intercostal muscle (intercostal endomysium) and the innermost intercostal muscle below the rib margin. After aspiration shows no blood, the drug is injected, and anechoic fluid can be seen diffusing below the internal intercostal muscle, with the local parietal pleura gradually descending as the injected fluid volume increases.

Other names: Ropivacaine Hydrochloride Injection , Naropin , AstraZeneca AB, Sweden

Primary outcomes

  1. The percentage decrease (/L) of the surgical side lung ventilation to total lung ventilation after blockade

    Time frame: 15 minutes after blockade

    The patient was placed in a supine position, and an EIT electrode strip was placed along the 4th intercostal space on the chest. Continuous monitoring of EIT (Drager Infinity C500, Germany) was performed, and tidal resistance changes during quiet breathing and deep breathing over at least 5 consecutive respiratory cycles were collected to construct lung ventilation distribution images. The main focus is to compare the changes in ROI% in different regions before and after the block, with comparisons made in 4 quadrants: "left upper, right upper, left lower, right lower".

Secondary outcomes

  1. Block success rate

    Time frame: 5 minutes after surgery

    The patient was able to undergo the surgery successfully without the need for additional rescue anesthesia measures.

Other outcomes

  1. Adverse events

    Time frame: 1 hour after surgery

    The number of cases with adverse events, adverse reactions, and serious adverse events (to be specified) such as local anesthetic toxicity, Horner's syndrome, and pneumothorax.

  2. Pain-related assessment

    Time frame: 24 hours after surgery

    The Numerical Rating Scale (NRS) was used to assess the patient's pain score via telephone.

  3. Pain-related assessment

    Time frame: 6 hours after surgery

    The Numerical Rating Scale (NRS) was used to assess the patient's pain score via telephone.

Sponsors and collaborators

Lead sponsor

Fudan University

Other

Registry information

Official study title

Electrical Impedance Tomography (EIT) to Evaluate the Effect of Different Concentrations of Ropivacaine on Pulmonary Ventilation Function During Intercostal Nerve Blockade

Acronym: EIT

Important dates

Study start
2025
Primary completion
2025
Study completion
2025
First posted
Jul 23, 2025
Registry last updated
Jul 23, 2025

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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