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NCT Number: NCT07446959

Minimum Effective Volume of Bupivacaine for Serratus Posterior Superior Intercostal Plane Block in Video-Assisted Thoracoscopic Surgery

This study aims to determine the minimum effective volume of bupivacaine required for the serratus posterior superior intercostal plane (SPSIP) block in patients undergoing video-assisted thoracoscopic surgery (VATS). The SPSIP block is an ultrasound-guided regional anesthesia technique used to provide postoperative pain relief after thoracic surgery.

Using a stepwise dose-adjustment method, the volume of local anesthetic will be increased or decreased based on the effectiveness of the block in each patient. The main outcome of the study is to identify the volume that provides effective pain control in 50% of patients. The results may help optimize pain management while minimizing drug exposure.

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Key information

Conditions

Postoperative Pain Management Video-assisted Thoracoscopic Surgery (VATS)

Age range

18 year and older

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

T.C. Sağlık Bakanlığı Bursa Şehir Hastanesi

Bursa, 16250, Turkey (Türkiye)

Location status: Recruiting

About this study

This prospective interventional dose-finding study is designed to determine the median effective volume (ED50) of 0.25% bupivacaine for ultrasound-guided serratus posterior superior intercostal plane (SPSIP) block in patients undergoing video-assisted thoracoscopic surgery (VATS).

The up-and-down sequential allocation method described by Dixon and Massey will be used. The initial volume of bupivacaine will be administered to the first patient, and subsequent volumes will be adjusted in 2 mL increments according to the response of the preceding patient. If the block is successful, the volume for the next patient will be decreased by 2 mL. In case of block failure, the volume will be increased by 2 mL.

Block success will be defined as the presence of sensory loss to cold in at least two consecutive dermatomes between T3 and T6, assessed 20-30 minutes after block performance, combined with a cumulative fentanyl requirement of less than 2 µg/kg within the first 60 minutes after induction of general anesthesia. Failure will be defined as absence of adequate sensory blockade or the need for fentanyl ≥2 µg/kg.

The up-and-down sequence will be continued until nine reversal points are obtained. The ED50 will be calculated as the mean of the midpoint doses of all independent success-failure pairs. Secondary outcomes will include postoperative pain scores and opioid consumption.

This study aims to provide clinically relevant data to optimize the volume of local anesthetic for SPSIP block while maintaining effective analgesia and minimizing potential adverse effects.

Who can participate

Healthy volunteers accepted: No

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

Inclusion criteria

  • Age 18 years or older
  • Scheduled for elective video-assisted thoracoscopic surgery (VATS)
  • American Society of Anesthesiologists (ASA) physical status I-III
  • Planned to receive ultrasound-guided serratus posterior superior intercostal plane block for postoperative analgesia
  • Ability to provide written informed consent

Exclusion criteria

  • Refusal to participate in the study
  • Known allergy or contraindication to local anesthetics
  • Infection at the block injection site
  • Coagulation disorders or anticoagulant therapy contraindicating regional anesthesia
  • Severe respiratory insufficiency
  • Chronic opioid use or chronic pain syndrome
  • Pregnancy
  • Inability to cooperate or communicate postoperative pain scores

Treatment and study plan

Ultrasound-Guided Serratus Posterior Superior Intercostal Plane Block

Other

Ultrasound-guided serratus posterior superior intercostal plane block performed prior to general anesthesia in patients undergoing video-assisted thoracoscopic surgery (VATS). A 0.5% bupivacaine solution is injected, and the volume is adjusted in 2 mL increments according to the Dixon up-and-down sequential allocation method to determine the median effective volume (ED50).

Primary outcomes

  1. Median Effective Volume (ED50) of 0.5% Bupivacaine for Successful SPSIP Block

    Time frame: Within the first 30 minutes after block performance

    The median effective volume (ED50) of 0.5% bupivacaine required to achieve successful postoperative analgesia following ultrasound-guided serratus posterior superior intercostal plane block, determined using the Dixon up-and-down sequential allocation method.

Secondary outcomes

  1. Postoperative Pain Scores (NRS)

    Time frame: Up to 24 hours postoperatively

    Numerical Rating Scale (NRS) pain scores ranging from 0 to 10, where 0 represents no pain and 10 represents the worst imaginable pain, assessed at rest and during movement at 0, 1, 2, 4, 8, 12, and 24 hours after surgery.

  2. Postoperative Morphine Consumption via Patient-Controlled Analgesia (PCA)

    Time frame: First 24 hours after surgery

    Total cumulative morphine dose administered through patient-controlled analgesia (PCA) within the first 24 postoperative hours, measured in milligrams. Higher values indicate increased analgesic requirement.

  3. Postoperative Adverse Effects

    Time frame: Up to 24 hours postoperatively

    Incidence of opioid- and block-related adverse effects including nausea, vomiting, pruritus, dizziness, hypotension, respiratory depression, and local complications at the block site.

  4. Quality of Recovery Score (QoR-15)

    Time frame: 24 hours after surgery

    Quality of Recovery assessed using the 15-item Quality of Recovery questionnaire (QoR-15), with scores ranging from 0 to 150, where higher scores indicate better postoperative recovery.

  5. Postoperative Pulmonary Function Parameters

    Time frame: Preoperative baseline and 24 hours after surgery

    Pulmonary function assessed using spirometric parameters including forced vital capacity (FVC) and forced expiratory volume in one second (FEV1) measured preoperatively and at 24 hours postoperatively.

Study contacts

Contact information is provided by the study sponsor or research team.

emre ulusoy

CONTACT

[email protected]

+905379492799

Sponsors and collaborators

Lead sponsor

Bursa City Hospital

Other Gov

Collaborators

  • Ulusoy, Emre, M.D.

Registry information

Official study title

Determination of the Median Effective Volume (ED50) of Bupivacaine for Serratus Posterior Superior Intercostal Plane Block in Patients Undergoing Video-Assisted Thoracoscopic Surgery Using the Dixon Up-and-Down Method

Acronym: SPSIP-EV50

Important dates

Study start
2026
Primary completion
2026
Study completion
2026
First posted
Mar 3, 2026
Registry last updated
May 12, 2026

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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