Postoperative Pain ManagementSPSIP-EV50NCT07446959
Minimum Effective Volume of Bupivacaine for Serratus Posterior Superior Intercostal Plane Block in Video-Assisted Thoracoscopic Surgery
A study testing Ultrasound-Guided Serratus Posterior Superior Intercostal Plane Block in people with Postoperative Pain Management and Video-assisted Thoracoscopic Surgery (VATS), run by Bursa City Hospital at 1 site in Turkey (Türkiye).
Trial summary
This study determined the median effective volume (EV50) of bupivacaine required for the serratus posterior superior intercostal plane (SPSIP) block in patients undergoing video-assisted thoracoscopic surgery (VATS). Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Postoperative Pain Management, Video-assisted Thoracoscopic Surgery (VATS)
- What is being tested?
- Ultrasound-Guided Serratus Posterior Superior Intercostal Plane Block
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 27 participants
- Where
- 1 siteTurkey (Türkiye)
- Study dates
- 15 Mar 2026to 15 Jul 2026
- Phase
- Interventional
- Are there results?
- None posted in the registry
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 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- 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
Who cannot join
- 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
Trial locations and contacts
1 site in 1 country.
Turkey (Türkiye)1 site
T.C. Sağlık Bakanlığı Bursa Şehir Hastanesi
Nilufer, Bursa, 16110
About this study
Official 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
This study determined the median effective volume (EV50) 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. All patients received bupivacaine at a final concentration of 0.25%, prepared by diluting the commercially available 0.5% preparation 1:1 with 0.9% sodium chloride. Using a sequential up-and-down dose-adjustment method, the volume of local anesthetic was increased or decreased according to the block outcome of the preceding patient. The main outcome of the study was the volume that provided an effective block in 50% of patients. EV50 is not a recommended clinical dose; the results are intended to inform future studies targeting higher effective percentiles.
Read the detailed description
This prospective interventional dose-finding study was designed to determine the median effective volume (EV50) of 0.25% bupivacaine for ultrasound-guided serratus posterior superior intercostal plane (SPSIP) block in patients undergoing video-assisted thoracoscopic surgery (VATS). The local anesthetic solution was prepared by diluting 0.5% bupivacaine (Buvacin 0.5%, Polifarma, Türkiye) 1:1 with 0.9% sodium chloride, yielding a final concentration of 0.25%; the 0.5% descriptor refers to the commercial preparation, not to the administered concentration. The concentration specified in the ethics committee-approved protocol is 0.25%.
The up-and-down sequential allocation method described by Dixon and Massey was used. The initial volume of bupivacaine was administered to the first patient, and subsequent volumes were adjusted in 2 mL increments according to the response of the preceding patient. If the block was successful, the volume for the next patient was decreased by 2 mL. In case of block failure, the volume was increased by 2 mL. Volumes were constrained to a range of 15 to 40 mL, and one patient was enrolled per day.
Block success was 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 was defined as absence of adequate sensory blockade or the need for fentanyl ≥2 µg/kg.
The up-and-down sequence was continued until nine reversal points were obtained. The EV50 was calculated as the mean of the midpoint doses of all independent success-failure pairs. Secondary outcomes included postoperative pain scores and opioid consumption. This study aimed to provide clinically relevant data to optimize the volume of local anesthetic for SPSIP block while maintaining effective analgesia and minimizing potential adverse effects.
- Being tested
- Ultrasound-Guided Serratus Posterior Superior Intercostal Plane Block
- Keywords
- SPSIP Block, Regional Anesthesia, Dose-Finding Study, Dixon Up-and-Down Method, Thoracic Analgesia
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Ultrasound-Guided Serratus Posterior Superior Intercostal Plane BlockOther
Ultrasound-guided serratus posterior superior intercostal plane block performed before induction of general anesthesia in patients undergoing video-assisted thoracoscopic surgery (VATS). With the patient seated, a high-frequency linear probe was placed in the sagittal plane over the superior angle of the scapula, and the needle was advanced in-plane until its tip lay between the serratus posterior superior muscle and the third rib. Bupivacaine 0.25%, prepared by 1:1 dilution of the 0.5% commercial preparation with 0.9% sodium chloride, was injected in 5 mL aliquots with intermittent aspiration after hydrodissection with 1 mL of saline. The injected volume was adjusted in 2 mL increments according to the Dixon up-and-down sequential allocation method to determine the median effective volume (EV50). The 0.5% descriptor refers to the commercial preparation only; all participants received bupivacaine at a final concentration of 0.25%.
| Study group | Role | What they receive |
|---|---|---|
| Serratus Posterior Superior Intercostal Plane Block (SPSIPB) | Experimental | Participants received an ultrasound-guided serratus posterior superior intercostal plane block (SPSIPB) with 0.25% bupivacaine before video-assisted thoracoscopic surgery (VATS). The solution was prepared by diluting commercially available 0.5% bupivacaine (Buvacin 0.5%, Polifarma, Türkiye) 1:1 with 0.9% sodium chloride, giving a final administered concentration of 0.25%, as specified in the ethics committee-approved protocol. The injected volume was determined using the Dixon up-and-down sequential allocation method, starting from an initial volume of 30 mL and adjusted by 2 mL increments or decrements based on block success or failure in the preceding patient, within a permitted range of 15 to 40 mL. Sensory block was assessed by an outcome assessor blinded to the administered volume, and intraoperative analgesic adequacy was assessed by an anesthesiologist blinded to the administered volume and to the block outcome, according to predefined criteria. Receives: Other: Ultrasound-Guided Serratus Posterior Superior Intercostal Plane Block |
What is being measured
The primary outcome is the main question the study is designed to answer.
Median Effective Volume (EV50) of 0.25% Bupivacaine for Successful SPSIP Block
The median effective volume (EV50) of 0.25% bupivacaine required for a successful ultrasound-guided serratus posterior superior intercostal plane block, determined using the Dixon up-and-down sequential allocation method. Bupivacaine 0.25% was prepared by diluting the commercial 0.5% preparation 1:1 with 0.9% sodium chloride; the concentration specified in the ethics committee-approved protocol is 0.25%. Block success was defined by a composite criterion: sensory loss to cold in at least two consecutive dermatomes between T3 and T6, combined with a cumulative fentanyl requirement of less than 2 µg/kg (including the 1 µg/kg induction dose) within the first 60 minutes after induction of general anesthesia. Failure was defined as absence of adequate sensory blockade or a cumulative fentanyl requirement of 2 µg/kg or more.
Measured: Within the first 30 minutes after block performance
Secondary outcomes (5)
Postoperative Pain Scores (NRS)
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.
Measured: Up to 24 hours postoperatively
Postoperative Morphine Consumption via Patient-Controlled Analgesia (PCA)
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.
Measured: First 24 hours after surgery
Postoperative Adverse Effects
Incidence of opioid- and block-related adverse effects including nausea, vomiting, pruritus, dizziness, hypotension, respiratory depression, and local complications at the block site.
Measured: Up to 24 hours postoperatively
Quality of Recovery Score (QoR-15)
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.
Measured: 24 hours after surgery
Postoperative Pulmonary Function Parameters
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.
Measured: Preoperative baseline and 24 hours after surgery
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted3 Mar 2026
- Study start15 Mar 2026
- Primary completion11 May 2026
- Study completion15 Jul 2026
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Postoperative Pain ManagementStudies 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
- Treatment
- Allocation
- Not applicable
- Intervention model
- Sequential
- Model description
- Sequential dose-adjustment design using the Dixon up-and-down method, in which local anesthetic volume is increased or decreased in fixed 2 mL steps based on the success or failure of the preceding block.
- Masking
- None (open label)
- Enrolment
- 27 participants (actual)
Sponsor and investigators
- Lead sponsor
- Bursa City Hospital
- Sponsor type
- Other government
- Collaborators
- Ulusoy, Emre, M.D.
- Responsible party
- Principal investigator, Mursel Ekinci, Bursa City Hospital
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07446959
- Sponsor's protocol ID
- Bursa City Hospital 15
- Acronym
- SPSIP-EV50
- Status last verified
- Sep 2026
- First submitted
- 26 Feb 2026
- Last updated
- 24 Sep 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: Individual participant data will not be shared due to institutional policies and patient confidentiality considerations.
Study at a glance
From the registry record, last updated by the sponsor on 24 Sep 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official 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
- ClinicalTrials.gov ID
- NCT07446959
- Acronym / sponsor ID
- SPSIP-EV50 / Bursa City Hospital 15
- Keywords
- SPSIP Block, Regional Anesthesia, Dose-Finding Study, Dixon Up-and-Down Method, Thoracic Analgesia
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 27 participants (actual)
- Lead sponsor
- Bursa City HospitalOther government
- Collaborators
- Ulusoy, Emre, M.D.
- Study start
- 15 Mar 2026 (actual)
- Primary completion
- 11 May 2026 (actual)
- Study completion
- 15 Jul 2026 (actual)
- First posted
- 3 Mar 2026 (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.
This study determined the median effective volume (EV50) 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. All patients received bupivacaine at a final concentration of 0.25%, prepared by diluting the commercially available 0.5% preparation 1:1 with 0.9% sodium chloride. Using a sequential up-and-down dose-adjustment method, the volume of local anesthetic was increased or decreased according to the block outcome of the preceding patient. The main outcome of the study was the volume that provided an effective block in 50% of patients. EV50 is not a recommended clinical dose; the results are intended to inform future studies targeting higher effective percentiles.
Detailed description
This prospective interventional dose-finding study was designed to determine the median effective volume (EV50) of 0.25% bupivacaine for ultrasound-guided serratus posterior superior intercostal plane (SPSIP) block in patients undergoing video-assisted thoracoscopic surgery (VATS). The local anesthetic solution was prepared by diluting 0.5% bupivacaine (Buvacin 0.5%, Polifarma, Türkiye) 1:1 with 0.9% sodium chloride, yielding a final concentration of 0.25%; the 0.5% descriptor refers to the commercial preparation, not to the administered concentration. The concentration specified in the ethics committee-approved protocol is 0.25%.
The up-and-down sequential allocation method described by Dixon and Massey was used. The initial volume of bupivacaine was administered to the first patient, and subsequent volumes were adjusted in 2 mL increments according to the response of the preceding patient. If the block was successful, the volume for the next patient was decreased by 2 mL. In case of block failure, the volume was increased by 2 mL. Volumes were constrained to a range of 15 to 40 mL, and one patient was enrolled per day.
Block success was 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 was defined as absence of adequate sensory blockade or the need for fentanyl ≥2 µg/kg.
The up-and-down sequence was continued until nine reversal points were obtained. The EV50 was calculated as the mean of the midpoint doses of all independent success-failure pairs. Secondary outcomes included postoperative pain scores and opioid consumption. This study aimed to provide clinically relevant data to optimize the volume of local anesthetic for SPSIP block while maintaining effective analgesia and minimizing potential adverse effects.
Study design
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Sequential
- Masking
- None (open label)
- Number of arms
- 1
- Model description
- Sequential dose-adjustment design using the Dixon up-and-down method, in which local anesthetic volume is increased or decreased in fixed 2 mL steps based on the success or failure of the preceding block.
| Arm | Type | Receives |
|---|---|---|
| Serratus Posterior Superior Intercostal Plane Block (SPSIPB) | Experimental | Other: Ultrasound-Guided Serratus Posterior Superior Intercostal Plane BlockParticipants received an ultrasound-guided serratus posterior superior intercostal plane block (SPSIPB) with 0.25% bupivacaine before video-assisted thoracoscopic surgery (VATS). The solution was prepared by diluting commercially available 0.5% bupivacaine (Buvacin 0.5%, Polifarma, Türkiye) 1:1 with 0.9% sodium chloride, giving a final administered concentration of 0.25%, as specified in the ethics committee-approved protocol. The injected volume was determined using the Dixon up-and-down sequential allocation method, starting from an initial volume of 30 mL and adjusted by 2 mL increments or decrements based on block success or failure in the preceding patient, within a permitted range of 15 to 40 mL. Sensory block was assessed by an outcome assessor blinded to the administered volume, and intraoperative analgesic adequacy was assessed by an anesthesiologist blinded to the administered volume and to the block outcome, according to predefined criteria. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (5 listed)
- 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
Key exclusion criteria (8 listed)
- 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
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 |
|---|---|---|
| Ultrasound-Guided Serratus Posterior Superior Intercostal Plane BlockUltrasound-guided serratus posterior superior intercostal plane block performed before induction of general anesthesia in patients undergoing video-assisted thoracoscopic surgery (VATS). With the patient seated, a high-frequency linear probe was placed in the sagittal plane over the superior angle of the scapula, and the needle was advanced in-plane until its tip lay between the serratus posterior superior muscle and the third rib. Bupivacaine 0.25%, prepared by 1:1 dilution of the 0.5% commercial preparation with 0.9% sodium chloride, was injected in 5 mL aliquots with intermittent aspiration after hydrodissection with 1 mL of saline. The injected volume was adjusted in 2 mL increments according to the Dixon up-and-down sequential allocation method to determine the median effective volume (EV50). The 0.5% descriptor refers to the commercial preparation only; all participants received bupivacaine at a final concentration of 0.25%. | Other | Serratus Posterior Superior Intercostal Plane Block (SPSIPB) |
Primary outcome
Median Effective Volume (EV50) of 0.25% Bupivacaine for Successful SPSIP Block
Time frame: Within the first 30 minutes after block performance
The median effective volume (EV50) of 0.25% bupivacaine required for a successful ultrasound-guided serratus posterior superior intercostal plane block, determined using the Dixon up-and-down sequential allocation method. Bupivacaine 0.25% was prepared by diluting the commercial 0.5% preparation 1:1 with 0.9% sodium chloride; the concentration specified in the ethics committee-approved protocol is 0.25%. Block success was defined by a composite criterion: sensory loss to cold in at least two consecutive dermatomes between T3 and T6, combined with a cumulative fentanyl requirement of less than 2 µg/kg (including the 1 µg/kg induction dose) within the first 60 minutes after induction of general anesthesia. Failure was defined as absence of adequate sensory blockade or a cumulative fentanyl requirement of 2 µg/kg or more.
5 secondary outcomes
Postoperative Pain Scores (NRS)
Time frame: Up to 24 hours postoperatively
Postoperative Morphine Consumption via Patient-Controlled Analgesia (PCA)
Time frame: First 24 hours after surgery
Postoperative Adverse Effects
Time frame: Up to 24 hours postoperatively
Quality of Recovery Score (QoR-15)
Time frame: 24 hours after surgery
Postoperative Pulmonary Function Parameters
Time frame: Preoperative baseline and 24 hours after surgery
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 24 Sep 2026.
- Individual participant dataSharing planned: No. Individual participant data will not be shared due to institutional policies and patient confidentiality considerations.
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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. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Ultrasound-Guided Serratus Posterior Superior Intercostal Plane Block in people with Postoperative Pain Management and Video-assisted Thoracoscopic Surgery (VATS), run by Bursa City Hospital 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 5 inclusion and 8 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: finished, as of the sponsor's last update on 24 Sep 2026. 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?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Median Effective Volume (EV50) of 0.25% Bupivacaine for Successful SPSIP Block (time frame: Within the first 30 minutes after block performance). 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 24 Sep 2026.