An interventional study of Group A (n=35): Ultrasound-guided RISS block (RISS): and Group B (n=35): Ultrasound-guided lower thoracic ESP block in Pain After Surgery, sponsored by Misr University for Science and Technology. Not yet recruiting at 1 site in Egypt. Open to participants aged 18 Years to 60 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-05-18.
Sponsored by Misr University for Science and Technology · Not applicable, Interventional, and Treatment
The goal of this clinical trial is to investigate the analgesic efficacy of ultrasound-guided Romboid Intercostal and Subserratus (RISS) block versus lower thoracic Erector Spinae Plane (ESP) block after laparoscopic abdominal surgery. The main questions it aims to answer are:
Does ultrasound-guided Romboid Intercostal and Subserratus (RISS) block is effective as the lower thoracic Erector Spinae Plane (ESP) block for intra and postoperative analgesia after laparoscopic abdominal surgery for the first 24 hours? What complications do participants have when doing these interventions?
Researchers will compare the analgesic efficacy of ultrasound-guided Romboid Intercostal and Subserratus (RISS) block with the lower thoracic Erector Spinae Plane (ESP) block after laparoscopic abdominal surgery.
Participants will:
Start general anesthesia and be given either block according to the randomization chart.
The blood pressure and heart rate will be measured at intervals to determine if the participants need extra intraoperative analgesics.
Numerical Rating Scale (NRS) will be used postoperatively to test pain severity.
Rescue morphine analgesia will be measured and compared in both groups.
Any complications will be reported.
Patient and surgeon satisfaction will be measured.
The aim of this study is to investigate the analgesic efficacy of ultrasound-guided Romboid Intercostal and Subserratus (RISS) block versus lower thoracic Erector Spinae Plane (ESP) block after laparoscopic abdominal surgery.
Hypothesis
This study hypothesize that both RISS and ESP blocks relieve somatic pain equally, but ESP block relieves visceral pain better than RISS block, thereby reducing opioid consumption and improving patient satisfaction.
Methodology using:
I. Study design
Double-blinded randomized clinical trial study.
II. Study setting and location The study will be conducted at the operative theater of Souad Kafafi University Hospital (SKUH), Misr University for Science and Technology (MUST).
III. Study population:
Patients aged from 18 to 60 years old scheduled for laparoscopic abdominal surgery will be randomized in a 1:1 ratio after induction of general anesthesia, either:
Group A: Receiving ultrasound-guided RISS block. A solution composed of 20 ml mixed xylocaine 1% + 0.25% bupivacaine + 4 mg dexamethasone on each side.
Group B: Receiving ultrasound-guided lower thoracic ESP block (T8-T9) A solution composed of 20 ml mixed xylocaine 1% + 0.25 % bupivacaine + 4 mg dexamethasone on each side.
The infiltrative local anesthesia will be administered via a 22-gauge, 80-mm Echogenic block needle.
Postoperative analgesia:
The participants in both groups will receive analgesia in accordance with the following protocol:
Pain will be assessed using a Numerical Rating Scale (NRS) 0-10.
Severe pain (NRS 7-10) will receive the above plus 0.1 mg/kg IV morphine when indicated.
Study outcomes:
Primary Outcome Measure:
Secondary Outcome Measures:
Sample size calculation The sample size calculation was performed using G. power 3.1.9.2 (Universität Kiel, Germany). The sample size was calculated according to the total morphine dose in 24hr (4.21 in RISS vs. 4.65 in ESP) according to previous studies (9, 10). Based on the following considerations: 0.05 α error and 80% power of the study. Four cases were added to overcome dropout. Therefore, 70 patients will be allocated.
Statistical Analysis Statistical analysis will be done by SPSS v26 (IBM Inc., Chicago, IL, USA). Shapiro-Wilks test and histograms will be used to evaluate the normality of the distribution of data. Quantitative parametric variables will be presented as mean and standard deviation (SD) and compared between the two groups utilizing unpaired Student's t- test. Quantitative non-parametric data will be presented as median and interquartile range (IQR) and will be analyzed by Mann Whitney-test. Qualitative variables will be presented as frequency and percentage (%) and will be analyzed utilizing the Chi-square test or Fisher's exact test when appropriate. A two tailed P value \< 0.05 will be considered statistically significant.
10,054 studies on the registry are indexed under Pain; 1,649 are open to participants now.
This study's planned enrollment of 70 is close to the median of 66 across 8,493 interventional studies indexed under Pain.
Browse Pain studies →Misr University for Science and Technology is the lead sponsor of 38 studies on the registry; 15 are open to participants now.
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Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
The anaesthetists’ scale of health before surgery: I is healthy, II has a mild illness that is under control, III a severe one, IV a severe illness that is a constant threat to life. V and VI are used for the critically ill and for organ donors.
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.
Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.
ASA physical status
The anaesthetists’ scale of health before surgery: I is healthy, II has a mild illness that is under control, III a severe one, IV a severe illness that is a constant threat to life. V and VI are used for the critically ill and for organ donors.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
BMI (body mass index)
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Cancer (malignancy)
Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.
Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
The patient will be positioned in the lateral decubitus with the ipsilateral arm abducted to move the scapula laterally and open the intercostal and subscapular spaces. A high-frequency linear probe (10-14 MHz) will be applied 1-2 cm medial to the medial scapular border in an oblique-sagittal plane at the T5-T6 level. Using an in-plane approach, a 22 G, 80 mm block needle will be advanced from superomedial to inferolateral (cephalocaudal) until the tip lies between RM and ICM. After negative aspiration and hydrodissection with 1-2 ml saline, 10 ml of the prepared solution (1% lidocaine + 0.25% bupivacaine + 4 mg dexamethasone) will be injected in 5 ml aliquots, with real-time observation of spread deep to RM. The probe will then be slid caudally and laterally to the T8-T9 level to visualize the fascial plane at the mid-axillary line between the serratus anterior (SA) muscle and the external intercostal muscle to inject the other 10 ml of local anesthetic.
Procedure: Group A (n=35): Ultrasound-guided RISS block (RISS):
The patient will be positioned laterally. A linear probe will be placed 3 cm lateral to the posterior midline at the T8-T9 level to identify the transverse process (TP) and erector spinae muscle (ESM). A 22 G, 80 mm Echogenic block needle will be advanced in-plane from cranial to caudal until the tip rests deep to ESM but superficial to the TP. After negative aspiration, 20 ml of the prepared solution (1% lidocaine + 0.25% bupivacaine + 4 mg dexamethasone) will be injected in 5 ml aliquots, with real-time ultrasound confirmation of longitudinal spread cranially and caudally along the fascial plane. The block will be performed bilaterally following the same stepsA solution composed of 20 ml mixed xylocaine 1% + 0.25 % bupivacaine + 4 mg dexamethasone on each side.
Procedure: Group B (n=35): Ultrasound-guided lower thoracic ESP block
The patient will be positioned in the lateral decubitus with the ipsilateral arm abducted to move the scapula laterally and open the intercostal and subscapular spaces. A high-frequency linear probe (10-14 MHz) will be applied 1-2 cm medial to the medial scapular border in an oblique-sagittal plane at the T5-T6 level. Using an in-plane approach, a 22 G, 80 mm block needle will be advanced from superomedial to inferolateral (cephalocaudal) until the tip lies between RM and ICM. After negative aspiration and hydrodissection with 1-2 ml saline, 10 ml of the prepared solution (1% lidocaine + 0.25% bupivacaine + 4 mg dexamethasone) will be injected in 5 ml aliquots, with real-time observation of spread deep to RM. The probe will then be slid caudally and laterally to the T8-T9 level to visualize the fascial plane at the mid-axillary line between the serratus anterior (SA) muscle and the external intercostal muscle to inject the other 10 ml of local anesthetic.
The patient will be positioned laterally. A linear probe will be placed 3 cm lateral to the posterior midline at the T8-T9 level to identify the transverse process (TP) and erector spinae muscle (ESM). A 22 G, 80 mm Echogenic block needle will be advanced in-plane from cranial to caudal until the tip rests deep to ESM but superficial to the TP. After negative aspiration, 20 ml of the prepared solution (1% lidocaine + 0.25% bupivacaine + 4 mg dexamethasone) will be injected in 5 ml aliquots, with real-time ultrasound confirmation of longitudinal spread cranially and caudally along the fascial plane. The block will be performed bilaterally following the same stepsA solution composed of 20 ml mixed xylocaine 1% + 0.25 % bupivacaine + 4 mg dexamethasone on each side.
Postoperative analgesia
Pain will be assessed using a Numerical Rating Scale (NRS) (0-10 scale). Will be measured by NRS at 0, 6, 12, 18, and 24 hours postoperative 1. Mild pain (NRS 1-3) will be treated with 1 g paracetamol IV every six hours (maximum 4 g/day). 2. Moderate pain (NRS 4-6) will receive the same paracetamol regimen plus ketorolac 30 mg IV every eight hours (maximum 120 mg/day). 3. Severe pain (NRS 7-10) will receive the above plus 0.1 mg/kg IV morphine when indicated.
Time frame: from 0 to 24 hours postoperative
Total morphine consumption (mg) in 24 h.
Doses of morphine given intravenous postoperatively according to severity of pain (NRS \> 6) during the first 24 hours postoperatively
Time frame: from 0 to 24 hours postoperative
Intra-operative vital signs (HR)
Measuring the patient's heart rate (HR) before induction of anesthesia and every 15 minutes during surgery.
Time frame: Before induction of anesthesia till the end of surgery
• Intra-operative vital signs: Mean Blood Pressure (MBP)
Measuring the patient's Mean Blood Pressure (MBP) before induction of anesthesia and every 15 minutes during surgery.
Time frame: Before induction of anesthesia till the end of surgery
Possible complications
pneumothorax, LAST, vascular puncture
Time frame: Intra- and post-operatively for 24 hours.
Plan to share: Yes — Demographic Information: Age, sex, race, and other relevant demographic details. Baseline Characteristics: Health status, medical history, and any pre-existing conditions prior to the trial. Treatment Assignment: Information on the intervention or treatment each participant received. Outcome Measures: Data on primary and secondary outcomes as defined in the trial protocol. Adverse Events: Reports of any side effects or adverse events experienced by participants during the trial. Follow-up Data: Information collected during follow-up periods, including long-term outcomes
Supporting information: Study protocol, Statistical analysis plan, Informed consent form
Time frame: may 2026 to December 2026
Access criteria: Researchers: Who: Academic researchers, industry scientists, and regulatory agencies. What: Full IPD, including demographic data, treatment assignments, and outcome measures. How: Through data sharing platforms or repositories after submitting a research proposal and obtaining necessary approvals. Regulatory Authorities: Who: Agencies like the FDA or EMA. What: Full IPD and supporting documentation for oversight and review. How: Direct access during the review process of clinical trial applications. Data Sharing Initiatives: Who: Collaborating institutions and consortia. What: Aggregated or anonymized IPD for meta-analyses or systematic reviews. How: Via established partnerships and shared databases. Public and Patient Advocacy Groups: Who: Organizations seeking to promote transparency. What: Summary data and aggregated results, but not individual-level data. How: Through publicly available reports or dashboards.
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