A Phase 2/3 interventional study of Rectus Sheath Block and Rectus Sheath Block with Clonidine in Hernia, Umbilical, Clonidine and Pain, Postoperative, sponsored by Universidade Federal do Rio de Janeiro. Recruiting at 1 site in Brazil. Open to participants aged 18 Years to 65 Years. Per ClinicalTrials.gov, last updated 2025-07-14.
Sponsored by Universidade Federal do Rio de Janeiro · Phase 2/3, Interventional, and Treatment
This clinical trial aims to evaluate the effectiveness of an ultrasound-guided nerve block technique as the sole anesthetic method for patients undergoing outpatient umbilical hernia surgery. The procedure, called rectus sheath block (RSB), involves injecting local anesthetic near the abdominal muscles to reduce pain during and after surgery. The study will compare two groups of adult patients: one receiving the nerve block with a medication called clonidine added to the anesthetic solution, and the other receiving the same block without clonidine. Clonidine may help improve pain control and reduce the need for additional pain medications. By analyzing pain scores, recovery quality, and potential side effects, the study seeks to determine whether the use of clonidine in this context is safe, cost-effective, and beneficial for patient recovery. Participants will answer questionnaires about their pain and recovery during the first 48 hours after surgery.
This is a prospective, randomized, double-blind, controlled clinical trial designed to evaluate the effectiveness and safety of adding clonidine to a local anesthetic solution for ultrasound-guided rectus sheath block (RSB) in adult patients undergoing ambulatory umbilical hernioplasty. The study will be conducted at the Ambulatory Surgery Unit of the Policlínica Universitária Piquet Carneiro, part of the Universidade do Estado do Rio de Janeiro (UERJ), between January 2025 and April 2026.
Eligible patients (ASA I or II, aged 18-65) scheduled for elective outpatient umbilical hernia repair with a hernial defect ≤ 4 cm will be randomized into two groups. The intervention group (BRA-CLO) will receive bilateral RSB with a solution containing 8 mL of lidocaine 2%, 8 mL of ropivacaine 1%, and clonidine 75 mcg, diluted in 0.9% saline to a total volume of 20 mL, administered on each side. The control group (BRA) will receive an identical volume and concentration of local anesthetic without the addition of clonidine.
RSB will be performed under real-time ultrasound guidance (Butterfly iQ+ probe) using an in-plane technique with a Quincke 22G needle. Sedation with midazolam, fentanyl, and propofol will be administered as required. The block will be performed preoperatively under standard monitoring, including ECG, pulse oximetry, and non-invasive blood pressure.
The primary hypothesis is that the addition of clonidine will enhance the quality of intraoperative and postoperative analgesia, reduce opioid consumption, and improve overall postoperative recovery without increasing the risk of adverse events. To assess recovery quality, the validated Quality of Recovery-15 (QoR-15) questionnaire will be administered at postoperative 24 and 48 hours. Pain will be assessed using the Numeric Rating Scale (NRS) at predefined intervals (PACU, 24h and 48h). Sedation will be measured with the Richmond Agitation-Sedation Scale (RASS), and adverse events such as bradycardia, nausea, vomiting, conversion to general anesthesia, and postoperative complications will be recorded.
Randomization will be performed using block randomization with variable block sizes (4, 6, or 8) generated in R (v4.4.1), and allocation concealment will be ensured with sealed opaque envelopes. Data will be collected and managed using the REDCap platform, ensuring confidentiality and integrity.
The study aims to fill an important gap in evidence regarding the use of alpha-2 adrenergic agonists as adjuvants in abdominal wall blocks, especially in the context of ambulatory surgery. It is expected that the findings will support the safe and effective use of clonidine to optimize regional anesthesia protocols in hernia repair.
67 studies on the registry are indexed under Hernia, Umbilical; 13 are open to participants now.
This study's planned enrollment of 62 is close to the median of 66 across 40 interventional studies indexed under Hernia, Umbilical.
Browse Hernia, Umbilical studies →Universidade Federal do Rio de Janeiro is the lead sponsor of 123 studies on the registry; 11 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.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
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.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hypersensitivity
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraindication
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Participants in this arm will receive bilateral ultrasound-guided rectus sheath block (RSB) without the addition of clonidine.
Drug: Rectus Sheath Block
Participants in this arm will receive bilateral ultrasound-guided rectus sheath block (RSB) with clonidine
Drug: Rectus Sheath Block with Clonidine
Participants in this arm will receive bilateral ultrasound-guided rectus sheath block (RSB) with a solution containing 8 mL of lidocaine 2% + 8 mL of ropivacaine 1%, diluted in 0.9% saline to a total volume of 20 mL, each side, without the addition of clonidine.
Also known as: RSB
Participants in this arm will receive bilateral ultrasound-guided rectus sheath block (RSB) with a solution containing 8 mL of lidocaine 2% + 8 mL of ropivacaine 1% + clonidine 75 mcg, diluted in 0.9% saline to a total volume of 20 mL, each side, without the addition of clonidine.
Also known as: RSB with clonidine
Total opioid postoperative consumption
Total amount of opioid analgesics (in milligrams of tramadol equivalents) administered from the end of the surgical procedure to 48 hours postoperatively.
Time frame: 48 hours postoperative
Postoperative pain intensity assessed by Numeric Rating Scale (NRS)
Pain scores reported by the patient using the 11-point Numeric Rating Scale (0 = no pain; 10 = worst imaginable pain) at each time point.
Time frame: At post-anesthesia care unit (PACU) admission (immediately after surgery), 24 hours after surgery, and 48 hours after surgery.
Total intraoperative opioid consumption
Total intraoperative fentanyl consumption
Time frame: From induction of anesthesia to the end of surgery.
Quality of recovery assessed by QoR-15 questionnaire
Patient-reported recovery quality measured using the Quality of Recovery-15 (QoR-15) instrument, scored from 0 to 150, with higher scores indicating better recovery.
Time frame: At post-anesthesia care unit (PACU) admission (immediately after surgery), 24 hours after surgery, and 48 hours after surgery.
Incidence of postoperative nausea and vomiting (PONV)
Number of patients who experience at least one episode of nausea and/or vomiting in the first 48 hours after surgery.
Time frame: 48 hours postoperatively
Postoperative Richmond Agitation-Sedation Scale (RASS) sedation score
The Richmond Agitation-Sedation Scale (RASS) is a 10-point scale used to assess the level of sedation and agitation in patients. The scale ranges from -5 (unarousable) to +4 (combative), where higher positive scores indicate higher levels of agitation (worse outcome), and lower negative scores indicate deeper sedation (also considered a worse outcome depending on clinical context). A score of 0 corresponds to an alert and calm patient, which is considered optimal.
Time frame: At post-anesthesia care unit (PACU) admission (immediately after surgery).
Bradycardia
Incidence of bradycardia
Time frame: From the start of surgery until discharge from the post-anesthesia care unit (PACU), 2 hours after surgery.
Hypotension
Incidence of hypotension
Time frame: From the start of surgery until discharge from the post-anesthesia care unit (PACU), 2 hours after surgery.
Plan to share: Yes — Individual participant data (IPD) will be made available upon reasonable request to the corresponding author, following appropriate de-identification procedures and in accordance with local ethical guidelines.
Supporting information: Study protocol, Statistical analysis plan, Analytic code
Time frame: Individual participant data (IPD) and supporting information will be made available beginning 6 months after publication of the primary results and will remain available for 5 years after publication.
Access criteria: Access to the de-identified individual participant data and supporting documents will be granted to qualified researchers upon reasonable request, provided that the proposed use is for scientific research purposes and complies with institutional and ethical guidelines. Requests should be submitted to the corresponding author and will be evaluated by the research team. Data will be shared under a data use agreement.
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