A Phase 4 interventional study of ropivacaine and lidocaine in Postoperative Pain, Upper Extremity Fracture and Anesthesia, Conduction, sponsored by Instituto Mexicano del Seguro Social. Completed at 1 site in Mexico. Open to participants aged 18 Years to 59 Years. Per ClinicalTrials.gov, last updated 2026-10-30.
Sponsored by Instituto Mexicano del Seguro Social · Phase 4, Interventional, and Treatment
This randomized controlled trial compared three local anesthetic solutions for ultrasound-guided supraclavicular brachial plexus block in adults aged 18 to 59 years undergoing upper limb orthopedic and trauma surgery at a general hospital of the Mexican Social Security Institute (IMSS) in Aguascalientes, Mexico. Participants were randomly assigned to receive 30 mL of ropivacaine 0.375% alone, ropivacaine 0.375% plus lidocaine 1%, or ropivacaine 0.375% plus lidocaine 1% with epinephrine. The main question was whether adding lidocaine, with or without epinephrine, to ropivacaine improves postoperative analgesia. Pain intensity (0 to 10 Numeric Rating Scale) at 6 hours after surgery was the primary outcome. Secondary outcomes were pain at 0 and 12 hours, need for rescue analgesia, analgesic and opioid consumption, motor block (modified Bromage scale) and adverse events during the first 12 postoperative hours. Block onset time was also recorded.
Background. Mixing a fast-onset local anesthetic with a long-acting agent is common practice in peripheral nerve blocks to shorten block onset, but its effect on the quality and duration of analgesia is controversial, and no study had evaluated these mixtures in patients of the Mexican Social Security Institute.
Design. Single-center, superiority, randomized controlled trial with three parallel groups (1:1:1 allocation) and blinded outcome assessment, conducted at Hospital General de Zona No. 3, IMSS, Aguascalientes, Mexico, from January 2 to April 16, 2026. The trial was approved by the local research and ethics committees (registration R-2026-101-005) and all participants gave written informed consent. This trial was registered retrospectively, after completion of enrollment.
Interventions. All participants received an ultrasound-guided supraclavicular brachial plexus block with a total volume of 30 mL: group C, 15 mL of ropivacaine 0.75% plus 15 mL of sterile water (ropivacaine 0.375%); group L, 15 mL of ropivacaine 0.75% plus 15 mL of lidocaine 2% (ropivacaine 0.375% plus lidocaine 1%); group E, 15 mL of ropivacaine 0.75% plus 15 mL of lidocaine 2% with epinephrine (ropivacaine 0.375% plus lidocaine 1%, final epinephrine concentration 2.5 micrograms/mL, 1:400,000). No perineural adjuvants were used. Blocks were performed by attending anesthesiologists and anesthesiology residents assigned to each operating room according to the department's daily roster. All participants received the institution's standard intraoperative sedation and analgesia (a corticosteroid, a nonsteroidal anti-inflammatory drug, acetaminophen, midazolam and fentanyl), except when a drug was contraindicated.
Randomization and blinding. The principal investigator generated the allocation sequence in Excel for folios 1 to 138. Allocation was concealed in sealed envelopes identified by folio number, kept by the thesis investigator together with the study syringes and opened immediately before the block. Outcomes were assessed by the attending anesthesiologists and residents in charge of each participant, who were unaware of group allocation.
Outcomes. Pain intensity was measured with the 0 to 10 Numeric Rating Scale and motor block with the modified Bromage scale for the upper limb (0 = full movement, 3 = complete motor block) at 0, 6 and 12 hours after the end of surgery; rescue analgesics, opioid use and adverse events were recorded at the same time points. Block onset time was marked on the monitor from local anesthetic administration to onset of anesthesia and recorded in the anesthesia record.
Withdrawal criteria. Withdrawal of consent, failed block (need for general anesthesia or additional intraoperative analgesia attributable to block failure), discharge before 6 postoperative hours, and block-related complications (puncture-site hematoma, pneumothorax, local anesthetic systemic toxicity, persistent neurological deficit or allergic reaction).
Sample size and analysis. A sample of 138 participants (46 per group) was calculated with G*Power (alpha 0.05, power 0.80, effect size d = 0.5). Analysis followed the intention-to-treat principle. Groups were compared with the Kruskal-Wallis test or one-way ANOVA with Bonferroni-corrected pairwise comparisons, and with the chi-square or Fisher-Freeman-Halton tests for categorical variables; effect estimates are reported with 95% confidence intervals. A p value below 0.05 was considered significant.
5,640 studies on the registry are indexed under Pain, Postoperative; 1,230 are open to participants now.
This study's enrollment of 138 is above the median of 75 across 4,821 interventional studies indexed under Pain, Postoperative.
Browse Pain, Postoperative studies →Instituto Mexicano del Seguro Social is the lead sponsor of 126 studies on the registry; 21 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.
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.
Ultrasound-guided supraclavicular brachial plexus block with 30 mL of ropivacaine 0.375% (15 mL of ropivacaine 0.75% plus 15 mL of sterile water for injection), single perineural injection.
Drug: ropivacaine
Ultrasound-guided supraclavicular brachial plexus block with 30 mL of ropivacaine 0.375% plus lidocaine 1% (15 mL of ropivacaine 0.75% plus 15 mL of lidocaine 2%), single perineural injection.
Drug: lidocaine
Ultrasound-guided supraclavicular brachial plexus block with 30 mL of ropivacaine 0.375% plus lidocaine 1% with epinephrine (15 mL of ropivacaine 0.75% plus 15 mL of lidocaine 2% with epinephrine; final epinephrine concentration 2.5 micrograms/mL, 75 micrograms total), single perineural injection.
Drug: lidocaine with epinephrine
Ropivacaine 112.5 mg (15 mL of 0.75%) administered perineurally in an ultrasound-guided supraclavicular brachial plexus block, diluted to a total volume of 30 mL.
Lidocaine 300 mg (15 mL of 2%) mixed with ropivacaine for perineural administration in the supraclavicular brachial plexus block (final lidocaine concentration 1%).
Drug pages: Lidocaine · Epinephrine
Lidocaine 300 mg with epinephrine 75 micrograms (15 mL of lidocaine 2% with epinephrine) mixed with ropivacaine for perineural administration (final concentrations: lidocaine 1%, epinephrine 2.5 micrograms/mL).
Postoperative Pain Intensity at 6 Hours
Pain intensity measured with the 11-point Numeric Rating Scale (NRS), from 0 (no pain) to 10 (worst imaginable pain), compared among the three groups.
Time frame: 6 hours after the end of surgery
Postoperative Pain Intensity at 0 and 12 Hours
Pain intensity measured with the 11-point Numeric Rating Scale (NRS), from 0 (no pain) to 10 (worst imaginable pain).
Time frame: Immediately after the end of surgery (0 hours) and 12 hours after the end of surgery
Number of Participants Requiring Rescue Analgesia (Duration of Analgesia)
Number of participants who received rescue analgesia at each assessment; participants without rescue at 6 hours were considered to have an analgesia duration of at least 6 hours.
Time frame: At 0, 6 and 12 hours after the end of surgery
Rescue Analgesic Consumption by Drug Type
Number of participants receiving each rescue analgesic (acetaminophen, ketorolac, diclofenac, lysine clonixinate or opioids) and dose administered.
Time frame: Up to 12 hours after the end of surgery
Number of Participants Receiving Postoperative Opioids
Number of participants who received at least one opioid
Time frame: Up to 12 hours after the end of surgery
Upper Limb Motor Block (Modified Bromage Scale)
Motor block of the blocked upper limb graded with the modified Bromage scale: 0 = full movement, 1 = decreased strength, 2 = partial movement, 3 = complete motor block.
Time frame: At 0, 6 and 12 hours after the end of surgery
Number of Participants With Block-Related Adverse Events
Nausea, vomiting, paresthesia, puncture-site hematoma, Horner syndrome, dyspnea or phrenic nerve block, and local anesthetic systemic toxicity.
Time frame: Up to 12 hours after the end of surgery
Block Onset Time
Time in minutes from local anesthetic administration to onset of anesthesia, marked on the monitor and recorded in the anesthesia record by the attending anesthesiologist.
Time frame: Intraoperative, from local anesthetic injection to onset of anesthesia
Plan to share: Yes — Deidentified individual participant data underlying the results reported (baseline characteristics, pain scores, motor block, rescue analgesia and adverse events), together with the data dictionary, study protocol, statistical analysis plan, informed consent form and analytic code.
Supporting information: Study protocol, Statistical analysis plan, Informed consent form, Clinical study report, Analytic code
Time frame: Beginning 6 months after publication of the results and for 5 years.
Access criteria: Researchers who provide a methodologically sound proposal approved by the principal investigator; a data use agreement will be required. Requests should be sent to the principal investigator.
No publications or documents are linked to this record.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
This study is completed, as verified in Oct 2026. You cannot join it, but the record below documents what was studied.
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Studies of the drugs tested here: Lidocaine · Epinephrine
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