Nociception Level Index After Brachial Plexus Block In Upper Extremity Surgery: Prospective Comparison Trial

What this Trial Is About

Researchers are investigating whether a unilateral brachial plexus block (BPB), used in upper extremity surgery, causes measurable differences in autonomic nervous system activity between the two arms. This observational study evaluates the lateralized autonomic modulation by monitoring nociception levels (NoL) in both hands during standardized stimuli under general anesthesia. The goal is to find objective physiological markers for regional anesthesia effectiveness, beyond traditional sensory and motor tests, especially when patients are sedated or anesthetized. Participants will receive a single-shot ultrasound-guided BPB using 10 mL of 0.5% bupivacaine alongside general anesthesia. General anesthesia includes midazolam, fentanyl, propofol, rocuronium, and maintenance with inhalational anesthetics plus continuous remifentanil infusion adjusted for hemodynamic response. Nociception levels will be recorded bilaterally during local anesthetic injection, endotracheal intubation, and nasogastric tube placement using a non-invasive NoL monitoring device attached to the index fingers. During the approximately 5-hour study, participants undergo thorough monitoring with standard anesthesia assessments and continuous NoL measurements. Postoperative pain intensity and analgesic consumption will also be recorded to analyze correlations with NoL values. Safety will be monitored through standard clinical evaluations and adverse event reporting. The primary outcome is the difference in NoL values between the blocked and non-blocked arms during specific stimuli. Secondary outcomes include correlations between NoL measurements and postoperative pain and analgesic use.

Nociception Level Index After Brachial Plexus Block In Upper Extremity Surgery