Early Detection of Supraclavicular Brachial Plexus Block Failure Using Infrared Thermography and Perfusion Index: Randomized Double-Blind Controlled Study
Trial Snapshot
- Phase
- Not Applicable
- Status
- Not yet recruiting
- Sponsor
- Assiut University
- Enrollment
- 80
- Primary Endpoint
- Change in Perfusion Index From Baseline to 10 Minutes Post-block
Study Overview
Brief Summary
Successful peripheral nerve blockade is fundamental to modern regional anesthesia, particularly for upper limb surgeries. Ensuring the efficacy of a nerve block early in the perioperative period is critical, as delayed recognition of block failure may lead to intraoperative pain, the need for additional sedation or general anesthesia, and overall poorer patient outcomes. Conventional methods for assessing block success, such as sensory testing with pinprick or cold stimuli and motor assessment using strength scales, require patient cooperation and often take 15-30 minutes to yield definitive results. These delays are especially limiting in fast-paced surgical environments or when early decisions regarding anesthesia management are necessary.
Emerging non-invasive monitoring technologies offer promising alternatives for the early, objective assessment of block efficacy. Infrared Thermography (IRT) measures skin surface temperature, which increases due to sympathetic nerve blockade-induced vasodilation.
Detailed Description
Successful peripheral nerve blockade is fundamental to modern regional anesthesia, particularly for upper limb surgeries. Ensuring the efficacy of a nerve block early in the perioperative period is critical, as delayed recognition of block failure may lead to intraoperative pain, the need for additional sedation or general anesthesia, and overall poorer patient outcomes. Conventional methods for assessing block success, such as sensory testing with pinprick or cold stimuli and motor assessment using strength scales, require patient cooperation and often take 15-30 minutes to yield definitive results. These delays are especially limiting in fast-paced surgical environments or when early decisions regarding anesthesia management are necessary.
Emerging non-invasive monitoring technologies offer promising alternatives for early, objective assessment of block efficacy. Infrared Thermography (IRT) measures skin surface temperature, which increases with sympathetic nerve blockade-induced vasodilation. Perfusion Index (PI), derived from pulse oximetry, reflects peripheral perfusion and also rises as vascular tone decreases following a successful nerve block. Both IRT and PI provide quantifiable, real-time physiological markers of sympathetic and circulatory changes that precede full sensory or motor blockade. Although several studies support their individual utility, there is limited evidence on their combined predictive value or their integration into routine clinical practice. Further investigation is needed to validate their role in enhancing the accuracy and timeliness of block assessment.
Study Design
- Study Type
- Interventional
- Allocation
- Na
- Intervention Model
- Single Group
- Primary Purpose
- Diagnostic
- Masking
- None
Eligibility Criteria
- Ages
- 18 Years to 70 Years (Adult, Older Adult)
- Sex
- All
- Accepts Healthy Volunteers
- No
Inclusion Criteria
- •Adults aged 18-70 years
- •ASA Physical Status I-III
Exclusion Criteria
- •Coagulopathy
- •Allergy to local anesthetics
- •Neurological deficits in the affected limb
- •Peripheral vascular disease or Raynaud's phenomenon
- •Infections or skin lesions at the site of injection
- •Use of a tourniquet
Arms & Interventions
Supraclavicular Brachial Plexus Block with Thermographic and Perfusion Monitoring
Participants will receive an ultrasound-guided supraclavicular brachial plexus block using 30 mL of 0.5% bupivacaine for upper limb surgery. Infrared thermography and perfusion index measurements will be recorded at baseline, and at 5, 10, and 15 minutes post-block to detect early physiological changes. Clinical assessment of sensory and motor block will be performed at 20 minutes post-injection using standardized testing. The goal is to evaluate the predictive accuracy of these non-invasive measures in detecting block success or failure.
Intervention: Ultrasound-Guided Supraclavicular Block (Procedure)
Supraclavicular Brachial Plexus Block with Thermographic and Perfusion Monitoring
Participants will receive an ultrasound-guided supraclavicular brachial plexus block using 30 mL of 0.5% bupivacaine for upper limb surgery. Infrared thermography and perfusion index measurements will be recorded at baseline, and at 5, 10, and 15 minutes post-block to detect early physiological changes. Clinical assessment of sensory and motor block will be performed at 20 minutes post-injection using standardized testing. The goal is to evaluate the predictive accuracy of these non-invasive measures in detecting block success or failure.
Intervention: Bupivacaine Hydrochloride 0.5 % Injectable Solution (Drug)
Supraclavicular Brachial Plexus Block with Thermographic and Perfusion Monitoring
Participants will receive an ultrasound-guided supraclavicular brachial plexus block using 30 mL of 0.5% bupivacaine for upper limb surgery. Infrared thermography and perfusion index measurements will be recorded at baseline, and at 5, 10, and 15 minutes post-block to detect early physiological changes. Clinical assessment of sensory and motor block will be performed at 20 minutes post-injection using standardized testing. The goal is to evaluate the predictive accuracy of these non-invasive measures in detecting block success or failure.
Intervention: Ultrasound (Device)
Supraclavicular Brachial Plexus Block with Thermographic and Perfusion Monitoring
Participants will receive an ultrasound-guided supraclavicular brachial plexus block using 30 mL of 0.5% bupivacaine for upper limb surgery. Infrared thermography and perfusion index measurements will be recorded at baseline, and at 5, 10, and 15 minutes post-block to detect early physiological changes. Clinical assessment of sensory and motor block will be performed at 20 minutes post-injection using standardized testing. The goal is to evaluate the predictive accuracy of these non-invasive measures in detecting block success or failure.
Intervention: Infrared Thermography Camera (Device)
Supraclavicular Brachial Plexus Block with Thermographic and Perfusion Monitoring
Participants will receive an ultrasound-guided supraclavicular brachial plexus block using 30 mL of 0.5% bupivacaine for upper limb surgery. Infrared thermography and perfusion index measurements will be recorded at baseline, and at 5, 10, and 15 minutes post-block to detect early physiological changes. Clinical assessment of sensory and motor block will be performed at 20 minutes post-injection using standardized testing. The goal is to evaluate the predictive accuracy of these non-invasive measures in detecting block success or failure.
Intervention: Pulse Oximeter (Device)
Outcomes
Primary Outcomes
Change in Perfusion Index From Baseline to 10 Minutes Post-block
Time Frame: Baseline, 5, and 10 minutes post-injection
PI measured via pulse oximeter; change calculated as ratio to baseline values.
Change in Skin Temperature (°C) Measured by Infrared Thermography From Baseline to 10 Minutes Post-block.
Time Frame: Baseline, 5, and 10 minutes post-injection
Mean change in skin temperature on the operative limb captured using infrared thermography at defined time points.
Secondary Outcomes
- Correlation Between Changes in Skin Temperature and Perfusion Index With Sensory and Motor Block Scores at 20 Minutes(20 minutes post-injection)
Investigators
Tarek Ashraf Ibrahim Abd Al-Hafiz
resident doctor at Assiut University hospital
Assiut University