Early Detection of Supraclavicular Brachial Plexus Block Failure Using Infrared Thermography and Perfusion Index

Official title

Early Detection of Supraclavicular Brachial Plexus Block Failure Using Infrared Thermography and Perfusion Index: Randomized Double-Blind Controlled Study

Overview

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.

Interventions

• Procedure Ultrasound-Guided Supraclavicular Block
  Ultrasound-guided supraclavicular brachial plexus block using a high-frequency linear ultrasound probe-real-time visualization of the brachial plexus for precise anesthetic delivery.
• Drug Bupivacaine Hydrochloride 0.5 % Injectable Solution
  30 mL used for supraclavicular brachial plexus block
• Device Ultrasound
  Imaging for block placement
• Device Infrared Thermography Camera
  Skin temperature monitoring
• Device Pulse Oximeter
  Perfusion Index monitoring

Primary outcome measures

• 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]
• Change in Perfusion Index From Baseline to 10 Minutes Post-block [Time frame: Baseline, 5, and 10 minutes post-injection]

Secondary outcome measures (1)

• Correlation Between Changes in Skin Temperature and Perfusion Index With Sensory and Motor Block Scores at 20 Minutes [Time frame: 20 minutes post-injection]

Eligibility criteria

Inclusion criteria

• Adults aged 18-70 years
• ASA Physical Status I-III

Exclusion criteria

• General

• Coagulopathy
• Allergy to local anesthetics
• Special

• 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

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: No

Study design

Allocation

N/A

Model

Single group

Masking

Open label

Primary purpose

Diagnostic

Study locations

Center list to be confirmed — check the primary protocol.

Publications

• Gamal M, Hasanin A, Adly N, Mostafa M, Yonis AM, Rady A, Abdallah NM, Ibrahim M, Elsayad M. Thermal Imaging to Predict Failed Supraclavicular Brachial Plexus Block: A Prospective Observational Study. Local Reg Anesth. 2023 Jun 9;16:71-80. doi: 10.2147/LRA.S406057. eCollection 2023. PMID 37323293
• Abdelnasser A, Abdelhamid B, Elsonbaty A, Hasanin A, Rady A. Predicting successful supraclavicular brachial plexus block using pulse oximeter perfusion index. Br J Anaesth. 2017 Aug 1;119(2):276-280. doi: 10.1093/bja/aex166. PMID 28854539

Identifiers

NCT: NCT07092891 · Brachial Plexus Block Failure

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗