Perfusion Index for Predicting Brachial Plexus Block Success Under General Anesthesia

Completed

• Conditions: Disorder of Shoulder
• Interventions: Procedure: Interscalene brachial plexus blocks with ultrasound guidance under general anesthesia

• Registration Number: NCT04925505
• Lead Sponsor: Korea University Guro Hospital

Brief Summary

This study was designed to determine whether the success or failure of interscalene brachial plexus block under general anesthesia can be predicted using perfusion index (PI).

Detailed Description

The success of peripheral nerve blocks is usually evaluated by assessment of sensory and motor function; however, this method cannot be applied in the patient who has uncheckable mental status, e.g. general anesthesia, or who is uncommunicable, e.g. different language user.

The perfusion index (PI) is a numerical value for the ratio between pulsatile and non-pulsatile blood flow measured by a special pulse oximeter, and PI had been proved as a useful tool for evaluation of successful supraclavicular nerve block in awake patients as an objective method.

With the use of ultrasound guidance in skilled hands, it is a reasonable option to perform neuraxial and peripheral regional blocks in sedated or anesthetized patients. However, there has been no evidence of applying PI for predicting the success of nerve block in general anesthetized patients.

Study Timeline

• Study First Submitted: 2021-06-02
• Study Start: 2021-06-03
• Study First Submitted QC: 2021-06-07
• Study First Posted: 2021-06-14
• Primary Completion: 2024-05-27
• Study Completion: 2024-07-05
• Status Verified: 2025-01
• Last Update Submitted: 2025-01-02
• Last Update Posted: 2025-01-03

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 70

Inclusion Criteria

• 20-70 years old,
• BMI 20-35 kg.m-2,
• elective shoulder surgery,
• ASA physical status I-III

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Exclusion Criteria

• refusal of the patient,
• comorbid with serious vascular disease,
• diabetes,
• allergy to local anesthetics,
• patients on regular opioids,
• peripheral neuropathy.

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Study & Design

• Study Type: OBSERVATIONAL
• Study Design: Not specified

Arm && Interventions

Group	Intervention	Description
BPB success	Interscalene brachial plexus blocks with ultrasound guidance under general anesthesia	The study included patients aged between 20 and 70 yr who are to undergo elective shoulder surgery under general anesthesia. Patients undergo general anesthesia induction before the interscalene block is performed. Ultrasound-guided interscalene brachial plexus block will be performed in anesthetized patients before surgery. PI monitor will be applied to both blocked and non-blocked limbs using two separate oximeters. And the SUCCESS (or failure) of the block will be confirmed by (1) 30% change of heart rate and blood pressure after incision during operation, and (2) pain score, motor and sensory function test after surgery in the post-anesthesia recovery unit.
BPB failure	Interscalene brachial plexus blocks with ultrasound guidance under general anesthesia	The study included patients aged between 20 and 70 yr who are to undergo elective shoulder surgery under general anesthesia. Patients undergo general anesthesia induction before the interscalene block is performed. Ultrasound-guided interscalene brachial plexus block will be performed in anesthetized patients before surgery. PI monitor will be applied to both blocked and non-blocked limbs using two separate oximeters. And the (success or) FAILURE of the block will be confirmed by (1) 30% change of heart rate and blood pressure after incision during operation, and (2) pain score, motor and sensory function test after surgery in the post-anesthesia recovery unit.

Primary Outcome Measures

Name	Time	Method
Perfusion Index	change between before and 15 minutes after brachial plexus block	perfusion index measured applied to both blocked and non-blocked limbs using two separate oximeters

Secondary Outcome Measures

Name	Time	Method
Motor function test on supraclavicular nerve and axillary nerve and	1 hour after surgery	0-2 scale where 0 = no block; 1 = paresis; 2 = paralysis
Heart rate	change between before and 5 minutes after incision of surgical procedure	heart rate in bpm during operation
Sensory function test on supraclavicular nerve and axillary nerve	1 hour after surgery	0-2 scale where 0=no block; 1=analgesia (patient can feel touch, not cold); 2=anesthesia (patient cannot feel touch)
Blood pressure	change between before and 5 minutes after incision of surgical procedure	blood pressure in mmHg during operation
Pain score	1 hour after surgery	Numeric rating scale for pain on a 0-10 scale where 0=no pain and 10=unbearable pain

Trial Locations

Locations (1)

Department of Anaesthesiology and Pain Medicine, Korea University Guro Hospital; 🇰🇷 Seoul, Korea, Republic of