Perfusion Index for Predicting Brachial Plexus Block Success Under General Anesthesia

Usefulness of Pulse Oximeter Perfusion Index for Predicting the Success of Interscalene Brachial Plexus Blockade Under General Anesthesia

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).

Study Overview

• Status: Completed
• Conditions: Disorder of Shoulder
• Intervention / Treatment: Procedure: Interscalene brachial plexus blocks with ultrasound guidance under general anesthesia

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 Type: Observational
• Enrollment (Actual): 70

Contacts and Locations

Study Locations

• Korea, Republic of
  • Seoul, Korea, Republic of, 08308
    • Department of Anaesthesiology and Pain Medicine, Korea University Guro Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 20 years to 70 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No

• Sampling Method: Probability Sample

Study Population

patients aged 20-70 who are scheduled for shoulder surgery under general anesthesia, with ASA physical status I-III

Description

Inclusion Criteria:

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

Exclusion Criteria:

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

Study Plan

How is the study designed?

Design Details

• Observational Models: Case-Control
• Time Perspectives: Prospective

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
BPB success; 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.	Procedure: Interscalene brachial plexus blocks with ultrasound guidance under general anesthesia; Ultrasound-guidance, interscalene brachial plexus blocks, in-plane technique, perineural injection, 0.5% ropivacaine 12.5ml and 0.2% lidocaine 12.5ml
BPB failure; 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.	Procedure: Interscalene brachial plexus blocks with ultrasound guidance under general anesthesia; Ultrasound-guidance, interscalene brachial plexus blocks, in-plane technique, perineural injection, 0.5% ropivacaine 12.5ml and 0.2% lidocaine 12.5ml

What is the study measuring?

Primary Outcome Measures

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

Secondary Outcome Measures

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

Collaborators and Investigators

• Sponsor: Korea University Guro Hospital

Publications and helpful links

General Publications

• 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.
• Misamore G, Webb B, McMurray S, Sallay P. A prospective analysis of interscalene brachial plexus blocks performed under general anesthesia. J Shoulder Elbow Surg. 2011 Mar;20(2):308-14. doi: 10.1016/j.jse.2010.04.043. Epub 2010 Aug 13.
• Marhofer P. Regional blocks carried out during general anesthesia or deep sedation: myths and facts. Curr Opin Anaesthesiol. 2017 Oct;30(5):621-626. doi: 10.1097/ACO.0000000000000504.

Study record dates

Study Major Dates

• Study Start (Actual): June 3, 2021
• Primary Completion (Actual): May 27, 2024
• Study Completion (Actual): July 5, 2024

Study Registration Dates

• First Submitted: June 2, 2021
• First Submitted That Met QC Criteria: June 7, 2021
• First Posted (Actual): June 14, 2021

Study Record Updates

• Last Update Posted (Actual): March 25, 2025
• Last Update Submitted That Met QC Criteria: January 2, 2025
• Last Verified: January 1, 2025

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Physiological Effects of Drugs; Central Nervous System Depressants; Anesthetics
• Other Study ID Numbers: 2021GR0104

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No