Perfusion Index and End Diastolic Velocity Ratios as Predictors of Supraclavicular Block Success in Vascular Access Surgery

Correlation Between Perfusion Index Ratio and End Diastolic Velocity Ratio After Supraclavicular Brachial Plexus Block as an Early Predictor of Successful Block in Superficialization Surgery of the Upper Limb

This is a prospective observational study investigating the correlation between Perfusion Index (PI) ratio and End Diastolic Velocity (EDV) ratio as early predictors of successful supraclavicular brachial plexus block (SCBPB) in patients undergoing superficialization surgery of the upper limb.

Study Overview

• Status: Not yet recruiting
• Conditions: Perfusion Index; End Diastolic Velocity

Detailed Description

Regional anesthesia is fundamental for upper limb surgeries, with SCBPB providing dense anesthesia. However, early confirmation of successful block performance remains challenging. Traditional clinical methods (sensory/motor testing) are subjective and delayed. This study proposes using objective, noninvasive indices - PI (evaluated via pulse oximetry) and EDV (measured by Doppler ultrasound) - to determine their accuracy in detecting sympathetic blockade shortly after SCBPB. Early and reliable detection of block success is particularly important in superficialization surgeries such as arteriovenous fistula (AVF) superficialization in patients with compromised vascular status. The results are expected to enhance anesthesia practice by providing quantitative, reproducible, and rapid assessment tools.

• Study Type: Observational
• Enrollment (Estimated): 50

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Probability Sample

Study Population

Participants are adult patients aged 18-65 years, both male and female, classified as ASA II-VI, and scheduled for elective superficialization procedures (mainly AV fistula superficialization). Patients must be capable of understanding and signing informed consent. Excluded are patients with contraindications to nerve block such as coagulopathy, local infection, allergy to local anesthetics, severe vascular disease, morbid obesity (BMI >35), severe neurological or psychiatric impairment, or those taking vasopressors or beta-blockers that could alter vascular reactivity.

Description

Inclusion Criteria:

• Adults aged 18-65 years

Both genders

ASA II-VI classification

Undergoing elective upper limb superficialization surgery (e.g., AVF superficialization)

Provided written informed consent

Exclusion Criteria:

• Patient refusal

Coagulopathy or bleeding disorders

Local infection at injection site

Allergy to local anesthetics

Use of vasopressors or beta-blockers

Severe peripheral vascular disease

Morbid obesity (BMI > 35)

Severe neurological or psychiatric disorders

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort
adult patients scheduled for elective superficialization surgery of the upper limb; Participants are adult patients aged 18-65 years, both male and female, classified as ASA II-VI, and scheduled for elective superficialization procedures (mainly AV fistula superficialization).

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in Perfusion Index ratio	Change in Perfusion Index ratio at 15 minutes after supraclavicular brachial plexus block in predicting successful block	15 minutes
Change in End Diastolic Velocity ratio	Change in End Diastolic Velocity ratio at 15 minutes after supraclavicular brachial plexus block in predicting successful block	15 minutes

Collaborators and Investigators

• Sponsor: Assiut University

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.

Study record dates

Study Major Dates

• Study Start (Estimated): May 1, 2026
• Primary Completion (Estimated): October 30, 2027
• Study Completion (Estimated): December 30, 2027

Study Registration Dates

• First Submitted: September 20, 2025
• First Submitted That Met QC Criteria: September 20, 2025
• First Posted (Estimated): September 29, 2025

Study Record Updates

• Last Update Posted (Estimated): September 29, 2025
• Last Update Submitted That Met QC Criteria: September 20, 2025
• Last Verified: September 1, 2025

More Information

Terms related to this study

• Keywords: brachial plexus block; Perfusion Index; End Diastolic Velocity
• Other Study ID Numbers: PI and EDV as Predictors

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

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