Dilute Epinephrine vs Tourniquet for Visualization in Ankle Arthroscopy: A RCT

The Effect of Dilute Epinephrine Saline Irrigation on Field Clarity in Ankle Arthroscopic Surgery Compared to a Tourniquet: a Double-blind, Randomized Controlled Trial

This multicenter, prospective randomized controlled trial investigates the effect of dilute epinephrine irrigation versus tourniquet use on visual field clarity (VFC) during ankle arthroscopy. Patients are randomized into an epinephrine group (normal saline with 1 mL of 1:1000 epinephrine per 3 L bag; tourniquet placed but not inflated unless needed) or a standard tourniquet group. The primary outcome is arthroscopic visual field clarity assessed using a 4-point Likert-style numeric rating scale. Secondary outcomes include postoperative pain intensity at 2 and 24 hours (VAS), and the incidence of hypotension, bradycardia, and cardiovascular adverse events.

Study Overview

• Status: Not yet recruiting
• Conditions: Chronic Ankle Instability; Ankle Ligament Injury; Ankle Arthroscopy
• Intervention / Treatment: Drug: Epinephrine group; Device: Tourniquet group

Detailed Description

Study Objective and Design

This study aims to evaluate the effect of dilute epinephrine irrigation versus tourniquet use on visual field clarity (VFC) during ankle arthroscopic surgery, while also assessing the incidence of hypotension/bradycardia events and potential cardiovascular adverse effects.

This is a multicenter, prospective, randomized controlled trial comparing the intraoperative arthroscopic field clarity between patients receiving epinephrine-containing irrigation and those undergoing surgery with a tourniquet.

Participants are randomized into two groups:

Epinephrine Group: Irrigation fluid consists of normal saline mixed with 1 mL of 1:1000 epinephrine per 3-liter bag. A tourniquet is placed but not inflated; it may be inflated as a rescue measure if necessary.

Tourniquet Group: Standard tourniquet application as routinely practiced.

3.2.4 Primary Efficacy Outcome

Visual field clarity (VFC) under ankle arthroscopy, assessed using a Likert-style 4-point numeric rating scale (NRS).

3.2.5 Secondary Efficacy Outcomes

Pain intensity scores at 2 and 24 hours postoperatively, measured using the Visual Analog Scale (VAS).

• Study Type: Interventional
• Enrollment (Estimated): 88
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: zongyou Pan, Doctoral degree; Phone Number: 86-19857004757; Email: panzongyou@gmail.com

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria:

• Able to understand the procedures and methods of the clinical trial
• voluntarily provide written informed consent
• Aged from 15 to 65 years old , regardless of sex
• Diagnosed with a condition requiring ankle surgery
• Be scheduled to undergo unilateral ankle arthroscopy

Exclusion Criteria:

• Patients who decline to participate in the study
• Known history of heart disease (e.g., coronary artery disease, cardiac conduction abnormalities), diabetes, or asthma
• Poorly controlled hypertension
• Age under 15 years or above 65 years old
• Intellectual disability
• Pregnant or breastfeeding women
• Known allergy to sulfites

Contraindications to ISBPB (including planned injection site infection, pre-existing neurological deficits, allergy to local anesthetics, severe chronic obstructive pulmonary disease, or contralateral phrenic nerve dysfunction)

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Triple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Epinephrine group	Drug: Epinephrine group; Irrigation fluid consisted of normal saline mixed with 1 mL of 1:1000 epinephrine per 3-liter bag. A tourniquet was placed but left deflated as a rescue measure and could be inflated intraoperatively if necessary.
Active Comparator: Tourniquet group	Device: Tourniquet group; Standard tourniquet application

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Visual field clarity (VFC) under ankle arthroscopy, assessed using a 4-point Likert-style numeric rating scale (NRS)	Scores are integers ranging from 0 to 4, with higher scores indicating clearer visual field	at 2 hours

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Pain intensity at 2 and 24 hours postoperatively, assessed using the Visual Analog Scale (VAS)	Scores range from 0 to 10, with higher scores indicating more severe pain	at 2 and 24 hours postoperatively

Collaborators and Investigators

• Sponsor: Second Affiliated Hospital, School of Medicine, Zhejiang University

Study record dates

Study Major Dates

• Study Start (Estimated): December 30, 2025
• Primary Completion (Estimated): November 30, 2026
• Study Completion (Estimated): December 30, 2026

Study Registration Dates

• First Submitted: December 21, 2025
• First Submitted That Met QC Criteria: January 11, 2026
• First Posted (Estimated): January 16, 2026

Study Record Updates

• Last Update Posted (Estimated): January 16, 2026
• Last Update Submitted That Met QC Criteria: January 11, 2026
• Last Verified: December 1, 2025

More Information

Terms related to this study

• Keywords: Arthroscopic visual field
• Other Study ID Numbers: 2025-1632

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