The Skin Wrinkle Test: a Simple Clinical Test of Regional Block Success

NCT03873896 | Completed

• 1 other identifier: 20190762
• Study Type: interventional
• Target: 4
• Locations: 1 country
• Sites: 1

Brief Summary

Wrinkling of the hands and feet with exposure to moist environments is a commonly observed phenomenon. This "stimulated skin wrinkling" (SSW) is the result of direct stimulation of digital nerve sympathetic fibers. The resulting effect is a sympathetically mediated vasoconstriction with loss of finger pulp volume, overlying skin traction and wrinkling. It has been established that multiple disease states of the sympathetic nervous system such as diabetic neuropathy, leprosy and nerve injury can lead to impaired SSW of the affected limb. While this test has been successfully utilized for over 80 years to assess patients with sympathetic pathology, it has never been evaluated as a tool to determine the success of a regional nerve block. A regional nerve block is a method of anesthesia that involves injecting a local anesthetic around a particular nerve or nerve bundle in order to block the sensation of pain from that particular body part. This is of particular importance in the paediatric or non verbal population. These patients may not be able to reliably confirm the effectiveness of their analgesia. Pediatric anesthesiologists often perform these regional blocks on already anesthetized children whereas the non-verbal or cognitively impaired population may not be able to verbalize block effectiveness. This test, if proven effective as a means of determining block success, would be a quick, non-invasive and inexpensive method of ensuring adequate intra-operative and post operative analgesia for patients. As this is a pilot project focused on establishing the SSW test as an effective tool for assessing regional block success on awake volunteers, further studies would need to be performed to assess test effectiveness in different clinical situations.

Conditions

Skin Manifestations

Outcome Measures

Primary Outcomes (1)

• Change in observed skin wrinkling

  Determined by judgements based on the "Wrinkling Assessment Scale" originally described by Ping Ng et. al. 2013: Grade 0: Wrinkling absent Grade 1: slight wrinkling and the fingertip is not smooth Grade 2: two or fewer lines of wrinkling on each side of the fingertip Grade 3: 3 or more lines of wrinkling on each side of the fingertip Grade 4: wrinkling completely distorts the pulp of the fingertip (see images presented in Wilder Smith et. al. 2015). A higher score indicates (3 or 4) full nerve function and the lower likelihood of nerve block. A lower score (0-2) indicate lower levels of nerve function and a higher likelihood of successful nerve blockade

  Assessed at baseline (prior to EMLA cream application) and 10, 20 and 30 minutes after its application

Study Arms (2)

Blocked finger

EXPERIMENTAL

The experimental arm will be the ring finger of the volunteer that is blocked (randomized either right or left hand) with a digital nerve block (described elsewhere in the submission). The skin wrinkle test (diagnostic test) will be applied to this arm

Diagnostic Test: Stimulated skin wrinkling test; Procedure: Digital Nerve Block

Unblocked finger

ACTIVE COMPARATOR

The control arm will be the finger of the same volunteer that is not under the influence of digital nerve block. This will be the corresponding digit (the ring finger) on the opposite hand of the side that was blocked (determined by coin toss). The skin wrinkle test (diagnostic test) will be applied to this arm

Diagnostic Test: Stimulated skin wrinkling test

Interventions

Stimulated skin wrinkling test DIAGNOSTIC_TEST

Stimulated skin wrinkling induced by the application of EMLA (eutectic mixture of local anesthetic) cream to the finger pads of blocked and unblocked fingers of study volunteers (test applied to both study arms)

Blocked finger; Unblocked finger

Digital Nerve Block PROCEDURE

A digital nerve block is performed by injecting a total of 3 millilitres of 2% Lidocaine at the base of the ring finger of randomized hand of the volunteer. The effect of the block is confirmed clinically before proceeding with the study data collection. Please see the description for more details on the procedure

Blocked finger

Eligibility Criteria

• Age: 18 Years - 65 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Healthy 18-65 year old of either gender

You may not qualify if:

• contraindication to regional block
• preexisting nerve damage
• hand or finger injury
• active skin infection
• allergy to local anesthetic
• disease states known to affect aquagenic skin wrinkling including cystic fibrosis, diabetic neuropathy, leprosy, vascular disease and diseases of autonomic function
• Patients with history of bleeding disorders or currently using anticoagulation agents
• contraindications to EMLA cream
• breaks in the skin on the finger EMLA is to be applied
• allergy to its constituents
• history of methemoglobinemia.

Sponsors & Collaborators

• Memorial University of Newfoundland: lead

Study Sites (1)

Memorial University

St. John's, Newfoundland and Labrador, A1B 3V6, Canada

Location

Related Publications (2)

• Wilder-Smith EP. Stimulated skin wrinkling as an indicator of limb sympathetic function. Clin Neurophysiol. 2015 Jan;126(1):10-6. doi: 10.1016/j.clinph.2014.08.007. Epub 2014 Sep 2.

  PMID: 25216595 BACKGROUND

• Vasudevan TM, van Rij AM, Nukada H, Taylor PK. Skin wrinkling for the assessment of sympathetic function in the limbs. Aust N Z J Surg. 2000 Jan;70(1):57-9. doi: 10.1046/j.1440-1622.2000.01744.x.

  PMID: 10696945 BACKGROUND

MeSH Terms

Conditions

Skin Manifestations

Condition Hierarchy (Ancestors)

Signs and Symptoms; Pathological Conditions, Signs and Symptoms

Study Officials

• Peter A Collins, MD

  Memorial University

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: SINGLE
• Who Masked: OUTCOMES ASSESSOR
• Masking Details: Photos of blocked digits will be taken and presented to blinded assessors to rate on a pre-determined scale of wrinkling
• Purpose: DIAGNOSTIC
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Peter Collins, Assistant Professor, Principal Investigator

Model Details: Blinded control trial assessing aquagenic skin wrinkling after digital nerve blockade in healthy volunteers. Digital nerve blocks to be performed on the left or right ring fingers of volunteers (to be randomized with coin toss) with the unblocked finger of each volunteer acting as its own control

Study Record Dates

• First Submitted: September 6, 2018
• First Posted: March 14, 2019
• Study Start: December 9, 2019
• Primary Completion: December 14, 2019
• Study Completion: December 14, 2019
• Last Updated: January 13, 2020

Record last verified: 2020-01

Data Sharing

• IPD Sharing: Will not share

Locations

CA (1)