Changes in Skin Conductance Measurement as an Endpoint Monitor for Sympathetic Blocks

Summary

This study is intended to evaluate a monitor that will facilitate ascertainment of an effective sympathetic blockade following Lumbar Sympathetic blocks. Utilization of a monitor with a rapid response and easy clinical applicability which can demonstrate effective sympathetic block would increase efficiency within the procedure suite and also serve to function as an objective endpoint for the evaluation of sympathetic blockade in future research.In current clinical practice, the most commonly used monitoring methods are clinical observations of sympathetic blockade, skin temperature monitoring, pulse pressure monitoring and any combination of these monitoring methods. The skin temperature and pulse pressure may increase after sympathetic block. However, changes in the skin temperature and pulse pressure often demonstrate an unpredictable or delayed response. Confounding variables, such as ambient temperature, coexisting vascular disease, use of other vasoactive medications may contribute to inconsistencies in the temperature or pulse pressure responses.

Normal sympathetic activity stimulates muscarinic receptors in the periphery that subsequently stimulate the sweat glands to secrete and fill with sweat containing sodium and other electrolytes. The electrolytes present in the sweat increase the electrical conductance while decreasing the electrical resistance at the skin level.

The real-time changes in skin conductance indices can be monitored at the skin level, by use of non-invasive electrodes attached to the skin (similar to EKG electrodes). A computer program analyzes the data and produces a real-time graphic and numeric data demonstrating the skin conductance response. The initiation of successful sympathetic blockade can cause rapid cessation of the skin sympathetic activity that leads to a decrease in skin conductance within seconds.

Conditions

• Nerve; Disorder, Sympathetic

Interventions

PROCEDURE

Lumbar Sympathetic Block

A lumbar sympathetic block is an injection in the middle of the lower back, toward the left or right side. The "lumbar sympathetic nerves" are a small bundle of nerves that carries "sympathetic" nerve signals from the lower extremities. In some instances, certain injuries to the lower extremities can cause a burning, unusual pain called complex regional pain syndrome or reflex sympathetic dystrophy. Injecting a small amount of local anesthetic on the lumbar sympathetic nerves can identify whether or not this pain is carried by the sympathetic nervous system.

DEVICE

Skin conductance algesimeter

The real-time changes in skin conductance indices can be monitored at the skin level, by use of non-invasive electrodes attached to the skin (similar to EKG electrodes) connected to the skin conductance algesimeter. A computer program analyzes the data and produces a real-time graphic and numeric data demonstrating the skin conductance response. The initiation of successful sympathetic blockade can cause rapid cessation of the skin sympathetic activity that leads to a decrease in skin conductance within seconds.

Sponsors & Collaborators

• Oslo University Hospital

  collaborator OTHER

• Hospital for Special Surgery, New York

  lead OTHER

Principal Investigators

• Semih Gungor, MD · Hospital for Special Surgery, New York

Study Design

Allocation

NA

Purpose

SUPPORTIVE_CARE

Masking

NONE

Model

SINGLE_GROUP

Eligibility

Min Age

18 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2014-01-31

Primary Completion

2014-09-30

Completion

2014-09-30