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Impact of Interscalene Nerve Block on Cerebral Perfusion During Surgery in the Beachchair Position

NCT01983618 · Status: COMPLETED · Phase: NA · Type: INTERVENTIONAL · Enrollment: 25

Last updated 2015-10-16

No results posted yet for this study

Summary

Beachchair position is used by many orthopaedic surgeons for shoulder surgery. Most patients undergoing surgery in this position have no complications. However, reported cases of postoperative neurological deficits have highlighted the risk of cerebral and spinal cord ischemia. The etiology of such complications remains unclear. The most plausible explanation for these events would be intraoperative hypotension followed by cerebral hypoperfusion.

General anesthesia is commonly used for shoulder surgery in conjunction with interscalene brachial plexus blockade. During the block, local anesthetic's spread is frequently observed leading to a block of sympathetic fibres. Since all nerves located in the head and neck area go through the stellate ganglion, its block will cause a sympathetic denervation and a decrease of the peripheral vascular resistance, thus increasing the circulation in cerebral blood vessels. In normal situations, there is a vasoconstriction of the cerebral blood vessels in response to a sympathetic stimulation and a vasodilation if sympathetic fibres are blocked.

Transcranial Doppler (TCD) is a non-invasive examination that provides a reliable evaluation of intracranial blood flow in real-time. It can help to detect sudden changes in perfusion and identify potential embolic events. Some studies using TCD have shown an increased ipsilateral cerebral blood flow (CBF) secondary to a reduced vascular tone associated with a stellate ganglion block. Others have shown a reduction of contralateral CBF that could theoretically increase the risk of ischemia in the affected area.

This study will assess the role of interscalene nerve blockade in the protection of cerebral ischemia and preservation of cerebral autoregulation. This study will also aim to identify changes in contralateral CBF.

The investigators hypothesize that:

1. Interscalene nerve block will increase CBF
2. Interscalene nerve block will not decrease contralateral CBF
3. Cerebral autoregulation will be preserved under general anesthesia in conjunction with an interscalene nerve block in this setting.

Conditions

  • Cerebral Ischemia

Interventions

PROCEDURE

Interscalene nerve block and catheter

PROCEDURE

Interscalene catheter

Sponsors & Collaborators

  • Centre hospitalier de l'Université de Montréal (CHUM)

    lead OTHER

Principal Investigators

  • Sébastien Garneau, MD, FRCPC · Centre hospitalier de l'Université de Montréal (CHUM)

Study Design

Allocation
RANDOMIZED
Purpose
PREVENTION
Masking
SINGLE
Model
PARALLEL

Eligibility

Min Age
18 Years
Sex
ALL
Healthy Volunteers
No

Timeline & Regulatory

Start
2014-02-28
Primary Completion
2015-02-28
Completion
2015-09-30

Countries

  • Canada

Study Locations

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Read the full study record

This page highlights key information. For complete eligibility criteria, study locations, investigator contacts, and the full protocol, visit the original record on ClinicalTrials.gov.

View NCT01983618 on ClinicalTrials.gov