The Effects of Horner's Syndrome Developing After Interscalene Brachial Plexus Block on Autonomic Nervous Activity

Daegu Catholic University Medical Center48 enrolled

Overview

This study evaluates the effects of Horner's syndrome on cardiac autonomic nervous activity after interscalene brachial plexus block. Cardiac autonomic nervous activity and bilateral pupil diameters will be measured in a scotopic light condition, 30 minutes after interscalene brachial plexus block under ultrasound guidance and 15 minutes after the subsequent sitting position.

Stellate ganglia provide sympathetic fibers to the heart. Ipsilateral stellate ganglion block accompanied by interscalene brachial plexus block causes Horner's syndrome presenting with miosis, ptosis, and anhidrosis. The extent of Horner's syndrome can be represented by the difference in pupil diameter between bilateral eyes. Cardiac autonomic nervous activity affected by stellate ganglion block can be measured by calculation of heart rate variability parameters.

Study Type

OBSERVATIONAL

Enrollment

Conditions

Brachial Plexus Block Horner Syndrome Autonomic Imbalance

Interventions

Interscalene brachial plexus blockPROCEDURE

Under ultrasound guidance, the 5th to 7th cervical nerve roots are identified between anterior and middle scalene muscles and subsequently blocked.

0.75% ropivacaineDRUG

Placement of 25 to 30 ml of 0.75% ropivacaine around the 5th to 7th cervical nerve roots

Eligibility

Sex: ALLMin age: 20 YearsMax age: 60 Years

Medical Language ↔ Plain English

Inclusion Criteria: * American Society of Anesthesiologists physical status 1 * Arthroscopic shoulder surgery under interscalene brachial plexus block Exclusion Criteria: * Coagulopathy * Infection at the site of brachial plexus block * Peripheral neuropathy or neurologic sequelae on the operative limb * Allergy to local anesthetics or history of allergic shock * Psychiatric diseases * Patient refusal * Difficulty communicating with medical personnel * Arrhythmias * Ischemic heart disease * Hypertension * Diabetes mellitus * Thyroid dysfunction * Conduction abnormalities on electrocardiogram * Electrolyte imbalance * Medications affecting cardiac conduction * Contralateral vocal cord palsy * Contralateral hemidiaphragmatic paresis or paralysis * Contralateral pneumothorax or hemothorax

Locations (1)

Daegu Catholic University Medical Center

Daegu, South Korea

Outcomes

Primary Outcomes

Post-sitting sympathetic nervous activity

Natural-log transformed low frequency power of heart rate variability calculated using R wave to R wave intervals obtained for 5 minutes between 10 and 15 minutes after the sitting position following interscalene brachial plexus block

Time frame: 15 minutes after the sitting position following interscalene brachial plexus block

Secondary Outcomes

Post-sitting ipsilateral pupil diameter

Ipsilateral pupil diameter measured under a mesopic condition 15 minutes after the sitting position following interscalene brachial plexus block

Time frame: 15 minutes after the sitting position following interscalene brachial plexus block

Post-sitting contralateral pupil diameter

Contralateral pupil diameter measured under a mesopic condition 15 minutes after the sitting position following interscalene brachial plexus block

Time frame: 15 minutes after the sitting position following interscalene brachial plexus block

Post-anesthetic ipsilateral pupil diameter

Ipsilateral pupil diameter measured under a mesopic condition 30 minutes after interscalene brachial plexus block

Time frame: 30 minutes after interscalene brachial plexus block

Post-anesthetic contralateral pupil diameter

Contralateral pupil diameter measured under a mesopic condition 30 minutes after interscalene brachial plexus block

Time frame: 30 minutes after interscalene brachial plexus block

Pre-anesthetic ipsilateral pupil diameter

Ipsilateral pupil diameter measured under a mesopic condition 15 minutes after baseline acclimation

Data from ClinicalTrials.gov

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Time frame: 15 minutes after baseline acclimation

Pre-anesthetic contralateral pupil diameter

Contralateral pupil diameter measured under a mesopic condition 15 minutes after baseline acclimation

Time frame: 15 minutes after baseline acclimation

Post-sitting parasympathetic nervous activity

Natural-log transformed high frequency power of heart rate variability calculated using R wave to R wave intervals obtained for 5 minutes between 10 and 15 minutes after the sitting position following interscalene brachial plexus block

Time frame: 15 minutes after the sitting position following interscalene brachial plexus block

Post-sitting sympathovagal balance

Low-to-high frequency power ratio of heart rate variability obtained for 5 minutes between 10 and 15 minutes after the sitting position following interscalene brachial plexus block

Time frame: 15 minutes after the sitting position following interscalene brachial plexus block

Post-sitting overall variability of autonomic nervous system

Natural-log transformed total power of heart rate variability obtained for 5 minutes between 10 and 15 minutes after the sitting position following interscalene brachial plexus block

Time frame: 15 minutes after the sitting position following interscalene brachial plexus block

Post-anesthetic sympathetic nervous activity

Natural-log transformed low frequency power of heart rate variability between 25 and 30 minutes after interscalene brachial plexus block

Time frame: Between 25 and 30 minutes after interscalene brachial plexus block

Post-anesthetic parasympathetic nervous activity

Natural-log transformed high frequency power of heart rate variability between 25 and 30 minutes after interscalene brachial plexus block

Time frame: Between 25 and 30 minutes after interscalene brachial plexus block

Post-anesthetic sympathovagal balance

Low-to-high frequency power ratio of heart rate variability between 25 and 30 minutes after interscalene brachial plexus block

Time frame: Between 25 and 30 minutes after interscalene brachial plexus block

Post-anesthetic overall variability of autonomic nervous system

Natural-log transformed total power of heart rate variability between 25 and 30 minutes after interscalene brachial plexus block

Time frame: Between 25 and 30 minutes after interscalene brachial plexus block

Pre-anesthetic sympathetic nervous activity

Natural-log transformed low frequency power of heart rate variability 15 minutes after baseline acclimation

Time frame: 15 minutes after baseline acclimiation

Pre-anesthetic parasympathetic nervous activity

Natural-log transformed high frequency power of heart rate variability 15 minutes after baseline acclimation

Time frame: 15 minutes after baseline acclimiation

Pre-anesthetic sympathovagal balance

Low-to-high frequency power ratio of heart rate variability 15 minutes after baseline acclimation

Time frame: 15 minutes after baseline acclimiation

Pre-anesthetic overall variability of autonomic nervous system

Natural-log transformed total power of heart rate variability 15 minutes after baseline acclimation

Time frame: 15 minutes after baseline acclimation

Sensory blockade

C5 to T1 dermatomal blockade of the shoulder graded from 0 to 2 (0 = no cold sensation, 1 = reduced cold sensation, and 2 = normal cold sensation) by applying ice to the shoulder

Time frame: 30 minutes after interscalene brachial plexus block

Motor blockade

Motor blockade of the radial, ulnar, median, musculocutaneous, and axillary nerves graded from 0 to 2 (0 = no block 1 = partial block, and 2 = complete block)

Time frame: 30 minutes after interscalene brachial plexus block