Changes in Pulse Wave Transit Time and Its Variability After Placement of Interscalene Brachial Plexus Block

Changes in Pulse Wave Transit Time and Its Variability Measured From the Ipsilateral First Finger After Placement of Interscalene Brachial Plexus Block

Pulse wave transit time (PWTT) increases due to decreased arterial vascular tone resulting from sympathetic blockade caused by regional anesthesia. Its oscillation (PWTT variability) also contains information on the interaction between autonomic nervous system and the cardiovascular system. The changes in PWTT and its variability have not been investigated in patients receiving interscalene brachial plexus block (ISBPB). It was hypothesized that ISBPB increases PWTT and reduces low frequency power of PWTT variability.

Study Overview

• Status: Completed
• Conditions: Interscalene Brachial Plexus Block
• Intervention / Treatment: Procedure: Interscalene brachial plexus block

• Study Type: Observational
• Enrollment (Actual): 59

Contacts and Locations

Study Locations

• Korea, Republic of
  • Daegu, Korea, Republic of, 42472
    • Daegu Catholic University Medical Center

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Probability Sample

Study Population

Tertiary university medical center

Description

Inclusion Criteria:

• American Society of Anesthesiologists status of 1
• Scheduled to receive interscalene brachial plexus block for arthroscopic shoulder surgery

Exclusion Criteria:

• Coagulopathy
• Infection of the skin area for interscalene brachial plexus block
• Peripheral neuropathy or neurologic sequelae in the upper limb ipsilateral to the surgery
• Allergy to local anesthetics or a history of allergic shock
• Contralateral vocal cord palsy, hemidiaphragmatic paresis/paralysis or pneumo/hemo thorax
• Arrhythmias
• Cardiac conduction abnormalities
• A history of medication affecting cardiac conduction
• Ischemic heart disease
• Hypertension
• Diabetes mellitus
• Thyroid disfunction
• Other medical conditions affecting autonomic nervous activity

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort

Intervention / Treatment

ISBPB group; Interscalene brachial plexus block involving the C5 to C8 nerve roots

Procedure: Interscalene brachial plexus block; Using a linear ultrasound transducer connected to an ultrasound machine, the compactly arranged brachial plexus is visualized lateral to the pulsating subclavian artery. The transducer is moved cephalad to visualize the 5th to 8th cervical (C5 to C8) nerve roots located between the anterior and middle scalene muscles. Using an in-plane technique, a block needle is inserted close to a nerve root in a lateral-to-medial direction. The needle is moved to place 0.75% ropivacaine around each nerve root. The C8 nerve root is blocked first, and the C5 nerve root is blocked last. After blocking the four cervical nerve roots, ropivacaine is placed in the intermuscular plane between the sternocleidomastoid and scalene muscles to block the supraclavicular nerves. A total of 26 ml of 0.75% ropivacaine is used for the interscalene brachial plexus block (6 ml per nerve root and 2 ml for the supraclavicular nerves).

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Natural-log-transformed low frequency power of pulse wave transit time variability	Calculated by integrating the power spectra of pulse wave transit time variability between 0.04 and 0.15 Hz.	Between 15 and 20 minutes after block needle insertion

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Natural-log-transformed low frequency power of pulse wave transit time variability	Calculated by integrating the power spectra of pulse wave transit time variability between 0.04 and 0.15 Hz.	During 5 minutes before the end of the acclimatization period
Natural-log-transformed low frequency power of pulse wave transit time variability	Calculated by integrating the power spectra of pulse wave transit time variability between 0.04 and 0.15 Hz.	Between 5 and 10 minutes after block needle insertion
Natural-log-transformed high frequency power of pulse wave transit time variability	Calculated by integrating the power spectra of pulse wave transit time variability between 0.15 and 0.4 Hz.	During 5 minutes before the end of the acclimatization period
Natural-log-transformed high frequency power of pulse wave transit time variability	Calculated by integrating the power spectra of pulse wave transit time variability between 0.15 and 0.4 Hz.	Between 5 and 10 minutes after block needle insertion
Natural-log-transformed high frequency power of pulse wave transit time variability	Calculated by integrating the power spectra of pulse wave transit time variability between 0.15 and 0.4 Hz.	Between 15 and 20 minutes after block needle insertion
Pulse wave transit time	Time difference in milliseconds between the R peak of the electrocardiographic waveform and the peak of the 2nd-derivative photoplethysmographic waveform.	During 5 minutes before the end of the acclimatization period
Pulse wave transit time	Time difference in milliseconds between the R peak of the electrocardiographic waveform and the peak of the 2nd-derivative photoplethysmographic waveform.	Between 5 and 10 minutes after block needle insertion
Pulse wave transit time	Time difference in milliseconds between the R peak of the electrocardiographic waveform and the peak of the 2nd-derivative photoplethysmographic waveform.	Between 15 and 20 minutes after block needle insertion
Sensory blockade	Assessed by grading the coldness with a 3-level scale consisting of 0 (no cold sensation), 1 (reduced cold sensation), and 2 (normal cold sensation) after applying an alcohol swab to the upper limb dermatomal areas innervated by the C5 to T1 nerve roots.	20 minutes after block needle insertion
Motor blockade	The muscle contraction power is rated as 0 (complete block), 1 (partial block), and 2 (no block) for shoulder abduction (axillary nerve), elbow flexion (musculocutaneous nerve), forearm supination (radial nerve), forearm pronation (median nerve), wrist extension (radial nerve), wrist flexion (median nerve), finger abduction (ulnar nerve), thumb abduction (radial nerve), thumb adduction (ulnar nerve), and thumb opposition (median nerve).	20 minutes after block needle insertion
Bilateral pupil diameters	Measured using a portable automated monocular infrared pupillometer (PLR-3000, NeurOptics Inc., Irvine, CA, the United States) at 30 Hz for 2 seconds.	Within 1 minute after acclimatization
Bilateral pupil diameters	Measured using a portable automated monocular infrared pupillometer (PLR-3000, NeurOptics Inc., Irvine, CA, the United States) at 30 Hz for 2 seconds.	20 minutes after block needle insertion
Incidence of side effects related to interscalene brachial plexus block	Horner's syndrome, subjective dyspnea, and hoarseness	20 minutes after block needle insertion

Collaborators and Investigators

• Sponsor: JongHae Kim
• Investigators: Principal Investigator: Jonghae Kim, M.D., Daegu Catholic University Medical Center

Study record dates

Study Major Dates

• Study Start (Actual): July 31, 2023
• Primary Completion (Actual): January 7, 2024
• Study Completion (Actual): January 7, 2024

Study Registration Dates

• First Submitted: June 28, 2023
• First Submitted That Met QC Criteria: July 11, 2023
• First Posted (Actual): July 13, 2023

Study Record Updates

• Last Update Posted (Estimated): January 23, 2024
• Last Update Submitted That Met QC Criteria: January 22, 2024
• Last Verified: January 1, 2024

More Information

Terms related to this study

• Other Study ID Numbers: 2023-01

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: IPD will be available from the primary investigator on reasonable request.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No