Pulse Wave Transit Time After Infraclavicular Block

June 20, 2026 updated by: Burçin Alaçam, MD, Sakarya University

Time-Dependent Changes in Pulse Wave Transit Time Following Infraclavicular Block: A Non-Invasive Assessment of Sympathetic Blockade

This prospective observational study aims to evaluate the time-dependent changes in Pulse Wave Transit Time (PWTT) following ultrasound-guided infraclavicular brachial plexus block. PWTT is a non-invasive hemodynamic parameter reflecting vascular tone and sympathetic nervous system activity. Patients undergoing upper extremity surgery under infraclavicular block will be monitored using standard perioperative monitoring devices. PWTT measurements will be obtained before and after block placement at predefined time intervals. Secondary outcomes will include perfusion index, skin temperature, heart rate, blood pressure, respiratory rate, and oxygen saturation. The study seeks to determine whether PWTT can serve as an objective and non-invasive marker of sympathetic blockade following infraclavicular block.

Study Overview

Status

Not yet recruiting

Conditions

Intervention / Treatment

Detailed Description

Regional anesthesia success is traditionally assessed using sensory and motor block evaluation methods that rely on patient cooperation and subjective responses to external stimuli. However, these methods may be difficult to apply in sedated, uncooperative, or communication-impaired patients. Therefore, objective and non-invasive indicators of sympathetic blockade have gained increasing interest in regional anesthesia practice.

Pulse Wave Transit Time (PWTT) is defined as the time interval between the R-wave on the electrocardiogram and the arrival of the corresponding pulse wave detected by a peripheral pulse oximeter. PWTT reflects vascular tone, arterial compliance, and hemodynamic status. Sympathetic blockade induced by peripheral nerve blocks results in vasodilation and reduced vascular resistance, potentially leading to measurable changes in PWTT. Previous studies have demonstrated the utility of objective parameters such as perfusion index, skin temperature, blood flow measurements, and PWTT in assessing block success. However, data regarding the temporal changes of PWTT following infraclavicular brachial plexus block remain limited.

The primary objective of this prospective observational study is to investigate the time-dependent changes in PWTT after ultrasound-guided infraclavicular brachial plexus block. The study will be conducted in patients undergoing upper extremity surgery under infraclavicular block at Sakarya Training and Research Hospital.

Patients scheduled to receive infraclavicular block as part of their routine clinical care will be enrolled after providing informed consent. The block procedure is not performed for research purposes and represents standard clinical practice. Following block administration, PWTT values will be recorded from the blocked extremity using standard monitoring equipment. Measurements will be obtained before block placement and at 0, 5, 10, 15, and 20 minutes after block completion. Baseline PWTT measurements will also be obtained from the contralateral upper extremity.

Secondary outcome measures will include perfusion index, skin temperature of both upper extremities, heart rate, non-invasive blood pressure, respiratory rate, and oxygen saturation. Demographic and clinical data will also be recorded.

All measurements will be collected according to a predefined protocol using standardized monitoring equipment. Since PWTT is an objective device-derived parameter, observer dependency is expected to be minimal. Data collection personnel will be separated from the clinician performing the block whenever feasible to reduce measurement bias. All collected data will be anonymized prior to statistical analysis.

This study is designed as a single-center, prospective observational investigation without randomization or intervention beyond routine clinical care. The findings may contribute to the development of PWTT as a practical, objective, and non-invasive marker of sympathetic blockade following infraclavicular brachial plexus block.

Study Type

Observational

Enrollment (Estimated)

25

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Locations

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

Yes

Sampling Method

Non-Probability Sample

Study Population

The study population will consist of adult patients aged 18-65 years with ASA physical status I who are scheduled to undergo elective upper extremity hand surgery under ultrasound-guided infraclavicular brachial plexus block. All participants will receive standard-of-care anesthesia management. Patients with contraindications to peripheral nerve block, significant systemic disease, obesity (BMI ≥30 kg/m²), coagulation disorders, opioid use, or conditions affecting sympathetic activity will be excluded. Only patients who provide informed consent will be enrolled.

Description

Inclusion Criteria:

  • Patients undergoing elective upper extremity hand surgery
  • 18 - 65 years
  • ASA I
  • No coagulopathy, thrombocytopenia, coagulation disorders
  • Patients who provide informed consent to participate in the study

Exclusion Criteria:

  • History of drug allergy relevant to study procedures or local anesthetics
  • Body mass index (BMI) ≥ 30 kg/m²
  • Body weight < 40 kg
  • Age < 18 years or > 65 years
  • History of significant cardiac disease (e.g., arrhythmia, conduction abnormalities)
  • Coagulopathy (INR > 1.5 or platelet count < 100,000/mm³)
  • Pregnancy or lactation
  • Infection at the site of peripheral nerve block
  • ASA II-IV
  • Failed block or motor block duration exceeding 30 minutes
  • Patients reporting pain (NRS ≥ 3), due to potential influence on sympathetic activity
  • Chronic opioid use

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Cohorts and Interventions

Group / Cohort
Intervention / Treatment
Infraclavicular Block Group
Patients undergoing routine ultrasound-guided infraclavicular brachial plexus block for upper extremity surgery will be included in this observational cohort. Pulse Wave Transit Time (PWTT) and other hemodynamic parameters will be measured at predefined time points before and after block administration. No additional intervention beyond standard clinical care will be performed for research purposes.
Procedure: Ultrasound-guided infraclavicular brachial plexus block
Ultrasound-guided infraclavicular brachial plexus block will be performed as part of routine clinical anesthesia practice for upper extremity surgery. Local anesthetic will be administered according to standard institutional protocols. No additional or experimental drug or procedure will be applied for research purposes. Pulse Wave Transit Time (PWTT) and other hemodynamic parameters will be recorded before and after block placement at predefined time intervals.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Change in Pulse Wave Transit Time
Time Frame: 20 minutes after infraclavicular block
The primary outcome is the time-dependent change in Pulse Wave Transit Time (PWTT) following ultrasound-guided infraclavicular brachial plexus block. PWTT will be measured as the interval between the R-wave of the electrocardiogram (ECG) and the corresponding pulse wave detected by peripheral pulse oximetry. Measurements will be recorded at baseline (pre-block) and at 0, 5, 10, 15, and 20 minutes after block placement. The primary analysis will evaluate the change in PWTT over time within the blocked extremity.
20 minutes after infraclavicular block

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Perfusion Index
Time Frame: 20 minutes after infraclavicular block
Changes in perfusion index (PI) measured from the pulse oximeter at the blocked and contralateral upper extremities at baseline and at 0, 5, 10, 15, and 20 minutes after infraclavicular block.
20 minutes after infraclavicular block
Skin Temperature
Time Frame: 20 minutes after infraclavicular block
Changes in skin temperature of the blocked and contralateral upper extremities measured at baseline and at 0, 5, 10, 15, and 20 minutes after block placement.
20 minutes after infraclavicular block
oxygen saturation
Time Frame: 20 minutes after infraclavicular block
Changes in peripheral oxygen saturation measured using pulse oximetry during the study period.
20 minutes after infraclavicular block

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sakarya University

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

July 20, 2026

Primary Completion (Estimated)

October 15, 2026

Study Completion (Estimated)

November 15, 2026

Study Registration Dates

First Submitted

June 20, 2026

First Submitted That Met QC Criteria

June 20, 2026

First Posted (Actual)

June 25, 2026

Study Record Updates

Last Update Posted (Actual)

June 25, 2026

Last Update Submitted That Met QC Criteria

June 20, 2026

Last Verified

June 1, 2026

More Information

Terms related to this study

Keywords

Other Study ID Numbers

  • SAU-ANE-BA-04

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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