Internal Jugular Vein Respiratory Variability as a Marker of Disease Severity in Infant Bronchiolitis (IJV-BRONCH)

August 20, 2026 updated by: Emre Güngör, Eskisehir Osmangazi University

Respiratory Variation of Internal Jugular Vein Diameter as a Novel Ultrasonographic Marker of Disease Severity in Infants With Acute Bronchiolitis: A Prospective Observational Cohort Study

This prospective observational cohort study evaluates whether respiratory-cycle variation in internal jugular vein (IJV) diameter, measured by point-of-care ultrasound, correlates with clinical disease severity in infants 1-23 months of age presenting with acute bronchiolitis. Using a standardized M-mode protocol, the IJV Variability Index ([IJVmax-IJVmin]/IJVmax x 100) will be calculated and compared with the Wang Bronchiolitis Severity Score, four additional validated clinical severity instruments (Modified Tal Score, Respiratory Distress Assessment Instrument, Kristjansson Respiratory Score, Respiratory Assessment Change Score), oxygen saturation, respiratory rate, need for high-flow nasal cannula or supplemental oxygen, pediatric intensive care unit admission, and length of hospital stay. Concurrent lung and diaphragm point-of-care ultrasound will be performed to build a multimodal ultrasound severity model. No intervention is assigned; all ultrasound assessments are performed in addition to standard clinical care and do not alter treatment decisions.

Study Overview

Status

Not yet recruiting

Conditions

Intervention / Treatment

Detailed Description

Bronchiolitis is among the leading causes of hospitalization in infants under 2 years of age. Existing clinical severity scores show limited inter-observer agreement and weak correlation with oxygenation. Point-of-care ultrasound (lung ultrasound, diaphragm ultrasound) has been studied as an adjunct severity marker in bronchiolitis. Still, respiratory-cycle variability of the internal jugular vein (IJV) diameter has not previously been investigated in this population. A prior reliability study in healthy children demonstrated that right internal jugular vein (RIJV) diameter can be reliably measured by M-mode ultrasound and does not vary significantly across the respiratory cycle in the absence of respiratory distress; the study authors explicitly proposed that RIJV diameter and its respiratory variation be investigated as a surrogate marker of pulmonary function in children with respiratory distress. This study extends that proposed application to infants with acute bronchiolitis. Eligible infants aged 1-23 months meeting AAP (2014) clinical criteria for acute bronchiolitis will undergo a standardized ultrasound protocol (45-degree head elevation, linear probe, right internal jugular vein imaged approximately 1 cm cephalad to the sternoclavicular junction, B-mode identification followed by M-mode measurement of maximal inspiratory and expiratory diameters) performed by a blinded, trained sonographer. We will record concurrent clinical severity scoring, lung ultrasound, and diaphragm ultrasound (excursion, thickening fraction). The primary analysis will test the correlation between the IJV Variability Index and the Wang Bronchiolitis Severity Score; secondary analyses will examine correlations with additional validated severity scores, physiologic parameters, and clinical outcomes (respiratory support escalation, length of stay), as well as inter-/intra-observer reliability and the discriminative performance of a multimodal point-of-care ultrasound model.

Study Type

Observational

Enrollment (Estimated)

120

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

  • Turkey (Türkiye)
    • Eskişehir
      • Eskişehir, Eskişehir, Turkey (Türkiye), 26480
        • Eskisehir Osmangazi University Faculty of Medicine, Pediatric Emergency Department
        • Contact:

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

  • Child

Accepts Healthy Volunteers

No

Sampling Method

Non-Probability Sample

Study Population

Infants aged 1 to 23 months presenting to the Pediatric Emergency Department with a clinical diagnosis of acute bronchiolitis according to the American Academy of Pediatrics (AAP) clinical criteria will be prospectively enrolled. Eligible participants will be evaluated within the first 6 hours of emergency department presentation after written informed consent is obtained from a parent or legal guardian. Participants will undergo standardized clinical severity assessment and point-of-care ultrasonography of the internal jugular vein, lungs, and diaphragm in addition to routine clinical care. No study-specific therapeutic intervention will be assigned.

Description

Inclusion Criteria:

  • Infants aged 1-23 months
  • Clinical diagnosis of acute bronchiolitis per AAP (2014) criteria (first wheezing episode following an upper respiratory infection prodrome, with tachypnea, retractions, and/or crackles)
  • Written informed consent obtained from parent/legal guardian
  • Evaluable within the first 6 hours of emergency department presentation

Exclusion Criteria:

  • Underlying congenital heart disease
  • Chronic lung disease (bronchopulmonary dysplasia, cystic fibrosis)
  • Prior history of recurrent wheezing/suspected asthma
  • Anatomical abnormality of the neck or prior history of central venous catheterization or jugular vein thrombosis
  • Hemodynamic instability/shock
  • Immediate need for intubation/mechanical ventilation precluding ultrasound assessment
  • Parent/legal guardian declines consent

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
Acute Bronchiolitis Cohort
Infants aged 1-23 months diagnosed with acute bronchiolitis per AAP (2014) clinical practice guideline criteria, undergoing a standardized point-of-care ultrasound assessment (internal jugular vein, lung, and diaphragm) in addition to standard clinical evaluation and treatment. No intervention is assigned as part of this study; the cohort will be stratified post hoc by clinical severity scores for descriptive and exploratory subgroup analyses.
Diagnostic test: Point-of-Care Ultrasonography
A standardized point-of-care ultrasonography assessment will be performed in addition to routine clinical evaluation. The protocol includes M-mode assessment of the right internal jugular vein (IJV) to measure maximal and minimal respiratory-cycle diameters and calculate the IJV Variability Index ([IJVmax-IJVmin]/IJVmax × 100). Concurrent lung ultrasonography and diaphragm ultrasonography, including diaphragm excursion and thickening fraction, will also be performed. Ultrasonographic assessments are performed for research measurements only and do not determine or modify clinical treatment decisions.
Other Names:
  • POCUS

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Correlation Between Internal Jugular Vein Respiratory Variability Index and Wang Bronchiolitis Severity Score
Time Frame: At enrollment (baseline, within 6 hours of emergency department presentation)
Correlation between the Internal Jugular Vein (IJV) Variability Index and the Wang Bronchiolitis Severity Score. The IJV Variability Index will be calculated as ([IJVmax - IJVmin] / IJVmax) × 100, where IJVmax and IJVmin represent the maximum and minimum IJV diameters measured during the respiratory cycle. The Wang Bronchiolitis Severity Score ranges from 0 to 12, with higher scores indicating greater disease severity. The association will be quantified using Pearson or Spearman correlation coefficients, as appropriate.
At enrollment (baseline, within 6 hours of emergency department presentation)

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Correlation Between IJV Variability Index and Oxygen Saturation, Respiratory Rate, and Retraction Severity
Time Frame: At enrollment (baseline, within 6 hours of emergency department presentation)
Correlation between the IJV Variability Index and oxygen saturation (SpO2, %), respiratory rate (breaths/minute), and the retraction component of the Wang Bronchiolitis Severity Score. The retraction component ranges from 0 to 3, with higher scores indicating more severe retractions.
At enrollment (baseline, within 6 hours of emergency department presentation)
Association Between IJV Variability Index and Need for High-Flow Nasal Cannula or Supplemental Oxygen Therapy
Time Frame: From enrollment through hospital discharge, assessed up to approximately 7 days
Comparison of baseline IJV Variability Index between infants who require and do not require high-flow nasal cannula (HFNC) or supplemental oxygen therapy during hospitalization.
From enrollment through hospital discharge, assessed up to approximately 7 days
Association Between IJV Variability Index and Pediatric Intensive Care Unit Admission
Time Frame: From enrollment through hospital discharge, assessed up to approximately 7 days
Comparison of baseline IJV Variability Index between infants admitted and not admitted to the pediatric intensive care unit (PICU) during hospitalization.
From enrollment through hospital discharge, assessed up to approximately 7 days
Correlation Between Diaphragm Ultrasound Parameters and IJV Variability Index and Clinical Severity Scores
Time Frame: At enrollment (baseline, within 6 hours of emergency department presentation)
Correlation of diaphragm excursion, diaphragm thickening fraction, and inspiratory/expiratory ratio with the IJV Variability Index and clinical severity scores. Clinical severity measures will include the Wang Bronchiolitis Severity Score (range 0-12), Modified Tal Score (range 0-12), Respiratory Distress Assessment Instrument (range 0-17), and Kristjansson Respiratory Score (range 0-10). For all four clinical severity scores, higher scores indicate greater disease or respiratory distress severity.
At enrollment (baseline, within 6 hours of emergency department presentation)
Correlation Between IJV Variability Index and Modified Tal Score
Time Frame: At enrollment (baseline, within 6 hours of emergency department presentation)
Correlation between the IJV Variability Index and the Modified Tal Score. The Modified Tal Score ranges from 0 to 12, with higher scores indicating greater bronchiolitis severity.
At enrollment (baseline, within 6 hours of emergency department presentation)
Correlation Between IJV Variability Index and Respiratory Distress Assessment Instrument
Time Frame: At enrollment (baseline, within 6 hours of emergency department presentation)
Correlation between the IJV Variability Index and the Respiratory Distress Assessment Instrument (RDAI). The RDAI assesses wheezing and retractions and ranges from 0 to 17, with higher scores indicating greater respiratory distress.
At enrollment (baseline, within 6 hours of emergency department presentation)
Association Between IJV Variability Index and Respiratory Assessment Change Score
Time Frame: Baseline and 2-4 hours after enrollment
Association between the baseline IJV Variability Index and the Respiratory Assessment Change Score (RACS). RACS quantifies change in respiratory status using the change in the Respiratory Distress Assessment Instrument together with a standardized change in respiratory rate between baseline and follow-up assessment. RACS is a change measure rather than a bounded scale and therefore does not have a fixed theoretical minimum or maximum.
Baseline and 2-4 hours after enrollment
Correlation Between IJV Variability Index and Kristjansson Respiratory Score
Time Frame: At enrollment (baseline, within 6 hours of emergency department presentation)
Correlation between the IJV Variability Index and the Kristjansson Respiratory Score. The Kristjansson Respiratory Score ranges from 0 to 10, with higher scores indicating greater respiratory disease severity.
At enrollment (baseline, within 6 hours of emergency department presentation)

Other Outcome Measures

Outcome Measure
Measure Description
Time Frame
Discriminative Performance of a Multimodal Point-of-Care Ultrasound Model Versus Wang Bronchiolitis Severity Score for Predicting Escalated Respiratory Support
Time Frame: From enrollment through 24 hours after enrollment
Area under the receiver operating characteristic curve (AUC, 95% confidence interval) for a multimodal model combining baseline IJV Variability Index, lung ultrasound score, and diaphragm ultrasound parameters, compared with the Wang Bronchiolitis Severity Score alone using the DeLong test. The lung ultrasound score ranges from 0 to 36, with higher scores indicating greater pulmonary aeration abnormality. The Wang Bronchiolitis Severity Score ranges from 0 to 12, with higher scores indicating greater bronchiolitis severity.
From enrollment through 24 hours after enrollment

Collaborators and Investigators

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

Sponsor

Eskisehir Osmangazi University

Investigators

  • Principal Investigator: Emre Güngör, Medical Doctor, Eskisehir Osmangazi University Faculty of Medicine, Department of Pediatrics, Division of Pediatric Emergency Medicine

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)

September 1, 2026

Primary Completion (Estimated)

March 31, 2027

Study Completion (Estimated)

August 31, 2027

Study Registration Dates

First Submitted

August 15, 2026

First Submitted That Met QC Criteria

August 20, 2026

First Posted (Actual)

August 21, 2026

Study Record Updates

Last Update Posted (Actual)

August 21, 2026

Last Update Submitted That Met QC Criteria

August 20, 2026

Last Verified

August 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • IJVBRONCH-2026-01

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

UNDECIDED

IPD Plan Description

The plan for sharing de-identified individual participant data has not yet been finalized. A data-sharing decision will be made before publication, taking into account participant confidentiality, ethics committee requirements, institutional policies, and applicable data protection regulations.

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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