Inferior Vena Cava Versus Subclavian Vein Collapsibility for Predicting Fluid Responsiveness in Trauma Hemorrhagic Shock

Hemorrhagic shock from severe bleeding is a leading cause of preventable death in trauma patients. Intravenous (IV) fluid resuscitation is essential for stabilizing blood pressure and organ perfusion, but administering too much or too little fluid can cause severe complications. Only about half of hemodynamically unstable patients show an increase in cardiac output after receiving fluids. Emergency physicians often use bedside ultrasound to measure respiratory changes in the inferior vena cava (IVC), known as the IVC collapsibility index (IVC-CI), to predict whether a patient will benefit from fluids. However, obtaining clear IVC views can be difficult or impossible in trauma patients due to abdominal pain, obesity, or abdominal injuries. Evaluating the subclavian vein (SCV) under the collarbone provides a potential alternative window.

The main purpose of this study is to compare the diagnostic accuracy of the subclavian vein collapsibility index (SCV-CI) against the inferior vena cava collapsibility index (IVC-CI) for predicting fluid responsiveness in adult trauma patients presenting with hemorrhagic shock.

Eligible adult trauma patients with hemorrhagic shock will undergo rapid bedside point-of-care ultrasound upon presentation to the emergency department. Physicians will measure respiratory diameter variations in both the subclavian vein and inferior vena cava. Patients will then receive a standardized fluid challenge of 10 mL/kg intravenous balanced crystalloid solution over 10 to 15 minutes as part of resuscitation. Fluid responsiveness will be assessed by measuring changes in blood flow through the neck using carotid artery Doppler ultrasound before and 5 to 10 minutes after the fluid challenge. The study will determine whether subclavian vein ultrasound offers comparable diagnostic performance and greater feasibility compared to inferior vena cava ultrasound in emergency trauma resuscitation.

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Key information

Conditions

Hemorrhagic Shock Fluid Responsiveness Hemorrhage Hypovolemia Pathologic Processes Pathological Conditions, Signs and Symptoms Shock Shock, Hemorrhagic Trauma Wounds and Injuries

Age range

18 year and older

Sex eligibility

All sexes

Study type

Observational

Who can participate

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

Adult patients aged 18 years or older.
Presentation with blunt or penetrating trauma.
Clinical evidence of hemorrhagic shock, defined by hypotension (systolic blood pressure < 90 mmHg or mean arterial pressure < 65 mmHg), tachycardia, or other clinical signs of tissue hypoperfusion requiring fluid resuscitation.
Spontaneously breathing patients.
Presentation to the Emergency Department within 6 hours of injury.
Feasibility of bedside point-of-care ultrasound examination prior to the initiation of definitive resuscitation.

Exclusion criteria

Age younger than 18 years.
Pregnancy.
Requirement for immediate endotracheal intubation and mechanical ventilation prior to ultrasound assessment.
Obstructive shock due to cardiac tamponade, tension pneumothorax, or other known causes.
Known severe heart failure with left ventricular ejection fraction (LVEF) < 40%.
Significant tricuspid regurgitation or known pulmonary hypertension that may affect systemic venous measurements.
Major neck or clavicular trauma preventing adequate subclavian vein ultrasound acquisition.
Extensive abdominal trauma, morbid obesity, or other conditions precluding adequate inferior vena cava (IVC) acoustic visualization.
Transfer from another facility after receiving large-volume fluid resuscitation (> 1 L of crystalloids or blood products prior to assessment).
Inability or refusal to provide informed consent by the patient or their legally authorized representative.

Treatment and study plan

Primary outcomes

Area Under the Receiver Operating Characteristic Curve (AUC) of Subclavian Vein Collapsibility Index (SCV-CI)

Time frame: 10 minutes post-fluid challenge

The area under the receiver operating characteristic curve (AUC-ROC) will be calculated to determine the diagnostic accuracy of baseline SCV-CI for predicting fluid responsiveness. Fluid responsiveness is defined as an increase of ≥ 15% in carotid artery velocity time integral (Carotid VTI) following a 10 mL/kg crystalloid bolus. AUC values range from 0.5 (no discriminative ability) to 1.0 (perfect diagnostic accuracy).

Sponsors and collaborators

Lead sponsor

Assiut University

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Registry information

Official study title

Comparison of Inferior Vena Cava Versus Subclavian Vein Collapsibility Indices for Prediction of Fluid Responsiveness in Adult Trauma Patients Presenting With Hemorrhagic Shock: A Prospective Comparative Cohort Study

Important dates

Study start: 2026
Primary completion: 2027
Study completion: 2027
First posted: Sep 14, 2026
Registry last updated: Sep 14, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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