Comparing Fluid Responsiveness Assessment Methods in Patients With Impaired Consciousness

NCT06180902 | Recruiting DMC

• 1 other identifier: COMPASS
• Study Type: interventional
• Target: 222
• Locations: 1 country
• Sites: 1

Brief Summary

Hypotension is a significant precursor to unfavorable clinical outcomes. To determine whether infusion therapy can positively impact the management of hypotension, several evaluative tests can be utilized. These include assessing the collapsibility and distensibility indices of the inferior vena cava, conducting a passive leg raising (PLR) test, and performing a fluid challenge (FC). Technologically advanced methods leveraging dynamic testing are capable of real-time prediction of a patient's response to infusion therapy. Nonetheless, the use of systolic pressure variability (SPV), pulse pressure variability (PPV), and stroke volume variability (SVV) is often limited by the prohibitive costs of the necessary equipment. In contrast, the PLR test and FC are not subject to this limitation. Despite being deemed unreliable by numerous clinical protocols, static measurements of central venous pressure (CVP) or pulmonary capillary wedge pressure (PCWP) persist in usage among certain traditionalists within the medical community. It must be noted that the patient's baseline state and the unique clinical context are pivotal in determining the precision of these methodologies. For example, the PLR test may yield limited information in fully conscious patients, and the prognostic value of CVP measurements is significantly diminished in cases of pneumothorax and hydrothorax. Regrettably, there is a paucity of data on the prognostic utility of these tests in patients with altered levels of consciousness, despite their growing presence in intensive care units. This gap underscores the necessity for comprehensive studies that evaluate the predictive efficacy of infusion therapy responsiveness in patients with concurrent hypotension and impaired consciousness. Purpose of the study: to investigate the sensitivity and specificity of methods for assessing fluid responsiveness in patients with hypotension and decreased level of consciousness.

Conditions

Hypotension; Cognitive Impairment

Keywords

Hypotension; Cognitive Impairment; Fluid Responsiveness; Intensive Care; Fluid Infusion

Outcome Measures

Primary Outcomes (1)

• Sensitivity and specificity of methods for assessing fluid responsiveness

  Sensitivity - proportion of actual positives that are correctly identified by the test. Specificity - proportion of actual negatives that are correctly identified by the test.

  Through study completion, an average of 1 year

Study Arms (1)

Fluid responsiveness testing

EXPERIMENTAL

In our clinical study to evaluate infusion therapy responsiveness, we'll start by measuring the inferior vena cava diameter. Two minutes later, we'll assess central venous pressure. After another two-minute pause, the passive leg raise test begins, followed by a 15-minute wait. Then, we conduct the fluid challenge. Post-evaluation, we administer balanced crystalloid solutions at 1000 ml, infused at 15 ml/kg/h, adjusting for any previous infusions during the fluid challenge.

Diagnostic Test: Inferior vena cava's diameter ratio; Diagnostic Test: Central venous pressure; Diagnostic Test: Passive leg raising test; Diagnostic Test: Fluid challenge; Procedure: Fluid infusion

Interventions

Inferior vena cava's diameter ratio DIAGNOSTIC_TEST

In mechanical ventilation, the Inferior Vena Cava's maximum diameter (IVCmax) is measured at peak inspiration, and minimum diameter (IVCmin) at expiration's end. The Distensibility Index (IVCDI) is calculated as \[(IVCmax - IVCmin) / IVCmin\] × 100%. In spontaneous breathing, IVCmax is the diameter at expiration's end, and IVCmin at inspiration's end. The Collapse Index (IVCCI) is \[(IVCmax - IVCmin) / IVCmax\] × 100%. Clinically, an IVCDI/IVCCI ≥ 18% indicates a 'responder'. Values \< 18% denote 'non-responders'.

Fluid responsiveness testing

Central venous pressure DIAGNOSTIC_TEST

In our protocol, patients lie flat, connected to a saline-filled system for intravenous infusion via a central venous catheter. The system, starting from the subclavian catheter, extends to the 2nd to 3rd intercostal space at the mid-axillary line. The tube's end is raised perpendicular to the bed until saline flow stops, marking the liquid level. The height from the mid-axillary line to this point is measured in millimeters. If the liquid column falls below the mid-axillary line, indicating continuous flow, the CVP is negative, and the catheter is closed to block air entry. CVP readings are taken at exhalation's end. CVP interpretation: * CVP ≤ 12 mmHg (16.3 cm H2O) indicates a responder. * CVP \> 12 mmHg (16.3 cm H2O) indicates a non-responder.

Fluid responsiveness testing

Passive leg raising test DIAGNOSTIC_TEST

In our protocol, the patient starts flat for initial CVP measurement. Then, the bed is tilted to 45 degrees for the first measurements: Systolic/Diastolic Blood Pressure, Mean Arterial Pressure, and Pulse Pressure (Systolic - Diastolic). Next, the bed is adjusted to elevate the feet, creating a 135-degree angle between torso and legs. After 90 seconds, the second set of measurements, including CVP, is taken. The patient is then returned to the initial position. Interpreting results: A responder is indicated by: * Over 10% Pulse Pressure (PP) increase in the second measurement; * The ratio of PP change to CVP change (∆PP / ∆CVP) \> 1; * Second measurement CVP ≤ 12 mmHg (16.3 cm H2O). A non-responder is indicated by the presence at least one of the following: * Less than 10% PP increase in the second measurement; * The ratio of PP change to CVP change (∆PP / ∆CVP) ≤ 1; * Second measurement CVP \> 12 mmHg (16.3 cm H2O).

Also known as: PLR-test

Fluid responsiveness testing

Fluid challenge DIAGNOSTIC_TEST

In our clinical procedure, patients start horizontally for initial measurements: Systolic, Diastolic, Mean Arterial, Pulse Blood Pressures, and Central Venous Pressure (CVP). Then, they receive a balanced crystalloid solution at 4 ml/kg body weight at maximum permissible infusion rate. After infusion, a second measurement set identical to the first is taken. Interpretation: A responder is indicated by: * Pulse Pressure (PP) increase \> 10% in second measurement; * Ratio of PP change to CVP change (∆PP / ∆CVP) \> 1; * Second CVP measurement ≤ 12 mmHg (16.3 cm H2O). A non-responder is indicated by the presence at least one of the following: * PP increase \< 10% in second measurement; * Ratio of PP change to CVP change (∆PP / ∆CVP) ≤ 1; * Second CVP measurement \> 12 mmHg (16.3 cm H2O).

Also known as: FC

Fluid responsiveness testing

Fluid infusion PROCEDURE

After assessing infusion therapy responsiveness, patients receive balanced crystalloid solutions at 1000 ml, infused at 15 ml/kg/hour, accounting for any prior infusions. Effectiveness evaluation follows, involving cardiac output reassessment (initially measured upon study enrollment). Effectiveness is determined by a ≥10% increase in cardiac output in the second measurement compared to the first. This is quantified as: \[(CO(after) - CO(before)) / CO(before)\] × 100% ≥ 10%, where CO(after) is the post-infusion cardiac output and CO(before) the pre-infusion output.

Fluid responsiveness testing

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Age ≥ 18 years.
• Hospitalization in an intensive care unit
• Level of consciousness on the FOUR scale ≤ 12 points
• Planned infusion therapy
• Presence of a central venous catheter or direct indication for catheterization
• The decision of the medical council to include the patient in the study

You may not qualify if:

• Pulmonary edema
• Absence of one or both lower extremities
• Chronic kidney disease according to KDIGO classification ≥ stage 3b
• Acute kidney injury grade 3
• Documented or suspected increased intracranial pressure (cerebral edema, brain compression, hydrocephalus, etc.).
• Presence of mitral valve regurgitation \> grade 1
• Presence of aortic valve regurgitation \> grade 1
• Patients previously enrolled in the "COMPASS" study in the period of 12 preceding hours

Sponsors & Collaborators

• Federal Research and Clinical Centre of Intensive Care Medicine and Rehabilitology: lead

Study Sites (1)

Federal Research and Clinical Center of Intensive Care Medicine and Rehabilitology

Moscow, Russia

RECRUITING

MeSH Terms

Conditions

Hypotension; Cognitive Dysfunction

Interventions

Central Venous Pressure

Condition Hierarchy (Ancestors)

Vascular Diseases; Cardiovascular Diseases; Cognition Disorders; Neurocognitive Disorders; Mental Disorders

Intervention Hierarchy (Ancestors)

Venous Pressure; Blood Pressure; Hemodynamics; Cardiovascular Physiological Phenomena; Circulatory and Respiratory Physiological Phenomena

Study Officials

• Valery Likhvantsev, PhD

  Federal Research and Clinical Center of Intensive Care Medicine and Rehabilitology

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Valery Likhvantsev, PhD

CONTACT

+79036235982; lik0704@gmail.com

Levan Berikashvili, MD

CONTACT

+79263308968; levan.berikashvili@mail.ru

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NA
• Masking: NONE
• Purpose: DIAGNOSTIC
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Principal Investigator

Model Details: For all patients included in the study, a designated algorithm will be applied. The initial phase of the clinical study, aimed at evaluating responsiveness to infusion therapy, starts with a precise measurement of the inferior vena cava's diameter. After a brief two-minute interval subsequent to the measurement, the focus shifts to the assessment of central venous pressure. A further two-minute pause following the central venous pressure evaluation signals the commencement of the passive leg raise test, an essential element in the protocol. The conclusion of the passive leg raise test is followed by a fifteen-minute waiting period, which precedes the start of the fluid challenge, completing the thorough evaluation sequence.

Study Record Dates

• First Submitted: December 11, 2023
• First Posted: December 26, 2023
• Study Start: January 16, 2024
• Primary Completion (Estimated): May 20, 2026
• Study Completion (Estimated): May 20, 2026
• Last Updated: January 23, 2026

Record last verified: 2026-01

Data Sharing

• IPD Sharing: Will not share

Locations

RU (1)