Fluid-responsiveness Assessment Simplified by Electric Cardiometry in Children (FAST)

In this study of diagnostic accuracy, the investigators aim to validate a faster, simpler, and noninvasive test of fluid-responsiveness in critically ill children. This test is based on an assessment of the hemodynamic effects of a standardized abdominal compression, using electrical cardiometry. This would help physicians to identify more easily which patient could benefit from a volume expansion, thus avoiding a potentially useless or even dangerous fluid expansion that could lead to fluid overload. To this end, the diagnostic accuracy of electrical cardiometry-based stroke volume (SV) variation induced by a standardized abdominal compression to predict fluid responsiveness (define as a 15% increase in echocardiographically measured SV after volume expansion) will be measured.

Study Overview

• Status: Recruiting
• Conditions: Fluid Therapy; Circulatory Failure; Shock State
• Intervention / Treatment: Diagnostic test: validation a test of fluid-responsiveness in critically ill children

Detailed Description

Volume expansion is the cornerstone of acute circulatory failure treatment in children. However, inappropriate administration can lead to fluid overload, which is associated with poor outcome. Thus, the search for indicators to predict fluid responsiveness is a major issue in pediatric intensive care unit. In such an emergency context, this assessment must be as simple and fast as possible, and ideally non-invasive. In children, respiratory variability of peak aortic velocity is the most studied test and has an excellent diagnostic accuracy but is only validated in the absence of any spontaneous respiratory movement, a rare situation in practice. Recently, the abdominal compression maneuver has been investigated. This classical clinical maneuver induces a transient and reversible preload increase by increasing the venous return via the mobilization of the hepato-splanchnic venous reservoir. The echocardiographic evaluation of this maneuver can accurately predict fluid responsiveness. However, this echocardiographic assessment is a pitfall, as it is an operator-dependent, discontinuous and time-consuming examination. Therefore, electrical cardiometry could be interesting. This continuous and non-invasive cardiac output monitor could be an interesting alternative to evaluate the hemodynamic effects of the abdominal compression maneuver in order to predict fluid responsiveness.

Therefore, the investigators will evaluate the diagnostic accuracy of an abdominal compression maneuver for the diagnosis of fluid responsiveness in critically ill children, for whom the physician in charge prescribed a 10ml/kg volume expansion for circulatory failure. The index test will be the SV variation induced by an abdominal compression maneuver, with SV being measured with electrical cardiometry. Fluid responsiveness will be defined as a > 15% increase in echocardiographically-measured SV between baseline and within one hour after fluid expansion (gold standard test).

In this non-interventional, prospective, multi-center study of diagnostic accuracy, children requiring a 10ml/kg volume expansion will be included. After a prescription of 10 ml/kg volume expansion by the physician in charge, screening for inclusion and exclusion criteria will be performed by an investigator physician. If the patient is included, volume expansion will be delayed for a few minutes (<3 min) while an echocardiography and the index test are performed, but no supplemental blood test or invasive parameters will be collected. Another echocardiographic evaluation will be conducted within one hour after volume expansion, to assess response to fluid expansion (gold-standard test). Patients will be follow-up until PICU discharge (28 days maximum).

The index test is the ΔSV-ACICON: percentage of SV variation between baseline and during a standardized abdominal compression. Stroke volume will be assessed by electrical cardiometry, a noninvasive cardiac output monitoring.

The abdominal compression maneuver, a common clinical test in critically ill children, will be standardized as follow: a sphygmomanometer will be inflated with 80ml of air and will be applied to the center of the patient's abdomen. Then, the operator's hand will be placed on the sphygmomanometer (which is thus interposed between the patient's abdomen and the operator's hand) and a gentle manual anteroposterior compression will be performed, calibrated at 30 cmH2O according to the sphygmomanometer. Parameters of interest will be collected 30 seconds after the start of the compression.

Patients included in this study would have received volume expansion anyway, as the prescription of 10ml/kg volume expansion by the physician in charge is the main inclusion criterion. The purpose of this study is to evaluate the diagnostic accuracy of a fluid responsiveness test. To this end, patients:

• Will undergo echocardiographic assessments, which is noninvasive, non-radiative, well tolerated and commonly used in this population as a standard of care in our center.
• Will undergo a standardized abdominal compression, a commonly used maneuver in our center and in other pediatric intensive care units, which differs only slightly from a standard physical examination.
• No additional blood test or invasive parameters will be collected be collected. Number of subjects: Forty-two patients are needed. This was calculated with an alpha risk of 0.05, an expected prevalence of 0.5, a predicted area under the receiver operating characteristics curve of 0.90 (based on previous studies) and a width of the 95% confidence interval narrow enough to exclude 0.80 which is a threshold for clinical relevance.

Statistical analysis: Comparisons between fluid "responders" and "non-responders" will be performed with Student's t-test or Mann-Whitney test for continuous variables; or with the Chi-2 test or Fisher's exact test for categorical variables. Spearman correlation coefficient will be used to test linear correlations.

Fluid responsiveness represents the gold standard test. Patients will be classified as fluid responders in case of at least 15% increase in SV after fluid expansion, compared to baseline.

Diagnostic accuracy of the index tests will be explored. As multiple cut-offs of theses index tests can be defined, the investigators will report a receiver operating characteristic (ROC) curve which graphically represents the combination of sensitivity and specificity for each possible test positivity threshold. The area under the ROC curve and its 95% confidence interval informs in a single numerical value about the overall diagnostic accuracy of the index test. The ROC curves of all index tests will be compared using a DeLong test.

A p value less than 0.05 will be considered statistically significant

• Study Type: Observational
• Enrollment (Estimated): 42

Contacts and Locations

• Study Contact: Name: Julien GOTCHAC, MD; Phone Number: +33 +33 5 24 54 92 19; Email: julien.gotchac@chu-bordeaux.fr

Study Locations

• France
  • France
    • Le Plessis-Robinson, France, France, 92350
      • Not yet recruiting
      • Hôpital Marie Lannelongue
      • Contact: Angèle BOËT, MD; Phone Number: +33 +33 1 40 94 85 92; Email: a.boet@ghpsj.fr
    • Montpellier, France, France, 34295
      • Not yet recruiting
      • Hôpital Arnaud de Villeneuve - CHU de Montpellier
      • Contact: Arthur GAVOTTO, MD; Phone Number: +33 +33 4 67 33 66 26; Email: a-gavotto@chu-montpellier.fr
    • Nantes, France, France, 44093
      • Not yet recruiting
      • Hôpital mère-enfant - CHU de Nantes
      • Contact: Pierre BOURGOIN, MD; Phone Number: +33 +33 2 76 64 36 12; Email: pierre.bourgoin@chu-nantes.fr
    • Pessac, France, France, 33600
      • Recruiting
      • Hôpital Cardiologique Haut Lévêque - CHU de Bordeaux
      • Contact: Julien GOTCHAC, MD; Phone Number: +33 +33 5 24 54 92 19; Email: julien.gotchac@chu-bordeaux.fr

Participation Criteria

Eligibility Criteria

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

• Sampling Method: Non-Probability Sample

Study Population

patient hospitalised in intensive care or in a continuous monitoring unit

Description

Inclusion Criteria:

• Age less than or equal to 8 years old
• Hospitalization in a pediatric intensive care unit
• Prescription by the attending physician of a fluid expansion of 10ml/kg
• Use of a non-invasive cardiac output monitoring device (electrical cardiometry) as part of routine care

Exclusion Criteria:

• Patient less than 37 weeks' corrected gestational age
• Hemodynamic instability making the delay necessary for any test dangerous
• Supine position contraindicated or deleterious
• Impairment of echocardiographic acoustic window or restless patient making ultrasonography impossible
• Opposition to participate expressed by the patient or by a parent or legal guardian
• Intra-abdominal hypertension, painful abdominal palpation or abdominal surgery in the last 15 days

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Patient in paediatric intensive care unit	Diagnostic test: validation a test of fluid-responsiveness in critically ill children; This test is based on an assessment of the hemodynamic effects of a standardized abdominal compression, using electrical cardiometry.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Area under the ROC curve (AUROC, %) of ΔSV-ACICON to diagnose fluid responsiveness	Description: The primary outcome measure of a diagnostic accuracy study is the discriminative ability of an index test (expressed as an area under the ROC curve) to diagnose a condition (defined by a positive gold-standard reference test). In this study: The index test is ΔSV-ACICON = difference between stroke volume measured by electrical cardiometry (ml) during a calibrated abdominal compression (30mmHg for 30 seconds) and stroke volume measured by electrical cardiometry at baseline.; The condition is "fluid responsiveness"; The gold-standard reference test to diagnose fluid responsiveness is a stroke volume (SV) increase of at least 15% between baseline and after volume expansion: ΔSV-VE > 15% = ((SV after volume expansion - SV at baseline) / SV at baseline) > 15%. SV (ml) will be measured by transthoracic echocardiography as the product of left ventricular outflow tract surface (cm², from a parasternal long axis view) and left ventricular outflow tract velocity-time integral	between baseline and 1 hour

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
AUROC (%) of the following index test to diagnose fluid responsiveness (same definition as above )	Respiratory variability of peak aortic velocity at baseline (%)	between baseline and 1 hour
AUROC (%) of the following index test to diagnose fluid responsiveness (same definition as above )	Respiratory variability of inferior vena cava diameter at baseline (%)	between baseline and 1 hour
AUROC (%) of the following index test to diagnose fluid responsiveness (same definition as above )	Stroke volume respiratory variations at baseline (%), measured with electrical cardiometry	between baseline and 1 hour
AUROC (%) of the following index test to diagnose fluid responsiveness (same definition as above )	Abdominal compression induced variations in arterial pressure (%)	between baseline and 1 hour
AUROC (%) of the following index test to diagnose fluid responsiveness (same definition as above )	Abdominal compression induced variations in perfusion index (%)	between baseline and 1 hour
AUROC (%) of the following index test to diagnose fluid responsiveness (same definition as above )	Abdominal compression induced variations in end-tidal carbon dioxide (%)	between baseline and 1 hour
AUROC (%) of the following index test to diagnose fluid responsiveness (same definition as above )	Abdominal compression induced variations in arterial pulse pressure variability index (%)	between baseline and 1 hour
Diagnostic accuracy (AUROC, %) of all tests above to diagnose a significant increase (>15%) in mean arterial pressure after volume expansion		between baseline and 1 hour
Subgroup analysis of the primary outcome: age, type of fluid expansion, ventilation status, circulatory physiology		between baseline and 1 hour
Correlation between fluid responsiveness and the following.	Age category (0 - 2 years / 2 - 8 years)	At baseline; 1 hour ; Day 28.
Correlation between fluid responsiveness and the following.	Reason for intensive care admission (cardiac surgery, univentricular circulation / cardiac surgery, biventricular circulation / other)	At baseline; 1 hour ; Day 28.
Correlation between fluid responsiveness and the following.	Sex	At baseline; 1 hour ; Day 28.
Correlation between fluid responsiveness and the following.	Weight at baseline (kg)	At baseline; After fluid expansion (see Primary Outcome Measure for Time Frame precise definition); Day 28.
Correlation between fluid responsiveness and the following.	Number of fluid expansion during the last 24 hours before inclusion	At baseline; After fluid expansion (see Primary Outcome Measure for Time Frame precise definition); Day 28.
Correlation between fluid responsiveness and the following.	Baseline Heart rate (bpm)	At baseline; After fluid expansion (see Primary Outcome Measure for Time Frame precise definition); Day 28.
Correlation between fluid responsiveness and the following.	Baseline arterial pressure (mmHg)	At baseline; After fluid expansion (see Primary Outcome Measure for Time Frame precise definition); Day 28.
Correlation between fluid responsiveness and the following.	Baseline urine output (ml/kg/h)	At baseline; After fluid expansion (see Primary Outcome Measure for Time Frame precise definition); Day 28.
Correlation between fluid responsiveness and the following.	Baseline capillary refill time (s)	At baseline; After fluid expansion (see Primary Outcome Measure for Time Frame precise definition); Day 28.
Correlation between fluid responsiveness and the following.	Baseline mottling (yes/no)	At baseline; 1 hour ; Day 28.
Correlation between fluid responsiveness and the following.	Baseline PELODS2 score (n)	At baseline; 1 hour ; Day 28.
Correlation between fluid responsiveness and the following.	Type of volume expansion (albumin or crystalloid)	At baseline; 1 hour ; Day 28.
Correlation between fluid responsiveness and the following.	Length of mechanical ventilation (days), evaluated 28 days after inclusion	At baseline; 1 hour ; Day 28.
Correlation between fluid responsiveness and the following.	Intensive care unit length of stay (days), evaluated 28 days after inclusion	At baseline; 1 hour ; Day 28.
Correlation between fluid responsiveness and the following.	Mortality at 28 days after inclusion (yes/no)	At baseline; 1 hour ; Day 28.
Correlation between fluid responsiveness and the following.	% of increase in mean perfusion pressure (i.e. difference between mean arterial pressure and central venous pressure, mmHg) between baseline and after volume expansion	At baseline; 1 hour ; Day 28.
Correlation between fluid responsiveness and the following.	% of increase in central venous pressure (mmHg) between baseline and after volume expansion	At baseline; 1 hour ; Day 28.
Correlation between fluid responsiveness and the following.	% of increase in stroke volume (ml) measured by electrical cardiometry between baseline and after volume expansion	At baseline; 1 hour ; Day 28.

Collaborators and Investigators

• Sponsor: University Hospital, Bordeaux
• Investigators: Study Director: Julien GOTCHAC, MD, Hôpital Cardiologique Haut Lévêque - CHU de Bordeaux

Study record dates

Study Major Dates

• Study Start (Actual): July 22, 2025
• Primary Completion (Estimated): July 22, 2027
• Study Completion (Estimated): August 19, 2027

Study Registration Dates

• First Submitted: September 1, 2025
• First Submitted That Met QC Criteria: April 3, 2026
• First Posted (Actual): April 13, 2026

Study Record Updates

• Last Update Posted (Actual): April 13, 2026
• Last Update Submitted That Met QC Criteria: April 3, 2026
• Last Verified: March 1, 2026

More Information

Terms related to this study

• Keywords: pediatrics; Fluid responsiveness; Echocardiography; Fluid therapy; Critical Care; volume expansion; Circulatory failure; Goal-directed fluid management; Electrical Cardiometry
• Additional Relevant MeSH Terms: Pathologic Processes; Pathological Conditions, Signs and Symptoms; Shock
• Other Study ID Numbers: CHUBX 2025/019; 2025-A01029-40 (Other Identifier: ID-RCB number)

Drug and device information, study documents

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