Evaluation of the Argos System to Estimate Cardiac Output

Evaluation of the Argos System to Estimate Cardiac Output in Critically Ill Patients

The goal of this observational study is to evaluate the reliability of the Argos system to track changes in cardiac output in critically ill patients. The main question it aims to answer is:

Does cardiac output changes induced by fluid administration or changes in norepinephrine dosage can be tracked by the Argos system, compared to transpulmonary thermodilution device.

Study Overview

• Status: Recruiting
• Conditions: Shock
• Intervention / Treatment: Drug: Fluid bolus; Drug: Norepinephrine

Detailed Description

In patients with acute circulatory failure, hemodynamic monitoring including cardiac index (CI) assessment is recommended for most severe patients. Transpulmonary thermodilution (TPTD) is one of the methods that are recommended for this purpose, in particular because it is considered as reliable in this type of patients. The PiCCO2 system (Pulsion Medical Systems, Getinge, Feldkirchen, Germany) relies on TPTD method and associate two methods to measure CI. On the one hand, TPTD is considered as one of the gold standards for CI evaluation (CITPTD). On the other hand, pulse contour analysis calculates stroke volume from the waveform of the systolic part of the arterial pressure curve (CIpwa). The way this estimation is performed and it is regularly re-evaluated differs among the devices that are available on the market. This estimation of CIpwa is calibrated when TPTD is performed. Thus, it allows a real-time pulse contour derived CI assessment, which is very precise. However, TPTD system are considered invasive, expensive and are not available in all settings.

The Argos monitor (Retia Medical, Valhalla, USA) uses the so-called multi-beat analysis (MBA) to estimate CI after analyzing the arterial pressure waveform over periods of multiple heartbeats (up to 20) and scaling CI estimations to biometric data. The algorithm estimates the theoretical central arterial blood pressure waveform using MBA, minimizing and avoiding the cofounding effect of the wave reflection phenomena. Based on this central arterial blood pressure waveform and biometric patient data, the system estimates cardiac output. The Argos monitor has a second advantage. It simply connects to the analogue output of the blood pressure signal from a compatible multi-parameter monitor and needs no additional specific pressure sensor. During cardiac surgery, the Argos monitor showed reasonable agreement and trending ability compared to the pulmonary artery catheter. However, in patients after cardiac surgery, including those with low cardiac output and arrhythmia, CI estimated by the device was not interchangeable with the continuous thermodilution method via a PAC.

The primary objective of the study is to evaluate the reliability of the Argos system to track changes of CI induced by changes in norepinephrine or fluid administration, compared to CITPTD in critically ill patients.

• Study Type: Observational
• Enrollment (Estimated): 120

Contacts and Locations

• Study Contact: Name: Christopher Lai, MD, PhD; Phone Number: 12633816521; Email: christopher.lai@aphp.fr

Study Locations

• France
  • Le Kremlin-Bicêtre, France
    • Recruiting
    • Bicêtre Hospital
    • Contact: Christopher Lai; Phone Number: 2633816521; Email: christopher.lai@aphp.fr

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

Patients with shock defined by one sign of hypoperfusion:

• systolic arterial pressure <90mmHg
• mean arterial pressure <65mmHg
• prolonged capillary refill time >3 sec
• mottling score > 2
• urine output < 0.1 mL/kg/h

Description

Inclusion Criteria:

• Age ≥18 years old
• Hospitalisation in intensive care
• Haemodynamic monitoring with transpulmonary thermodilution already in place

• Hemodynamic intervention deemed necessary by the clinician in charge of the patient

  • Administration of a fluid bolus
  • Change in norepinephrine dosage or performance of a vasopressor test

Exclusion Criteria:

• Pregnancy
• Other therapeutic modification during volume expansion or the vasopressor test
• Refusal to participate by relatives of the patient or the patient himself or herself
• Non availability of investigators

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
patients with shock; Patients with shock defined by one sign of hypoperfusion: systolic arterial pressure <90mmHg; mean arterial pressure <65mmHg; prolonged capillary refill time >3 sec; mottling score > 2; urine output < 0.1 mL/kg/h	Drug: Fluid bolus; Giving a fluid bolus of 500mL of normal saline (NaCl 0.9%); Drug: Norepinephrine; brief, transient increase in norepinephrine to achieve a 15mmHg increase in mean arterial pressure and evaluates if tissue perfusion improves

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
To compare the changes in cardiac output provided by the Argos system induced by changes in norepinephrine or fluid bolus, compared to cardiac output provided by the transpulmonary thermodilution device in critically ill patients.	1 hour (before and after intervention)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Accuracy of the Argos system	To evaluate the accuracy of the Argos system to measure absolute values of cardiac output compared to transpulmonary thermodilution	1 hour (before and after intervention)
Precision of the Argos system	To evaluate the precision and least significant change of cardiac output provided by the Argos system	1 hour (before and after intervention)

Collaborators and Investigators

• Sponsor: Bicetre Hospital

Study record dates

Study Major Dates

• Study Start (Actual): February 1, 2026
• Primary Completion (Estimated): December 31, 2026
• Study Completion (Estimated): January 31, 2027

Study Registration Dates

• First Submitted: July 20, 2026
• First Submitted That Met QC Criteria: July 20, 2026
• First Posted (Actual): July 24, 2026

Study Record Updates

• Last Update Posted (Actual): July 24, 2026
• Last Update Submitted That Met QC Criteria: July 20, 2026
• Last Verified: July 1, 2026

More Information

Terms related to this study

• Keywords: fluids; cardiac output; hemodynamic monitoring; vasopressor
• Additional Relevant MeSH Terms: Pathologic Processes; Pathological Conditions, Signs and Symptoms; Shock; Organic Chemicals; Hydrocarbons; Hydrocarbons, Cyclic; Hydrocarbons, Aromatic; Amines; Catechols; Phenols; Benzene Derivatives; Alcohols; Amino Alcohols; Ethanolamines; Biogenic Monoamines; Biogenic Amines; Catecholamines; Norepinephrine
• Other Study ID Numbers: Argos study; CE-SRLF 24-100 (Other Identifier: SRLF)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No