Pharmacodynamic Analysis of the HaemOdynamic Effects of a Standard Fluid BolUS

Official title

Pharmacodynamic Analysis of the HaemOdynamic Effects of a Standard Fluid BolUS - the PHOEBUS Study

Overview

When the flow of blood ejected by the heart drops significantly, that is to say when there is "shock", one of the first treatments undertaken is often volume expansion. This treatment consists of injecting a liquid intravenously, generally in the form of a bolus, that is to say a dose of solute administered all at once, of 250 to 500 mL of fluid over approximately 10 to 30 minutes. The injected fluid expands the blood volume and fills the heart pump, in order to increase the flow it ejects. However, this treatment poses two problems. First, it is only inconsistently effective. It is possible that of the 250-500 mL of fluid administered in the standard way, only a part is effective, whereas, as the effectiveness decreases during the infusion, the rest does not increase cardiac output significantly. However, the average part of the total volume that is ineffective on a large population of patients is not well known. Second, the effects of volume expansion on cardiac output decrease rapidly after the end of administration. However, the average duration of effectiveness of a 250-500 mL fluid bolus, and the factors that influence this duration of effectiveness, are not well determined. The main objective of this research is to measure, among the volume of a fluid bolus, which part does not significantly increase cardiac output. The secondary objective is to measure the average time of effectiveness after the end of the infusion and the factors that influence it.

Interventions

• Drug fluid challenge
  Fluid bolus of 500 mL of crystalloids given at a constant rate between 10 and 15 minutes

Primary outcome measures

• To measure, during the administration of a fluid bolus in order to perform volume expansion, the volume of fluid which causes an increase in cardiac output of less than 15%. [Time frame: During the fluid bolus administration (<15min)]

Secondary outcome measures (4)

• The maximum amplitude of the change induced by volume expansion in cardiac output, mean arterial pressure and central venous pressure [Time frame: During the fluid bolus administration (<15min)]
• The delay at which this maximum effect appears in terms of cardiac output, mean arterial pressure and central venous pressure [Time frame: During the fluid bolus administration (<15min)]
• The time following the end of the infusion from which the cardiac output becomes ≤5% of the baseline value [Time frame: A period of 120 minutes following the fluid infusion]
• The factors that influence these pharmacokinetic variables will be determined [Time frame: During the study period (during fluid administration and the period of 120 minutes following the infusion)]

Eligibility criteria

Inclusion criteria

• Age ≥18 years old
• Hospitalisation in intensive care
• Haemodynamic monitoring already in place with a pulse wave contour analysis-derived estimation of cardiac output (either calibrated or uncalibrated)
• Decision taken by the clinicians in charge of the patient to perform volume expansion by intravenous infusion of a 6 mL/kg crystalloid bolus

Exclusion criteria

• Pregnancy
• Refusal to participate by relatives of the patient or the patient himself
• Other therapeutic modification during volume expansion

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: No

Study design

Observational model

Cohort

Study locations

France · 1 center

• Bicêtre Hospital — Le Kremlin-Bicêtre

Identifiers

NCT: NCT06839404 · PHOEBUS study · SRLF 22-033

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗