MedPath

A Net Ultrafiltration Challenge to Predict Preload-dependence (UF CHALLENGE)

Not Applicable
Recruiting
Conditions
Acute Kidney Injury
Interventions
Diagnostic Test: Fast ultrafiltration challenge
Diagnostic Test: Slow ultrafiltration challenge
Registration Number
NCT05214729
Lead Sponsor
Hospices Civils de Lyon
Brief Summary

Hemodynamic instability episodes are a frequent complication of renal replacement therapies in critically ill patients, and their incidence is associated with worse survival. Hypovolemia, identified by the existence of biventricular preload dependence, is responsible for one episode out of two, and may justify a decrease in or cessation of fluid removal by net ultrafiltration (UF). To date, preload dependence is most frequently identified by evaluating the effects on cardiac output of postural changes (passive leg raising), impact of cardio-pulmonary interactions in ventilated patients, or fluid challenge. However, none of these tests may help identify a patient whose cardiac output is at risk of becoming preload dependent, that is situated at the inflexion point of the Frank Starling curve.

Our study aims to evaluate the effects on cardiac output (measured by a transpulmonary thermodilution technique) of 2 net ultrafiltration challenges, consisting fast removal of 250 ml of ultrafiltrate over 15 and 30 minutes respectively, and compare their diagnostic performance to the reference technique of preload dependence assessed by postural changes (passive leg raising) performed after the UF challenge.

Enrolled participants will undergo both UF challenges, following a randomized crossover design, in which the order of UF challenge duration (15 or 30 minutes) is randomized, separated by a washout period of 24 hours.

Detailed Description

Not available

Recruitment & Eligibility

Status
RECRUITING
Sex
All
Target Recruitment
20
Inclusion Criteria
  • adult patient, aged 18 year or older
  • under mechanical ventilation and continuous general anesthesia, with a positive end-expiratory pressure of 5 cmH2O or more
  • with stage 3 KDIGO acute kidney injury
  • treated with continuous renal replacement therapy for less than 14 days
  • ongoing continuous cardiac output monitoring
  • with a predicted intensive care length of stay of 24 hours or more at time of screening
Read More
Exclusion Criteria
  • High arterial lactate concentration, > 4.0 mmol/L at time of screening
  • Calibrated cardiac index < 2.0 L/min/m2 or > 4.0 L/min/m2 at time of screening
  • Positive postural change maneuver in the last 2 hours preceding screening
  • Patient under extracorporeal membrane oxygenation
  • Patient with active bleeding requiring emergent transfusion
  • Patient under chronic maintenance dialysis or renal transplant recipient
  • Acute ischemic or hemorrhagic stroke complicated with coma and requiring mechanical ventilation
  • Fulminant hepatitis (acute liver injury, hepatic encephalopathy, icterus and a drop in prothrombin < 50% in less that 15 days
  • Impossible postural change maneuver
  • Pregnant or lactating patient
  • Imminent death
  • Patient under legal protection measures as by French regulation
  • Patient already enrolled in the present study
  • Patient already participates in a study with protocolized net ultrafiltration, ongoing at time of screening
Read More

Study & Design

Study Type
INTERVENTIONAL
Study Design
CROSSOVER
Arm && Interventions
GroupInterventionDescription
Fast to Slow GroupFast ultrafiltration challengeThe Fast to Slow Group corresponds to enrolled patients randomized, following the sequential crossover design, to first perform the fast UF challenge immediately after inclusion, followed by the slow UF challenge after a washout period of 24 hours.
Slow to Fast GroupFast ultrafiltration challengeThe Slow to Fast Group corresponds to enrolled patients randomized, following the sequential crossover design, to first perform the slow UF challenge immediately after inclusion, followed by the fast UF challenge after a washout period of 24 hours.
Slow to Fast GroupSlow ultrafiltration challengeThe Slow to Fast Group corresponds to enrolled patients randomized, following the sequential crossover design, to first perform the slow UF challenge immediately after inclusion, followed by the fast UF challenge after a washout period of 24 hours.
Fast to Slow GroupSlow ultrafiltration challengeThe Fast to Slow Group corresponds to enrolled patients randomized, following the sequential crossover design, to first perform the fast UF challenge immediately after inclusion, followed by the slow UF challenge after a washout period of 24 hours.
Primary Outcome Measures
NameTimeMethod
UF challenge diagnostic performance to identify preload dependence risk, evaluated by the area under the curve of the receiver-operating characteristic curve (ROC) of the relative cardiac output variationThe relative variation in cardiac output induced by UF challenges is quantified immediately at the end of UF challenges. The postural maneuver is performed immediately after the end of UF challenges.

The discriminatory performance of the relative variation in cardiac output (in %) between baseline and after the UF challenge will be quantified using the ROC, using the result of the postural change maneuver (negative or positive) performed after the UF challenge as the reference binary classifier. A 95% confidence interval of the ROC will be computed, as well as its statistical significance, as compared to a random guess, using the Delong method.

Secondary Outcome Measures
NameTimeMethod
UF challenge diagnostic performance to identify pre-existing preload dependence, evaluated by the ROC of the relative cardiac output variation.The relative variation in cardiac output induced by UF challenges is quantified immediately at the end of UF challenges. The postural maneuver is performed immediately before UF challenges.

The discriminatory performance of the relative variation in cardiac output (in %) between baseline and after the UF challenge will be quantified using the ROC, using the result of the postural change maneuver (negative or positive) performed before the UF challenge as the reference binary classifier. A 95% confidence interval of the ROC will be computed, as well as its statistical significance, as compared to a random guess, using the Delong method.

Comparison of slow and fast UF challenge diagnostic performance, using their respective ROC of relative cardiac output variation.The relative variation in cardiac output induced by UF challenges is quantified immediately at the end of UF challenges.

Statistical comparison of slow and fast UF challenges ROCs will be performed using the Delong methods

Impact of UF challenges on hemodynamics: central venous pressure (mmHg), heart rate (bpm), mean and pulse arterial pressures (mmHg), extravascular lung water (ml/kg), vascular permeability, and global end diastolic volume (ml/kg).The variation in hemodynamic parameters induced by UF challenges is quantified immediately at the end of UF challenges.

Each parameter will be evaluated individually, and its absolute and relative variations from baseline reported. The respective effect of slow and fast UF challenges will also be compared, using mixed effects models, accounting for the repetition of measurements in enrolled patients.

Association of UF challenges with hemodynamic instability, quantified by the elapsed time between the UF challenge and the occurrence of first hemodynamic instability episode, censored at 8 hours.Censor time at 8 hours after the end of the UF challenge. This evaluation and time frame is applied twice, after each UF challenge in all enrolled patients.

Following UF challenges, and over the 8 following hours, we will record all following hemodynamic events: mottles appearance or extension, de novo tachycardia \> 120 bpm, de novo arterial hypotension (defined as a mean arterial pressure \< 65 mmHg requiring immediate clinical intervention), or de novo cardiac output drop (defined as a decrease \> 15% or below 2.2 L/min/m2). The time to event will be analyzed using a Cox mixed effects regression model, adjusted for patient severity of illness.

Respective diagnostic performances of slow and fast UF challenges to identify preload dependence risk, evaluated by their respective ROC of the relative cardiac output variation.The relative variation in cardiac output induced by UF challenges is quantified immediately at the end of UF challenges. The postural maneuver is performed immediately after the end of UF challenges.

The discriminatory performance of the relative variation in cardiac output (in %) between baseline and after each UF challenge (slow and fast) will be quantified using the ROC, using the result of the postural change maneuver (negative or positive) performed after the UF challenge as the reference binary classifier. A 95% confidence interval of the ROC will be computed, as well as its statistical significance, as compared to a random guess, using the Delong method.

Optimal threshold value of the relative cardiac output variation (in %) following a UF challengeThe relative variation in cardiac output induced by UF challenges is quantified immediately at the end of UF challenges.

using the ROC of the relative cardiac output variation induced by UF challenges, an optimal cutoff value will be determined, using the Youden method. This optimal threshold will allow the associated parameters describing its diagnostic performance: sensitivity, specificity, positive and negative predictive values, likelihood ratios.

Trial Locations

Locations (1)

Department of Intensive Care, Croix Rousse hospital, Hospices Civils de Lyon

🇫🇷

Lyon, France

© Copyright 2025. All Rights Reserved by MedPath