Hemodynamic Effects of Variations in Net Ultrafiltration Rate During Continuous Renal Replacement Therapy.

Not Applicable

Recruiting

• Conditions: Fluid Overload; Hemodynamic Instability
• Interventions: Device: Net Ultra Filtration Rate

• Registration Number: NCT06071026
• Lead Sponsor: Centre Hospitalier Universitaire de Nīmes

Brief Summary

Net ultra filtration (NUF) is one of the most important parameters during renal replacement therapy (RRT) whose role is to control fluid balance by water removal.

To our knowledge, there are no prospective studies or guidelines about the setting of this parameter.

In the NEPTUNE study, we aim to compare the hemodynamic effect of three NUF rates during RRT: 1 ml/kg/h, 2 ml/kg/h and 3 ml/kg/h.

The research hypothesis is that one of the three flow rates evaluated induces the fewest hemodynamic instabilities related to RRT, while guaranteeing the best possible fluid balance.

Detailed Description

Renal renal replacement therapy (RRT) for severe acute kidney injury is one of the most widely used life-support techniques in intensive care. One of its main functions is to maintain the water balance in oligo-anuric patients by means of net ultrafiltration (NUF), defined as the volume of water removed from the patient by the RRT per unit time and indexed to the patient's weight.

Surprisingly, the setting of this parameter, which is one of the most important, there are no guidelines. If net ultrafiltration is too low, it may prolong RRT dependency and length of stay in the ICU, with all the associated care-related complications, and increase mortality. If net ultrafiltration is too high, it may transiently induce hypovolemia, leading to hemodynamic instability related to renal replacement therapy (HIRRT).

A recent survey of French practices shows that the average NUF flow rate used in intensive care units in France is 119 ± 77 ml/h, and the median flow rate is 100 ml/h \[min-max 20-300\]; in this study, NUF was not indexed by weight, but for a patient with an average weight of 75 kg, corresponding to an average NUF of 1.6 ± 1 ml/kg/h.

In the NEPTUNE study, the investigators aim to compare the hemodynamic effect of three net ultrafiltration rates during RRT: 1 ml/kg/h, 2 ml/kg/h and 3 ml/kg/h. These three flow rates are within the range of those usually used in clinical practice.The research hypothesis is that one of the three flow rates evaluated induces the fewest hemodynamic instabilities related to RRT, while guaranteeing the best possible fluid balance.

Study Timeline

• Study First Submitted: 2023-09-19
• Study First Submitted QC: 2023-10-02
• Study Start: 2023-10-06
• Study First Posted: 2023-10-06
• Status Verified: 2025-04
• Last Update Submitted: 2025-04-09
• Last Update Posted: 2025-04-13
• Primary Completion: 2025-12-21
• Study Completion: 2025-12-21

Recruitment & Eligibility

• Status: RECRUITING
• Sex: All
• Target Recruitment: 39

Inclusion Criteria

• Patients hospitalised in the intensive care unit of one of the two participating centres

• Patients with Kidney Disease: Improving Global Outcomes 3 (KDIGO3) acute kidney injury (AKI) requiring a continuous RRT during their stay in the intensive care unit, regardless of the aetiology of the AKI

• Need to prescribe water loss by net ultrafiltration (NUF), defined by at least one of the following sub-criteria:

  1. weight gain ≥ 1 kg relative to entry weight
  2. oligo-anuria ≥ 24 hours
  3. clinical impact of fluid overload as judged by the clinician: acute lung oedema clinical or at CT-scan, difficulty of weaning from mechanical ventilation.

• Hemodynamic stability in the 2 hours preceding the start of NUF, defined by all of the following sub-criteria:

  1. absence of vasopressors (noradrenaline) or stability or reduction in their dosage
  2. no need for resuscitative fluids as judged by the clinician

• Patient or his/her trusted support person/legal representative/family member having given free and informed consent, and having signed the consent form or patient included in an emergency situation.

• Patient affiliated to or benefiting from a health insurance scheme.

Exclusion Criteria

• Patient moribund, with life expectancy too low to benefit from treatment, or with decision to discontinue treatment
• Patient participating in an another interventional study
• Patient in exclusion period determined by another study
• Patient under court protection or guardianship
• Patient/trusted person/legal representative/family member for whom it is impossible to give informed information.
• Pregnant, parturient or breast-feeding patient.

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: CROSSOVER

Arm && Interventions

Group	Intervention	Description
2 ml/kg/h	Net Ultra Filtration Rate	Net ultra filtration setting: 2 ml/kg/h
1 ml/kg/h	Net Ultra Filtration Rate	Net ultra filtration setting: 1 ml/kg/h
3 ml/kg/h	Net Ultra Filtration Rate	Net ultra filtration setting: 3 ml/kg/h

Primary Outcome Measures

Name	Time	Method
Occurrence of HIRRT	6 hours	Occurrence of Hemodynamic Instability related to Renal Replacement Therapy

Secondary Outcome Measures

Name	Time	Method
Water depletion	6 hours	Total volume of water depleted during 6-hour session \[ml/kg/6h\]
Variations in natremia	6 hours	Variations in natremia \[mmol/L\] between h0 and h6
Number of HIRRT	6 hours	Number of HIRRT episodes in 6-hour sessions, i.e. number of hypotensive episodes during the 6-hour UFN cycle with mean arterial pressure \< 65 mmHg \[n\]
Variations in hematocrit	6 hours	Variations between h0 and h6 in hematocrit \[%\].
Fluid intake	6 hours	The volume of all fluid intake (resuscitative fluids, transfusions of blood derivatives) during the 6-hour session \[ml/kg/6h\].
Atrial fibrillation	28 days	Proportion of sessions with onset of atrial fibrillation (%)
Variation in norepinephrine	6 hours	- variation between h0 and h6 in norepinephrine dosage \[µg/kg/min\].
Time before HIRRT in each session	6 hours	Time in hours between start of session and onset of hemodynamic instability (h)
Time between start of RRT and HIRRT	28 days	Time in hours between start of RRT and onset of hemodynamic instability (h)
Variations in arterial lactate levels	6 hours	Variations between h0 and h6 in arterial lactate levels \[mmol/l\].
Variations in albuminemia	6 hours	Variations between h0 and h6 in albuminemia \[g/L\].
Variations in central venous pressure	6 hours	Variations between h0 and h6 in central venous pressure (CVP) \[mmHg\].
Variations in heart rate	6 hours	Variations between h0 and h6 in heart rate \[bpm\].
Variations in arterial pressure	6 hours	Variations between h0 and h6 in systolic, diastolic and mean arterial pressure (MAP) \[mmHg\].
Slope of arterial pressure	6 hours	Slope of variation in systolic, diastolic and mean arterial pressure between h0 and h6 obtained with repeated hourly measurements
Frequency of episodes of arterial hypertension	6 hours	Frequency of episodes between h0 and h6 of arterial hypertension defined by a systolic blood pressure greater than 180 mmHg \[n\].
Variations in central venous oxygen saturation (SvcO2)	6 hours	Variations between h0 and h6 in central venous oxygen saturation (SvcO2) measured in the superior vena cava \[%\].
Frequency of mottling	6 hours	Frequency of clinical signs/symptoms potentially associated with per-dialytic hypotension during the session: mottling. \[n\]

Trial Locations

Locations (1)

Centre Hospitalier Universitaire de Nîmes; 🇫🇷 Nimes, France