Feasibility and Safety of Targeting Neutral vs Liberal Fluid Balance in Traumatic Brain Injured Patients- LIMIT-TBI Trial

Official title

Feasibility and Safety of Targeting Neutral vs Liberal Fluid Balance in Traumatic Brain Injured Patients: a Phase II Randomized Controlled Trial - LIMIT-TBI Trial

Overview

The LIMIT-TBI trial is a multicenter, international, randomized, phase II clinical trial designed to evaluate the feasibility and safety of targeting a neutral fluid balance compared to standard care in critically ill adult patients with traumatic brain injury (TBI). Fluid therapy is a cornerstone of TBI management, but optimal fluid balance remains uncertain, with both fluid overload and restriction potentially leading to adverse outcomes. This study aims to determine whether maintaining a daily fluid balance close to zero (±500 mL) during the first 5 days of ICU admission is achievable and safe. Participants will be randomized within 48 hours of ICU admission to either a protocolized neutral fluid balance strategy or standard care. Outcomes include feasibility of achieving the target balance, organ complications, hemodynamic parameters, ICU resource utilization, and mortality and neurological outcomes up to 6 months.

Detailed description

Severe traumatic brain injury (TBI) is a major cause of mortality and long-term disability worldwide and frequently requires intensive care management. In these patients, preventing secondary brain injury is essential and involves optimizing cerebral perfusion pressure (CPP), systemic hemodynamics, and organ function. Fluid therapy plays a central role in achieving these goals.

However, the optimal fluid management strategy in TBI remains unclear. Excessive fluid administration may lead to complications such as pulmonary edema and worsening cerebral edema, while restrictive strategies may increase the risk of hypovolemia and impaired cerebral perfusion. Current guidelines provide limited or no specific recommendations due to the lack of high-quality randomized evidence. Observational data suggest that a more positive fluid balance is associated with worse outcomes, but causality has not been established.

The LIMIT-TBI trial is a pragmatic, international, multicenter, randomized, unblinded, parallel-group phase II study designed to address this evidence gap. Adult patients with TBI admitted to the ICU will be randomized within 48 hours in a 1:1 ratio to either:

A neutral fluid balance strategy, targeting a daily balance of 0 mL (±500 mL) and cumulative neutrality over the first 5 days, using a protocolized approach combining fluid restriction, vasopressors, and diuretics when needed; A standard of care strategy, in which fluid administration is guided by local practice and clinician judgment.

In the intervention group, all fluid inputs (intravenous fluids, medications, and enteral nutrition) and outputs are strictly monitored. Maintenance fluids are minimized, and adjustments are made daily to achieve neutrality while maintaining adequate mean arterial pressure and cerebral perfusion pressure targets.

The primary objective is to assess the feasibility and safety of achieving a neutral fluid balance, defined as maintaining a daily balance within ±500 mL. Secondary outcomes include systemic complications, hemodynamic parameters (including CPP), fluid administration metrics, vasopressor and diuretic use, organ support-free days, and ICU/hospital mortality. Long-term outcomes include 6-month mortality and neurological status assessed using the Glasgow Outcome Scale Extended (GOSE).

A total of 88 patients will be enrolled to provide adequate power to detect differences in fluid balance between groups. Statistical analyses will include linear mixed models for repeated measures and appropriate comparative tests for secondary outcomes, with multiple imputation for missing primary endpoint data.

This trial will provide important preliminary randomized evidence on fluid management in TBI and inform the design of future large-scale trials aimed at improving outcomes in this high-risk population.

Interventions

• Other Neutral Fluid Balance Strategy
  Protocolized strategy targeting a daily fluid balance of 0 ± 500 mL for 5 days using restricted fluids, diuretics, and vasopressors to maintain hemodynamic and cerebral perfusion targets.

Primary outcome measures

• Feasibility of achieving a neutral daily fluid balance [Time frame: At 5 days after randomisation]

Secondary outcome measures (11)

• Incidence of systemic organ complications [Time frame: ICU discharge]
• Cerebral perfusion pressure (CPP) [Time frame: From randomisation to day 5 after randomisation]
• Daily fluid balance and fluid input [Time frame: From randomisation to day 5 after randomisation]
• Vasopressor and diuretic use [Time frame: ICU discharge]
• Vasopressor-free days [Time frame: From randomisation to day 28 after randomisation]
• Ventilator-free days [Time frame: From randomisation to day 28 after randomisation]
• Therapy intensity level (TIL) [Time frame: At day 5 after randomisation]
• ICU and hospital mortality [Time frame: Hospital discharge]
• Neurological outcome (GOSE) [Time frame: Hospital discharge]
• Long-term mortality [Time frame: 180 days after randomization]
• Long-term neurological outcome (GOSE) [Time frame: 180 days after randomization]

Eligibility criteria

Inclusion criteria

• Adult patients with traumatic brain injury (isolated or associated with extracranial injuries), with or without intracranial pressure monitoring
• Admission to the intensive care unit
• Age >18 years
• Enrollment within 48 hours after ICU admission

Exclusion criteria

• Enrollment in another clinical trial not approved for co-enrollment
• Pregnancy or suspected pregnancy
• Concomitant hemorrhagic shock expected to require surgical treatment within 24 hours from inclusion or requiring massive transfusion protocol
• Hemodynamic instability at ICU admission, defined as heart rate >120 beats/min and systolic arterial pressure <100 mmHg despite at least 1 L of fluid resuscitation, or requirement for high-dose norepinephrine (>0.5 mcg/kg/min) or any inotropic support
• Need for continuous venovenous hemodiafiltration (CVVHDF) at admission
• Expected survival <48 hours

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

Healthy volunteers: No

Study design

Allocation

Randomized

Model

Parallel assignment

Masking

Open label

Primary purpose

Treatment

Study locations

Italy · 2 centers

• IRCCS Ospedale Policlinico San Martino — Genova
• Fondazione Policlinico Universitario Agostino Gemelli IRCCS — Roma

Belgium · 1 center

• Erasme University Hospital — Brussels

Publications

• Wiegers EJA, Lingsma HF, Huijben JA, Cooper DJ, Citerio G, Frisvold S, Helbok R, Maas AIR, Menon DK, Moore EM, Stocchetti N, Dippel DW, Steyerberg EW, van der Jagt M; CENTER-TBI; OzENTER-TBI Collaboration Groups. Fluid balance and outcome in critically ill patients with traumatic brain injury (CENTER-TBI and OzENTER-TBI): a prospective, multicentre, comparative effectiveness study. Lancet Neurol. PMID 34302787
• Oddo M, Poole D, Helbok R, Meyfroidt G, Stocchetti N, Bouzat P, Cecconi M, Geeraerts T, Martin-Loeches I, Quintard H, Taccone FS, Geocadin RG, Hemphill C, Ichai C, Menon D, Payen JF, Perner A, Smith M, Suarez J, Videtta W, Zanier ER, Citerio G. Fluid therapy in neurointensive care patients: ESICM consensus and clinical practice recommendations. Intensive Care Med. 2018 Apr;44(4):449-463. doi: 10.1 PMID 29500701
• Carney N, Totten AM, O'Reilly C, Ullman JS, Hawryluk GW, Bell MJ, Bratton SL, Chesnut R, Harris OA, Kissoon N, Rubiano AM, Shutter L, Tasker RC, Vavilala MS, Wilberger J, Wright DW, Ghajar J. Guidelines for the Management of Severe Traumatic Brain Injury, Fourth Edition. Neurosurgery. 2017 Jan 1;80(1):6-15. doi: 10.1227/NEU.0000000000001432. PMID 27654000
• Messina A, Bakker J, Chew M, De Backer D, Hamzaoui O, Hernandez G, Myatra SN, Monnet X, Ostermann M, Pinsky M, Teboul JL, Cecconi M. Pathophysiology of fluid administration in critically ill patients. Intensive Care Med Exp. 2022 Nov 4;10(1):46. doi: 10.1186/s40635-022-00473-4. PMID 36329266
• Clifton GL, Miller ER, Choi SC, Levin HS. Fluid thresholds and outcome from severe brain injury. Crit Care Med. 2002 Apr;30(4):739-45. doi: 10.1097/00003246-200204000-00003. PMID 11940738
• Majdan M, Plancikova D, Brazinova A, Rusnak M, Nieboer D, Feigin V, Maas A. Epidemiology of traumatic brain injuries in Europe: a cross-sectional analysis. Lancet Public Health. 2016 Dec;1(2):e76-e83. doi: 10.1016/S2468-2667(16)30017-2. Epub 2016 Nov 29. PMID 29253420

Identifiers

NCT: NCT07625995 · SRB2023231

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗