Clinical Research Directory

Evaluation of the Variation of the Sub-pulmonary Velocity-time Integral to Predict Fluid Responsiveness

Fluid administration is the first-line treatment in hypovolemic states in critically ill patients. Prediction of fluid responsiveness is possible with echocardiography by assessing the variation of the sub-aortic velocity-time integral (AoVTI) during a passive leg raising test (PLR) or Mini-fluid challenge. However, VTI-Ao measurement is not feasible in all patients due to poor echogenicity. Validation of new fluid-responsiveness indices may facilitate the evaluation in this patient population. Among the available indices, variation of the sub-pulmonary VTI is a potential criterion.

Impact of Fluid Resuscitation on Venous Congestion in Cardiac Critically-ill Patients

The objective of this study is to assess how fluid resuscitation, in the context of fluid responsiveness, affects the incidence and progression of systemic venous congestion in critically ill cardiac patients. Additionally, the study aims to evaluate the impact on clinical outcomes, with a particular focus on acute kidney dysfunction. This assessment will utilize the VExUS score in conjunction with comprehensive bedside echocardiographic evaluations.

Critical Closing Pressure and PCO₂ Gap in Fluid Resuscitation for Septic Shock

This study is based on the following key hypotheses: PvaCO₂ (Venous-to-Arterial CO₂ Gap) Hypothesis: Changes in PvaCO₂ (ΔPvaCO₂) following fluid resuscitation correlate with changes in cardiac output (CO) and can serve as a reliable predictor of fluid responsiveness in septic shock patients. The relationship between PvaCO₂ and CO is influenced by metabolic factors (VCO₂), hemodynamic status, and the Haldane effect (oxygenation-dependent CO₂ binding to hemoglobin). Pcrit (Critical Closing Pressure) \& TPP (Tissue Perfusion Pressure) Hypothesis: Elevated Pcrit and reduced TPP (TPP = MAP - Pcrit) are associated with impaired microcirculatory flow and worse clinical outcomes (e.g., 28-day mortality, organ dysfunction). Restoring the "vascular waterfall" phenomenon (Pcrit \> mean systemic filling pressure) may improve macrocirculation-microcirculation coupling and tissue oxygenation. 2\. Study Design Overview 2.1 Study Type Prospective observational cohort with a retrospective validation arm using external databases (e.g., MIMIC-IV). Single-center study (Peking Union Medical College Hospital ICU). 2.2 Study Population Inclusion Criteria Adults (18-80 years) with septic shock (Sepsis-3 criteria + vasopressor-dependent hypotension + lactate \>2 mmol/L). Requires invasive hemodynamic monitoring (arterial line, central venous catheter). Undergoing fluid challenge (clinically indicated). Exclusion Criteria Pregnancy, non-septic shock (e.g., cardiogenic), mechanical circulatory support (ECMO/IABP). Severe COPD, intracardiac shunts, or conditions interfering with CO₂/VO₂ measurements. 2.3 Interventions \& Measurements Fluid Resuscitation Protocol 500 mL 4% gelatin infused over 15 min (pressure bag at 300 mmHg). Hemodynamic/metabolic data collected pre- and post-fluid challenge (within 10 min). Key Data Collected Hemodynamics: MAP, CVP, CO (PiCCO/ultrasound), Pcrit (derived from MAP-CO curve fitting). TPP = MAP - Pcrit. Metabolic Parameters: PvaCO₂, CvaCO₂, VCO₂, VO₂ (Es-COVX module). Lactate, ScvO₂, Hb, arterial/venous blood gases. Outcomes: Primary: 28-day mortality. Secondary: Lactate clearance, AKI incidence, ICU length of stay, vasopressor requirements.

Evolution of Tissue Perfusion and Venous Congestion Markers in Fluid-Responsive Septic Shock Patients

Septic shock remains a leading cause of mortality in intensive care, and while fluid resuscitation (FR) is a cornerstone of early management, its benefit-risk balance is highly variable. Excessive fluid administration can cause venous congestion and organ dysfunction, while insufficient resuscitation risks hypoperfusion. Current strategies often rely on fluid responsiveness (i.e., increased cardiac output after fluids), but this does not guarantee improved outcomes, particularly if congestion ensues. This prospective, multicenter, observational study aims to assess the clinical impact of FR in septic shock patients who are fluid responsive. The primary objective is to evaluate changes in tissue perfusion and venous congestion markers following FR. Patients will be categorized into four response profiles based on the presence or absence of perfusion improvement and congestion worsening. Secondary objectives include exploring the prognostic implications of each profile (organ dysfunction, mortality), identifying pre-FR predictors of adverse responses, evaluating changes in congestion markers after passive leg raising (PLR), and performing phenotypic clustering and mediation analyses. Eligible patients are adults with septic shock requiring vasopressors and mechanical ventilation, with confirmed fluid responsiveness via echocardiography. Each patient will undergo standardized pre- and post-FR assessments, including cardiac ultrasound, Doppler of hepatic/portal veins (VeXUS), CVP, perfusion markers, and blood gases. Data on SOFA scores, organ support duration, and 28-day mortality will be collected. Approximately 170 patients will be enrolled across five ICUs experienced in advanced hemodynamic monitoring. Statistical analyses will include multivariate modeling, clustering, ROC curves, and mediation analyses. By identifying phenotypes of fluid-responsive but fluid-intolerant patients, the study aims to refine fluid management strategies and improve outcomes through more personalized care in septic shock.

Effect of Colloids Versus Crystalloids on Heart Mechanics: a Double-blind Cross Over Randomized Trial

The debate over whether to use colloid or crystalloid solutions for fluid resuscitationis still ongoing. Colloid solutions consist of large molecules that generally cannot pass through healthy capillary membranes, whereas crystalloid solutions contain ions that easily move from the intravascular space to the interstitial compartment. Therefore, it is traditionally argued that colloids are more effective at expanding intravascular volume, with a suggested ratio of 1:3 compared to crystalloids. However, there is currently limited evidence to suggest that resuscitation with one type of fluid is more effective or safer than t he other. Despite these theoretically advantageousphysiological properties, colloids have not demonstrated a clear hemodynamic benefit over crystalloids. We hypothesized that these unexpected discrepancies may be attributed to different mechanical heart responses.

Dextran 40 Plus Ringer's Lactate Vs. Ringer's Lactate Alone for Fluid Resuscitation in Acute Pancreatitis

This clinical trial aims to learn if a combination of Dextran 40 and Ringer's lactate solution can improve fluid resuscitation in mild and moderate acute pancreatitis (AP) and prevent complications. The main questions it aims to answer are: Does early fluid resuscitation with Dextran 40 plus Ringer's lactate improve patient outcomes compared to Ringer's alone? Does this treatment reduce inflammation, organ failure, and the need for intensive care unit (ICU) admission? Researchers will compare Dextran 40 plus Ringer's lactate to Ringer's alone to see if the combination therapy is more effective in reducing disease severity and complications. Participants will: Receive either Dextran 40 plus Ringer's lactate (1:3 ratio) or Ringer's lactate alone. Have blood tests every 24 hours to measure inflammation and organ function. Be monitored for changes in disease severity, need for ICU admission, and hospitalization duration. This study will help determine the best fluid resuscitation strategy for treating mild and moderate acute pancreatitis.

Restricted or Liberal Fluid for Haemodynamic Resuscitation in Sepsis

A prospective, individual patient data meta-analysis (IPDMA) of four multicentre, open-label, randomised clinical trials of initial haemodynamic resuscitation in patients with septic shock.

Effect of Fluid Resuscitation on Lactate in Traumatic Injury Patients

The study aims to investigate the effect of 3% hypertonic saline resuscitation on lactate clearance in comparison to ringer's lactated solution and 0.9% normal saline in traumatic injury patients. Also to provide insights into the optimal fluid resuscitation strategy for traumatic injury patients