Clinical Research Directory

A Study of the Determinants of Neurological Outcomes in Patients With Acute Respiratory Distress Syndrome

Acute respiratory distress syndrome (ARDS) is characterized by pathological pulmonary edema caused by direct or indirect damage to the alveolar-capillary membrane. Its management relies on etiological treatment, invasive mechanical ventilation, and the use of sedatives and neuromuscular blockers, depending on the patient's condition. Improvements in patient care have led to an improved prognosis. However, in-hospital mortality remains high (between 35% and 45%). Notably, morbidity among surviving patients is very high and is largely dominated by neuropsychological sequelae. Attention and executive function disorders, confusion, disorientation, or memory impairment are thus found in 70 to 100% of patients following ARDS. These disorders are still present in 46 to 80% of surviving patients one year after ARDS and in 20% of them five years later. Although essential to treatment, mechanical ventilation carries a risk of significant complications. Beyond the risk of infection and complications related to sedation and neuromuscular blockade, the use of mechanical ventilation is associated with a risk of ventilator-induced lung injury (VILI). The use of so-called protective ventilation reduces the risk of VILI and improves patient outcomes. However, analysis of relevant physiological parameters shows that the risk of VILI may still exist even when ventilator settings comply with recommendations and the concept of protective ventilation. Driving pressure (which represents Strain) is a good marker of VILI; it represents the distension of the lung with each breath relative to the initial lung volume. Values above 14 cmH₂O are associated with high mortality in patients with ARDS. Inspiratory transpulmonary pressure represents Stress-that is, the pressure that distends the alveoli at the end of inspiration-and is also associated with the risk of VILI. Finally, mechanical power represents the amount of energy delivered to the lung by the ventilator and has been validated as a marker of VILI. The advantage of mechanical power over the other indices described is that it incorporates all components that can lead to VILI. Among the various sources of neurological damage during ARDS, inflammatory processes appear to play a major role. Numerous inflammatory mediators (TNF-α, IL-6, IL-8, IL-1β) are secreted during ARDS, and animal studies have demonstrated a link between inflammation and hippocampal damage. Furthermore, cerebral ischemic lesions, exacerbated by systemic inflammation and endothelial activation leading to coagulation activation with thrombus formation, may also contribute to the development of cognitive impairments. In addition to the inflammatory processes associated with ARDS, mechanical ventilation itself may have a significant impact on neuroinflammatory damage. Recently, the term "ventilator-associated brain injury" (VABI) has been proposed to describe these secondary neurological lesions induced by mechanical ventilation. Studies in mouse and pig models have demonstrated a relationship between the dose and duration of VILI, apoptosis, neuroinflammation, and neuronal damage. An animal study in mice also showed an association between the duration of mechanical ventilation and the onset of cognitive impairments. During brain injury, proteins and neurotransmitters are released and serve as biomarkers of brain damage. Elevated plasma levels of S100B protein indicate astrocyte damage caused by traumatic, anoxic-ischemic, or inflammatory mechanisms. It correlates with neurological prognosis following cardiac arrest, in ischemic or hemorrhagic strokes, in neurodegenerative diseases, and in patients with traumatic brain injury. Clinical studies have shown a negative correlation between elevated S100B protein levels, the MoCA (Montreal Cognitive Assessment) score, and the MMSE (Mini-mental state evaluation ) in patients with OSA (Obstructive Sleep Apnea) or COPD (chronic obstructive pulmonary disease), respectively, indicating an association between this protein and cognitive impairment. The investigators therefore hypothesize that mechanical ventilation associated with high mechanical power is linked to a significant risk of brain injury, reflected by elevated serum S100B protein levels and the presence of neurocognitive disorders long after ARDS.

Ethnic Specificities of S100B Protein Blood Level in Guadeloupe: Cross-sectional Study in Healthy Subjects

Numerous studies have demonstrated the significant contribution of S100B blood level measurement in the management of minor to moderate traumatic brain injuries, notably by reducing the number of cranial computed tomography (CT) scans by at least one-third. However, physiological blood concentrations of the S100B protein may be higher in individuals with a Black phenotype compared to those with Asian or, in particular, Caucasian phenotypes. Assessing S100B protein levels in healthy individuals will help confirm the variability of its physiological concentration according to skin phenotype.

Cord Blood S100B Protein Levels in Neonates Following Intrauterine Transfusions for HDFN-Associated Fetal Anemia

levated levels of S100B protein are a well-established marker of central nervous system (CNS) damage. Fetal anemia resulting from hemolytic disease of the fetus and newborn (HDFN) often necessitates intrauterine transfusions (IUTs) and represents a significant risk factor for CNS injury. However, it remains uncertain whether S100B protein levels can reliably predict which fetuses are at higher risk for CNS complications in this context. Furthermore, the potential role of measuring S100B concentrations before IUT in prenatal assessments, and its relationship to the severity of anemia and fetal cerebral blood flow, remains poorly understood. This study aims to investigate the concentration of S100B protein in cord blood from newborns with HDFN-related fetal anemia requiring IUT. The study group comprises pregnancies complicated by HDFN with abnormal middle cerebral artery (MCA) blood flow, indicating the need for IUT. In this group, S100B protein levels will be measured before each IUT, with additional measurements if further transfusions are required. The control group consists of pregnancies with HDFN that do not require IUT. Cord blood samples will be collected at birth to evaluate S100B protein levels in both groups. Additionally, fetal MCA blood flow will be monitored, and in the study group, fetal hemoglobin and hematocrit levels will be assessed before each IUT. The primary endpoints of the study include the measurement of cord blood S100B protein levels before IUT in the study group and at birth in both groups. Secondary endpoints will explore the potential correlations between S100B protein levels and umbilical cord blood gas parameters (e.g., pH, BE, lactate), fetal cerebral blood flow parameters (e.g., MCA-PSV values), and blood count parameters (e.g., hemoglobin and hematocrit levels), both before IUT in the study group and after birth in both groups.

Cord Blood S100B Protein Concentration in Neonates With Fetal Growth Restriction

S100B protein is a biomarker that increases following central nervous system (CNS) damage. Measuring this protein's levels may allow for the early identification of infants at high risk for developmental abnormalities, such as fetal growth restriction (FGR), even on the first day of life, in a non-invasive manner. Early detection could enable timely interventions and rehabilitation, potentially improving the child's prognosis and long-term outcomes. This study investigates two groups of full-term pregnancies: a study group with prenatally diagnosed late FGR, and a control group with normal fetal growth. Following delivery, cord blood samples from both groups will be analyzed for S100B protein concentrations, pH, base excess (BE), and lactate levels. Additionally, fetal blood flow parameters in the umbilical artery (UA), uterine arteries (UtA), ductus venosus (DV), and middle cerebral artery (MCA) will be monitored via ultrasound within 48 hours before delivery. This study aims to compare S100B protein concentrations in umbilical cord blood between the two groups and to assess correlations with fetal Doppler parameters, pH, BE, and lactate levels in cord blood gas analysis. Ultimately, we seek to determine the effectiveness of S100B protein concentration as a biomarker for diagnosing fetal CNS hypoxia- ischemia in FGR-affected children, compared to those with normal growth.