Clinical Research Directory

Impact of Prepartum Intravenous Fluid Intake on Newborn Weight Loss in the First Days of Life

At birth, the infant's weight was measured daily to assess the adequacy of nutritional intake. This indicator can be influenced by various factors related to the mother, her pregnancy, as well as medical interventions during the pre-delivery phase, such as pre-partum maternal fluid intakes, and the subsequent feeding method chosen for the newborn infant. This study aimed at exploring the association between maternal vascular fluid loading during labor in the pre-partum period and neonatal weight loss in the first two days of life. The study focuses on infants fedded with infant formula. This observational, retrospective, single-center study was carried out at the Amiens University Hospital Center. The participants were mothers aged 18 and older, hospitalized in the maternity ward following full-term delivery (\> 37 weeks of gestation). Data were collected through the medical records of the patient and their newborn. The investigators hypothesize that a relationship may exist between maternal pre-partum vascular fluid loading and neonatal weight loss in the first two days of life, in infants fed with infant formula. These results could raise awareness and help adapt medical and parental approaches to neonatal weight loss.

Training Strategies to Maintain Performance

• Statement of the Problem and Justification Cognitive performance under physiologically stressful conditions is critical in high-demand environments such as military operations, diving, and firefighting. One such stressor is restricted breathing, which can occur due to equipment (e.g., masks, regulators) or environmental pressures (e.g., underwater). Restricted breathing has been shown to increase physiological strain, which may in turn impact attention, reaction time, and task execution. Despite this, there is limited research examining how different breathing strategies can mitigate the cognitive effects of restricted respiration. Understanding whether specific breathing techniques can preserve cognitive function under stress has practical implications for operational readiness, safety, and task performance in extreme or demanding environments. • Synopsis of Relevant Research Previous human studies have shown that controlled breathing techniques, such as tactical or box breathing (inhale-hold-exhale-hold patterns), can reduce anxiety and improve focus in stressful situations. For example, tactical breathing has been adopted in military and law enforcement settings to enhance performance under pressure. Other research in sports psychology and respiratory therapy suggests that altering breathing frequency or depth can modulate autonomic nervous system activity, potentially affecting cognitive control and reaction time. Additionally, psychomotor vigilance tasks (PVTs) have been widely used to assess the impact of physiological stressors - such as sleep deprivation, hypoxia, and fatigue - on sustained attention and reaction time. However, few studies have directly examined the interaction between structured breathing patterns and PVT performance during restrictive breathing loads. • Importance and Next Step This study represents a logical next step in understanding how breathing techniques can buffer against cognitive decline under conditions that simulate real-world respiratory restriction (e.g., underwater diving). By directly comparing the effects of two distinct breathing strategies during a controlled, restrictive breathing task, this research will help determine whether certain techniques are more effective in preserving attention and reaction time. The findings could inform training and operational protocols for individuals working in challenging environments, as well as guide future studies into breathing-cognition interactions under physical stress.

External Validation of the BREF Models

Introduction High-flow oxygen therapy is increasingly used to treat acute respiratory failure (ARF). It can reduce intubation rates without increasing mortality. Moreover, it is better tolerated than other non-invasive respiratory support therapies. However, patients with ARF often make strong breathing efforts, which may cause several harm. They can fatigue the respiratory muscles. They can increase whole-body oxygen consumption and carbon dioxide production. They can cause pulmonary edema. They might also injure the diaphragm and the lungs. For all these reasons, strong breathing efforts should be recognized and treated. During spontaneous breathing, inspiratory muscle contractions produce parallel deflections of the pleural and esophageal pressure (ΔPes), which reflect the magnitude of the effort. Unlike changes in pleural pressure, ΔPes can be easily measured at the bedside using a catheter similar to a typical nasogastric tube. In healthy subjects, ΔPes is only a few cmH2O during quiet breathing but \>10-15 cmH2O during vigorous exercise or carbon dioxide inhalation. In patients with ARF, the upper limit for a "safe" ΔPes is unknown. Nonetheless, according to experts, breathing efforts with a ΔPes \>10-15 cmH2O are probably too strong to be tolerated for a long time. However, esophageal manometry is not widely available. Estimating breathing efforts without it is complex, especially in non-intubated patients. Doctors mostly rely on their gestalt or overall impression. Therefore, it is unsurprising that they may disagree when rating their patients' breathing efforts or debating whether to proceed to intubation. The investigators have recently developed two clinical prediction models for estimating the breathing effort of patients with ARF from a few variables readily available at the bedside. The first, "linear", model estimates the continuous value of ΔPes (in cmH2O) from the presence or absence of COVID-19, arterial base excess concentration (BEa) (in mmol/L), respiratory rate (in bpm), the ratio of the arterial tension to the inspiratory fraction of oxygen (PaO2:FiO2) (in mmHg), and the product term between COVID-19 and PaO2:FiO2. The calibration slope was 1, and the adjusted R2 was 0.39. The second, "logistic", model estimates the probability of ΔPes being \>10 cmH2O (dichotomous outcome) from BEa (in mmol/L), respiratory rate (in bpm), and PaO2:FiO2 (in mmHg). When this model was tested on the same data set used to develop it (apparent performance), the area under the ROC curve (AUROC) was 0.79 (95% CI, 0.73-0.85). At internal validation (optimism-corrected performance), the AUROC was 0.76 (0.71-0.81). The investigators called these models BREF, which stands for BReathing EFfort, but also to the three main predictors: BEa (B), respiratory rate (RE), and PaO2:FiO2 (F). Study aims The main goal of this study is to evaluate the BREF models' predictive performance in a new population. This process is known as "external validation". Additionally, there are two other secondary objectives. The investigators aim to update the BREF models by adding more variables unavailable in the development dataset (method "extension") and compare the accuracy of the BREF models with that of doctors who do not use them in assessing their patients' breathing efforts. Study population Inclusion criteria: * adult (≥18 years of age) patients in the ICU * treated with high-flow oxygen delivered via nasal cannula * equipped with an esophageal balloon as per local clinical practice. Exclusion criteria: * history of chronic lung disease * cardiogenic pulmonary edema * \>96 hours from admission to the participating unit. Methods First, participants will record all the variables needed to estimate ΔPes using the original version of the BREF models. These are the presence or absence of COVID-19, BEa, respiratory rate, PaO2:FiO2, and the product term between COVID-19 and PaO2:FiO2. Moreover, participants will record other variables that may help predict ΔPes based on scientific reasoning. Next, the attending doctor (blinded to the actual ΔPes) will assess the patient's breathing effort based on clinical judgment. Third, the actual ΔPes will be measured with esophageal manometry. Finally, the participants will record the type of respiratory support provided to the patient in the 72 hours following the study, the length of stay in the unit, and the vital status of the patient (dead or alive) at discharge from the unit. Sample size calculation This study aims to enroll 250 patients in approximately two years.

Virtual Reality Application During High Flow Nasal Oxygen Therapy in Children Effect on Anxiety Levels

Determination of the effect of virtual reality goggles used during high-flow oxygen therapy on child anxiety in children