Clinical Research Directory

Identification of Clinical, Genetic and Immunological Factors Involved in the Development of Severe Bacterial Infections in Pediatrics

Severe bacterial infections (SBI) are responsible for significant morbidity and mortality in the paediatric population. There is considerable individual variability in children's susceptibility to developing SBIs. This variability is multifactorial, and the mechanisms at work are not yet fully understood. The investigators of this study therefore propose to study a population of children who had particularly severe bacterial infections requiring hospitalization in a pediatric intensive care unit in France between 2015 and 2018. This study is part of a global approach to understanding the mechanisms favoring the occurrence of IBS in pediatrics. The study will initially focus on analyzing the clinical phenotype of these children in terms of the type of infection presented, as well as immunologically with an immune workup of all these patients. The investigators also plan to contact each family individually to identify other episodes of personal or family IBS or other elements suggestive of immune deficiency (opportunistic infections, autoimmune manifestations, severe atopy). The investigators will also assess the persistent sequelae since their infectious episode, and their quality of life following this IBS. In parallel, the genetic analysis of these patients and their parents will be carried out using whole-exome sequencing. The investigators will compare the results with those obtained in 2 IBS-free control populations (N=70 and N=116). The goal is to identify genetic variants that favor the occurrence of IBS in general, and some that are specific to certain bacteria or clinical presentations.

Evaluation of the Dialytic Clearance of the Combination of Peracillin and Tazobactam

Severe bacterial infections, often responsible for sepsis and septic shock, are a major challenge in critical care: approximately 50% of patients are affected, with a mortality rate of up to 40%. Their initial management consists of antibiotic therapy with an adapted spectrum of activity and dose. One of the most widely used antibiotic therapies in intensive care is the piperacillin-tazobactam (pip-taz) combination, a beta-lactam combined with a beta-lactamase inhibitor, which is indicated probabilistically in many infections (pneumopathies, intra-abdominal infections, urinary tract infections, etc.). Mortality rates of up to 40%. Their initial management consists of antibiotic therapy with an appropriate spectrum of activity and dose. One of the most widely used antibiotic therapies in intensive care is the piperacillin-tazobactam (pip-taz) combination, a beta-lactam combined with a beta-lactamase inhibitor, which is indicated probabilistically in many infections (pneumonia, intra-abdominal infections, urinary tract infections, etc.). Intensive care patients with septic shock exhibit specific pharmacokinetics with an increased volume of distribution, notably due to significant capillary leakage, often disrupted hepatic metabolism, possible hypoalbuminemia, the presence of renal hyperclearance in the initial phase or conversely, the onset of renal failure with altered glomerular filtration rate, sometimes leading to extrarenal clearance, changes that have consequences for the efficacy and toxicity of the administered antibiotic therapy. Sepsis itself also causes renal dysfunction, with the main pathophysiological hypotheses being an alteration of microcirculation, cellular metabolic reprogramming, and deregulation of the inflammatory response. It is therefore essential to focus on the dosages administered and the pharmacokinetics of these patients. Indeed, underdosing is associated with the emergence of resistance and a poorer prognosis in intensive care patients: increased risk of treatment failure, length of stay and mortality. Conversely, significant overdoses can be associated with a poorer renal prognosis, seizures, encephalopathy which can lead to delayed awakening, prolonged duration of mechanical ventilation and intensive care stay.