Effect of Fluid Bolus Administration on Cardiovascular Collapse Among Critically Ill Patients Undergoing Tracheal Intubation: A Randomized Clinical Trial.

Importance: Hypotension is common during tracheal intubation of critically ill adults and increases the risk of cardiac arrest and death. Whether administering an intravenous fluid bolus to critically ill adults undergoing tracheal intubation prevents severe hypotension, cardiac arrest, or death remains uncertain.

Objective: To determine the effect of fluid bolus administration on the incidence of severe hypotension, cardiac arrest, and death.

Effect of a fluid bolus on cardiovascular collapse among critically ill adults undergoing tracheal intubation (PrePARE): a randomised controlled trial.

Background: Tracheal intubation is common in the care of critically ill adults and is frequently complicated by hypotension, cardiac arrest, or death. We aimed to evaluate administration of an intravenous fluid bolus to prevent cardiovascular collapse during intubation of critically ill adults.

Methods: We did a pragmatic, multicentre, unblinded, randomised trial in nine sites (eight ICUs and one emergency department) around the USA.

Emulating a Novel Clinical Trial Using Existing Observational Data. Predicting Results of the PreVent Study.

"Target trial emulation" has been proposed as an observational method to answer comparative effectiveness questions, but it has rarely been attempted concurrently with a randomized clinical trial (RCT). We tested the hypothesis that blinded analysts applying target trial emulation to existing observational data could predict the results of an RCT. PreVent (Preventing Hypoxemia with Manual Ventilation during Endotracheal Intubation) was a multicenter RCT examining the effects of positive-pressure ventilation during tracheal intubation on oxygen saturation and severe hypoxemia.

Bag-Mask Ventilation during Tracheal Intubation of Critically Ill Adults.

Background: Hypoxemia is the most common complication during tracheal intubation of critically ill adults and may increase the risk of cardiac arrest and death. Whether positive-pressure ventilation with a bag-mask device (bag-mask ventilation) during tracheal intubation of critically ill adults prevents hypoxemia without increasing the risk of aspiration remains controversial.

Methods: In a multicenter, randomized trial conducted in seven intensive care units in the United States, we randomly assigned adults undergoing tracheal intubation to receive either ventilation with a bag-mask device or no ventilation between induction and laryngoscopy.

Manual ventilation to prevent hypoxaemia during endotracheal intubation of critically ill adults: protocol and statistical analysis plan for a multicentre randomised trial.

Introduction: Hypoxaemia is the most common complication during endotracheal intubation of critically ill adults, and it increases the risk of cardiac arrest and death. Manual ventilation between induction and intubation has been hypothesised to decrease the incidence of hypoxaemia, but efficacy and safety data are lacking.

Methods And Analysis: The Preventing Hypoxemia with Manual Ventilation during Endotracheal Intubation trial is a prospective, multicentre, non-blinded randomised clinical trial being conducted in seven intensive care units in the USA.

Immunodominance of the VH1-46 antibody gene segment in the primary repertoire of human rotavirus-specific B cells is reduced in the memory compartment through somatic mutation of nondominant clones.

Detailed characterization of Ag-specific naive and memory B cell Ab repertoires elucidates the molecular basis for the generation of Ab diversity and the optimization of Ab structures that bind microbial Ags. In this study, we analyzed the immunophenotype and VH gene repertoire of rotavirus (RV) VP6-specific B cells in three circulating naive or memory B cell subsets (CD19+IgD+CD27-, CD19+IgD+CD27+, or CD19+IgD-CD27+) at the single-cell level. We aimed to investigate the influence of antigenic exposure on the molecular features of the two RV-specific memory B cell subsets.

Evidence for preferential Ig gene usage and differential TdT and exonuclease activities in human naïve and memory B cells.

Memory B cells and the antibodies they encode are important for protective immunity against infectious pathogens. Characterization of naïve and memory B cell antibody repertoires will elucidate the molecular basis for the generation of antibody diversity in human B cells and the optimization of antibody structures that bind microbial antigens. In this study we aimed to investigate the influence of antigenic selection on the antibody genes of the two CD27+ memory B cell subsets, comparing them with the naïve repertoire in CD27- cells.

Low expression of the interleukin (IL)-4 receptor alpha chain and reduced signalling via the IL-4 receptor complex in human neonatal B cells.

Diminished neonatal antibody responses following infection or immunization may stem in part from intrinsic characteristics of neonatal B cells. In this study, we used B-cell subset sorting combined with gene expression assays to investigate major differences in the expression of host genes in neonatal and adult naïve B cells. We discovered significantly reduced expression of the interleukin (IL)-4 receptor alpha chain and reduced IL-4-induced signalling in neonatal B cells.