Reproducibility of LPS-Induced ex vivo Cytokine Response of Healthy Volunteers Using a Whole Blood Assay.

Introduction: Lipopolysaccharide (LPS) stimulation of human whole blood ex vivo has been widely used to investigate human innate immune responses. However, there are uncertainties regarding the reproducibility and reliability of this assay. Methods: In this prospective, single-center study, cytokine responses (interleukin 8, interferon-α, interferon-γ, interleukin 10, interleukin 1-ß, interleukin 6, and tumor necrosis factor-α) to ex vivo whole blood LPS stimulation were assessed in 12 healthy volunteers. Cytokine levels were measured at 0, 2, and 4 h using a multiplex immunoassay (Luminex ®). Stimulation was repeated after six weeks. We examined reproducibility across technical and biological replicates at baseline and between repeated experiments after 6 weeks based on the area under the curve (AUC) of the individual cytokines using Pearson's correlation coefficient and the mean coefficient of variation. Results: The lowest mean coefficients of variation were observed for the technical replicates (5.4 to 9.2%), followed by the biological replicates (8.1 to 24.8%), and the repeated experiments after 6 weeks (17 to 31.2%). Between the baseline and 6-week AUCs, the following Pearson correlation coefficients R were observed: interleukin 10, 0.97; interferon-α, 0.84; interleukin 1-ß, 0.83; interleukin 8, 0.79; interleukin 6, 0.73; interferon-γ, 0.73; and tumor necrosis factor-α, 0.63. Discussion: The level of agreement between the baseline and week-6 cytokine response to ex vivo LPS stimulation was high across the seven cytokines analyzed. While interleukin 10 exhibited the lowest level of variability over time, tumor necrosis factor-α showed the highest variability in repeated experiments, which should be considered in the design and interpretation of future studies.

Liposomal Bupivacaine for Peripheral Nerve Blockade: A Randomized, Controlled, Crossover, Triple-blinded Pharmacodynamic Study in Volunteers.

BACKGROUND: Little is known about the pharmacodynamic characteristics of liposomal bupivacaine. Hypothesizing that they would not identify pharmacodynamic differences from plain bupivacaine during the initial period after administration, but would find better long-term pharmacodynamic characteristics, the authors designed a randomized, controlled, triple-blinded, single-center study in volunteers. METHODS: Volunteers aged 18 to 55 yr (body mass index, 18 to 35 kg/m2) received two ulnar nerve blocks under ultrasound guidance. Using a crossover design with a washout phase of 36 days or more, one block was performed with liposomal and one with plain bupivacaine. Which came first was determined by randomization. Sensory data were collected by pinprick testing and motor data by thumb adduction, either way in comparison with the contralateral arm. Endpoints included success, time to onset, and duration of blockade. Residual efficacy was assessed by the volunteers keeping a diary. Statistical analysis included Wilcoxon signed-rank and exact McNemar's tests, as well as a generalized estimation equation model. RESULTS: Successful sensory blockade was noted in 8 of 25 volunteers (32%) after liposomal and in 25 of 25 (100%) after plain bupivacaine (P < 0.0001). Significant differences emerged for time to onset, defined as 0% response to pinpricking in four of five hypothenar supply areas (P < 0.0001), and for time from onset to 80% or 20% in one of five areas (P < 0.001; P < 0.001). Carryover effects due to the randomized sequencing were unlikely (estimate, -0.6286; sequence effect, 0.8772; P = 0.474). Self-assessment greater than 3.5 days did reveal, for liposomal bupivacaine only, intermittent but unpredictable episodes of residual sensory blockade. CONCLUSIONS: The results show that liposomal bupivacaine is not a suitable "sole" drug for intraoperative regional anesthesia. Findings of its limited long-term efficacy add to existing evidence that a moderate effect, at best, should be expected on postoperative pain therapy.

Efficacy and Safety of Corticosteroid Therapy for Community-Acquired Pneumonia: A Meta-Analysis and Meta-Regression of Randomized, Controlled Trials.

BACKGROUND: Community-acquired pneumonia (CAP) is associated with high morbidity and mortality. In the present study, we aimed to assess the effect of corticosteroids on all-cause mortality in patients hospitalized with CAP. METHODS: For this meta-analysis and meta-regression, we conducted a systematic search of trials that evaluated the effect of corticosteroid therapy in patients hospitalized with CAP through March 2023. We included randomized, controlled trials, comparing adjunctive corticosteroid therapy with the standard of care alone for treatment of patients hospitalized with CAP and reporting all-cause mortality. We excluded retrospective analyses, observational data, and trial protocols. The primary outcome was all-cause mortality within 30 days after hospital admission. The safety analysis included the frequency of adverse events and steroid-associated adverse events. RESULTS: The literature search identified 35 713 citations, of which 15 studies and 3367 patients were eligible for the final analysis. The all-cause mortality at 30 days was significantly lower in the corticosteroid group (104 of 1690, 6.15%) than in the control group (152 of 1677, 9.06%; risk ratio [RR], 0.67; 95% confidence interval [CI], .53 to .85; P = .001; I2 = 0%). In 9 studies (2549 patients) that reported the occurrence of adverse events, corticosteroid therapy was not associated with an increased risk of developing any adverse event compared with standard care (RR, 0.90; 95% CI, .65 to 1.24; P = .5; I2 = 88%). CONCLUSIONS: Adjunctive systemic corticosteroid therapy in patients hospitalized with CAP was associated with a reduction in all-cause mortality by day 30. The benefits were more pronounced in patients with severe pneumonia.

Incidence of Post-extubation Stridor in Infants With Cuffed vs. Uncuffed Endotracheal Tube: A Retrospective Cohort Analysis.

Background: Endotracheal intubation is a common procedure in Neonatal Intensive Care. While cuffed endotracheal tubes (ETT) are the standard of care in adults and children, their use in infants is controversial. The aim of this study was to compare the incidence of post-extubation stridor between uncuffed and cuffed ETTs in infants. We further evaluated the safety of cuffed ETTs in infants with a bodyweight between 2 and 3 kg and performed baseline analysis on development of subglottic stenosis. Methods: In this retrospective study, we screened all infants admitted to two NICUs of the Medical University of Vienna between 2012 and 2019.The study cohort was screened twice: In the first screening we selected all infants who underwent the first intubation when attaining a bodyweight >2 kg (but <6 kg) to analyze the incidence of post-extubation stridor and only considered the first intubation of each included infant. Post-extubation stridor was defined as the administration of either epinephrine aerosol or any corticosteroid within 6 h post-extubation. In the second screening we searched for all infants diagnosed with acquired severe subglottic stenosis during the study period regardless their bodyweight and numbers of intubations. Results: A total of 389 infants received at least one intubation during the study period. After excluding infants who underwent the first intubation below a bodyweight of 2 kg, 271 infants remained for final analysis with an average gestational age of 38.7 weeks at the time of intubation. Among those, 92 (33.9%) were intubated with a cuffed and 179 (66.1%) with an uncuffed ETT. Seven infants (2.6%) developed a clinically significant stridor: five of those were intubated with a cuffed and two with an uncuffed ETT (71.4 vs. 28.6%, p = 0.053). All of them had a bodyweight >3 kg at the time of intubation. Infants who developed subglottic stenosis were more often intubated with an uncuffed ETT. Conclusion: In this study, no difference in the incidence of post-extubation stridor between cuffed and uncuffed ETTs in infants with a bodyweight from 2 to 6 kg could be found. The use of uncuffed ETTs does not exhibit higher risk for the acquired subglottic stenosis in this cohort.