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Background Limited data are available concerning comparative outcomes of redo aortic valve interventions, including surgery after aortic valve replacement (AVR) with either stented or stentless bioprostheses. We investigated the comparative outcomes of redo aortic valve interventions, including surgery after AVR with either stented or stentless bioprostheses. Methods The cohort consisted of 112 patients who underwent aortic valve intervention for infective endocarditis or structural valve deterioration between 2001 and 2020. One hundred patients received a stented valve (stented group) and 12 patients received a stentless valve (stentless group) during the initial surgery. Early and late outcomes were evaluated. Results The mean [IQR] ages during the current interventions were 66 [54, 77] years in the stented group and 74 [67, 79] years in the stentless group ( P  = 0.13). In the stented group, aortic valve interventions included redo AVRs with stented valves (n = 54), mechanical valves (n = 26), stentless valves (n = 16), and transcatheter aortic valve implantations (n = 4). In the stentless group, redo AVRs were performed with stented valves (n = 4), mechanical valves (n = 2), stentless valves (n = 1), and transcatheter valve implantations (n = 5). Hospital mortality was observed in 2 (2%) patients in the stented group and 1 (8%) patients in the stentless group ( P  = 0.29). The 5-year survival was 80.8% [66.8, 88.5] in the stented group and 91.7% [53.9, 98.8] in stentless group. Statistically significant differences in thromboembolisms were observed between the groups. Conclusions No significant differences in early and mid-term outcomes (except thromboembolism) after aortic valve interventions were detected between patients with stented and stentless AVRs.

Background Liberating patients from mechanical ventilation (MV) requires a systematic approach. In the context of a clinical trial, we developed a simple algorithm to identify patients who tolerate assisted ventilation but still require ongoing MV to be randomized. We report on the use of this algorithm to screen potential trial participants for enrollment and subsequent randomization in the Proportional Assist Ventilation for Minimizing the Duration of MV (PROMIZING) study. Methods The algorithm included five steps: enrollment criteria, pressure support ventilation (PSV) tolerance trial, weaning criteria, continuous positive airway pressure (CPAP) tolerance trial (0 cmH 2 O during 2 min) and spontaneous breathing trial (SBT): on fraction of inspired oxygen (F i O 2 ) 40% for 30–120 min. Patients who failed the weaning criteria, CPAP Zero trial, or SBT were randomized. We describe the characteristics of patients who were initially enrolled, but passed all steps in the algorithm and consequently were not randomized. Results Among the 374 enrolled patients, 93 (25%) patients passed all five steps. At time of enrollment, most patients were on PSV (87%) with a mean (± standard deviation) F i O 2 of 34 (± 6) %, PSV of 8.7 (± 2.9) cmH 2 O, and positive end-expiratory pressure of 6.1 (± 1.6) cmH 2 O. Minute ventilation was 9.0 (± 3.1) L/min with a respiratory rate of 17.4 (± 4.4) breaths/min. Patients were liberated from MV with a median [interquartile range] delay between initial screening and extubation of 5 [1–49] hours. Only 7 (8%) patients required reintubation. Conclusion The trial algorithm permitted identification of 93 (25%) patients who were ready to extubate, while their clinicians predicted a duration of ventilation higher than 24 h .

Background We previously published the protocol and statistical analysis plan for a randomized controlled trial of Proportional Assist Ventilation for Minimizing the Duration of Mechanical Ventilation: the PROMIZING study in Trials ( https://doi.org/10.1186/s13063-023-07163-w ). This update summarizes changes made to the statistical analysis plan for the trial since the publication of the original protocol and statistical analysis plan. Methods/design The Proportional Assist Ventilation for Minimizing the Duration of Mechanical Ventilation (PROMIZING) study is a multi-center, open-label, randomized controlled trial designed to determine if ventilation with proportional assist ventilation with load-adjustable gain factors will result in a shorter duration of time spent on mechanical ventilation compared to ventilation with pressure support ventilation for patients with acute respiratory failure. The statistical analysis plan for the trial was incorporated into the original publication of the protocol in Trials ( https://doi.org/10.1186/s13063-023-07163-w ) and was based on version 5.0 of the study protocol and version 1.0 of the statistical analysis plan (SAP), which included plans for both frequentist and Bayesian analyses. We have since updated the SAP to refine the Bayesian analysis plan, update the multistate model diagram, and include plans for a cluster analysis to determine if there is heterogeneity of treatment effect. This update summarizes the changes made and their rationale and provides a refined SAP for the PROMIZING trial with additional background information, in adherence with guidelines for the prospective reporting of SAPs for randomized controlled trials. Trial registration ClinicalTrials.gov Identifier: NCT02447692 prospectively registered May 19, 2015.

In this randomized trial, proportional-assist ventilation with load-adjustable gain factors did not differ significantly from pressure-support ventilation with respect to the time to liberation from mechanical ventilation.

Deep brain stimulation of the basal ganglia and other brain regions has been used successfully to treat a variety of neurological disorders. However, the mechanisms by which it works, remain unclear. In a previous study, we showed that locally delivered single current pulses delivered from a nearby microelectrode are sufficient to inhibit firing in the internal globus pallidus for tens of milliseconds. The GPi and the substantia nigra pars reticulata are the output nuclei of the basal ganglia and share many anatomical and physiological features. The goal of the current study was to examine the after-effects of trains of high-frequency microstimulation on neuronal firing in the GPi of Parkinson's disease and dystonia patients as well as in the SNr of PD patients. Microelectrode recordings and microstimulation were performed in a total of 57 patients during stereotactic surgery. We found that firing in the GPi and SNr is inhibited for several hundreds of milliseconds following the end of a short, 200 Hz high-frequency train delivered through the recording electrode (e.g., on average 618 ms when stimulating in the SNr with a 0.5 s train of 4 μA pulses at 200 Hz). Inhibition duration usually increased with increasing current intensity, train frequency and generally peaked for trains of 1-2 s, while it decreased with increasing train durations. Statistical analysis with general linear models revealed a significant linear relationship between current intensity and inhibition duration in all nuclei and patient groups. There was also a significant relationship between train frequency and inhibition duration in the SNr and GPi of PD patients and between train duration and inhibition duration in the GPi of PD patients. There was no significant difference in inhibition duration across patient groups but the current threshold for inhibition was significantly different in the SNr compared to the GPi. The characteristics of the inhibition observed are consistent with stimulation-induced GABA release following activation of the GABAergic afferents in the SNr and GPi. The findings suggest that high-frequency microstimulation of the GPi and SNr depresses local neuronal activity and synaptic transmission, and such mechanisms may contribute to the therapeutic effects of DBS.