Samir Jaber

Purpose Obesity is increasingly encountered among patients requiring extracorporeal membrane oxygenation (ECMO) for severe respiratory or cardiac failure. It alters respiratory and cardiovascular physiology and drug pharmacokinetics and introduces technical and logistical challenges that may complicate patient selection, ECMO initiation, cannulation, anticoagulation, and monitoring. This review summarizes current evidence regarding the epidemiology, physiological implications, outcomes, and management of obesity in patients supported with veno-venous (VV) or veno-arterial (VA) ECMO. Results Available evidence, largely retrospective and based on body mass index classifications, suggests that obesity should not be considered a contraindication to VV-ECMO, with outcomes comparable to or potentially better than those of patients without obesity. However, obesity-related respiratory mechanics may exaggerate the apparent severity of lung injury, emphasizing the need for optimized conventional ARDS management, including appropriate ventilatory strategies and prone positioning, before ECMO initiation. In contrast, outcomes during VA-ECMO are more heterogeneous, particularly in extracorporeal cardiopulmonary resuscitation (ECPR), and may be influenced by patient selection, comorbidities, and timing of support. Obesity also creates important technical challenges requiring individualized cannulation, anticoagulation, and perfusion strategies. Conclusion Obesity alone should not preclude access to ECMO, particularly VV-ECMO. Successful management requires anticipation of obesity-related challenges, appropriate infrastructure, and structured multidisciplinary protocols. Further prospective studies are needed to clarify obesity-specific risks, optimize management strategies, and evaluate long-term outcomes. Graphic abstract

Objectives: To assess the impact of Molecular Adsorbent Recirculating System (MARS) therapy on total plasma piperacillin concentrations in critically ill patients with acute liver failure or acute-on-chronic liver failure. Design: Retrospective, single-center observational cohort study. Setting: University ICU. Patients: Consecutive adult patients treated with MARS therapy and piperacillin-tazobactam between March 2023 and June 2025. Interventions: MARS therapy was delivered as 8-hour sessions for up to three consecutive days. Piperacillin-tazobactam was administered by continuous infusion following a loading dose. Measurements and Main Results: Venous blood samples were collected immediately before and after each MARS session. Total piperacillin concentrations were quantified using ultrahigh-performance liquid chromatography. The primary endpoint was the relative reduction in plasma piperacillin concentration induced by MARS therapy. Thirty patients (121 piperacillin measurements across 77 sessions) were analyzed. Seventy-three percent had cirrhosis (median Model for End-Stage Liver Disease Score 31 [23–38]). The mean relative reduction in piperacillin concentration per session was 34% (± 7.9%; p < 0.05). In univariable mixed-effects analysis, MARS session (β –47.49 mg/L; p < 0.001) and creatinine clearance (β –0.37 mg/L per mL/min; p < 0.001) were associated with lower concentrations. In multivariable modeling, higher creatinine clearance was independently associated with greater intra-session piperacillin loss ( p < 0.001), whereas higher bilirubin levels were associated with reduced drug loss ( p = 0.01). Overall, 31.6% of post-session concentrations were less than 80 mg/L, and 38% of patients had at least one concentration outside the predefined target range. Conclusions: MARS therapy was associated with a one-third reduction in total plasma piperacillin concentrations per session. These findings support systematic therapeutic drug monitoring and individualized antibiotic dose adjustment during MARS therapy.

Postoperative patients have been underrepresented in randomized controlled trials of acute respiratory distress syndrome (ARDS). Whether postoperative ARDS

Introduction: Mental health problems among undergraduate medical students are a major global public health concern that emerge early during training and are shaped by demanding educational environments, emotional stressors and organisational pressures. Although research has expanded rapidly, the literature remains fragmented across themes, regions and methods. This scoping review aims to map the global quantitative literature on medical students’ mental health and identify gaps in scope, geography, methodology and equity. Methods and analysis: This scoping review will be conducted in accordance with the Joanna Briggs Institute methodological guidance and reported in accordance with PRISMA-ScR (Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews) guidelines. We will include quantitative studies assessing mental health among undergraduate medical students. MEDLINE (Ovid), Web of Science (Clarivate), the Cochrane Library (Wiley) and PsycINFO (Ovid) will be searched without date or language restrictions using a keyword-based search strategy. Two reviewers will independently screen titles, abstracts and full texts and extract data using a standardised form. Data will include publication year, country, study design, sample size, mental health measures, thematic domains and patterns of collaboration. Mental health domains will be classified using an a priori thematic framework encompassing psychological symptoms and distress, psychological resources, academic environment, social support and physical health and lifestyle factors. Equity-related variables (sex, gender identity, sexual orientation, race/ethnicity, socioeconomic status) will be operationalised based on analytical use. Results will be synthesised descriptively using tables and visualisations. Ethics and dissemination: Ethical approval is not required. Findings will be disseminated through publication and presentations. The dataset and code will be openly available on publication. Trial registration details: Protocol registration will be made available online via the Open Science Framework (doi:10.17605/OSF.IO/2EHNU).