Evaluating the clinical and cost-effectiveness of a conservative approach to oxygen therapy for invasively ventilated adults in intensive care: Protocol for the UK-ROX trial.

Background: In the United Kingdom, around 184,000 adults are admitted to an intensive care unit (ICU) each year with over 30% receiving mechanical ventilation. Oxygen is the commonest therapeutic intervention provided to these patients but it is unclear how much oxygen should be administered for the best clinical outcomes. Methods: The UK-ROX trial will evaluate the clinical and cost-effectiveness of conservative oxygen therapy (the minimum oxygen concentration required to maintain an oxygen saturation of 90% ± 2%) versus usual oxygen therapy in critically ill adults receiving supplemental oxygen when invasively mechanically ventilated in ICUs in England, Wales and Northern Ireland. The trial will recruit 16,500 patients from approximately 100 UK adult ICUs. Using a deferred consent model, enrolled participants will be randomly allocated (1:1) to conservative or usual oxygen therapy until ICU discharge or 90 days after randomisation. Objectives: The primary clinical outcome is all cause mortality at 90 days following randomisation. Discussion: The UK-ROX trial has received ethical approval from the South Central - Oxford C Research Ethics Committee (Reference: 20/SC/0423) and the Confidentiality Advisory Group (Reference: 22/CAG/0154). The trial commenced in May 2021 and, at the time of publication, 95 sites had opened to recruitment.

Liposomes for Inhalation.

Inhalation of liposomes formulated with phospholipids similar to endogenous lung surfactants and lipids offers biocompatibility and versatility within the pulmonary medicine field to treat a range of diseases such as lung cancer, cystic fibrosis and lung infections. Manipulation of the physicochemical properties of liposomes enables innovative design of the carrier to meet specific delivery, release and targeting requirements. This delivery system offers several benefits: improved pharmacokinetics with reduced toxicity, enhanced therapeutic efficacy, increased delivery of poorly soluble drugs, taste masking, biopharmaceutics degradation protection and targeted cellular therapy. This section provides an overview of liposomal formulation and delivery, together with their applications for different disease states in the lung.

A Yeast Modular Cloning (MoClo) Toolkit Expansion for Optimization of Heterologous Protein Secretion and Surface Display in Saccharomyces cerevisiae.

Saccharomyces cerevisiae is an attractive host for the expression of secreted proteins in a biotechnology context. Unfortunately, many heterologous proteins fail to enter, or efficiently progress through, the secretory pathway, resulting in poor yields. Similarly, yeast surface display has become a widely used technique in protein engineering but achieving sufficient levels of surface expression of recombinant proteins is often challenging. Signal peptides (SPs) and translational fusion partners (TFPs) can be used to direct heterologous proteins through the yeast secretory pathway, however, selection of the optimal secretion promoting sequence is largely a process of trial and error. The yeast modular cloning (MoClo) toolkit utilizes type IIS restriction enzymes to facilitate an efficient assembly of expression vectors from standardized parts. We have expanded this toolkit to enable the efficient incorporation of a panel of 16 well-characterized SPs and TFPs and five surface display anchor proteins into S. cerevisiae expression cassettes. The secretion promoting signals are validated by using five different proteins of interest. Comparison of intracellular and secreted protein levels reveals the optimal secretion promoting sequence for each individual protein. Large, protein of interest-specific variations in secretion efficiency are observed. SP sequences are also used with the five surface display anchors, and the combination of SP and anchor protein proves critical for efficient surface display. These observations highlight the value of the described panel of MoClo compatible parts to allow facile screening of SPs and TFPs and anchor proteins for optimal secretion and/or surface display of a given protein of interest in S. cerevisiae.

Individualized Treatment Effects of Oxygen Targets in Mechanically Ventilated Critically Ill Adults.

Importance: Among critically ill adults, randomized trials have not found oxygenation targets to affect outcomes overall. Whether the effects of oxygenation targets differ based on an individual's characteristics is unknown. Objective: To determine whether an individual's characteristics modify the effect of lower vs higher peripheral oxygenation-saturation (Spo2) targets on mortality. Design, Setting, and Participants: A machine learning model to predict the effect of treatment with a lower vs higher Spo2 target on mortality for individual patients was derived in the Pragmatic Investigation of Optimal Oxygen Targets (PILOT) trial and externally validated in the Intensive Care Unit Randomized Trial Comparing Two Approaches to Oxygen Therapy (ICU-ROX) trial. Critically ill adults received invasive mechanical ventilation in an intensive care unit (ICU) in the United States between July 2018 and August 2021 for PILOT (n = 1682) and in 21 ICUs in Australia and New Zealand between September 2015 and May 2018 for ICU-ROX (n = 965). Exposures: Randomization to a lower vs higher Spo2 target group. Main Outcome and Measure: 28-Day mortality. Results: In the ICU-ROX validation cohort, the predicted effect of treatment with a lower vs higher Spo2 target for individual patients ranged from a 27.2% absolute reduction to a 34.4% absolute increase in 28-day mortality. For example, patients predicted to benefit from a lower Spo2 target had a higher prevalence of acute brain injury, whereas patients predicted to benefit from a higher Spo2 target had a higher prevalence of sepsis and abnormally elevated vital signs. Patients predicted to benefit from a lower Spo2 target experienced lower mortality when randomized to the lower Spo2 group, whereas patients predicted to benefit from a higher Spo2 target experienced lower mortality when randomized to the higher Spo2 group (likelihood ratio test for effect modification P = .02). The use of a Spo2 target predicted to be best for each patient, instead of the randomized Spo2 target, would have reduced the absolute overall mortality by 6.4% (95% CI, 1.9%-10.9%). Conclusion and relevance: Oxygenation targets that are individualized using machine learning analyses of randomized trials may reduce mortality for critically ill adults. A prospective trial evaluating the use of individualized oxygenation targets is needed.

Public perception of participation in low-risk clinical trials in critical care using waived consent: a Canadian national survey.

PURPOSE: The acceptability of waiver of consent for participation in clinical research in intensive care unit (ICU) settings is uncertain. We sought to survey the Canadian public to assess levels of support, comfort, and acceptability for waived consent for low-risk clinical trials. METHODS: We performed a prospective cross-sectional survey of the Canadian public aged 18 yr or older. The survey was conducted by Ipsos between 19 and 23 November 2020. The survey content was derived from a literature review and in consultation with a patient and family partnership committee. The survey focused on attitudes and beliefs on waived consent for participation in low-risk clinical trials in ICU settings. The survey contained 35 items focused on sociodemographics, general health status, participation in medical research, and levels of support and comfort with research and with waived consent. The survey used a case study of a low-risk clinical trial intervention in ICU patients. Analysis was descriptive. RESULTS: We included 2,000 participants, 38% of whom reported experience with ICU and 16% with medical research. Participation in medical research was more common among those with postsecondary education, those with chronic disease, and those who were employed in health care. Most (80%) would support a model of waived consent for low-risk clinical trials, citing medical benefits (36%) and low perceived risk (34%). Most (77%) were comfortable with personally participating in a low-risk clinical trial. Most (80%) believed waived consent approaches were acceptable. Half (52%) believed the waived consent process should provide information about the research and include the option of opting out. When asked whether participants should always give full informed consent, regardless of the practicality or level of risk, 74% and 72% agreed, respectively. CONCLUSIONS: There is public support for models of waived consent for participation in low-risk pragmatic clinical trials in ICU settings in Canada; however, this is not universal. This information can inform and guide education, ethics, policy, and legal discussion on consent models.

RéSUMé: OBJECTIF: L'acceptabilité de la renonciation au consentement pour la participation à la recherche clinique à l'unité de soins intensifs (USI) est incertaine. Nous avons cherché à sonder la population canadienne afin d'évaluer les niveaux de soutien, de confort et d'acceptabilité de la renonciation au consentement pour les études cliniques à faible risque. MéTHODE: Nous avons réalisé un sondage transversal prospectif auprès de la population canadienne âgée de 18 ans et plus. Le sondage a été réalisé par Ipsos entre le 19 et le 23 novembre 2020. Le contenu du sondage a été élaboré à partir d'une revue de la littérature et en consultation avec un comité de partenariat composé de patient·es et de familles. Le sondage portait sur les attitudes et les croyances à l'égard de la renonciation au consentement pour participer à des études cliniques à faible risque dans les unités de soins intensifs. Le sondage comportait 35 questions axées sur les données sociodémographiques, l'état de santé général, la participation à la recherche médicale et les niveaux de soutien et de confort à l'égard de la recherche et de la renonciation au consentement. Le sondage s'est appuyé sur une étude de cas d'une intervention d'étude clinique à faible risque chez des patient·es des soins intensifs. L'analyse était descriptive. RéSULTATS: Nous avons inclus 2000 personnes, dont 38 % ont déclaré avoir eu des expériences en soins intensifs et 16 % en recherche médicale. La participation à la recherche médicale était plus fréquente chez les personnes ayant fait des études postsecondaires, celles atteintes de maladies chroniques et celles qui travaillaient dans le domaine des soins de santé. La plupart d'entre elles (80 %) appuieraient un modèle de renonciation au consentement pour les études cliniques à faible risque, citant les avantages médicaux (36 %) et le faible risque perçu (34 %). La majorité des personnes répondantes (77 %) étaient à l'aise à l'idée de participer personnellement à une étude clinique à faible risque. La plupart d'entre elles (80 %) croyaient que les approches fondées sur la renonciation au consentement étaient acceptables. La moitié (52 %) estimaient que le processus de renonciation au consentement devrait fournir des renseignements sur la recherche et inclure la possibilité de se retirer. Lorsqu'on leur a demandé si les participant·es devraient toujours donner un consentement éclairé complet, quel que soit l'aspect pratique ou le niveau de risque, 74 % et 72 % ont répondu par l'affirmative, respectivement. CONCLUSION: Il y a un appui public pour les modèles de renonciation au consentement quant à la participation à des études cliniques pragmatiques à faible risque dans les unités de soins intensifs au Canada; cet appui n'est toutefois pas universel. Ces renseignements peuvent éclairer et orienter l'éducation, l'éthique, les politiques et les discussions juridiques sur les modèles de consentement.

Structural basis for CFTR inhibition by CFTRinh-172.

The cystic fibrosis transmembrane conductance regulator (CFTR) is an anion channel that regulates electrolyte and fluid balance in epithelial tissues. While activation of CFTR is vital to treating cystic fibrosis, selective inhibition of CFTR is a potential therapeutic strategy for secretory diarrhea and autosomal dominant polycystic kidney disease. Although several CFTR inhibitors have been developed by high-throughput screening, their modes of action remain elusive. In this study, we determined the structure of CFTR in complex with the inhibitor CFTRinh-172 to an overall resolution of 2.7 Å by cryogenic electron microscopy. We observe that CFTRinh-172 binds inside the pore near transmembrane helix 8, a critical structural element that links adenosine triphosphate hydrolysis with channel gating. Binding of CFTRinh-172 stabilizes a conformation in which the chloride selectivity filter is collapsed, and the pore is blocked from the extracellular side of the membrane. Single-molecule fluorescence resonance energy transfer experiments indicate that CFTRinh-172 inhibits channel gating without compromising nucleotide-binding domain dimerization. Together, these data reconcile previous biophysical observations and provide a molecular basis for the activity of this widely used CFTR inhibitor.

Poly-γ-glutamylation of biomolecules.

Poly-γ-glutamate tails are a distinctive feature of archaeal, bacterial, and eukaryotic cofactors, including the folates and F420. Despite decades of research, key mechanistic questions remain as to how enzymes successively add glutamates to poly-γ-glutamate chains while maintaining cofactor specificity. Here, we show how poly-γ-glutamylation of folate and F420 by folylpolyglutamate synthases and γ-glutamyl ligases, non-homologous enzymes, occurs via processive addition of L-glutamate onto growing γ-glutamyl chain termini. We further reveal structural snapshots of the archaeal γ-glutamyl ligase (CofE) in action, crucially including a bulged-chain product that shows how the cofactor is retained while successive glutamates are added to the chain terminus. This bulging substrate model of processive poly-γ-glutamylation by terminal extension is arguably ubiquitous in such biopolymerisation reactions, including addition to folates, and demonstrates convergent evolution in diverse species from archaea to humans.

Associations between the intraoperative fraction of inspired intraoperative oxygen administration and days alive and out of hospital after surgery.

Background: There is limited knowledge about the effect of liberal intraoperative oxygen on non-infectious complications and overall recovery from surgery. Methods: In this retrospective cohort study, we investigated associations between mean intraoperative fraction of inspired oxygen (FiO2), and outcome in adults undergoing elective surgery lasting more than 2 h at a large metropolitan New Zealand hospital from 2012 to 2020. Patients were divided into low, medium, and high oxygen groups (FiO2 ≤ 0.4, 0.41-0.59, ≥0.6). The primary outcome was days alive and out of hospital at 90 days (DAOH90). The secondary outcomes were post-operative complications and admission to the ICU. Results: We identified 15,449 patients who met the inclusion criteria. There was no association between FiO2 and DAOH90 when high FiO2 was analysed according to three groups. Using high FiO2 as the reference group there was an adjusted mean (95% confidence interval [CI]) difference of 0.09 (-0.06 to 0.25) days (P = 0.25) and 0.28 (-0.05 to 0.62) days (P = 0.2) in the intermediate and low oxygen groups, respectively. Low FiO2 was associated with increased surgical site infection: the adjusted odds ratio (OR) for low compared with high FiO2 was 1.53 (95% CI 1.12-2.10). Increasing FiO2 was associated with respiratory complications: the adjusted OR associated with each 10% point increase in FiO2 was 1.17 (95% CI 1.08-1.26) and the incidence of being admitted to an ICU had an adjusted OR of 1.1 (95% CI 1.03-1.18). Conclusions: We found potential benefits, and risks, associated with liberal intraoperative oxygen administration indicating that randomised controlled trials are warranted.

Phase-3 trial of recombinant human alkaline phosphatase for patients with sepsis-associated acute kidney injury (REVIVAL).

PURPOSE: Ilofotase alfa is a human recombinant alkaline phosphatase with reno-protective effects that showed improved survival and reduced Major Adverse Kidney Events by 90 days (MAKE90) in sepsis-associated acute kidney injury (SA-AKI) patients. REVIVAL, was a phase-3 trial conducted to confirm its efficacy and safety. METHODS: In this international double-blinded randomized-controlled trial, SA-AKI patients were enrolled < 72 h on vasopressor and < 24 h of AKI. The primary endpoint was 28-day all-cause mortality. The main secondary endpoint was MAKE90, other secondary endpoints were (i) days alive and free of organ support through day 28, (ii) days alive and out of the intensive care unit (ICU) through day 28, and (iii) time to death through day 90. Prior to unblinding, the statistical analysis plan was amended, including an updated MAKE90 definition. RESULTS: Six hundred fifty patients were treated and analyzed for safety; and 649 for efficacy data (ilofotase alfa n = 330; placebo n = 319). The observed mortality rates in the ilofotase alfa and placebo groups were 27.9% and 27.9% at 28 days, and 33.9% and 34.8% at 90 days. The trial was stopped for futility on the primary endpoint. The observed proportion of patients with MAKE90A and MAKE90B were 56.7% and 37.4% in the ilofotase alfa group vs. 64.6% and 42.8% in the placebo group. Median [interquartile range (IQR)] days alive and free of organ support were 17 [0-24] and 14 [0-24], number of days alive and discharged from the ICU through day 28 were 15 [0-22] and 10 [0-22] in the ilofotase alfa and placebo groups, respectively. Adverse events were reported in 67.9% and 75% patients in the ilofotase and placebo group. CONCLUSION: Among critically ill patients with SA-AKI, ilofotase alfa did not improve day 28 survival. There may, however, be reduced MAKE90 events. No safety concerns were identified.

Enhancement of cellular immunity following needle-free vaccination of mice with SARS-CoV-2 spike protein.

The COVID-19 pandemic has highlighted the need for vaccines capable of providing rapid and robust protection. One way to improve vaccine efficacy is delivery via microarray patches, such as the Vaxxas high-density microarray patch (HD-MAP). We have previously demonstrated that delivery of a SARS-CoV-2 protein vaccine candidate, HexaPro, via the HD-MAP induces potent humoral immune responses. Here, we investigate the cellular responses induced by HexaPro HD-MAP vaccination. We found that delivery via the HD-MAP induces a type one biassed cellular response of much greater magnitude as compared to standard intramuscular immunization.

The Pitfalls of Using Pop-Off Valves in Adult Emergency Airway.

BACKGROUND: Although common in pediatric airway equipment, positive-pressure relief ("pop-off") valves are also present on some adult resuscitator bags. These valves are designed to decrease barotrauma but, in doing so, limit the airway pressure provided during manual bag-assisted ventilation. In critically ill adult patients with high airway pressures, these valves can be detrimental and result in hypoventilation and subsequent hypoxemia. CASE REPORTS: In the 7 days after an unannounced introduction of new resuscitator bags with pop-off valves in the emergency department, there were 3 adult patients for whom an open pop-off valve resulted in hypoventilation and hypoxemia. These cases involved both medical and traumatic pathologies. In each case, there was a delay in discovering the change to a resuscitator bag equipped with a pop-off valve. Once the emergency physicians noticed the pop-off valve and closed them, there was significant improvement in ventilation and oxygenation. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Hand-operated resuscitator bags are an essential tool for airway management. These cases represent two main lessons: changing airway equipment without notifying staff is dangerous, and an open pop-off valve will result in inadequate ventilation when patients have high airway pressures, without the tactile feedback of difficult bagging. Emergency physicians should be aware of equipment changes and know to disable the pop-off valve on resuscitator bags if they find them in their departments.

Polygenic Risk in Families With Spontaneous Coronary Artery Dissection.

Importance: Spontaneous coronary artery dissection (SCAD) is a poorly understood cause of acute coronary syndrome that predominantly affects women. Evidence to date suggests a complex genetic architecture, while a family history is reported for a minority of cases. Objective: To determine the contribution of rare and common genetic variants to SCAD risk in familial cases, the latter via the comparison of a polygenic risk score (PRS) with those with sporadic SCAD and healthy controls. Design, Setting, and Participants: This genetic association study analyzed families with SCAD, individuals with sporadic SCAD, and healthy controls. Genotyping was undertaken for all participants. Participants were recruited between 2017 and 2021. A PRS for SCAD was calculated for all participants. The presence of rare variants in genes associated with connective tissue disorders (CTD) was also assessed. Individuals with SCAD were recruited via social media or from a single medical center. A previously published control database of older healthy individuals was used. Data were analyzed from January 2022 to October 2023. Exposures: PRS for SCAD comprised of 7 single-nucleotide variants. Main Outcomes and Measures: Disease status (familial SCAD, sporadic SCAD, or healthy control) associated with PRS. Results: A total of 13 families with SCAD (27 affected and 12 unaffected individuals), 173 individuals with sporadic SCAD, and 1127 healthy controls were included. A total of 188 individuals with SCAD (94.0%) were female, including 25 of 27 with familial SCAD and 163 of 173 with sporadic SCAD; of 12 unaffected individuals from families with SCAD, 6 (50%) were female; and of 1127 healthy controls, 672 (59.6%) were female. Compared with healthy controls, the odds of being an affected family member or having sporadic SCAD was significantly associated with a SCAD PRS (where the odds ratio [OR] represents an increase in odds per 1-SD increase in PRS) (affected family member: OR, 2.14; 95% CI, 1.78-2.50; adjusted P = 1.96 × 10-4; sporadic SCAD: OR, 1.63; 95% CI, 1.37-1.89; adjusted P = 5.69 × 10-4). This association was not seen for unaffected family members (OR, 1.03; 95% CI, 0.46-1.61; adjusted P = .91) compared with controls. Further, those with familial SCAD were overrepresented in the top quintile of the control PRS distribution (OR, 3.70; 95% CI, 2.93-4.47; adjusted P = .001); those with sporadic SCAD showed a similar pattern (OR, 2.51; 95% CI, 1.98-3.04; adjusted P = .001). Affected individuals within a family did not share any rare deleterious variants in CTD-associated genes. Conclusions and Relevance: Extreme aggregation of common genetic risk appears to play a significant role in familial clustering of SCAD as well as in sporadic case predisposition, although further study is required.

Combined bisalbuminemia and Bisalbuminuria: A rare finding on serum and urine electrophoresis.

BACKGROUND: Bisalbuminemia and bisalbuminuria are rarely encountered serum and urine albumin anomalies characterized by the presence of a bifid albumin band on serum/urine protein electrophoresis (SPE/UPE) and serum/urine immunofixation electrophoresis (SIFE/UIFE). They are usually detected incidentally while screening for monoclonal gammopathy with a cumulative frequency of 1:1,000---1:10,000. CASE REPORT: We report two cases of bisalbuminemia in two adult male diabetic patients. The first patient had a history of rheumatoid arthritis and strong clinical suspicion for Sjogren syndrome. The SPEP/UPEP and SIFE/UIFE in this patient showed combined bisalbuminemia and bisalbuminuria. While the second patient had chronic kidney disease due to nephrotic syndrome but showed bisalbuminemia alone. CONCLUSION: Bisalbuminemia and bisalbuminuria are rare findings with few case reports available in the English literature. These findings may occur secondary to inherited albumin variants or may be acquired. Diabetes mellitus is the medical condition most associated with acquired bisalbuminemia and bisalbuminuria. Although most cases of bisalbuminemia and bisalbuminuria are clinically insignificant, some albumin variants may have altered affinity for steroid hormones (e.g., thyroxine) and/or drugs which potentially could be clinically significant.

A counter-swirl design concept for dry powder inhalers.

A swirling airflow is incorporated in several dry powder inhalers (DPIs) for effective powder de-agglomeration. This commonly requires the use of a flow-straightening grid in the DPI to reduce drug deposition loss caused by large lateral spreading of the emerging aerosol. Here, we propose a novel grid-free DPI design concept that improves the aerosol flow characteristics and reduces the aforementioned drug loss. The basis of this design is the implementation of a secondary airflow that swirls in the opposite direction (counter-swirl) to that of a primary swirling airflow. In-vitro deposition, computational fluid dynamics simulations and particle image velocimetry measurements are used to evaluate the counter-swirl DPI aerosol performance and flow characteristics. In comparison with a baseline-DPI that has only a primary swirling airflow, the counter-swirl DPI has 20% less deposition of the emitted drug dose in the induction port and pre-separator of a next generation impactor (NGI). This occurs as a result of the lower flow-swirl generated from the counter-swirl DPI which eliminates the axial reverse flow outside of the mouthpiece and substantially reduces lateral spreading in the exiting aerosol. Modifications to the counter-swirl DPI design were made to prevent drug loss from the secondary airflow tangential inlets, which involved the addition of wall perforations in the tangential inlets and the separation of the primary and secondary swirling airflows by an annular channel. These modified DPI devices were successful in that aspect but had higher flow-swirl than that in the counter-swirl DPI and thus had higher drug mass retained in the device and deposited in the induction port and pre-separator of the NGI. The fine particle fraction in the aerosols generated from all the counter-swirl-based DPIs and the baseline-DPI are found to be statistically similar to each other.

The role of N-glycosylation in spike antigenicity for the SARS-CoV-2 gamma variant.

The emergence of SARS-CoV-2 variants alters the efficacy of existing immunity towards the viral spike protein, whether acquired from infection or vaccination. Mutations that impact N-glycosylation of spike may be particularly important in influencing antigenicity, but their consequences are difficult to predict. Here, we compare the glycosylation profiles and antigenicity of recombinant viral spike of ancestral Wu-1 and the Gamma strain, which has two additional N-glycosylation sites due to amino acid substitutions in the N-terminal domain (NTD). We found that a mutation at residue 20 from threonine to asparagine within the NTD caused the loss of NTD-specific antibody COVA2-17 binding. Glycan site-occupancy analyses revealed that the mutation resulted in N-glycosylation switching to the new sequon at N20 from the native N17 site. Site-specific glycosylation profiles demonstrated distinct glycoform differences between Wu-1, Gamma, and selected NTD variant spike proteins, but these did not affect antibody binding. Finally, we evaluated the specificity of spike proteins against convalescent COVID-19 sera and found reduced cross-reactivity against some mutants, but not Gamma spike compared to Wuhan spike. Our results illustrate the impact of viral divergence on spike glycosylation and SARS-CoV-2 antibody binding profiles.

Balanced crystalloids versus saline for critically ill patients (BEST-Living): a systematic review and individual patient data meta-analysis.

BACKGROUND: The effect of balanced crystalloids compared with that of saline in critically ill patients overall and in specific subgroups is unclear. We aimed to assess whether use of balanced solutions, compared with 0·9% sodium chloride (saline), decreased in-hospital mortality in adult patients in intensive care units (ICUs). METHODS: For this systematic review and individual patient data meta-analysis, we searched PubMed, Embase, and CENTRAL databases from inception until March 1, 2022 (updated Sept 1, 2023) for individually randomised and cluster-randomised trials comparing balanced solutions with saline for adult patients in the ICU. Eligible trials were those that allocated patients to receive balanced solutions or saline for fluid resuscitation and maintenance fluids, or for maintenance fluids only; and administered the allocated fluid throughout ICU admission or, for trials using landmark mortality as their primary outcome, until the timepoint at which mortality was assessed (if ≥28 days). Authors of eligible trials were contacted to request individual patient data. Data obtained from eligible trials were merged, checked for accuracy, and centrally analysed by use of Bayesian regression models. The primary outcome was in-hospital mortality. Prespecified subgroups included patients with traumatic brain injury. This study was registered with PROSPERO (CRD42022299282). FINDINGS: Our search identified 5219 records, yielding six eligible randomised controlled trials. Data obtained for 34 685 participants from the six trials, 17 407 assigned to receive balanced crystalloids and 17 278 to receive saline, were included in the analysis. The mean age of participants was 58·8 years (SD 17·5). Of 34 653 participants with available data, 14 579 (42·1%) were female and 20 074 (57·9%) were male. Among patients who provided consent to report in-hospital mortality, 2907 (16·8%) of 17 313 assigned balanced solutions and 2975 (17·3%) of 17 166 assigned saline died in hospital (odds ratio [OR] 0·962 [95% CrI 0·909 to 1·019], absolute difference -0·4 percentage points [-1·5 to 0·2]). The posterior probability that balanced solutions reduced mortality was 0·895. In patients with traumatic brain injury, 191 (19·1%) of 999 assigned balanced and 141 (14·7%) of 962 assigned saline died (OR 1·424 [1·100 to 1·818], absolute difference 3·2 percentage points [0·7 to 8·7]). The probability that balanced solutions increased mortality in patients with traumatic brain injury was 0·975. In an independent risk of bias assessment, two trials were deemed to be at low risk of bias and four at high risk of bias. INTERPRETATION: The probability that using balanced solutions in the ICU reduces in-hospital mortality is high, although the certainty of the evidence was moderate and the absolute risk reduction was small. In patients with traumatic brain injury, using balanced solutions was associated with increased in-hospital mortality. FUNDING: HCor (Brazil) and The George Institute for Global Health (Australia).

Selective digestive tract decontamination in critically ill adults with acute brain injuries: a post hoc analysis of a randomized clinical trial.

PURPOSE: The aim of this study was to determine whether selective decontamination of the digestive tract (SDD) reduces in-hospital mortality in mechanically ventilated critically ill adults admitted to the intensive care unit (ICU) with acute brain injuries or conditions. METHODS: We carried out a post hoc analysis from a crossover, cluster randomized clinical trial. ICUs were randomly assigned to adopt or not to adopt a SDD strategy for two alternating 12-month periods, separated by a 3-month inter-period gap. Patients in the SDD group (n = 2791; 968 admitted to the ICU with an acute brain injury) received a 6-hourly application of an oral paste and administration of a gastric suspension containing colistin, tobramycin, and nystatin for the duration of mechanical ventilation, plus a 4-day course of an intravenous antibiotic with a suitable antimicrobial spectrum. Patients in the control group (n = 3191; 1093 admitted to the ICU with an acute brain injury) received standard care. The primary outcome was in-hospital mortality within 90 days. There were four secondary clinical outcomes: death in ICU, ventilator-, ICU- and hospital-free days to day 90. RESULTS: Of 2061 patients with acute brain injuries (mean age, 55.8 years; 36.4% women), all completed the trial. In patients with acute brain injuries, there were 313/968 (32.3%) and 415/1093 (38%) in-hospital deaths in the SDD and standard care groups (unadjusted odds ratio [OR], 0.76, 95% confidence interval [CI] 0.63-0.92; p = 0.004). The use of SDD was associated with statistically significant improvements in the four clinical secondary outcomes compared to standard care. There was no significant heterogeneity of treatment effect between patients with and without acute brain injuries (interaction p = 0.22). CONCLUSIONS: In this post hoc analysis of a randomized clinical trial in critically ill patients with acute brain injuries receiving mechanical ventilation, the use of SDD significantly reduced in-hospital mortality in patients compared to standard care without SDD. These findings require confirmation.

Reduced Ejection Fraction in Elite Endurance Athletes: Clinical and Genetic Overlap With Dilated Cardiomyopathy.

BACKGROUND: Exercise-induced cardiac remodeling can be profound, resulting in clinical overlap with dilated cardiomyopathy, yet the significance of reduced ejection fraction (EF) in athletes is unclear. The aim is to assess the prevalence, clinical consequences, and genetic predisposition of reduced EF in athletes. METHODS: Young endurance athletes were recruited from elite training programs and underwent comprehensive cardiac phenotyping and genetic testing. Those with reduced EF using cardiac magnetic resonance imaging (defined as left ventricular EF <50%, or right ventricular EF <45%, or both) were compared with athletes with normal EF. A validated polygenic risk score for indexed left ventricular end-systolic volume (LVESVi-PRS), previously associated with dilated cardiomyopathy, was assessed. Clinical events were recorded over a mean of 4.4 years. RESULTS: Of the 281 elite endurance athletes (22±8 years, 79.7% male) undergoing comprehensive assessment, 44 of 281 (15.7%) had reduced left ventricular EF (N=12; 4.3%), right ventricular EF (N=14; 5.0%), or both (N=18; 6.4%). Reduced EF was associated with a higher burden of ventricular premature beats (13.6% versus 3.8% with >100 ventricular premature beats/24 h; P=0.008) and lower left ventricular global longitudinal strain (-17%±2% versus -19%±2%; P<0.001). Athletes with reduced EF had a higher mean LVESVi-PRS (0.57±0.13 versus 0.51±0.14; P=0.009) with athletes in the top decile of LVESVi-PRS having an 11-fold increase in the likelihood of reduced EF compared with those in the bottom decile (P=0.034). Male sex and higher LVESVi-PRS were the only significant predictors of reduced EF in a multivariate analysis that included age and fitness. During follow-up, no athletes developed symptomatic heart failure or arrhythmias. Two athletes died, 1 from trauma and 1 from sudden cardiac death, the latter having a reduced right ventricular EF and a LVESVi-PRS >95%. CONCLUSIONS: Reduced EF occurs in approximately 1 in 6 elite endurance athletes and is related to genetic predisposition in addition to exercise training. Genetic and imaging markers may help identify endurance athletes in whom scrutiny about long-term clinical outcomes may be appropriate. REGISTRATION: URL: https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=374976&isReview=true; Unique identifier: ACTRN12618000716268.