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1.
Mol Cell ; 77(5): 1014-1031.e13, 2020 03 05.
Artigo em Inglês | MEDLINE | ID: mdl-32017898

RESUMO

The La-related protein 7 (LARP7) forms a complex with the nuclear 7SK RNA to regulate RNA polymerase II transcription. It has been implicated in cancer and the Alazami syndrome, a severe developmental disorder. Here, we report a so far unknown role of this protein in RNA modification. We show that LARP7 physically connects the spliceosomal U6 small nuclear RNA (snRNA) with a distinct subset of box C/D small nucleolar RNAs (snoRNAs) guiding U6 2'-O-methylation. Consistently, these modifications are severely compromised in the absence of LARP7. Although general splicing remains largely unaffected, transcriptome-wide analysis revealed perturbations in alternative splicing in LARP7-depleted cells. Importantly, we identified defects in 2'-O-methylation of the U6 snRNA in Alazami syndrome siblings carrying a LARP7 mutation. Our data identify LARP7 as a bridging factor for snoRNA-guided modification of the U6 snRNA and suggest that alterations in splicing fidelity contribute to the etiology of the Alazami syndrome.


Assuntos
Processamento Alternativo , Deficiências do Desenvolvimento/metabolismo , RNA Nuclear Pequeno/metabolismo , Ribonucleoproteínas/metabolismo , Spliceossomos/metabolismo , Sítios de Ligação , Linhagem Celular Tumoral , Criança , Pré-Escolar , Sequência Conservada , Deficiências do Desenvolvimento/genética , Feminino , Predisposição Genética para Doença , Células HEK293 , Humanos , Masculino , Metilação , Pessoa de Meia-Idade , Mutação , Conformação de Ácido Nucleico , Ligação Proteica , Domínios e Motivos de Interação entre Proteínas , RNA Nuclear Pequeno/genética , Ribonucleoproteínas/genética , Spliceossomos/genética
2.
Nature ; 584(7820): 215-220, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32788735

RESUMO

Two-dimensional atomic crystals can radically change their properties in response to external influences, such as substrate orientation or strain, forming materials with novel electronic structure1-5. An example is the creation of weakly dispersive, 'flat' bands in bilayer graphene for certain 'magic' angles of twist between the orientations of the two layers6. The quenched kinetic energy in these flat bands promotes electron-electron interactions and facilitates the emergence of strongly correlated phases, such as superconductivity and correlated insulators. However, the very accurate fine-tuning required to obtain the magic angle in twisted-bilayer graphene poses challenges to fabrication and scalability. Here we present an alternative route to creating flat bands that does not involve fine-tuning. Using scanning tunnelling microscopy and spectroscopy, together with numerical simulations, we demonstrate that graphene monolayers placed on an atomically flat substrate can be forced to undergo a buckling transition7-9, resulting in a periodically modulated pseudo-magnetic field10-14, which in turn creates a 'post-graphene' material with flat electronic bands. When we introduce the Fermi level into these flat bands using electrostatic doping, we observe a pseudogap-like depletion in the density of states, which signals the emergence of a correlated state15-17. This buckling of two-dimensional crystals offers a strategy for creating other superlattice systems and, in particular, for exploring interaction phenomena characteristic of flat bands.

3.
Nano Lett ; 24(18): 5625-5630, 2024 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-38662431

RESUMO

Recent experiments have revealed that the macroscopic Kelvin equation remains surprisingly accurate even for nanoscale capillaries. This phenomenon was so far explained by the oscillatory behavior of the solid-liquid interfacial free energy. We here demonstrate thermodynamic and capillarity inconsistencies with this explanation. After revising the Kelvin equation, we ascribe its validity at nanoscale confinement to the effect of disjoining pressure. To substantiate our hypothesis, we employed molecular dynamics simulations to evaluate interfacial heat transfer and wetting properties. Our assessments unveil a breakdown in a previously established proportionality between the work of adhesion and the Kapitza conductance at capillary heights below 1.3 nm, where the dominance of the work of adhesion shifts primarily from energy to entropy. Alternatively, the peak density of the initial water layer can effectively probe the work of adhesion. Unlike under bulk conditions, high confinement renders the work of adhesion entropically unfavorable.

4.
Nano Lett ; 24(14): 4108-4116, 2024 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-38536003

RESUMO

Symmetry breaking plays a pivotal role in unlocking intriguing properties and functionalities in material systems. For example, the breaking of spatial and temporal symmetries leads to a fascinating phenomenon: the superconducting diode effect. However, generating and precisely controlling the superconducting diode effect pose significant challenges. Here, we take a novel route with the deliberate manipulation of magnetic charge potentials to realize unconventional superconducting flux-quantum diode effects. We achieve this through suitably tailored nanoengineered arrays of nanobar magnets on top of a superconducting thin film. We demonstrate the vital roles of inversion antisymmetry and its breaking in evoking unconventional superconducting effects, namely a magnetically symmetric diode effect and an odd-parity magnetotransport effect. These effects are nonvolatilely controllable through in situ magnetization switching of the nanobar magnets. Our findings promote the use of antisymmetry (breaking) for initiating unconventional superconducting properties, paving the way for exciting prospects and innovative functionalities in superconducting electronics.

5.
Emerg Infect Dis ; 30(2): 333-336, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38181801

RESUMO

Because of constrained personnel time, the Philadelphia Department of Public Health (Philadelphia, PA, USA) adjusted its COVID-19 contact tracing protocol in summer 2021 by prioritizing recent cases and limiting staff time per case. This action reduced required staff hours to prevent each case from 21-30 to 8-11 hours, while maintaining program effectiveness.


Assuntos
COVID-19 , Humanos , COVID-19/prevenção & controle , Busca de Comunicante/métodos , SARS-CoV-2 , Philadelphia/epidemiologia , Saúde Pública
6.
Br J Surg ; 111(5)2024 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-38747328

RESUMO

BACKGROUND: Team diversity is recognized not only as an equity issue but also a catalyst for improved performance through diversity in knowledge and practices. However, team diversity data in healthcare are limited and it is not known whether it may affect outcomes in surgery. This study examined the association between anaesthesia-surgery team sex diversity and postoperative outcomes. METHODS: This was a population-based retrospective cohort study of adults undergoing major inpatient procedures between 2009 and 2019. The exposure was the hospital percentage of female anaesthetists and surgeons in the year of surgery. The outcome was 90-day major morbidity. Restricted cubic splines were used to identify a clinically meaningful dichotomization of team sex diversity, with over 35% female anaesthetists and surgeons representing higher diversity. The association with outcomes was examined using multivariable logistic regression. RESULTS: Of 709 899 index operations performed at 88 hospitals, 90-day major morbidity occurred in 14.4%. The median proportion of female anaesthetists and surgeons was 28 (interquartile range 25-31)% per hospital per year. Care in hospitals with higher sex diversity (over 35% female) was associated with reduced odds of 90-day major morbidity (OR 0.97, 95% c.i. 0.95 to 0.99; P = 0.02) after adjustment. The magnitude of this association was greater for patients treated by female anaesthetists (OR 0.92, 0.88 to 0.97; P = 0.002) and female surgeons (OR 0.83, 0.76 to 0.90; P < 0.001). CONCLUSION: Care in hospitals with greater anaesthesia-surgery team sex diversity was associated with better postoperative outcomes. Care in a hospital reaching a critical mass with over 35% female anaesthetists and surgeons, representing higher team sex-diversity, was associated with a 3% lower odds of 90-day major morbidity.


Assuntos
Equipe de Assistência ao Paciente , Complicações Pós-Operatórias , Humanos , Feminino , Estudos Retrospectivos , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias/epidemiologia , Complicações Pós-Operatórias/etiologia , Idoso , Adulto , Cirurgiões/estatística & dados numéricos , Procedimentos Cirúrgicos Operatórios/estatística & dados numéricos , Médicas/estatística & dados numéricos
7.
Phys Rev Lett ; 132(18): 184001, 2024 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-38759191

RESUMO

Nanoscale extension and refinement of the Lucas-Washburn model is presented with a detailed analysis of recent experimental data and extensive molecular dynamics simulations to investigate rapid water flow and water imbibition within nanocapillaries. Through a comparative analysis of capillary rise in hydrophilic nanochannels, an unexpected reversal of the anticipated trend, with an abnormal peak, of imbibition length below the size of 3 nm was discovered in hydrophilic nanochannels, surprisingly sharing the same physical origin as the well-known peak observed in flow rate within hydrophobic nanochannels. The extended imbibition model is applicable across diverse spatiotemporal scales and validated against simulation results and existing experimental data for both hydrophilic and hydrophobic nanochannels.

8.
Phys Chem Chem Phys ; 26(13): 10265-10272, 2024 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-38497764

RESUMO

Graphene oxide (GO) is one of the most promising candidates for next generation of atomically thin membranes. Nevertheless, one of the major issues for real world application of GO membranes is their undesirable swelling in an aqueous environment. Recently, we demonstrated that generation of H3O+ and OH- ions (e.g., with an external electric field) in the interlayer gallery could impart aqueous stability to the layered GO membranes (A. Gogoi, ACS Appl. Mater. Interfaces, 2022, 14, 34946). This, however, compromises the water flux through the membrane. In this study, we report on reducing the GO nanosheets as a solution to this issue. With the reduction of the GO nanosheets, the water flux through the layered GO membrane initially increases and then decreases again beyond a certain degree of reduction. Here, two key factors are at play. Firstly, the instability of the H-bond network between water molecules and the GO nanosheets, which increases the water flux. Secondly, the pore size reduction in the interlayer gallery of the membranes, which decreases the water flux. We also observe a significant improvement in the salt rejection of the membranes, due to the dissociation of water molecules in the interlayer gallery. In particular, for the case of 10% water dissociation, the water flux through the membranes can be enhanced without altering its selectivity. This is an encouraging observation as it breaks the traditional tradeoff between water flux and salt rejection of a membrane.

9.
Phys Chem Chem Phys ; 26(4): 3285-3295, 2024 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-38197170

RESUMO

In two-dimensional (2D) materials, breaking the inversion symmetry plays an important role in valleytronics. Ferrovalley (FV) materials can achieve spontaneous valley polarization (VP) without additional modulation due to the magnetic exchange interaction and strong spin-orbit coupling. Using first-principles calculations, we predict a new 2D material, Janus FeClSH, which exhibits a large spontaneous VP. This monolayer is a perfect FV material, where the valence band maximum and conduction band minimum are located at the K/K' point. A large VP of 102.95 meV is spontaneously generated for the case of out-of-plane magnetization. Additionally, we propose that the irradiating circularly polarized light can be used to realize VP for the case of in-plane magnetization. Remarkably, a triangular nanoflake of FeClSH with armchair edges can show nontrivial corner states, exhibiting a second-order topological insulator (SOTI) state. The VP effect and SOTI state are tunable with the Hubbard U parameter, making the FeClSH monolayer promising for the study of the coupling between VP and SOTI.

10.
BMC Public Health ; 24(1): 1013, 2024 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-38609903

RESUMO

BACKGROUND: Facing a surge of COVID-19 cases in late August 2021, the U.S. state of Illinois re-enacted its COVID-19 mask mandate for the general public and issued a requirement for workers in certain professions to be vaccinated against COVID-19 or undergo weekly testing. The mask mandate required any individual, regardless of their vaccination status, to wear a well-fitting mask in an indoor setting. METHODS: We used Illinois Department of Public Health's COVID-19 confirmed case and vaccination data and investigated scenarios where masking and vaccination would have been reduced to mimic what would have happened had the mask mandate or vaccine requirement not been put in place. The study examined a range of potential reductions in masking and vaccination mimicking potential scenarios had the mask mandate or vaccine requirement not been enacted. We estimated COVID-19 cases and hospitalizations averted by changes in masking and vaccination during the period covering October 20 to December 20, 2021. RESULTS: We find that the announcement and implementation of a mask mandate are likely to correlate with a strong protective effect at reducing COVID-19 burden and the announcement of a vaccinate-or-test requirement among frontline professionals is likely to correlate with a more modest protective effect at reducing COVID-19 burden. In our most conservative scenario, we estimated that from the period of October 20 to December 20, 2021, the mask mandate likely prevented approximately 58,000 cases and 1,175 hospitalizations, while the vaccinate-or-test requirement may have prevented at most approximately 24,000 cases and 475 hospitalizations. CONCLUSION: Our results indicate that mask mandates and vaccine-or-test requirements are vital in mitigating the burden of COVID-19 during surges of the virus.


Assuntos
COVID-19 , Vacinas , Humanos , Saúde Pública , COVID-19/epidemiologia , COVID-19/prevenção & controle , Illinois/epidemiologia , Vacinação
11.
Tech Coloproctol ; 28(1): 51, 2024 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-38684547

RESUMO

Endometriosis is a benign gynecologic affection that may lead to major surgeries, such as colorectal resections. Rectovaginal fistulas (RVF) are among the possible complications. When they occur, it is necessary to adapt the repair surgery as best as possible to limit their functional consequences. This video shows three different techniques for correcting RVF after rectal resection for endometriosis, with a combination of perineal surgery and laparoscopy: a mucosal flap, a transanal transection and single stapled anastomosis (TTSS) and a pull through. Supplementary file1 (MP4 469658 KB).


Assuntos
Endometriose , Laparoscopia , Fístula Retovaginal , Humanos , Feminino , Fístula Retovaginal/cirurgia , Fístula Retovaginal/etiologia , Endometriose/cirurgia , Laparoscopia/métodos , Laparoscopia/efeitos adversos , Complicações Pós-Operatórias/etiologia , Complicações Pós-Operatórias/cirurgia , Protectomia/efeitos adversos , Protectomia/métodos , Reto/cirurgia , Anastomose Cirúrgica/efeitos adversos , Anastomose Cirúrgica/métodos , Retalhos Cirúrgicos , Períneo/cirurgia , Adulto
12.
Nano Lett ; 23(21): 9683-9689, 2023 Nov 08.
Artigo em Inglês | MEDLINE | ID: mdl-37883804

RESUMO

The highly tunable band structure of the zero-energy Landau level (zLL) of bilayer graphene makes it an ideal platform for engineering novel quantum states. However, the zero-energy Landau level at high electric fields has remained largely unexplored. Here we present magnetotransport measurements of bilayer graphene in high transverse electric fields. We observe previously undetected Landau level crossings at filling factors ν = -2, 1, and 3 at high electric fields. These crossings provide constraints for theoretical models of the zero-energy Landau level and show that the orbital, valley, and spin character of the quantum Hall states at high electric fields is very different from low electric fields. At high E, new transitions between states at ν = -2 with different orbital and spin polarization can be controlled by the gate bias, while the transitions between ν = 0 → 1 and ν = 2 → 3 show anomalous behavior.

13.
Br J Cancer ; 128(3): 474-477, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36434156

RESUMO

In our 2020 consensus paper, we devised ten recommendations for conducting Complex Innovative Design (CID) trials to evaluate cancer drugs. Within weeks of its publication, the UK was hit by the first wave of the SARS-CoV-2 pandemic. Large CID trials were prioritised to compare the efficacy of new and repurposed COVID-19 treatments and inform regulatory decisions. The unusual circumstances of the pandemic meant studies such as RECOVERY were opened almost immediately and recruited record numbers of participants. However, trial teams were required to make concessions and adaptations to these studies to ensure recruitment was rapid and broad. As these are relevant to cancer trials that enrol patients with similar risk factors, we have added three new recommendations to our original ten: employing pragmatism such as using focused information sheets and collection of only the most relevant data; minimising negative environmental impacts with paperless systems; and using direct-to-patient communication methods to improve uptake. These recommendations can be applied to all oncology CID trials to improve their inclusivity, uptake and efficiency. Above all, the success of CID studies during the COVID-19 pandemic underscores their efficacy as tools for rapid treatment evaluation.


Assuntos
COVID-19 , Humanos , SARS-CoV-2 , Pandemias , Consenso , Oncologia
14.
Ann Surg ; 278(4): e820-e826, 2023 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-36727738

RESUMO

OBJECTIVE: Examine between-hospital and between-anesthesiologist variation in anesthesiology provider-volume (PV) and delivery of high-volume anesthesiology care. BACKGROUND: Better outcomes for anesthesiologists with higher PV of complex gastrointestinal cancer surgery have been reported. The factors linking anesthesiology practice and organization to volume are unknown. METHODS: We identified patients undergoing elective esophagectomy, hepatectomy, and pancreatectomy using linked administrative health data sets (2007-2018). Anesthesiology PV was the annual number of procedures done by the primary anesthesiologist in the 2 years before the index surgery. High-volume anesthesiology was PV>6 procedures/year. Funnel plots to described variation in anesthesiology PV and delivery of high-volume care. Hierarchical regression models examined between-anesthesiologist and between-hospital variation in delivery of high-volume care use with variance partition coefficients (VPCs) and median odds ratios (MORs). RESULTS: Among 7893 patients cared for at 17 hospitals, funnel plots showed variation in anesthesiology PV (median ranging from 1.5, interquartile range: 1-2 to 11.5, interquartile range: 8-16) and delivery of HV care (ranging from 0% to 87%) across hospitals. After adjustment, 32% (VPC 0.32) and 16% (VPC: 0.16) of the variation were attributable to between-anesthesiologist and between-hospital differences, respectively. This translated to an anesthesiologist MOR of 4.81 (95% CI, 3.27-10.3) and hospital MOR of 3.04 (95% CI, 2.14-7.77). CONCLUSIONS: Substantial variation in anesthesiology PV and delivery of high-volume anesthesiology care existed across hospitals. The anesthesiologist and the hospital were key determinants of the variation in high-volume anesthesiology care delivery. This suggests that targeting anesthesiology structures of care could reduce variation and improve delivery of high-volume anesthesiology care.


Assuntos
Anestesiologia , Procedimentos Cirúrgicos do Sistema Digestório , Neoplasias Gastrointestinais , Humanos , Anestesiologistas , Atenção à Saúde , Neoplasias Gastrointestinais/cirurgia
15.
Ann Surg ; 278(3): e503-e510, 2023 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-36538638

RESUMO

OBJECTIVE: To examine the association of between hospital rates of high-volume anesthesiology care and of postoperative major morbidity. BACKGROUND: Individual anesthesiology volume has been associated with individual patient outcomes for complex gastrointestinal cancer surgery. However, whether hospital-level anesthesiology care, where changes can be made, influences the outcomes of patients cared at this hospital is unknown. METHODS: We conducted a population-based retrospective cohort study of adults undergoing esophagectomy, pancreatectomy, or hepatectomy for cancer from 2007 to 2018. The exposure was hospital-level adjusted rate of high-volume anesthesiology care. The outcome was hospital-level adjusted rate of 90-day major morbidity (Clavien-Dindo grade 3-5). Scatterplots visualized the relationship between each hospital's adjusted rates of high-volume anesthesiology and major morbidity. Analyses at the hospital-year level examined the association with multivariable Poisson regression. RESULTS: For 7893 patients at 17 hospitals, the rates of high-volume anesthesiology varied from 0% to 87.6%, and of major morbidity from 38.2% to 45.4%. The scatter plot revealed a weak inverse relationship between hospital rates of high-volume anesthesiology and of major morbidity (Pearson: -0.23). The adjusted hospital rate of high-volume anesthesiology was independently associated with the adjusted hospital rate of major morbidity (rate ratio: 0.96; 95% CI, 0.95-0.98; P <0.001 for each 10% increase in the high-volume rate). CONCLUSIONS: Hospitals that provided high-volume anesthesiology care to a higher proportion of patients were associated with lower rates of 90-day major morbidity. For each additional 10% patients receiving care by a high-volume anesthesiologist at a given hospital, there was an associated reduction of 4% in that hospital's rate of major morbidity.


Assuntos
Anestesiologia , Neoplasias Gastrointestinais , Adulto , Humanos , Estudos Retrospectivos , Neoplasias Gastrointestinais/cirurgia , Hepatectomia/efeitos adversos , Hospitais , Hospitais com Alto Volume de Atendimentos
16.
Curr Opin Oncol ; 35(3): 178-185, 2023 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-36966498

RESUMO

PURPOSE OF REVIEW: Despite recent advances, treatment personalization remains an issue for recurrent metastatic head and neck squamous cell carcinoma (RM HNSCC) patients. After human papilloma virus (HPV) and programmed death ligand 1 (PDL1) expression, Harvey rat sarcoma viral oncogene homolog (HRAS) appears as an emerging target in this field. In this review, we summarize the features of HRAS -mutated HNSCC and its targeting by farnesyl transferase inhibitors. RECENT FINDINGS: HRAS mutations define a small subgroup of RM HNSCC patients with a poor prognosis and often refractory to the standard treatments. Posttranslational processing of HRAS being dependent on farnesylation, farnesyl transferase inhibitors have been evaluated in HRAS -mutated tumors. Tipifarnib, a first in class farnesyl transferase inhibitor, has shown efficacy in phase 2 trials with HRAS -mutated tumors. Despite reported high response rates in selected population, the efficacy of Tipifarnib is inconsistent and always transient, probably because of limiting hematological toxicities leading to dose reduction and occurrence of secondary resistance mutations. SUMMARY: Tipifarnib is the first in the class of farnesyl transferase inhibitors to show efficacy in HRAS -mutated RM HNSCC. The understanding of mechanisms of resistance will pave the way for the design of second-generation farnesyl transferases inhibitors.


Assuntos
Carcinoma , Neoplasias de Cabeça e Pescoço , Humanos , Carcinoma de Células Escamosas de Cabeça e Pescoço , Proteínas Proto-Oncogênicas p21(ras)/genética , Neoplasias de Cabeça e Pescoço/tratamento farmacológico , Neoplasias de Cabeça e Pescoço/genética , Transferases , Oncogenes
17.
Phys Rev Lett ; 130(5): 057001, 2023 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-36800469

RESUMO

A supersolid, a counterintuitive quantum state in which a rigid lattice of particles flows without resistance, has to date not been unambiguously realized. Here we reveal a supersolid ground state of excitons in a double-layer semiconductor heterostructure over a wide range of layer separations outside the focus of recent experiments. This supersolid conforms to the original Chester supersolid with one exciton per supersolid site, as distinct from the alternative version reported in cold-atom systems of a periodic density modulation or clustering of the superfluid. We provide the phase diagram augmented by the supersolid. This new phase appears at layer separations much smaller than the predicted exciton normal solid, and it persists up to a solid-solid transition where the quantum phase coherence collapses. The ranges of layer separations and exciton densities in our phase diagram are well within reach of the current experimental capabilities.

18.
Crit Care ; 27(1): 343, 2023 09 04.
Artigo em Inglês | MEDLINE | ID: mdl-37667379

RESUMO

BACKGROUND: Respiratory mechanics is a key element to monitor mechanically ventilated patients and guide ventilator settings. Besides the usual basic assessments, some more complex explorations may allow to better characterize patients' respiratory mechanics and individualize ventilation strategies. These advanced respiratory mechanics assessments including esophageal pressure measurements and complete airway closure detection may be particularly relevant in critically ill obese patients. This study aimed to comprehensively assess respiratory mechanics in obese and non-obese ICU patients with or without ARDS and evaluate the contribution of advanced respiratory mechanics assessments compared to basic assessments in these patients. METHODS: All intubated patients admitted in two ICUs for any cause were prospectively included. Gas exchange and respiratory mechanics including esophageal pressure and end-expiratory lung volume (EELV) measurements and low-flow insufflation to detect complete airway closure were assessed in standardized conditions (tidal volume of 6 mL kg-1 predicted body weight (PBW), positive end-expiratory pressure (PEEP) of 5 cmH2O) within 24 h after intubation. RESULTS: Among the 149 analyzed patients, 52 (34.9%) were obese and 90 (60.4%) had ARDS (65.4% and 57.8% of obese and non-obese patients, respectively, p = 0.385). A complete airway closure was found in 23.5% of the patients. It was more frequent in obese than in non-obese patients (40.4% vs 14.4%, p < 0.001) and in ARDS than in non-ARDS patients (30% vs. 13.6%, p = 0.029). Respiratory system and lung compliances and EELV/PBW were similarly decreased in obese patients without ARDS and obese or non-obese patients with ARDS. Chest wall compliance was not impacted by obesity or ARDS, but end-expiratory esophageal pressure was higher in obese than in non-obese patients. Chest wall contribution to respiratory system compliance differed widely between patients but was not predictable by their general characteristics. CONCLUSIONS: Most respiratory mechanics features are similar in obese non-ARDS and non-obese ARDS patients, but end-expiratory esophageal pressure is higher in obese patients. A complete airway closure can be found in around 25% of critically ill patients ventilated with a PEEP of 5 cmH2O. Advanced explorations may allow to better characterize individual respiratory mechanics and adjust ventilation strategies in some patients. Trial registration NCT03420417 ClinicalTrials.gov (February 5, 2018).


Assuntos
Estado Terminal , Síndrome do Desconforto Respiratório , Humanos , Peso Corporal , Obesidade/complicações , Respiração Artificial , Síndrome do Desconforto Respiratório/complicações , Síndrome do Desconforto Respiratório/terapia , Mecânica Respiratória
19.
Can J Anaesth ; 70(10): 1648-1659, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37498442

RESUMO

PURPOSE: Postoperative pulmonary complications (PPCs) are a common cause of morbidity. Postoperative atelectasis is thought to be a significant risk factor in their development. Recent imaging studies suggest that patients' extubation may result in similar postoperative atelectasis regardless of the intraoperative mechanical ventilation strategy used. In this pilot trial, we hypothesized that a study investigating the effects of an open lung extubation strategy compared with a conventional one on PPCs would be feasible. METHODS: We conducted a pilot, single-centre, double-blinded randomized controlled trial. Adult patients at moderate to high risk of PPCs and scheduled for elective surgery were eligible. Patients were randomized to an open lung extubation strategy (semirecumbent position, fraction of inspired oxygen [FIO2] 50%, pressure support ventilation, unchanged positive end-expiratory pressure) or to a conventional extubation strategy (dorsal decubitus position, FIO2 100%, manual bag ventilation). The primary feasibility outcome was global protocol adherence while the primary exploratory efficacy outcome was PPCs. RESULTS: We randomized 35 patients to the conventional extubation group and 34 to the open lung extubation group. We observed a global protocol adherence of 96% (95% confidence interval, 88 to 99), which was not different between groups. Eight PPCs occurred (two in the conventional extubation group vs six in the open lung extubation group). Less postoperative supplemental oxygen and better lung aeration were observed in the open lung extubation group. CONCLUSIONS: In this single-centre pilot trial, we observed excellent feasibility. A multicentre pilot trial comparing the effect of an open lung extubation strategy with that of a conventional extubation strategy on the occurrence of PPCs is feasible. STUDY REGISTRATION DATE: ClinicalTrials.gov (NCT04993001); registered 6 August 2021.


RéSUMé: OBJECTIF: Les complications pulmonaires postopératoires (CPP) sont une cause fréquente de morbidité. L'atélectasie postopératoire est considérée comme un facteur de risque important de CPP. Des études d'imagerie récentes suggèrent que l'extubation des patient·es peut entraîner une atélectasie postopératoire semblable, quelle que soit la stratégie de ventilation mécanique peropératoire utilisée. Dans cet essai pilote, nous avons émis l'hypothèse qu'une étude examinant les effets sur les CPP d'une stratégie d'extubation à poumon ouvert par rapport à une stratégie d'extubation conventionnelle serait réalisable. MéTHODE: Nous avons mené une étude randomisée contrôlée pilote, monocentrique et à double insu. Les patient·es adultes présentant un risque modéré à élevé de CPP et devant bénéficier d'une chirurgie non urgente étaient éligibles. Les patient·es ont été randomisé·es à une prise en charge par une stratégie d'extubation à poumon ouvert (position semi-couchée, fraction d'oxygène inspiré [FIO2] 50 %, ventilation par aide inspiratoire, pression positive télé-expiratoire inchangée) ou à une stratégie d'extubation conventionnelle (décubitus dorsal, FIO2 100 %, ventilation manuelle par masque). Le principal critère de faisabilité était l'adhésion au protocole global, tandis que les CPP constituaient le principal critère d'efficacité exploratoire. RéSULTATS: Nous avons randomisé 35 patient·es dans le groupe d'extubation conventionnelle et 34 dans le groupe d'extubation à poumon ouvert. Nous avons observé une adhésion globale au protocole de 96 % (intervalle de confiance à 95 %, 88 à 99), qui n'était pas différente entre les groupes. Huit CPP sont survenues (deux dans le groupe d'extubation conventionnelle vs six dans le groupe d'extubation à poumon ouvert). Nous avons observé des besoins moins importants en oxygène supplémentaire postopératoire et une meilleure aération pulmonaire dans le groupe extubé à poumon ouvert. CONCLUSION: Dans cet essai pilote monocentrique, nous avons observé une excellente faisabilité. Une étude pilote multicentrique comparant l'effet d'une stratégie d'extubation à poumon ouvert à celui d'une stratégie d'extubation conventionnelle sur la survenue de CPP est réalisable. DATE D'ENREGISTREMENT DE L'éTUDE: ClinicalTrials.gov (NCT04993001); enregistrée le 6 août 2021.


Assuntos
Extubação , Atelectasia Pulmonar , Adulto , Humanos , Projetos Piloto , Extubação/efeitos adversos , Pulmão , Atelectasia Pulmonar/epidemiologia , Atelectasia Pulmonar/etiologia , Atelectasia Pulmonar/prevenção & controle , Complicações Pós-Operatórias/epidemiologia , Complicações Pós-Operatórias/prevenção & controle , Complicações Pós-Operatórias/etiologia , Anestesia Geral/efeitos adversos , Oxigênio
20.
Can J Anaesth ; 70(7): 1155-1166, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-37266852

RESUMO

PURPOSE: The objective of this study was to describe some components of the perioperative practice in liver transplantation as reported by clinicians. METHODS: We conducted a cross-sectional clinical practice survey using an online instrument containing questions on selected themes related to the perioperative care of liver transplant recipients. We sent email invitations to Canadian anesthesiologists, Canadian surgeons, and French anesthesiologists specialized in liver transplantation. We used five-point Likert-type scales (from "never" to "always") and numerical or categorical answers. Results are presented as medians or proportions. RESULTS: We obtained answers from 130 participants (estimated response rate of 71% in Canada and 26% in France). Respondents reported rarely using transesophageal echocardiography routinely but often using it for hemodynamic instability, often using an intraoperative goal-directed hemodynamic management strategy, and never using a phlebotomy (medians from ordinal scales). Fifty-nine percent of respondents reported using a restrictive fluid management strategy to manage hemodynamic instability during the dissection phase. Forty-two percent and 15% of respondents reported using viscoelastic tests to guide intraoperative and postoperative transfusions, respectively. Fifty-four percent of respondents reported not pre-emptively treating preoperative coagulations disturbances, and 91% reported treating them intraoperatively only when bleeding was significant. Most respondents (48-64%) did not have an opinion on the maximal graft ischemic times. Forty-seven percent of respondents reported that a piggyback technique was the preferred vena cava anastomosis approach. CONCLUSION: Different interventions were reported to be used regarding most components of perioperative care in liver transplantation. Our results suggest that significant equipoise exists on the optimal perioperative management of this population.


RéSUMé: OBJECTIF: L'objectif de cette étude était de décrire certaines composantes de la pratique périopératoire en transplantation hépatique telles que rapportées par les cliniciens. MéTHODE: Nous avons mené un sondage transversal sur la pratique clinique à l'aide d'un instrument en ligne comportant des questions sur des thèmes sélectionnés liés aux soins périopératoires des receveurs de greffe du foie. Nous avons envoyé des invitations par courriel à des anesthésiologistes canadiens, des chirurgiens canadiens et des anesthésiologistes français spécialisés en transplantation hépatique. Nous avons utilisé des échelles de type Likert à cinq points (de « jamais ¼ à « toujours ¼) et des réponses numériques ou catégorielles. Les résultats sont présentés sous forme de médianes ou de proportions. RéSULTATS: Nous avons obtenu des réponses de 130 participants (taux de réponse estimé à 71 % au Canada et à 26 % en France). Les répondants ont déclaré utiliser rarement l'échocardiographie transœsophagienne de routine, mais l'utiliser fréquemment pour l'instabilité hémodynamique, souvent en utilisant une stratégie de prise en charge hémodynamique peropératoire axée sur les objectifs, et jamais en utilisant une phlébotomie (médianes des échelles ordinales). Cinquante-neuf pour cent des répondants ont déclaré utiliser une stratégie restrictive de gestion liquidienne pour prendre en charge l'instabilité hémodynamique pendant la phase de dissection. Quarante-deux pour cent et 15 % des répondants ont déclaré utiliser des tests viscoélastiques pour guider les transfusions peropératoires et postopératoires, respectivement. Cinquante-quatre pour cent des répondants ont déclaré ne pas traiter préventivement les troubles préopératoires de la coagulation, et 91 % ont déclaré les traiter en peropératoire uniquement lorsque les saignements étaient importants. La plupart des répondants (48-64 %) n'avaient pas d'opinion sur les temps ischémiques maximaux du greffon. Quarante-sept pour cent des répondants ont déclaré qu'une technique de 'piggyback' (anastomose latéroterminale) était l'approche préférée pour l'anastomose de la veine cave. CONCLUSION: Différentes interventions ont été signalées pour la plupart des composantes des soins périopératoires dans la transplantation hépatique. Nos résultats suggèrent qu'il existe une incertitude significative concernant la prise en charge périopératoire optimale de cette population.


Assuntos
Transplante de Fígado , Humanos , Transplante de Fígado/métodos , Estudos Transversais , Canadá , Assistência Perioperatória/métodos , Hemorragia
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