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Knowledge of molecular weight is an integral factor in polymer synthesis, and while many synthetic strategies have been developed to help control this, determination of the final molecular weight is often only measured at the end of the reaction. Herein, we provide a technique for the online determination of polymer molecular weight using a universal, solvent-independent diffusion ordered spectroscopy (DOSY) calibration and evidence its use in a variety of polymerization reactions.
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BACKGROUND: Cerebrospinal fluid creatine kinase BB isoenzyme (CSF CK-BB) after cardiac arrest (CA) has been shown to have a high positive predictive value for poor neurological outcome, but it has not been evaluated in the setting of targeted temperature management (TTM) and modern CA care. We aimed to evaluate CSF CK-BB as a prognostic biomarker after CA. METHODS: We performed a retrospective cohort study of patients with CA admitted between 2010 and 2020 to a three-hospital health system who remained comatose and had CSF CK-BB assayed between 36 and 84 h after CA. We examined the proportion of patients at hospital discharge who achieved favorable or intermediate neurological outcome, defined as Cerebral Performance Category score of 1-3, compared with those with poor outcome (Cerebral Performance Category score 4-5) for various CSF CK-BB thresholds. We also evaluated additive value of bilateral absence of somatosensory evoked potentials (SSEPs). RESULTS: Among 214 eligible patients, the mean age was 54.7 ± 4.8 years, 72% of patients were male, 33% were nonwhite, 17% had shockable rhythm, 90% were out-of-hospital CA, and 83% received TTM. A total of 19 (9%) awakened. CSF CK-BB ≥ 230 U/L predicted a poor outcome at hospital discharge, with a specificity of 100% (95% confidence interval [CI] 82-100%) and sensitivity of 69% (95% CI 62-76%). When combined with bilaterally absent N20 response on SSEP, specificity remained 100% while sensitivity increased to 80% (95% CI 73-85%). Discordant CK-BB and SSEP findings were seen in 13 (9%) patients. CONCLUSIONS: Cerebrospinal fluid creatine kinase BB isoenzyme levels accurately predicted poor neurological outcome among CA survivors treated with TTM. The CSF CK-BB cutoff of 230 U/L optimizes sensitivity to 69% while maintaining a specificity of 100%. CSF CK-BB could be a useful addition to multimodal neurological prognostication after CA.
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Measurement of molecular weight is an integral part of macromolecular and polymer characterization which usually has limitations. Herein, this article presents the use of a bench-top 80 MHz Nuclear Magnetic Resonance (NMR) spectrometer for diffusion-ordered spectroscopy as a practical and rapid approach for the determination of molecular weight/size using a novel solvent and polymer-independent universal calibration.
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Sustancias Macromoleculares , Espectroscopía de Resonancia Magnética , Peso Molecular , Polímeros , Polímeros/química , Espectroscopía de Resonancia Magnética/métodos , Sustancias Macromoleculares/química , DifusiónRESUMEN
n-Type organic electrochemical transistors (OECTs) and organic field-effect transistors (OFETs) are less developed than their p-type counterparts. Herein, polynaphthalenediimide (PNDI)-based copolymers bearing novel fluorinated selenophene-vinylene-selenophene (FSVS) units as efficient materials for both n-type OECTs and n-type OFETs are reported. The PNDI polymers with oligo(ethylene glycol) (EG7) side chains P(NDIEG7-FSVS), affords a high µC* of > 0.2 F cm-1 V-1 s-1 , outperforming the benchmark n-type Pg4NDI-T2 and Pg4NDI-gT2 by two orders of magnitude. The deep-lying LUMO of -4.63 eV endows P(NDIEG7-FSVS) with an ultra-low threshold voltage of 0.16 V. Moreover, the conjugated polymer with octyldodecyl (OD) side chains P(NDIOD-FSVS) exhibits a surprisingly low energetic disorder with an Urbach energy of 36 meV and an ultra-low activation energy of 39 meV, resulting in high electron mobility of up to 0.32 cm2 V-1 s-1 in n-type OFETs. These results demonstrate the great potential for simultaneously achieving a lower LUMO and a tighter intermolecular packing for the next-generation efficient n-type organic electronics.
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BACKGROUND: In-hospital cardiac arrest (IHCA) with the return of spontaneous circulation (ROSC) is a clinical scenario associated with potentially devastating outcomes. OBJECTIVE: Inconsistencies in post-ROSC care exist and we sought to find a low cost way to decrease this variability. DESIGNS, SETTINGS, AND PARTICIPANTS: We obtained pre and post intervention metrics including percentage of IHCA with a timely electrocardiogram (ECG), arterial blood gas (ABG), physician documentation, and documentation of patient surrogate communication after ROSC. INTERVENTION: We developed and implemented a post-ROSC checklist for IHCA and measured post-ROSC clinical care delivery metrics at our hospital during a 1-year pilot period. MAIN OUTCOME AND RESULTS: After the introduction of the checklist, 83.7% of IHCA had an ECG within 1 h of ROSC, compared to a baseline of 62.8% (p = 0.01). The rate of physician documentation within 6 h of ROSC was 74.4% after introduction of the checklist, compared to a baseline of 49.5% (p < 0.01). The percentage of IHCA with ROSC that completed all four of the critical post-ROSC tasks after the introduction of the post-ROSC checklist was 51.1% as compared to 19.4% before implementation (p < 0.01). CONCLUSIONS: Our study demonstrated improved consistency in completing post-ROSC clinical tasks after the introduction of a post-ROSC checklist to our hospital. This work suggests that the implementation of a checklist can have meaningful impacts on task completion in the post-ROSC setting. Despite this, considerable inconsistencies in post-ROSC care persisted after the intervention indicating the limits of checklists in this setting. Future work is needed to identify interventions that can further improve post-ROSC processes of care.
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Reanimación Cardiopulmonar , Paro Cardíaco , Humanos , Proyectos Piloto , Lista de Verificación , Paro Cardíaco/terapia , HospitalesRESUMEN
Recent studies have drawn increasing attention to brain-lung crosstalk in critically ill patients. However, further research is needed to investigate the pathophysiological interactions between the brain and lungs, establish neuroprotective ventilatory strategies for brain-injured patients, provide guidance on potentially conflicting treatment priorities in patients with concomitant brain and lung injury, and enhance prognostic models to inform extubation and tracheostomy decisions. To bring together such research, BMC Pulmonary Medicine welcomes submissions to its new Collection on 'Brain-lung crosstalk'.
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Lesión Pulmonar , Respiración , Humanos , Encéfalo , Extubación Traqueal , PulmónRESUMEN
BACKGROUND: There is insufficient evidence to guide ventilatory targets in acute brain injury (ABI). Recent studies have shown associations between mechanical power (MP) and mortality in critical care populations. We aimed to describe MP in ventilated patients with ABI, and evaluate associations between MP and clinical outcomes. METHODS: In this preplanned, secondary analysis of a prospective, multi-center, observational cohort study (ENIO, NCT03400904), we included adult patients with ABI (Glasgow Coma Scale ≤ 12 before intubation) who required mechanical ventilation (MV) ≥ 24 h. Using multivariable log binomial regressions, we separately assessed associations between MP on hospital day (HD)1, HD3, HD7 and clinical outcomes: hospital mortality, need for reintubation, tracheostomy placement, and development of acute respiratory distress syndrome (ARDS). RESULTS: We included 1217 patients (mean age 51.2 years [SD 18.1], 66% male, mean body mass index [BMI] 26.3 [SD 5.18]) hospitalized at 62 intensive care units in 18 countries. Hospital mortality was 11% (n = 139), 44% (n = 536) were extubated by HD7 of which 20% (107/536) required reintubation, 28% (n = 340) underwent tracheostomy placement, and 9% (n = 114) developed ARDS. The median MP on HD1, HD3, and HD7 was 11.9 J/min [IQR 9.2-15.1], 13 J/min [IQR 10-17], and 14 J/min [IQR 11-20], respectively. MP was overall higher in patients with ARDS, especially those with higher ARDS severity. After controlling for same-day pressure of arterial oxygen/fraction of inspired oxygen (P/F ratio), BMI, and neurological severity, MP at HD1, HD3, and HD7 was independently associated with hospital mortality, reintubation and tracheostomy placement. The adjusted relative risk (aRR) was greater at higher MP, and strongest for: mortality on HD1 (compared to the HD1 median MP 11.9 J/min, aRR at 17 J/min was 1.22, 95% CI 1.14-1.30) and HD3 (1.38, 95% CI 1.23-1.53), reintubation on HD1 (1.64; 95% CI 1.57-1.72), and tracheostomy on HD7 (1.53; 95%CI 1.18-1.99). MP was associated with the development of moderate-severe ARDS on HD1 (2.07; 95% CI 1.56-2.78) and HD3 (1.76; 95% CI 1.41-2.22). CONCLUSIONS: Exposure to high MP during the first week of MV is associated with poor clinical outcomes in ABI, independent of P/F ratio and neurological severity. Potential benefits of optimizing ventilator settings to limit MP warrant further investigation.
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Lesiones Encefálicas , Síndrome de Dificultad Respiratoria , Adulto , Humanos , Masculino , Persona de Mediana Edad , Femenino , Extubación Traqueal , Estudios Prospectivos , Respiración Artificial/efectos adversos , Cuidados Críticos , Unidades de Cuidados Intensivos , Lesiones Encefálicas/terapia , Lesiones Encefálicas/etiología , Encéfalo , OxígenoRESUMEN
BACKGROUND: Patients admitted to an intensive care unit (ICU) requiring invasive mechanical ventilation who are discharged alive from the ICU within 24 h are poorly characterized in the literature. OBJECTIVE: Our aim was to characterize a cohort of intubated emergency department (ED) patients who are extubated and discharged from the ICU within 24 h. METHODS: We conducted a retrospective, observational cohort study at a single level I trauma center from January 2017 to December 2019. We included adults who were admitted to an ICU from the ED requiring invasive mechanical ventilation. Our primary outcome was the proportion of patients who were discharged from the ICU alive within 24 h. RESULTS: Of 13,374 ED patients admitted to an ICU during the study period, 2871 patients were intubated and ventilated in the prehospital or ED settings. Of these, 14% were discharged alive from the ICU within 24 h of admission. Only 21% of these patients were intubated in the ED. We identified the following two distinct subpopulations comprising 62% of this short-stay group: patients with a primary discharge diagnosis of intoxication (47%) and minimally injured trauma patients (53%), with 4% of patients in both subgroups. CONCLUSIONS: A total of 14% of patients receiving intubation with mechanical ventilation in the prehospital environment or in the ED were discharged alive from the ICU within 24 h. We identified two distinct subgroups of patients with a short stay in intensive care who may be candidates for ED extubation, including patients with intoxication and minimally injured trauma patients.
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Cuidados Críticos , Respiración Artificial , Adulto , Humanos , Respiración Artificial/efectos adversos , Estudios Retrospectivos , Tiempo de Internación , Servicio de Urgencia en Hospital , Unidades de Cuidados IntensivosRESUMEN
Extracorporeal membrane oxygenation (ECMO) has emerged in the COVID-19 pandemic as a potentially beneficial yet scare resource for treating critically ill patients, with variable allocation across the United States. The existing literature has not addressed barriers patients may face in access to ECMO as a result of healthcare inequity. We present a novel patient-centered framework of ECMO access, providing evidence for potential bias and opportunities to mitigate this bias at every stage between a marginalized patient's initial presentation to treatment with ECMO. While equitable access to ECMO support is a global challenge, this piece focuses primarily on patients in the United States with severe COVID-19-associated ARDS to draw from current literature on VV-ECMO for ARDS and does not address issues that affect ECMO access on a more international scale.
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COVID-19 , Oxigenación por Membrana Extracorpórea , Síndrome de Dificultad Respiratoria , Humanos , Pandemias , Síndrome de Dificultad Respiratoria/terapiaRESUMEN
BACKGROUND: The objective of this study is to describe incidence and factors associated with early withdrawal of life-sustaining therapies based on presumed poor neurologic prognosis (WLST-N) and practices around multimodal prognostication after out-of-hospital cardiac arrest (OHCA). METHODS: We performed a subanalysis of a randomized controlled trial assessing prehospital therapeutic hypothermia in adult patients admitted to nine hospitals in King County with nontraumatic OHCA between 2007 and 2012. Patients who underwent tracheal intubation and were unconscious following return of spontaneous circulation were included. Our outcomes were (1) incidence of early WLST-N (WLST-N within < 72 h from return of spontaneous circulation), (2) factors associated with early WLST-N compared with patients who remained comatose at 72 h without WLST-N, (3) institutional variation in early WLST-N, (4) use of multimodal prognostication, and (5) use of sedative medications in patients with early WLST-N. Analysis included descriptive statistics and multivariable logistic regression. RESULTS: We included 1,040 patients (mean age was 65 years, 37% were female, 41% were White, and 44% presented with arrest due to ventricular fibrillation) admitted to nine hospitals. Early WLST-N accounted for 24% (n = 154) of patient deaths and occurred in half (51%) of patients with WLST-N. Factors associated with early WLST-N in multivariate regressions were older age (odds ratio [OR] 1.02, 95% confidence interval [CI]: 1.01-1.03), preexisting do-not-attempt-resuscitation orders (OR 4.67, 95% CI: 1.55-14.01), bilateral absent pupillary reflexes (OR 2.4, 95% CI: 1.42-4.10), and lack of neurological consultation (OR 2.60, 95% CI: 1.52-4.46). The proportion of patients with early WLST-N among all OHCA admissions ranged from 19-60% between institutions. A head computed tomography scan was obtained in 54% (n = 84) of patients with early WLST-N; 22% (n = 34) and 5% (n = 8) underwent ≥ 1 and ≥ 2 additional prognostic tests, respectively. Prognostic tests were more frequently performed when neurological consultation occurred. Most patients received sedating medications (90%) within 24 h before early WLST-N; the median time from last sedation to early WLST-N was 4.2 h (interquartile range 0.4-15). CONCLUSIONS: Nearly one quarter of deaths after OHCA were due to early WLST-N. The presence of concerning neurological examination findings appeared to impact early WLST-N decisions, even though these are not fully reliable in this time frame. Lack of neurological consultation was associated with early WLST-N and resulted in underuse of guideline-concordant multimodal prognostication. Sedating medications were often coadministered prior to early WLST-N and may have further confounded the neurological examination. Standardizing prognostication, restricting early WLST-N, and a multidisciplinary approach including neurological consultation might improve outcomes after OHCA.
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Reanimación Cardiopulmonar , Servicios Médicos de Urgencia , Hipotermia Inducida , Paro Cardíaco Extrahospitalario , Adulto , Humanos , Femenino , Anciano , Masculino , Paro Cardíaco Extrahospitalario/terapia , Paro Cardíaco Extrahospitalario/complicaciones , Coma/etiología , Pronóstico , Reanimación Cardiopulmonar/efectos adversos , Hipotermia Inducida/métodosRESUMEN
To investigate the pandemic's impact on critically ill patients with neurological emergencies, we compared care metrics and outcomes of patients with severe acute brain injury (SABI) before and during the initial COVID-19 surge at our institution. We included adult patients with SABI during two separate three-month time periods: 'pre-COVID vs COVID'. We further stratified the COVID cohort to characterize outcomes in patients requiring COVID-19 precautions (Patient Under Investigation, 'PUI'). The primary endpoint was in-hospital mortality; secondary endpoints included length of stay (LOS), diagnostic studies performed, time to emergent decompressive craniectomies (DCHC), ventilator management, and end-of-life care. We included 394 patients and found the overall number of admissions for SABI declined by 29 % during COVID (pre-COVID n = 231 vs COVID, n = 163). Our primary outcome of mortality and most secondary outcomes were similar between study periods. There were more frequent extubation attempts (72.1 % vs 76 %) and the mean time to extubation was shorter during COVID (55.5 h vs 38.2 h). The ICU LOS (6.10 days vs 4.69 days) and hospital LOS (15.32 days vs 11.74 days) was shorter during COVID. More PUIs died than non-PUIs (51.7 % vs 11.2 %), but when adjusted for markers of illness severity, this was not significant. We demonstrate the ability to maintain a consistent care delivery for patients with SABI during the pandemic at our institution. PUIs represent a population with higher illness severity at risk for delays in care. Multicenter, longitudinal studies are needed to explore the impact of the pandemic on patients with acute neurological emergencies.
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Lesiones Encefálicas , COVID-19 , Adulto , Humanos , COVID-19/epidemiología , Urgencias Médicas , Pandemias , Enfermedad Crítica , Unidades de Cuidados Intensivos , Estudios RetrospectivosRESUMEN
Purpose of Review: To summarize pathophysiology, key conflicts, and therapeutic approaches in managing concomitant severe acute brain injury (SABI) and acute respiratory distress syndrome (ARDS). Recent Findings: ARDS is common in SABI and independently associated with worse outcomes in all SABI subtypes. Most landmark ARDS trials excluded patients with SABI, and evidence to guide decisions is limited in this population. Potential areas of conflict in the management of patients with both SABI and ARDS are (1) risk of intracranial pressure (ICP) elevation with high levels of positive end-expiratory pressure (PEEP), permissive hypercapnia due to lung protective ventilation (LPV), or prone ventilation; (2) balancing a conservative fluid management strategy with ensuring adequate cerebral perfusion, particularly in patients with symptomatic vasospasm or impaired cerebrovascular blood flow; and (3) uncertainty about the benefit and harm of corticosteroids in this population, with a mortality benefit in ARDS, increased mortality shown in TBI, and conflicting data in other SABI subtypes. Also, the widely adapted partial pressure of oxygen (PaO2) target of > 55 mmHg for ARDS may exacerbate secondary brain injury, and recent guidelines recommend higher goals of 80-120 mmHg in SABI. Distinct pathophysiology and trajectories among different SABI subtypes need to be considered. Summary: The management of SABI with ARDS is highly complex, and conventional ARDS management strategies may result in increased ICP and decreased cerebral perfusion. A crucial aspect of concurrent management is to recognize the risk of secondary brain injury in the individual patient, monitor with vigilance, and adjust management during critical time windows. The care of these patients requires meticulous attention to oxygenation and ventilation, hemodynamics, temperature management, and the neurological exam. LPV and prone ventilation should be utilized, and supplemented with invasive ICP monitoring if there is concern for cerebral edema and increased ICP. PEEP titration should be deliberate, involving measures of hemodynamic, pulmonary, and brain physiology. Serial volume status assessments should be performed in SABI and ARDS, and fluid management should be individualized based on measures of brain perfusion, the neurological exam, and cardiopulmonary status. More research is needed to define risks and benefits in corticosteroids in this population.
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BACKGROUND: Few guidelines have focused on the care delivered after return of spontaneous circulation (ROSC). Post ROSC best practice guidelines lack clarity about important tasks to accomplish in the first hours after ROSC. OBJECTIVES AND METHODS: We conducted a retrospective cohort analysis of adults who had suffered an in hospital cardiac arrest (IHCA) with ROSC over a two-year period to determine the completion rate of critical tasks in the immediate post-ROSC period: ECG within one hour, ABG within one hour, physician documentation within six hours, and surrogate communication within six hours. RESULTS: In the 113 reviewed cases, there was significant variance between completion of all four (19.4%), three (35.3%), two (32.7%), one (20.6%) and none (1.7%) of these critical post ROSC tasks. We observed that 62.8% of IHCA with ROSC had an ECG obtained within one hour of ROSC. The rate of obtaining an ABG within one hour of ROSC was 76.9%. 49.5% of cases had physician documentation of the resuscitation within six hours of ROSC. The rate of documenting surrogate communication within six hours of ROSC was 69.9%. CONCLUSIONS: Our study demonstrated that the completion rates of critical tasks in the post ROSC setting were suboptimal within our patient cohort. This provides a baseline for the development of future best practice guidelines and clinical decision-making aids for post ROSC care after IHCA. This can lead to future research in coupling specific care tasks to post ROSC patient outcomes.
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Reanimación Cardiopulmonar , Paro Cardíaco , Centros Médicos Académicos , Adulto , Paro Cardíaco/terapia , Hospitales , Humanos , Estudios Retrospectivos , Atención Terciaria de SaludRESUMEN
BACKGROUND: Brazil has been disproportionately affected by COVID-19, placing a high burden on ICUs. RESEARCH QUESTION: Are perceptions of ICU resource availability associated with end-of-life decisions and burnout among health care providers (HCPs) during COVID-19 surges in Brazil? STUDY DESIGN AND METHODS: We electronically administered a survey to multidisciplinary ICU HCPs during two 2-week periods (in June 2020 and March 2021) coinciding with COVID-19 surges. We examined responses across geographical regions and performed multivariate regressions to explore factors associated with reports of: (1) families being allowed less input in decisions about maintaining life-sustaining treatments for patients with COVID-19 and (2) emotional distress and burnout. RESULTS: We included 1,985 respondents (57% physicians, 14% nurses, 12% respiratory therapists, 16% other HCPs). More respondents reported shortages during the second surge compared with the first (P < .05 for all comparisons), including lower availability of intensivists (66% vs 42%), ICU nurses (53% vs 36%), ICU beds (68% vs 22%), and ventilators for patients with COVID-19 (80% vs 70%); shortages were highest in the North. One-quarter of HCPs reported that families were allowed less input in decisions about maintaining life-sustaining treatments for patients with COVID-19, which was associated with lack of intensivists (adjusted relative risk [aRR], 1.37; 95% CI, 1.05-1.80) and ICU beds (aRR, 1.71; 95% CI, 1.16-2.62) during the first surge and lack of N95 masks (aRR, 1.43; 95% CI, 1.10-1.85), noninvasive positive pressure ventilation (aRR, 1.56; 95% CI, 1.18-2.07), and oxygen concentrators (aRR, 1.50; 95% CI, 1.13-2.00) during the second surge. Burnout was higher during the second surge (60% vs 71%; P < .001), associated with witnessing colleagues at one's hospital contract COVID-19 during both surges (aRR, 1.55 [95% CI, 1.25-1.93] and 1.31 [95% CI, 1.11-1.55], respectively), as well as worries about finances (aRR, 1.28; 95% CI, 1.02-1.61) and lack of ICU nurses (aRR, 1.25; 95% CI, 1.02-1.53) during the first surge. INTERPRETATION: During the COVID-19 pandemic, ICU HCPs in Brazil experienced substantial resource shortages, health care disparities between regions, changes in end-of-life care associated with resource shortages, and high proportions of burnout.
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Agotamiento Profesional , COVID-19 , Brasil/epidemiología , Agotamiento Profesional/epidemiología , Agotamiento Profesional/terapia , COVID-19/epidemiología , COVID-19/terapia , Cuidados Críticos , Personal de Salud , Humanos , Unidades de Cuidados Intensivos , Pandemias , Encuestas y CuestionariosRESUMEN
The air tolerant precatalyst, [Rh(L)(NBD)]Cl ([1]Cl) [L = κ3-(iPr2PCH2CH2)2NH, NBD = norbornadiene], mediates the selective synthesis of N-methylpolyaminoborane, (H2BNMeH)n, by dehydropolymerization of H3B·NMeH2. Kinetic, speciation, and DFT studies show an induction period in which the active catalyst, Rh(L)H3 (3), forms, which sits as an outer-sphere adduct 3·H3BNMeH2 as the resting state. At the end of catalysis, dormant Rh(L)H2Cl (2) is formed. Reaction of 2 with H3B·NMeH2 returns 3, alongside the proposed formation of boronium [H2B(NMeH2)2]Cl. Aided by isotopic labeling, Eyring analysis, and DFT calculations, a mechanism is proposed in which the cooperative "PNHP" ligand templates dehydrogenation, releasing H2BâNMeH (ΔGcalc = 19.6 kcal mol-1). H2BâNMeH is proposed to undergo rapid, low barrier, head-to-tail chain propagation for which 3 is the catalyst/initiator. A high molecular weight polymer is formed that is relatively insensitive to catalyst loading (Mn â¼71â¯000 g mol-1; D, of â¼ 1.6). The molecular weight can be controlled using [H2B(NMe2H)2]Cl as a chain transfer agent, Mn = 37â¯900-78â¯100 g mol-1. This polymerization is suggested to arise from an ensemble of processes (catalyst speciation, dehydrogenation, propagation, chain transfer) that are geared around the concentration of H3B·NMeH2. TGA and DSC thermal analysis of polymer produced on scale (10 g, 0.01 mol % [1]Cl) show a processing window that allows for melt extrusion of polyaminoborane strands, as well as hot pressing, drop casting, and electrospray deposition. By variation of conditions in the latter, smooth or porous microstructured films or spherical polyaminoboranes beads (â¼100 nm) result.
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BACKGROUND: Patients with coronavirus disease 2019 (COVID-19) often develop acute hypoxemic respiratory failure and receive invasive mechanical ventilation. Much remains unknown about their respiratory mechanics, including the trajectories of pulmonary compliance and [Formula: see text]/[Formula: see text], the prognostic value of these parameters, and the effects of prone positioning. We described respiratory mechanics among subjects with COVID-19 who were intubated during the first month of hospitalization. METHODS: We included patients with COVID-19 who were mechanically ventilated between February and May 2020. Daily values of pulmonary compliance, [Formula: see text], [Formula: see text], and the use of prone positioning were abstracted from electronic medical records. The trends were analyzed separately over days 1-10 and days 1-35 of intubation, stratified by prone positioning use, survival, and initial [Formula: see text]/[Formula: see text]. RESULTS: Among 49 subjects on mechanical ventilation day 1, the mean compliance was 41 mL/cm H2O, decreasing to 25 mL/cm H2O by day 14, the median duration of mechanical ventilation. In contrast, the [Formula: see text]/[Formula: see text] on day 1 was similar to day 14. The overall mean compliance was greater among the non-survivors versus the survivors (27 mL/cm H2O vs 24 mL/cm H2O; P = .005), whereas [Formula: see text]/[Formula: see text] was higher among the survivors versus the non-survivors over days 1-10 (159 mm Hg vs 138 mm Hg; P = .002) and days 1-35 (175 mm Hg vs 153 mm Hg; P < .001). The subjects who underwent early prone positioning had lower compliance during days 1-10 (27 mL/cm H2O vs 33 mL/cm H2O; P < .001) and lower [Formula: see text]/[Formula: see text] values over days 1-10 (139.9 mm Hg vs 167.4 mm Hg; P < .001) versus those who did not undergo prone positioning. After day 21 of hospitalization, the average compliance of the subjects who had early prone positioning surpassed that of the subjects who did not have prone positioning. CONCLUSIONS: Respiratory mechanics of the subjects with COVID-19 who were on mechanical ventilation were characterized by persistently low respiratory system compliance and [Formula: see text]/[Formula: see text], similar to ARDS due to other etiologies. The [Formula: see text]/[Formula: see text] was more tightly associated with mortality than with compliance.
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COVID-19 , Síndrome de Dificultad Respiratoria , Enfermedad Crítica , Humanos , Posición Prona , Respiración Artificial , Mecánica Respiratoria , SARS-CoV-2RESUMEN
BACKGROUND: COVID-19 has a widely variable clinical syndrome that is difficult to distinguish from bacterial sepsis, leading to high rates of antibiotic use. Early studies indicate low rates of secondary bacterial infections (SBIs) but have included heterogeneous patient populations. Here, we catalogue all SBIs and antibiotic prescription practices in a population of mechanically ventilated patients with COVID-19 induced acute respiratory distress syndrome (ARDS). METHODS: This was a retrospective cohort study of all patients with COVID-19 ARDS requiring mechanical ventilation from 3 Seattle, Washington hospitals in 2020. Data were obtained via electronic and manual review of the electronic medical record. We report the incidence and site of SBIs, mortality, and antibiotics per day using descriptive statistics. RESULTS: We identified 126 patients with COVID-19 induced ARDS during the study period. Of these patients, 61% developed clinical infection confirmed by bacterial culture. Ventilator associated pneumonia was confirmed in 55% of patients, bacteremia in 20%, and urinary tract infection (UTI) in 17%. Staphylococcus aureus was the most commonly isolated bacterial species. A total of 97% of patients received antibiotics during their hospitalization, and patients received nearly one antibiotic per day during their hospital stay. CONCLUSIONS: Mechanically ventilated patients with COVID-19 induced ARDS are at high risk for secondary bacterial infections and have extensive antibiotic exposure.