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1.
Artigo em Inglês | MEDLINE | ID: mdl-38629915

RESUMO

OBJECTIVES: Management of hypotension is a fundamental part of pediatric critical care, with cardiovascular support in the form of fluids or vasoactive drugs offered to every hypotensive child. However, optimal blood pressure (BP) targets are unknown. The PRotocolised Evaluation of PermiSSive BP Targets Versus Usual CaRE (PRESSURE) trial aims to evaluate the clinical and cost-effectiveness of a permissive mean arterial pressure (MAP) target of greater than a fifth centile for age compared with usual care. DESIGN: Pragmatic, open, multicenter, parallel-group randomized control trial (RCT) with integrated economic evaluation. SETTING: Eighteen PICUs across the United Kingdom. PATIENTS: Infants and children older than 37 weeks corrected gestational age to 16 years accepted to a participating PICU, on mechanical ventilation and receiving vasoactive drugs for hypotension. INTERVENTIONS: Adjustment of hemodynamic support to achieve a permissive MAP target greater than fifth centile for age during invasive mechanical ventilation. MEASUREMENTS AND MAIN RESULTS: Randomization is 1:1 to a permissive MAP target or usual care, stratified by site and age group. Due to the emergency nature of the treatment, approaching patients for written informed consent will be deferred until after randomization. The primary clinical outcome is a composite of death and days of ventilatory support at 30 days. Baseline demographics and clinical status will be recorded as well as daily measures of BP and organ support, and discharge outcomes. This RCT received Health Research Authority approval (reference 289545), and a favorable ethical opinion from the East of England-Cambridge South Research Ethics Committee on May 10, 2021 (reference number 21/EE/0084). The trial is registered and has an International Standard RCT Number (reference 20609635). CONCLUSIONS: Trial findings will be disseminated in U.K. national and international conferences and in peer-reviewed journals.

3.
Trials ; 24(1): 215, 2023 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-36949524

RESUMO

BACKGROUND: Adaptive clinical trials may use conditional power (CP) to make decisions at interim analyses, requiring assumptions about the treatment effect for remaining patients. It is critical that these assumptions are understood by those using CP in decision-making, as well as timings of these decisions. METHODS: Data for 21 outcomes from 14 published clinical trials were made available for re-analysis. CP curves for accruing outcome information were calculated using and compared with a pre-specified objective criteria for original and transformed versions of the trial data using four future treatment effect assumptions: (i) observed current trend, (ii) hypothesised effect, (iii) 80% optimistic confidence limit, (iv) 90% optimistic confidence limit. RESULTS: The hypothesised effect assumption met objective criteria when the true effect was close to that planned, but not when smaller than planned. The opposite was seen using the current trend assumption. Optimistic confidence limit assumptions appeared to offer a compromise between the two, performing well against objective criteria when the end observed effect was as planned or smaller. CONCLUSION: The current trend assumption could be the preferable assumption when there is a wish to stop early for futility. Interim analyses could be undertaken as early as 30% of patients have data available. Optimistic confidence limit assumptions should be considered when using CP to make trial decisions, although later interim timings should be considered where logistically feasible.


Assuntos
Futilidade Médica , Projetos de Pesquisa , Humanos , Estudos Retrospectivos , Tamanho da Amostra
4.
Resuscitation ; 186: 109750, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-36842674

RESUMO

AIMS: The incidence of in hospital cardiac arrest (IHCA) varies throughout the day. This study aimed to report the variation in incidence of IHCA, presenting rhythm and outcome based on the hour in which IHCA occurred. METHODS: We conducted a retrospective analysis of the National Cardiac Arrest Audit (NCAA) including patients who suffered an IHCA from 1st April 2011 to 31st December 2019. We then linked the NCAA and intensive care Case Mix Programme databases to explore the effect of time of IHCA on hospital survival in the subgroup of patients admitted to intensive care following IHCA. RESULTS: We identified 115,690 eligible patients in the NCAA database. Pulseless electrical activity was the commonest presenting rhythm (54.8%). 66,885 patients died in the immediate post resuscitation period. Overall, hospital survival in the NCAA cohort was 21.3%. We identified 13,858 patients with linked ICU admissions in the Case Mix Programme database; 37.0% survived to hospital discharge. The incidence of IHCA peaked at 06.00. Rates of return of spontaneous circulation, survival to hospital discharge and good neurological outcome were lowest between 05.00 and 07.00. Among those admitted to ICU, no clear diurnal variation in hospital survival was seen in the unadjusted or adjusted analysis. This pattern was consistent across all presenting rhythms. CONCLUSIONS: We observed higher rates of IHCA, and poorer outcomes at night. However, in those admitted to ICU, this variation was absent. This suggests patient factors and processes of care issues contribute to the variation in IHCA seen throughout the day.


Assuntos
Reanimação Cardiopulmonar , Parada Cardíaca , Humanos , Estudos Retrospectivos , Parada Cardíaca/epidemiologia , Parada Cardíaca/terapia , Hospitalização , Hospitais , Mortalidade Hospitalar , Reino Unido/epidemiologia
5.
Br J Oral Maxillofac Surg ; 60(8): 1108-1113, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-35680462

RESUMO

Surgery for head and neck malignancy may be complex with postoperative admission to critical care units (CCUs) often required. There are, however, increasing demands on this resource. We examined a national intensive care database to assess patterns of admission and outcomes for patients following surgery for malignancies of the oral cavity and oropharynx. An analysis was performed of the Intensive Care National Audit and Research Centre (ICNARC) Case Mix Programme database. Data were extracted on case mix and outcomes for patients coded as 'malignant neoplasm of the oropharynx requiring surgery' admitted to critical care between 2010 and 2019. Data included admission numbers, demographics, comorbidities, physiology scores, and outcomes including length of stay and mortality. There were 9,843 admissions for patients with malignancies of the oral cavity and oropharynx from 156 CCUs over the ten-year period. Admissions increased from 486 in 2010 to 1,381 in 2019. These admissions accounted for 0.42% of overall admissions in 2010 and 0.78% in 2019. The median age of patients was 63 years and 63.5% were male. The median length of stay in critical care was 38 hours (Interquartile range (IQR) 20.4-64.3 hours). The median length of total hospital stay was 15 days (IQR 10-23 days). Mortality in critical care was low (0.7%). Admissions to CCUs following surgery for malignancies of the oral cavity and oropharynx have increased over the last decade but remain low overall. With increasing demand for this resource, ongoing monitoring of utilisation is important.


Assuntos
Cuidados Críticos , Neoplasias Orofaríngeas , Grupos Diagnósticos Relacionados , Feminino , Mortalidade Hospitalar , Humanos , Tempo de Internação , Masculino , Pessoa de Meia-Idade , Boca , Neoplasias Orofaríngeas/cirurgia , Reino Unido/epidemiologia
6.
Br J Oral Maxillofac Surg ; 60(8): 1074-1079, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-35760643

RESUMO

Facial infections are common and can occasionally be severe. A small number of patients may develop severe sepsis or airway compromise requiring critical care admission. We examined a national intensive care database to assess patterns of admission and outcomes for patients in this cohort. An analysis was performed of the Intensive Care National Audit and Research Centre (ICNARC) Case Mix Programme database. Data were extracted on case mix and outcomes for patients coded as 'mandible, facial bones, dental, and salivary infection' admitted to critical care between 2010 and 2019. Data included admission numbers, demographics, comorbidities, physiology scores, and outcomes including length of stay and mortality. There were 2820 admissions for patients with facial infections from 212 CCUs over the ten-year period. Admissions increased from 194 in 2010 to 368 in 2019. These admissions accounted for 0.16% of overall admissions in 2010 and 0.21% in 2019, a statistically significant increase in the rate of admissions, p < 0.001. The median age of patients was 48 years and 62.7% were male. Sepsis was present in 77.6% of patients. The median length of stay in critical care was 49 hours (IQR 23.2, 100.3 hours). The median total hospital stay was 7 days (IQR 4, 16 days). The rate of admissions to CCUs for facial infection remains low overall but has significantly increased over the last decade. With increasing demand for this resource ongoing monitoring of utilisation is important.


Assuntos
Unidades de Terapia Intensiva , Sepse , Cuidados Críticos , Grupos Diagnósticos Relacionados , Feminino , Mortalidade Hospitalar , Humanos , Tempo de Internação , Masculino , Pessoa de Meia-Idade , Sepse/epidemiologia , Reino Unido/epidemiologia
7.
Resuscitation ; 173: 4-11, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35151777

RESUMO

AIMS: To compare in-hospital cardiac arrest (IHCA) rates and patient outcomes during the first COVID-19 wave in the United Kingdom (UK) in 2020 with the same period in previous years. METHODS: A retrospective, multicentre cohort study of 154 UK hospitals that participate in the National Cardiac Arrest Audit and have intensive care units participating in the Case Mix Programme national audit of intensive care. Hospital burden of COVID-19 was defined by the number of patients with confirmed SARS-CoV2 infection admitted to critical care per 10,000 hospital admissions. RESULTS: 16,474 patients with IHCA where a resuscitation team attended were included. Patients admitted to hospital during 2020 were younger, more often male, and of non-white ethnicity compared with 2016-2019. A decreasing trend in IHCA rates between 2016 and 2019 was reversed in 2020. Hospitals with higher burden of COVID-19 had the greatest difference in IHCA rates (21.8 per 10,000 admissions in April 2020 vs 14.9 per 10,000 in April 2019). The proportions of patients achieving ROSC ≥ 20 min and surviving to hospital discharge were lower in 2020 compared with 2016-19 (46.2% vs 51.2%; and 21.9% vs 22.9%, respectively). Among patients with IHCA, higher hospital burden of COVID-19 was associated with reduced survival to hospital discharge (OR = 0.95; 95% CI 0.93 to 0.98; p < 0.001). CONCLUSIONS: In comparison with 2016-2019, the first COVID-19 wave in 2020 was associated with a higher rate of IHCA and decreased survival among patients attended by resuscitation teams. These changes were greatest in hospitals with the highest COVID-19 burden.


Assuntos
COVID-19 , Reanimação Cardiopulmonar , Parada Cardíaca , COVID-19/epidemiologia , Estudos de Coortes , Parada Cardíaca/epidemiologia , Parada Cardíaca/terapia , Hospitais , Humanos , Masculino , Pandemias , RNA Viral , Estudos Retrospectivos , SARS-CoV-2 , Reino Unido/epidemiologia
8.
J Intensive Care Soc ; 23(4): 493-497, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36751345

RESUMO

Critical illness-related cardiac arrest (CIRCA) as a distinct entity is not well described epidemiologically. There is currently a knowledge gap regarding how many occur in the UK or the impact on patient outcome. The CIRCA study is a prospective multi-centre observational cohort study of patients in the United Kingdom experiencing a cardiac arrest while in a Critical Care Unit embedded in the Case Mix Programme and National Cardiac Arrest Audit. The duration of data collection is 12 months, with surviving patients and family members receiving questionnaire follow-up at 90 days, 180 days and 12 months. This paper describes the protocol for the CIRCA study which received favourable ethical opinion from South Central - Berkshire Research Ethics Committee and approval from the Health Research Authority. Study registration is on clinicaltrials.gov (NCT04219384).

9.
J Card Surg ; 36(6): 1985-1995, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33710658

RESUMO

BACKGROUND: The success of coronary artery bypass grafting surgery (CABG) is dependent on long-term graft patency, which is negatively related to early wall thickening. Avoiding high-pressure distension testing for leaks and preserving the surrounding pedicle of fat and adventitia during vein harvesting may reduce wall thickening. METHODS: A single-centre, factorial randomized controlled trial was carried out to compare the impact of testing for leaks under high versus low pressure and harvesting the vein with versus without the pedicle in patients undergoing CABG. The primary outcomes were graft wall thickness, as indicator of medial-intimal hyperplasia, and lumen diameter assessed using intravascular ultrasound after 12 months. RESULTS: Ninety-six eligible participants were recruited. With conventional harvest, low-pressure testing tended to yield a thinner vessel wall compared with high-pressure (mean difference [MD; low minus high] -0.059 mm, 95% confidence interval (CI) -0.12, +0.0039, p = .066). With high pressure testing, veins harvested with the pedicle fat tended to have a thinner vessel wall than those harvested conventionally (MD [pedicle minus conventional] -0.057 mm, 95% CI: -0.12, +0.0037, p = .066, test for interaction p = .07). Lumen diameter was similar across groups (harvest comparison p = .81; pressure comparison p = .24). Low-pressure testing was associated with fewer hospital admissions in the 12 months following surgery (p = .0008). Harvesting the vein with the pedicle fat was associated with more complications during the index admission (p = .0041). CONCLUSIONS: Conventional saphenous vein graft preparation with low-pressure distension and harvesting the vein with a surrounding pedicle yielded similar graft wall thickness after 12 months, but low pressure was associated with fewer adverse events.


Assuntos
Ponte de Artéria Coronária , Veia Safena , Humanos , Veia Safena/diagnóstico por imagem , Coleta de Tecidos e Órgãos , Ultrassonografia , Grau de Desobstrução Vascular
10.
J Cardiothorac Surg ; 16(1): 58, 2021 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-33771192

RESUMO

BACKGROUND: Acute Kidney Injury (AKI) adversely affects outcomes after cardiac surgery. A major mediator of AKI is the activation of leukocytes through exposure to the cardiopulmonary bypass circuit. We evaluate the use of leukodepletion filters throughout bypass to protect against post-operative AKI by removing activated leukocytes during cardiac surgery. METHODS: This is a single-centre, double-blind, randomized controlled trial comparing the use of leukodepletion versus a standard arterial filter throughout bypass. Elective adult patients undergoing heart valve surgery with or without concomitant procedures were investigated. The primary clinical outcome measured was the development of AKI according to the KDIGO criteria. Secondary measures included biomarkers of renal tubular damage (urinary Retinol Binding Protein and Kidney Injury Molecule-1), glomerular kidney injury (urinary Micro Albumin and serum Cystatin C) and urinary Neutrophil Gelatinase Associated Lipocalin, as well as the length of hospital stay and quality of life measures through EQ-5D-5L questionnaires. RESULTS: The ROLO trial randomized 64 participants with a rate of recruitment higher than anticipated (57% achieved, 40% anticipated). The incidence of AKI was greater in the leukodepletion filter group (44% versus 23%, risk difference 21, 95% CI - 2 to 44%). This clinical finding was supported by biomarker levels especially by a tendency toward glomerular insult at 48 h, demonstrated by a raised serum Cystatin C (mean difference 0.11, 95% CI 0.00 to 0.23, p = 0.068) in the leukodepleted group. There was however no clear association between the incidence or severity of AKI and length of hospital stay. On average, health related quality of life returned to pre-operative levels in both groups within 3 months of surgery. CONCLUSIONS: Leukocyte depletion during cardiopulmonary bypass does not significantly reduce the incidence of AKI after valvular heart surgery. Other methods to ameliorate renal dysfunction after cardiac surgery need to be investigated. TRIAL REGISTRATION: The trial was registered by the International Standard Randomized Controlled Trial Number Registry ISRCTN42121335 . Registered on the 18 February 2014. The trial was run by the Bristol Clinical Trials and Evaluation Unit. This trial was financially supported by the National Institute of Health Research (Research for Patient Benefit), award ID: PB-PG-0711-25,090.


Assuntos
Injúria Renal Aguda/prevenção & controle , Procedimentos Cirúrgicos Cardíacos/métodos , Doenças das Valvas Cardíacas/cirurgia , Valvas Cardíacas/cirurgia , Procedimentos de Redução de Leucócitos/métodos , Qualidade de Vida , Injúria Renal Aguda/etiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Método Duplo-Cego , Feminino , Humanos , Período Intraoperatório , Testes de Função Renal , Tempo de Internação , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Adulto Jovem
11.
Trials ; 21(1): 1000, 2020 Dec 04.
Artigo em Inglês | MEDLINE | ID: mdl-33276810

RESUMO

INTRODUCTION: Sample size calculations require assumptions regarding treatment response and variability. Incorrect assumptions can result in under- or overpowered trials, posing ethical concerns. Sample size re-estimation (SSR) methods investigate the validity of these assumptions and increase the sample size if necessary. The "promising zone" (Mehta and Pocock, Stat Med 30:3267-3284, 2011) concept is appealing to researchers for its design simplicity. However, it is still relatively new in the application and has been a source of controversy. OBJECTIVES: This research aims to synthesise current approaches and practical implementation of the promising zone design. METHODS: This systematic review comprehensively identifies the reporting of methodological research and of clinical trials using promising zone. Databases were searched according to a pre-specified search strategy, and pearl growing techniques implemented. RESULTS: The combined search methods resulted in 270 unique records identified; 171 were included in the review, of which 30 were trials. The median time to the interim analysis was 60% of the original target sample size (IQR 41-73%). Of the 15 completed trials, 7 increased their sample size. Only 21 studies reported the maximum sample size that would be considered, for which the median increase was 50% (IQR 35-100%). CONCLUSIONS: Promising zone is being implemented in a range of trials worldwide, albeit in low numbers. Identifying trials using promising zone was difficult due to the lack of reporting of SSR methodology. Even when SSR methodology was reported, some had key interim analysis details missing, and only eight papers provided promising zone ranges.


Assuntos
Projetos de Pesquisa , Humanos , Tamanho da Amostra
15.
J Wound Ostomy Continence Nurs ; 42(6): 632-9, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26528874

RESUMO

PURPOSE: We evaluated the performance of prototype underwear designed to detect urine leakage from continence pads, their acceptability to users, and their effect on health-related quality of life and psychosocial factors. DESIGN: Prototype product evaluation. SUBJECTS AND SETTING: Participants were 81 women with an average age of 67 years (range, 32-98 years) recruited between October 2010 and February 2012 from outpatient clinics, general practice surgeries, community continence services, and through charities and networks. METHODS: The TACT3 project developed and manufactured a prototype undergarment designed to alert the wearer to a pad leak before it reaches outer clothing or furniture. The study was conducted in 2 stages: a pilot/feasibility study to assess general performance and a larger study to measure performance, acceptability to users, health-related quality of life, and psychosocial impact. Participants were asked to wear the prototype underwear for a period of 2 weeks, keeping a daily diary of leakage events for the first 7 days. They also completed validated instruments measuring lower urinary tract symptoms, health-related quality of life, and psychosocial impact. RESULTS: On average, 86% of the time participants were alerted to pad leakage events. More than 90% thought the prototype underwear was "good" or "OK" and that it would or could give them more confidence. Mean scores for the International Consultation on Incontinence Questionnaire-Urinary Incontinence Short Form indicated no change in the level of symptoms reported before or after the intervention, and no significant changes in health-related quality of life status occurred, except improvement in for travel restrictions. Evaluation via the Psychosocial Impact of Assistive Devices Scale also indicated a positive impact. CONCLUSION: The prototype underwear evaluated in this study was effective and acceptable for 5 out of every 10 wearers. Findings also suggest that the prototype underwear is suitable for women of all ages, dress sizes, and continence severity.


Assuntos
Vestuário , Tampões Absorventes para a Incontinência Urinária , Urina , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Pessoa de Meia-Idade , Qualidade de Vida
16.
Acta Crystallogr E Crystallogr Commun ; 71(Pt 9): m158-9, 2015 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-26396864

RESUMO

The title compound, [Re6Se8{O3SC6H4(CH3)}{P(C2H5)3}5](CH3C6H4SO3)·2CH2Cl2, contains the face-capped hexa-nuclear [Re6(µ3-Se)8](2+) cluster core. The [Re6Se8](2+) cluster core displays a non-crystallographic center of symmetry and is bonded through the Re(III) atoms to five tri-ethyl-phosphane ligands and one p-toluene-sulfonate ligand. One p-toluene-sulfonate counter-ion and two di-chloro-methane solvent mol-ecules are also present in the asymmetric unit. One of the ethyl chains of one triethylphos-phane ligand and one of the CH2Cl2 solvent molecules are disordered over two sets of sites (occupancy ratios 0.65:0.35 and 0.5:0.5, respectively). The Re-O(sulfon-ate) bond length of 2.123 (5) Šis similar to other Re-O bond lengths of hexa-nuclear rhenium chalcogenide clusters containing other O-donor ligands such as dimethyl sulfoxide (DMSO), di-methyl-formamide (DMF) and hydroxide.

17.
BJU Int ; 114(2): 278-85, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24261817

RESUMO

OBJECTIVE: To test the performance and acceptability of an early warning sensor to predict encrustation and blockage of long-term indwelling urinary catheters. PATIENTS AND METHODS: In all, 17 long-term indwelling catheter users, 15 'blockers' and two 'non-blockers' (controls) were recruited; 11 participants were followed prospectively until catheter change, three withdrew early and three did not start. Two sensors were placed in series between the catheter and the urine bag at catheter change. The sensor nearest the bag was changed at the same time as the bag change (weekly); the sensor nearest the catheter remained in situ for the duration of the catheter's life. Bacteriology and pH determinations were performed on urine samples at each bag, sensor and catheter change. The colour of the sensors was recorded daily. On removal, each sensor and the catheter were examined for visible evidence of encrustation and blockage. Participants were asked to keep a daily diary to record colour change and any other relevant observations and to complete a psychosocial impact of assistive devices tool at the end of the study. Participants and carers/healthcare professionals (when involved in urine bag or catheter change) were asked to complete a questionnaire about the sensor. RESULTS: Urease-producing bacteria were isolated from seven of the 14 patients (including early withdrawals; P. mirabilis in four, Morganella or Providencia in three). In six of the seven patients the sensors turned blue-black; two of these were early withdrawals, two went to planned catheter change (one of these was recruited as a 'non-blocker') and three had catheter blockage. The number of days of catheterisation before blockage was 22, 23 and 25 days, and the sensor changed colour within 24-48 h after insertion. The urine mean (range) pH of the sensors that turned blue-black was 7.6 (5.5-9.0) and of the sensors that remained yellow 6.1 (5.1-7.5). The sensor was generally well-received and was positive in the psychosocial assessment. CONCLUSIONS: The sensor is a useful indicator of urine pH and of the conditions that lead to catheter blockage. It may be particularly useful for new indwelling catheter users. To be a universally acceptable predictor of catheter blockage, the time from sensor colour change to blockage needs to be reduced.


Assuntos
Biofilmes/crescimento & desenvolvimento , Obstrução do Cateter/etiologia , Aceitação pelo Paciente de Cuidados de Saúde , Cateterismo Urinário/instrumentação , Cateteres Urinários/microbiologia , Cateteres de Demora/efeitos adversos , Cateteres de Demora/microbiologia , Cristalização , Feminino , Humanos , Concentração de Íons de Hidrogênio , Masculino , Morganella/fisiologia , Projetos Piloto , Valor Preditivo dos Testes , Estudos Prospectivos , Proteus mirabilis/fisiologia , Providencia/fisiologia , Fatores de Tempo , Urinálise/instrumentação , Cateteres Urinários/efeitos adversos
18.
Dermatol Online J ; 15(3): 12, 2009 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-19379656

RESUMO

Paramedian forehead flaps are sometimes required to resurface large or deep nasal defects. The flap often needs to be thinned to match the contour of the surrounding skin at the recipient site. We describe a technique to thin the distal potion of the paramedian forehead flap using a flexible razor blade, the Dermablade. Once familiar with it, this same technique may be applied to thin other interpolation flaps.


Assuntos
Rinoplastia/instrumentação , Retalhos Cirúrgicos , Testa , Humanos , Rinoplastia/métodos
19.
Inorg Chem ; 47(16): 7271-8, 2008 Aug 18.
Artigo em Inglês | MEDLINE | ID: mdl-18646747

RESUMO

Four hexanuclear molybdenum chloride cluster complexes containing terminal thiolate ligands have been synthesized and fully characterized. (Bu 4N) 2[Mo 6Cl 8(SEt) 6] was prepared by reacting Na 2[Mo 6Cl 8(OMe) 6] with an excess of ethanethiol in refluxing tetrahydrofuran. (PPN) 2[Mo 6Cl 8(SBu) 6], (Bu 4N) 2[Mo 6Cl 8(SBn) 6], and (Bu 4N) 2[Mo 6Cl 8(SNC 8H 6) 6] (C 8H 6NS (-) = 3-indolylthiolate) were subsequently prepared in the reaction of [Mo 6Cl 8(SEt) 6] (2-) with an excess of HSR (R = Bu, Bn or 3-indolyl). Single crystal X-ray diffraction analyses were performed on two of these complexes: (PPN) 2[Mo 6Cl 8(SEt) 6].Et 2O, crystallizes in the triclinic space group P1 with a = 12.3894(11), b = 13.7651(12), c = 15.0974(13), alpha = 103.975(2), beta = 99.690(2), gamma = 98.062(2), and Z = 1; (PPh 3Me) 2[Mo 6Cl 8(SBn) 6].2NO 2CH 3, also crystallizes in the P1 space group with a = 12.1574(16), b = 13.4441(17), c = 14.2132(18), alpha = 89.654(2), beta = 88.365(2), gamma = 71.179(2), and Z = 1. Our studies demonstrate that [Mo 6Cl 8(SEt) 6] (2-) displays luminescent properties and that the same complex undergoes substitution reactions with different thiols, as well as reaction with electrophilic reagents such as MeI.

20.
Am J Cardiol ; 94(4): 459-64, 2004 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-15325929

RESUMO

Aortic regurgitation (AR) is a known complication of discrete subvalvar aortic stenosis (DSS), and its detection often triggers referral for surgery. However, risk factors for aortic valve dysfunction in children with DSS remain incompletely defined. The primary goal of this study was to determine independent risk factors for moderate or severe AR at mid-term follow-up in patients with DSS. Clinical records and echocardiograms of 220 patients with DSS (109 patients had DSS resection and 111 had no surgery) were analyzed. The primary outcome variable was AR grade (based on the width of the vena contracta) at latest follow-up. Age at diagnosis, gender, and duration of follow-up (median 7.2 years, range 1 to 20.4) did not differ significantly between medical and surgical patients. By multivariate analysis, independent risk factors for moderate to severe AR (n = 30) were older age at diagnosis of DSS (odds ratio [OR] for age > or =17 years 5.13, p = 0.024), previous balloon or surgical aortic valvuloplasty (OR 19.6, p <0.001), and a longer follow-up period (OR for 1-year increase 1.15, p = 0.032). Excluding patients with previous surgical or balloon aortic valvuloplasty, a higher maximal Doppler gradient was an independent risk factor for moderate to severe AR (OR for peak gradient > or =50 mm Hg 10.8, p = 0.001). Independent predictors of low-risk patients (none or trivial AR and peak gradient < or =30 mm Hg) included thin and mobile aortic valve leaflets (OR 7.86, p = 0.006) and an associated ventricular septal defect (OR 2.18, p = 0.019). These clinical and echocardiographic variables can be used to stratify risk of aortic valve dysfunction in patients with DSS and aid in timing of surgical resection.


Assuntos
Estenose Aórtica Subvalvar/complicações , Insuficiência da Valva Aórtica/etiologia , Adolescente , Adulto , Estenose Aórtica Subvalvar/cirurgia , Criança , Pré-Escolar , Ecocardiografia , Ecocardiografia Doppler , Eletrocardiografia , Feminino , Seguimentos , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias/etiologia , Fatores de Risco , Obstrução do Fluxo Ventricular Externo/complicações , Obstrução do Fluxo Ventricular Externo/cirurgia
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