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1.
Ultrasound Obstet Gynecol ; 54(6): 740-745, 2019 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-30977215

RESUMEN

OBJECTIVES: To describe a new first-trimester sonographic sign, the 'crash sign', associated with fetal open spina bifida, and to evaluate its clinical usefulness in the first-trimester diagnosis of spina bifida. METHODS: This was a retrospective review of patients referred to three fetal medicine centers in the first trimester (11 + 0 to 13 + 6 weeks) with suspected spina bifida. Spina bifida was confirmed by direct visualization of the spinal defect on ultrasound by two experts and, when possible, by fetal postmortem examination. Ultrasound images were reviewed for the presence of the crash sign, which is the posterior displacement of the mesencephalon and deformation against the occipital bone in the axial view. The first-trimester ultrasound images of a mixed group of 10 cases and 40 control fetuses without spina bifida were assessed for the presence of the crash sign by two assessors blinded to the diagnosis. RESULTS: The crash sign was present in 48 out of 53 confirmed cases of spina bifida. Of these, 27 had isolated spina bifida and 21 had an associated anomaly. Of the five cases without the crash sign, one had isolated spina bifida and four had an associated anomaly. The crash sign was not reported in any of the control fetuses. CONCLUSIONS: We have described a new first-trimester sonographic marker for the diagnosis of spina bifida. Our results suggest that the crash sign may be a useful tool in the first-trimester detection of spina bifida. Prospective evaluation of the crash sign would be beneficial, ideally in a routine clinical screening ultrasound setting. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.


Asunto(s)
Enfermedades Fetales/diagnóstico por imagen , Malformaciones del Sistema Nervioso/diagnóstico por imagen , Espina Bífida Quística/diagnóstico por imagen , Disrafia Espinal/diagnóstico por imagen , Ultrasonografía Prenatal/métodos , Adulto , Autopsia , Diagnóstico Precoz , Femenino , Enfermedades Fetales/patología , Feto/anomalías , Feto/diagnóstico por imagen , Humanos , Malformaciones del Sistema Nervioso/patología , Embarazo , Primer Trimestre del Embarazo , Estudios Retrospectivos , Espina Bífida Quística/patología , Disrafia Espinal/patología
2.
Ultrasound Obstet Gynecol ; 49(1): 78-84, 2017 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-27859800

RESUMEN

OBJECTIVE: Birth weight (BW) is thought to be determined by maternal health and genetic, nutritional and placental factors, the latter being influenced by anatomical development and perfusion. Maternal cardiovascular changes contribute to uteroplacental perfusion; however, they have not yet been investigated in relation to fetal growth or BW. Our aim was to explore the relationship between maternal cardiovascular adaptation, fetal growth and BW in healthy pregnancies. METHODS: This was a longitudinal prospective study of women planning to conceive a pregnancy. Maternal cardiac output (CO), cardiac index (CI), pulse-wave velocity, aortic augmentation index, central blood pressure and peripheral vascular resistance were assessed prior to pregnancy and at 6, 23 and 33 weeks' gestation. Fetal growth was assessed using serial ultrasound measurements of biometry. RESULTS: In total, 143 women volunteered to participate and were eligible for study inclusion. A total of 101 women conceived within 18 months and there were 64 live births with normal pregnancy outcome. There were positive correlations between BW and the pregnancy-induced changes in CO (ρ = 0.4, P = 0.004), CI (ρ = 0.3, P = 0.02) and peripheral vascular resistance (ρ = 0.3, P = 0.02). There were significant associations between second-to-third-trimester fetal weight gain and the prepregnancy-to-second-trimester increase in CO (Δ, 0.8 ± 1.2 L/min; ρ = 0.3, P = 0.02) and CI (Δ, 0.4 ± 0.6 L/min/m2 ; ρ = 0.3, P = 0.04) and reduction in aortic augmentation index (Δ, -10 ± 9%; ρ = -0.3, P = 0.04). CONCLUSIONS: In healthy pregnancy, incremental changes in maternal CO in early pregnancy are associated with third-trimester fetal growth and BW. It is plausible that this association is causative as the changes predate third-trimester fetal growth and eventual BW. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.


Asunto(s)
Peso al Nacer , Gasto Cardíaco/fisiología , Desarrollo Fetal , Adulto , Presión Sanguínea , Femenino , Humanos , Estudios Longitudinales , Embarazo , Segundo Trimestre del Embarazo , Estudios Prospectivos
3.
Anaesthesia ; 72(3): 350-358, 2017 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-27804116

RESUMEN

Although the incidence of major adverse events in surgical daycare centres is low, these critical events may not be managed optimally due to the absence of resources that exist in larger hospitals. We aimed to study the impact of operating theatre critical event checklists on medical management and teamwork during whole-team operating theatre crisis simulations staged in a surgical daycare facility. We studied 56 simulation encounters (without and with a checklist available) divided between an initial session and then a retention session several months later. Medical management and teamwork were quantified via percentage adherence to key processes and the Team Emergency Assessment Measure, respectively. In the initial session, medical management was not improved by the presence of a checklist (56% without checklist vs. 62% with checklist; p = 0.50). In the retention session, teams performed significantly worse without the checklists (36% without checklist vs. 60% with checklist; p = 0.04). We did not observe a change in non-technical skills in the presence of a checklist in either the initial or retention sessions (68% without checklist vs. 69% with checklist (p = 0.94) and 69% without checklist vs. 65% with checklist (p = 0.36), respectively). Critical events checklists do not improve medical management or teamwork during simulated operating theatre crises in an ambulatory surgical daycare setting.


Asunto(s)
Procedimientos Quirúrgicos Ambulatorios/normas , Lista de Verificación , Complicaciones Intraoperatorias/terapia , Quirófanos/organización & administración , Grupo de Atención al Paciente/organización & administración , Competencia Clínica , Urgencias Médicas , Adhesión a Directriz/estadística & datos numéricos , Humanos , Ontario , Guías de Práctica Clínica como Asunto , Distribución Aleatoria , Análisis y Desempeño de Tareas
4.
Anaesthesia ; 70(10): 1119-29, 2015 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-26293587

RESUMEN

A key factor that may contribute to communication failures is status asymmetry between team members. We examined the effect of a consultant anaesthetist's interpersonal behaviour on trainees' ability to effectively challenge clearly incorrect clinical decisions. Thirty-four trainees were recruited to participate in a video-recorded scenario of an airway crisis. They were randomised to a group in which a confederate consultant anaesthetist's interpersonal behaviour was scripted to recreate either a strict/exclusive or an open/inclusive communication dynamic. The scenario allowed trainees four opportunities to challenge clearly wrong decisions. Performances were scored using the modified Advocacy-Inquiry Score. The highest median (IQR [range]) score was 3.0 (2.2-4.0 [1.0-5.0]) in the exclusive communication group, and 3.5 (3.0-4.5 [2.5-6.0]) in the inclusive communication group (p = 0.06). The study did not show a significant effect of consultant behaviour on trainees' ability to challenge their superior. It did demonstrate trainees' inability to challenge their seniors effectively, resulting in critical communication gaps.


Asunto(s)
Manejo de la Vía Aérea/normas , Anestesiología/educación , Educación de Postgrado en Medicina/organización & administración , Relaciones Interprofesionales , Poder Psicológico , Comunicación , Conflicto Psicológico , Consultores/psicología , Toma de Decisiones , Urgencias Médicas , Femenino , Humanos , Masculino , Cuerpo Médico de Hospitales/psicología , Ontario , Simulación de Paciente , Distribución Aleatoria
5.
Elife ; 122023 01 17.
Artículo en Inglés | MEDLINE | ID: mdl-36648063

RESUMEN

Touch system function requires precise interactions between specialized skin cells and somatosensory axons, as exemplified by the vertebrate mechanosensory Merkel cell-neurite complex. Development and patterning of Merkel cells and associated neurites during skin organogenesis remain poorly understood, partly due to the in utero development of mammalian embryos. Here, we discover Merkel cells in the zebrafish epidermis and identify Atonal homolog 1a (Atoh1a) as a marker of zebrafish Merkel cells. We show that zebrafish Merkel cells derive from basal keratinocytes, express neurosecretory and mechanosensory machinery, extend actin-rich microvilli, and complex with somatosensory axons, all hallmarks of mammalian Merkel cells. Merkel cells populate all major adult skin compartments, with region-specific densities and distribution patterns. In vivo photoconversion reveals that Merkel cells undergo steady loss and replenishment during skin homeostasis. Merkel cells develop concomitant with dermal appendages along the trunk and loss of Ectodysplasin signaling, which prevents dermal appendage formation, reduces Merkel cell density by affecting cell differentiation. By contrast, altering dermal appendage morphology changes the distribution, but not density, of Merkel cells. Overall, our studies provide insights into touch system maturation during skin organogenesis and establish zebrafish as an experimentally accessible in vivo model for the study of Merkel cell biology.


Asunto(s)
Células de Merkel , Pez Cebra , Animales , Piel , Epidermis , Queratinocitos , Mamíferos
6.
Ultrasound Obstet Gynecol ; 40(6): 630-5, 2012 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-22858888

RESUMEN

OBJECTIVE: To determine the impact of ovulation and implantation timing on first-trimester crown-rump length (CRL) and the derived gestational age (GA). METHOD: One hundred and forty-three women who were trying to conceive were recruited prospectively. The timing of ovulation and implantation and the ovulation to implantation (O-I) interval were established in 101 pregnancies using home urinary tests for luteinizing hormone and human chorionic gonadotropin. In 71 ongoing pregnancies, GA determined by measurement of fetal CRL at 10-14 weeks' gestation was compared with GA based on ovulation and implantation day. First-trimester growth was determined by serial ultrasound scans at 6-7, 8-9 and 10-14 weeks. RESULTS: The median ovulation and implantation days were 16 and 27, respectively, with an O-I interval of 11 days. GA estimated from CRL at 10-14 weeks was on average 1.3 days greater than that derived from ovulation timing. CRL Z-score was inversely related to O-I interval (ρ= -0.431, P=0.0009). There was no significant relationship between CRL growth rate and the difference between observed CRL and expected CRL based on GA from last menstrual period (ρ=0.224, P=0.08). CONCLUSIONS: Early implantation leads to a larger CRL and late implantation to a smaller CRL at 10-14 weeks, independent of CRL growth rate. Implantation timing is a major determinant of fetal size at 10-14 weeks and largely explains the variation in estimates of GA in the first trimester derived from embryonic or fetal CRL.


Asunto(s)
Largo Cráneo-Cadera , Implantación del Embrión/fisiología , Desarrollo Fetal/fisiología , Ovulación/fisiología , Adulto , Femenino , Edad Gestacional , Humanos , Embarazo , Primer Trimestre del Embarazo , Estudios Prospectivos , Ultrasonografía Prenatal
7.
Anaesthesia ; 72(8): 1042, 2017 08.
Artículo en Inglés | MEDLINE | ID: mdl-28695592
9.
J Obstet Gynaecol ; 30(7): 697-700, 2010.
Artículo en Inglés | MEDLINE | ID: mdl-20925613

RESUMEN

Laparoscopic surgical techniques are increasingly being used to treat gynaecological malignancies as studies confirm long-term results similar to open procedures. Within the UK National Health Service, there is a drive towards day of surgery admission and reducing inpatient stay. We audited the length of inpatient stay, acceptability to patients of day of surgery admission and timing of discharge and accessibility to early community follow-up, among women undergoing laparoscopic assisted vaginal hysterectomy and bilateral salpingo-oophorectomy in our unit over a 6-month period. We show that women find short inpatient stays acceptable and that many can be safely discharged, with no postoperative hospital follow-up, within 24 h. Adequate pre-admission procedures and easy access to advice, post-discharge must be ensured.


Asunto(s)
Procedimientos Quirúrgicos Ambulatorios/normas , Histeroscopía/normas , Laparoscopía/normas , Evaluación de Resultado en la Atención de Salud , Ovariectomía/normas , Adulto , Anciano , Anciano de 80 o más Años , Continuidad de la Atención al Paciente/normas , Bases de Datos Factuales , Femenino , Estudios de Seguimiento , Humanos , Tiempo de Internación , Auditoría Médica , Persona de Mediana Edad , Alta del Paciente , Reino Unido
10.
J Emerg Med ; 36(1): 26-9, 2009 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-17976762

RESUMEN

Insulin glargine (Lantus, Aventis Pharmaceuticals, Bridgewater, NJ) is a long-acting once-daily dosed form of insulin intended to maintain a constant baseline insulin level. As a relatively new medication, there is limited experience in overdoses of Lantus. We present a case of a 37-year-old male insulin-dependent diabetic presenting with refractory hypoglycemia secondary to an intentional overdose of Lantus insulin to illustrate the varied management concerns in overdoses of long-acting insulins. The patient was managed with oral intake, intravenous dextrose bolus, peripheral 10% dextrose solution, 25% dextrose sliding scale via central line, and psychiatry evaluation for suicide attempt. Other potential treatments discussed for possible use with long-acting insulin overdoses include incision and drainage of the injection site, glucagon, and octreotide.


Asunto(s)
Hipoglucemiantes/envenenamiento , Insulina/análogos & derivados , Intento de Suicidio , Adulto , Sobredosis de Droga/tratamiento farmacológico , Glucosa/administración & dosificación , Humanos , Infusiones Intravenosas , Insulina/envenenamiento , Insulina Glargina , Insulina de Acción Prolongada , Masculino , Edulcorantes/administración & dosificación
11.
Ann Emerg Med ; 51(2): 135-7, 2008 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-18036703

RESUMEN

Therapeutic hypothermia is an exciting new treatment modality that has been shown to have significantly improved outcomes in comatose survivors of cardiac arrest. One of the exclusion criteria of the landmark studies on therapeutic hypothermia was a potential toxin-induced cause of the persistent comatose state and presumably of the cardiac arrest itself. We present the first reported case of a comatose survivor of cocaine-induced cardiac arrest successfully treated with therapeutic hypothermia.


Asunto(s)
Trastornos Relacionados con Cocaína/complicaciones , Paro Cardíaco/terapia , Hipotermia Inducida , Resucitación/métodos , Adulto , Coma/terapia , Electrocardiografía , Femenino , Paro Cardíaco/inducido químicamente , Humanos
12.
BMC Microbiol ; 6: 89, 2006 Oct 06.
Artículo en Inglés | MEDLINE | ID: mdl-17026754

RESUMEN

BACKGROUND: In Escherichia coli, pH regulates genes for amino-acid and sugar catabolism, electron transport, oxidative stress, periplasmic and envelope proteins. Many pH-dependent genes are co-regulated by anaerobiosis, but the overall intersection of pH stress and oxygen limitation has not been investigated. RESULTS: The pH dependence of gene expression was analyzed in oxygen-limited cultures of E. coli K-12 strain W3110. E. coli K-12 strain W3110 was cultured in closed tubes containing LBK broth buffered at pH 5.7, pH 7.0, and pH 8.5. Affymetrix array hybridization revealed pH-dependent expression of 1,384 genes and 610 intergenic regions. A core group of 251 genes showed pH responses similar to those in a previous study of cultures grown with aeration. The highly acid-induced gene yagU was shown to be required for extreme-acid resistance (survival at pH 2). Acid also up-regulated fimbriae (fimAC), periplasmic chaperones (hdeAB), cyclopropane fatty acid synthase (cfa), and the "constitutive" Na+/H+ antiporter (nhaB). Base up-regulated core genes for maltodextrin transport (lamB, mal), ATP synthase (atp), and DNA repair (recA, mutL). Other genes showed opposite pH responses with or without aeration, for example ETS components (cyo,nuo, sdh) and hydrogenases (hya, hyb, hyc, hyf, hyp). A hypF strain lacking all hydrogenase activity showed loss of extreme-acid resistance. Under oxygen limitation only, acid down-regulated ribosome synthesis (rpl,rpm, rps). Acid up-regulated the catabolism of sugar derivatives whose fermentation minimized acid production (gnd, gnt, srl), and also a cluster of 13 genes in the gadA region. Acid up-regulated drug transporters (mdtEF, mdtL), but down-regulated penicillin-binding proteins (dacACD, mreBC). Intergenic regions containing regulatory sRNAs were up-regulated by acid (ryeA, csrB, gadY, rybC). CONCLUSION: pH regulates a core set of genes independently of oxygen, including yagU, fimbriae, periplasmic chaperones, and nhaB. Under oxygen limitation, however, pH regulation is reversed for genes encoding electron transport components and hydrogenases. Extreme-acid resistance requires yagU and hydrogenase production. Ribosome synthesis is down-regulated at low pH under oxygen limitation, possibly due to the restricted energy yield of catabolism. Under oxygen limitation, pH regulates metabolism and transport so as to maximize alternative catabolic options while minimizing acidification or alkalinization of the cytoplasm.


Asunto(s)
Proteínas Portadoras/genética , Escherichia coli K12/citología , Escherichia coli K12/efectos de los fármacos , Regulación Bacteriana de la Expresión Génica/efectos de los fármacos , Hidrogenasas/genética , Oxígeno/farmacología , Regulación hacia Abajo/efectos de los fármacos , Farmacorresistencia Bacteriana Múltiple/fisiología , Escherichia coli K12/genética , Escherichia coli K12/metabolismo , Proteínas de Escherichia coli/genética , Genes Bacterianos/genética , Concentración de Iones de Hidrógeno , Oxígeno/metabolismo , Regulación hacia Arriba/efectos de los fármacos
13.
Circulation ; 103(23): 2857-61, 2001 Jun 12.
Artículo en Inglés | MEDLINE | ID: mdl-11401945

RESUMEN

BACKGROUND: We hypothesized that frequency domain analysis of a wide bipolar interatrial electrogram describes the global organization of atrial fibrillation (AF) and should vary over time. By timing shocks to periods of high organization of AF, cardioversion efficacy should improve. METHODS AND RESULTS: A total of 15 dogs (weight, 28.2+/-3.4 kg) were rapidly paced for 48 to 72 hours to induce AF. Coil electrodes with a surface area of 1.80 cm(2) were then placed in the left and right atria to form a wide bipole. Wide bipolar electrograms were digitally filtered, and a fast Fourier transform was performed over a sliding 2-s window every 0.5 s. The organization index (OI) was calculated as the ratio of the area of the dominant peak and its harmonics to the total area of the magnitude spectrum. The atrial defibrillation threshold (ADFT(50)) was determined using a 3-ms/3-ms biphasic shock and an up-down-up protocol. Additional shocks with higher and lower energies were delivered in a random sequence to develop a distribution curve. The OI varied over time, with a mean of 0.42+/-0.03, a maximum of 0.65+/-0.07, and a minimum of 0.20+/-0.06. The OI changed rapidly, with durations of high organization (OI>0.5) ranging from 1 to 5 s. The ADFT(50) for QRS complex-synchronized shocks was 183+/-56 V, versus 142+/-49 V for shocks synchronized to an OI>0.5 (P<0.001). The distribution curve shifted leftward when shocks were synchronized to an OI>0.5. CONCLUSIONS: AF signals show a high degree of variability. Shock efficacy is increased when shocks are delivered during periods of high AF organization as determined by the OI method.


Asunto(s)
Fibrilación Atrial/fisiopatología , Fibrilación Atrial/terapia , Cardioversión Eléctrica/métodos , Algoritmos , Animales , Estimulación Cardíaca Artificial/métodos , Modelos Animales de Enfermedad , Perros , Electrocardiografía , Electrodos Implantados , Técnicas Electrofisiológicas Cardíacas , Análisis de Fourier , Sistema de Conducción Cardíaco/fisiopatología , Umbral Sensorial , Procesamiento de Señales Asistido por Computador , Resultado del Tratamiento
14.
Circulation ; 102(12): 1454-60, 2000 Sep 19.
Artículo en Inglés | MEDLINE | ID: mdl-10993867

RESUMEN

BACKGROUND: In patients with recurrent persistent atrial fibrillation (AF), vulnerability to AF persists indefinitely despite presumed completion of reverse electrical remodeling within days of return to normal sinus rhythm. Atrial electrical and anatomic remodeling and reverse remodeling were studied in a canine model of chronic AF. METHODS AND RESULTS: Chronic AF was induced in 8 dogs by creating moderate mitral regurgitation and rapidly pacing the right atrium at 640 bpm for >8 weeks. Measurements performed at baseline, after establishment of chronic AF, and then at 4 hours and again at 7 to 14 days after cardioversion to sinus rhythm included atrial effective refractory periods, AF cycle lengths, left atrial dimensions, premature atrial contraction (PAC) frequency, and atrial vulnerability to atrial extrastimuli. After establishing chronic AF, atrial effective refractory period shortening, increases in spontaneous PAC frequency, increases in left atrial size with loss of contractility, and multiple ultrastructural abnormalities were demonstrated. Complete reverse electrical remodeling and decreases in PACs were observed after 7 to 14 days of sinus rhythm, but there was no resolution of anatomic and ultrastructural abnormalities. Occurrence of spontaneous AF paralleled PAC frequency, but vulnerability to AF induction persisted (75% immediately after conversion versus 63% at 4 hours and 50% at 7 to 14 days) despite reverse electrical remodeling. CONCLUSIONS: After conversion from chronic AF to sinus rhythm in this canine model, electrical remodeling occurs rapidly. However, gross and ultrastructural anatomic changes persist, as does vulnerability to induced AF. Vulnerability to AF initiation 7 to 14 days after cardioversion is more dependent on persisting structural abnormalities than on electrophysiological abnormalities.


Asunto(s)
Fibrilación Atrial/patología , Fibrilación Atrial/fisiopatología , Modelos Animales de Enfermedad , Insuficiencia de la Válvula Mitral/fisiopatología , Animales , Fibrilación Atrial/terapia , Estimulación Cardíaca Artificial , Enfermedad Crónica , Perros , Ecocardiografía , Electrocardiografía , Femenino , Frecuencia Cardíaca , Microscopía Electrónica , Contracción Miocárdica , Recurrencia , Factores de Tiempo
15.
J Clin Oncol ; 19(6): 1698-706, 2001 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-11250999

RESUMEN

PURPOSE: HER-2 is overexpressed in 20% to 30% of human breast cancer and is associated with poor outcome. Studies suggest an association between HER-2 overexpression and resistance to alkylating agents. To further evaluate this relationship, we assessed the interaction of HER-2, measured by different methods, and outcome after dose intensification with alkylating agents in metastatic breast cancer. PATIENTS AND METHODS: From 1988 to 1995 at Duke University, 425 patients with metastatic breast cancer were enrolled in a study of high-dose alkylating agents (HDC) with autologous cellular support after doxorubicin-based therapy (AFM). HER-2 was measured in serum for shed extracellular domain (ECD) and in tissue by immunohistochemistry (IHC) and fluorescent in situ hybridization (FISH). RESULTS: HER-2 ECD was positive in 29% (19 of 65) of patients pre-AFM and in 11.7% (34 of 290) pre-HDC. Higher pre-AFM and higher pre-HDC HER-2 ECD predicted worse overall survival (P =.045 and P =.0096, respectively). HER-2 overexpression by IHC and FISH showed no correlation with worse disease-free survival or overall survival. FISH and ECD were highly specific for IHC (97.3% and 97.7% respectively). However, ECD had a low sensitivity for IHC-only 22% of patients with HER-2 in the primary tumor shed ECD into the serum. CONCLUSION: These data suggest that the method of measuring HER-2 is important in predicting clinical outcome. HER2 ECD may identify a poor prognosis subgroup of HER-2-positive tumors. Lack of association of HER2 by IHC/FISH with worse outcome suggests that therapy with AFM and/or HDC therapy may be able to overcome the effect of this prognostic factor or it may not be a prognostic factor in this setting.


Asunto(s)
Antineoplásicos Alquilantes/farmacología , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Biomarcadores de Tumor/análisis , Neoplasias de la Mama/genética , Regulación Neoplásica de la Expresión Génica , Genes erbB-2/genética , Receptor ErbB-2/biosíntesis , Adulto , Anciano , Protocolos de Quimioterapia Combinada Antineoplásica/farmacología , Neoplasias de la Mama/tratamiento farmacológico , Neoplasias de la Mama/patología , Supervivencia sin Enfermedad , Resistencia a Antineoplásicos , Femenino , Humanos , Hibridación Fluorescente in Situ , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Pronóstico , Receptor ErbB-2/análisis , Estudios Retrospectivos
16.
IEEE Trans Biomed Eng ; 48(9): 969-78, 2001 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-11534845

RESUMEN

We hypothesized that frequency domain analysis of an interatrial atrial fibrillation (AF) electrogram would show a correlation of the variance of the signal and the amplitude of harmonic peaks with the periodicity and morphology (organization) of the AF signal and defibrillation efficacy. We sought to develop an algorithm that would provide a high-resolution measurement of the changes in the spatiotemporal organization of AF. AF was initiated with burst atrial pacing in ten dogs. The atrial defibrillation threshold (ADFT50) was determined, and defibrillation was repeated at the ADFT50. Bipolar electrograms from the shocking electrodes were acquired immediately preshock, digitally filtered, and a FFT was performed. The organization index (OI) was calculated as the ratio of the area under the first four harmonic peaks to the total area of the spectrum. For a 4-s window, the mean OI was 0.505 +/- 0.087 for successful shocks, versus 0.352 +/- 0.068 for unsuccessful shocks (p < 0.001). Receiver operator characteristic (ROC) curve analysis was used to determine the optimal sampling window for predicting successful shocks. The area of the ROC curve was 0.8 for a 1-s window, and improved to 0.9 for a 4-s window. We conclude that the spectrum of an AF signal contains information relating to its organization, and can be used in predicting a successful defibrillation.


Asunto(s)
Algoritmos , Fibrilación Atrial/fisiopatología , Cardioversión Eléctrica/métodos , Procesamiento de Señales Asistido por Computador , Animales , Fibrilación Atrial/terapia , Estimulación Cardíaca Artificial/métodos , Perros , Análisis de Fourier , Curva ROC
18.
JAMA Intern Med ; 174(4): 509-15, 2014 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-24534899

RESUMEN

IMPORTANCE The mean cost of medical care in the United States is growing at an unsustainable rate; from 2003 through 2011, the cost for an emergency department (ED) visit rose 240%, from $560 to $1354. The diagnostic tests, treatments, and hospitalizations that emergency clinicians order result in significant costs. OBJECTIVE To create a "top-five" list of tests, treatments, and disposition decisions that are of little value, are amenable to standardization, and are actionable by emergency medicine clinicians. DESIGN, SETTING, AND PARTICIPANTS Modified Delphi consensus process and survey of 283 emergency medicine clinicians (physicians, physician assistants, and nurse practitioners) from 6 EDs. INTERVENTION We assembled a technical expert panel (TEP) and conducted a modified Delphi process to identify a top-five list using a 4-step process. In phase 1, we generated a list of low-value clinical decisions from TEP brainstorming and e-mail solicitation of clinicians. In phase 2, the TEP ranked items on contribution to cost, benefit to patients, and actionability by clinicians. In phase 3, we surveyed all ordering clinicians from the 6 EDs regarding distinct aspects of each item. In phase 4, the TEP voted for a final top-five list based on survey results and discussion. MAIN OUTCOMES AND MEASURES A top-five list for emergency medicine. The TEP ranked items on contribution to cost, benefit to patients, and actionability by clinicians. The survey asked clinicians to score items on the potential benefit or harm to patients and the provider actionability of each item. Voting and surveys used 5-point Likert scales. A Pearson interdomain correlation was used. RESULTS Phase 1 identified 64 low-value items. Phase 2 narrowed this list to 7 laboratory tests, 3 medications, 4 imaging studies, and 3 disposition decisions included in the phase 3 survey (71.0% response rate). All 17 items showed a significant positive correlation between benefit and actionability (r, 0.19-0.37 [P ≤ .01]). One item received unanimous TEP support, 4 received majority support, and 12 received at least 1 vote. CONCLUSIONS AND RELEVANCE Our TEP identified clinical actions that are of low value and within the control of ED health care providers. This method can be used to identify additional actionable targets of overuse in emergency medicine.


Asunto(s)
Medicina de Emergencia/economía , Medicina de Emergencia/normas , Servicio de Urgencia en Hospital/economía , Servicio de Urgencia en Hospital/normas , Mejoramiento de la Calidad , Pruebas de Coagulación Sanguínea/estadística & datos numéricos , Consenso , Ahorro de Costo , Toma de Decisiones , Técnica Delphi , Diagnóstico por Imagen/estadística & datos numéricos , Humanos , Proyectos Piloto , Encuestas y Cuestionarios , Estados Unidos
19.
Placenta ; 33(11): 893-901, 2012 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-22902007

RESUMEN

The uterine artery Doppler waveform has been extensively investigated, though its widespread clinical use as a predictor of adverse pregnancy outcome remains under debate. The determinants of the waveform have classically been ascribed to transformation of the spiral arteries and the development of a low resistance uteroplacental circulation, failure of which predisposes to pre-eclampsia, fetal growth restriction and other adverse outcomes. It has become increasingly evident that although spiral artery transformation determines in some part the characteristics of the Doppler waveform, factors pertaining to maternal vascular and endothelial function are also important.


Asunto(s)
Placenta/irrigación sanguínea , Circulación Placentaria , Arteria Uterina/fisiología , Diagnóstico Precoz , Femenino , Humanos , Modelos Biológicos , Placenta/diagnóstico por imagen , Embarazo , Complicaciones del Embarazo/diagnóstico por imagen , Diagnóstico Prenatal/tendencias , Ultrasonografía Doppler , Arteria Uterina/diagnóstico por imagen
20.
Placenta ; 33(7): 572-7, 2012 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-22538229

RESUMEN

OBJECTIVE: To assess the relationship between uterine artery Doppler pulsatility index (PI) and maternal global arterial stiffness and aortic stiffness in women at high a priori risk of preeclampsia in the late second trimester of pregnancy. METHODS: A prospective cohort study was performed. 99 women were recruited from the high-risk obstetric ultrasound clinic in the second trimester; median (±IQR) age and gestation were 33 (29-37) years and 23(+6) (23(+3)-24(+4)) weeks respectively. Transabdominal uterine artery Doppler was performed and mean values recorded. Women returned at a later date, median gestation (±IQR) 26(+5) (25(+6)-28(+0)) weeks, for measurement of blood pressure, augmentation index (AIx) and aortic pulse wave velocity (aPWV). RESULTS: Uterine artery PI is positively associated with both AIx (r = 0.4, P <0.0001, 95% CI: 0.22-0.55) and aPWV (r = 0.22, P = 0.03, 95% CI: 0.02-0.40). No relationship was found between uterine artery PI and mean arterial pressure or pulse pressure. AIx was significantly higher in women with uterine artery PI > 1.45 (P = 0.003, 95% CI: 3.1-14.9) but not aPWV (P = 0.45). AIx, but not aPWV, was significantly higher in women who developed preeclampsia (14% vs 9%, 95% CI: 2.0-8.6, P = 0.0018) or IUGR (11% vs 9%, 95% CI: 0.3-4.2, P = 0.027). AIx showed a negative correlation with birth weight z-score (r = -0.25, 95% CI: -0.43 to -0.06, P = 0.013). CONCLUSION: Increasing uterine artery Doppler PI reflects impaired placentation and increasing risk of preeclampsia. We show a positive association between uterine artery Doppler PI and both global arterial and aortic stiffness. We also show that increased maternal arterial stiffness is associated with a lower birth weight. These findings may represent evidence of an early effect of impaired placentation on the maternal vasculature. Alternatively, given the association between preeclampsia and later cardiovascular disease, ineffective placentation may result from impaired arterial function.


Asunto(s)
Edad Gestacional , Preeclampsia/fisiopatología , Embarazo de Alto Riesgo/fisiología , Arteria Uterina/fisiopatología , Rigidez Vascular/fisiología , Adulto , Peso al Nacer , Presión Sanguínea , Estudios de Cohortes , Femenino , Humanos , Placentación/fisiología , Preeclampsia/diagnóstico , Embarazo , Estudios Prospectivos , Flujo Pulsátil , Factores de Riesgo , Ultrasonografía , Arteria Uterina/diagnóstico por imagen
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