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1.
Children (Basel) ; 11(3)2024 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-38539355

RESUMO

Background: The use of laryngeal masks in the surgical treatment of infantile lacrimal duct stenosis is controversial due to the potential risk of aspiration. Aims: This study investigates airway procedures in children aged <6 years for surgery of lacrimal duct stenosis in a tertiary care university hospital. Methods: After institutional approval, airway procedures, duration of anesthesiological measures, and airway-related complications were retrospectively analyzed. Patients were divided into two groups according to the airway procedures used (endotracheal tube [ET] vs. laryngeal mask [LMA] airway). Associations were calculated using the Chi-square test or Mann-Whitney U-test. Results: Clinical data of 84 patients (ET n = 36 [42.9%] vs. LMA n = 48 [57.1%]) were analyzed. There were no significant differences in surgical treatment, age distribution, and pre-existing conditions between the groups. None of the patients showed evidence of tracheal aspiration or changes in measured oxygen saturation. LMA airway shortened time for anesthesia induction (p = 0.006) and time for recovery/emergence period (p = 0.03). In contrast, the time to discharge from the recovery room was significantly prolonged using LMA (p = 0.001). A total of 7 adverse events were recorded. Five of these were directly or indirectly related to ET (laryngo-/bronchospasm; muscle relaxant residual). Conclusions: LMA airway for infantile lacrimal duct stenosis seems to be a safe procedure and should be used in appropriate pediatric patients due to its lower invasiveness, low complication rate, and time savings.

3.
Cardiol Young ; 34(3): 637-642, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37694525

RESUMO

BACKGROUND: Paediatric early warning score systems are used for early detection of clinical deterioration of patients in paediatric wards. Several paediatric early warning scores have been developed, but most of them are not suitable for children with cyanotic CHD who are adapted to lower arterial oxygen saturation. AIM: The present study compared the original paediatric early warning system of the Royal College of Physicians of Ireland with a modification for children with cyanotic CHD. DESIGN: Retrospective single-centre study in a paediatric cardiology intermediate care unit at a German university hospital. RESULTS: The distribution of recorded values showed a significant shift towards higher score values in patients with cyanotic CHD (p < 0.001) using the original score, but not with the modification. An analysis of sensitivity and specificity for the factor "requirement of action" showed an area under the receiver operating characteristic for non-cyanotic patients of 0.908 (95% CI 0.862-0.954). For patients with cyanotic CHD, using the original score, the area under the receiver operating characteristic was reduced to 0.731 (95% CI 0.637-0.824, p = 0.001) compared to 0.862 (95% CI 0.809-0.915, p = 0.207), when the modified score was used. Using the critical threshold of scores ≥ 4 in patients with cyanotic CHD, sensitivity and specificity for the modified score was higher than for the original (sensitivity 78.8 versus 72.7%, specificity 78.2 versus 58.4%). CONCLUSION: The modified score is a uniform scoring system for identifying clinical deterioration, which can be used in children with and without cyanotic CHD.


Assuntos
Cardiologia , Deterioração Clínica , Escore de Alerta Precoce , Cardiopatias Congênitas , Humanos , Criança , Estudos Retrospectivos , Cardiopatias Congênitas/diagnóstico
4.
Br J Ophthalmol ; 107(10): 1522-1525, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-35817561

RESUMO

BACKGROUND/AIMS: Perioperative pain in children is often inadequately treated, and emergence agitation is common. The purpose of this analysis was to determine whether nalbuphine is suitable for perioperative eye pain and to analyse if it influences the occurrence of emergence delirium/agitation (EDA) in children undergoing ophthalmic surgery in general anaesthesia. METHODS: Retrospective cohort analysis of 50 children in preschool age undergoing general anaesthesia for ophthalmic surgery receiving nalbuphine as a postoperative analgesic in a German university hospital from June 2020 to February 2021.Scores and values for pain and EDA were routinely recorded after awakening and during the stay in the recovery room. Data were evaluated retrospectively from the medical records. RESULTS: A total of 50 children (17 girls and 33 boys) underwent general anaesthesia for ophthalmic surgery. The median age of the children included was 20.5 months (range, 1-68 months), the median body weight was 12.25 kg (range, 2.9-29 kg). All patients received ibuprofen (10 mg/kg1) during induction of anaesthesia and nalbuphine (0.1 mg/kg) at the end of surgery. All patients had an Paediatric-Anaesthesia-Emergence-Delirium-I-score (PAED-ED-I Score) of less than 6 and acceptable Face-Legs-Activity-Cry-Consolability-scores (FLACC less than 3) on waking and on leaving the recovery room. CONCLUSION: Nalbuphine shows a sufficient analgesic effect for pain therapy following ophthalmic surgery in preschool children. Nalbuphine seems to reduce the incidence of EDA in children undergoing ophthalmic surgery.


Assuntos
Delírio do Despertar , Nalbufina , Masculino , Feminino , Criança , Pré-Escolar , Humanos , Lactente , Nalbufina/uso terapêutico , Estudos Retrospectivos , Dor , Analgésicos/uso terapêutico
5.
Cardiol Young ; 33(9): 1517-1522, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35920053

RESUMO

INTRODUCTION: This study investigates the hygiene standards in the context of the COVID-19 pandemic and their impact on the perioperative incidence of human metapneumovirus as well as the typical symptom burden of human metapneumovirus-infected children with CHDs. MATERIALS AND METHODS: Between March 2018 and July 2021, all patients of a cardiac paediatric ICU of a German university hospital were included in this retrospective cohort analysis. RESULTS: A total of 589 patients with CHD were included in the analysis. Three hundred and fifty-two patients (148 females and 204 males) were admitted before the introduction of social distancing and face masks between March 2018 and 15 April 2020 (cohort A). Two hundred and thirty-seven patients (118 females and 119 males) were admitted after the introduction between April 16 and July 2021 (cohort B). In cohort A, human metapneumovirus was detected in 11 out of 352 patients (3.1%) during their stay at cardiac paediatric ICU. In cohort B, one patient out of 237 (0.4%) tested positive for human metapneumovirus. Patients who tested positive for human metapneumovirus stayed in cardiac paediatric ICU for a median of 17.5 days (range, 2-45 days). Patients without a detected human metapneumovirus infection stayed in the cardiac paediatric ICU for a median of 4 days (range, 0.5-114 days). Nine out of 12 (75%) human metapneumovirus-positive patients showed atelectasis. CONCLUSION: Perioperative human metapneumovirus infections prolong cardiac paediatric ICU stay in children with CHD. In affected patients, pulmonary impairment with typical symptoms appears. Under certain circumstances, a complication-rich perioperative infection with human metapneumovirus could be prevented in paediatric cardiac high-risk patients by prophylactic hygiene intervention.


Assuntos
COVID-19 , Metapneumovirus , Infecções por Paramyxoviridae , Masculino , Feminino , Humanos , Criança , COVID-19/epidemiologia , Estudos Retrospectivos , Pandemias , Estudos de Coortes , Infecções por Paramyxoviridae/epidemiologia , Unidades de Terapia Intensiva Pediátrica
6.
Opt Express ; 30(26): 46564-46574, 2022 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-36558608

RESUMO

We demonstrate an optical phased-array equipped with a 3D-printed facet-attached element for shaping and deflection of the emitted beam. The beam shaper combines freeform refractive surfaces with total-internal-reflection mirrors and is in-situ printed to edge-emitting waveguide facets using high-resolution multi-photon lithography, thereby ensuring precise alignment with respect to on-chip waveguide structures. In a proof-of-concept experiment, we achieve a grating-lobe free steering range of ±30∘ and a full-width-half-maximum beam divergence of approximately 2∘. The concept opens an attractive alternative to currently used grating structures and is applicable to a wide range of integration platforms.

7.
Paediatr Anaesth ; 32(8): 907-915, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35434867

RESUMO

BACKGROUND: Many different sedation concepts for magnetic resonance imaging have been described for prematurely and term-born infants, ranging from "no sedation" to general anesthesia. Dexmedetomidine is an alpha-2 receptor agonist that is frequently used to sedate older children, because the anesthesiologist can easily adjust sedation depth, the patient maintains spontaneous breathing, and awakens rapidly afterwards. AIMS: The present study evaluates whether dexmedetomidine could safely be used as the sole sedative for prematurely and term-born infants less than 60 weeks postconceptional age undergoing diagnostic procedures. METHODS: We performed a retrospective monocentric analysis of n = 39 prematurely and term-born infants (<60 weeks postconceptional age or a body weight <5 kg) who were sedated with dexmedetomidine for an MRI at a German university hospital from August 2016 to November 2018. RESULTS: Successful imaging was achieved in all cases. The median initial bolus of dexmedetomidine administered over 10 min was 1.39 µg kg-1 body weight (range 0.34-3.64 µg kg-1 ), followed with a continuous infusion at a median rate of 1.00 µg kg-1  h-1 (range 0.5-3.5 µg kg-1  h-1 ); however, 3 patients (7%) needed some additional sedation (ketamine or propofol). All patients, including 10 infants who had previously required respiratory support, underwent the procedure without any relevant desaturation or apnea. Bradycardia was observed in up to 15 out of 39 cases (38.5%), but only four (10.3% in total and 26.7% of bradycardia) required atropine. CONCLUSIONS: These results indicate that dexmedetomidine can be safely used for procedural sedation in the high-risk cohort of prematurely and term-born infants less than 60 weeks postconceptional age. Apnea during procedural sedation and subsequent stay in the recovery room is avoided, but bradycardia remains a relevant risk that may require treatment.


Assuntos
Dexmedetomidina , Hipnóticos e Sedativos , Adolescente , Apneia , Peso Corporal , Bradicardia/induzido quimicamente , Criança , Humanos , Lactente , Recém-Nascido , Estudos Retrospectivos
8.
Medicina (Kaunas) ; 57(3)2021 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-33803807

RESUMO

Background and Objectives: Pediatric extracorporeal membrane oxygenation (ECMO) support is often the ultimate therapy for neonatal and pediatric patients with congenital heart defects after cardiac surgery. The impact of lactate clearance in pediatric patients during ECMO therapy on outcomes has been analyzed. Materials andMethods: We retrospectively analyzed data from 41 pediatric vaECMO patients between January 2006 and December 2016. Blood lactate and lactate clearance have been recorded prior to ECMO implantation and 3, 6, 9 and 12 h after ECMO start. Receiver operating characteristic (ROC) analysis was used to identify cut-off levels for lactate clearance. Results: Lactate levels prior to ECMO therapy (9.8 mmol/L vs. 13.5 mmol/L; p = 0.07) and peak lactate levels during ECMO support (10.4 mmol/L vs. 14.7 mmol/L; p = 0.07) were similar between survivors and nonsurvivors. Areas under the curve (AUC) of lactate clearance at 3, 9 h and 12 h after ECMO start were significantly predictive for mortality (p = 0.017, p = 0.049 and p = 0.006, respectively). Cut-off values of lactate clearance were 3.8%, 51% and 56%. Duration of ECMO support and respiratory ventilation was significantly longer in survivors than in nonsurvivors (p = 0.01 and p < 0.001, respectively). Conclusions: Dynamic recording of lactate clearance after ECMO start is a valuable tool to assess outcomes and effectiveness of ECMO application. Poor lactate clearance during ECMO therapy in pediatric patients is a significant marker for higher mortality.


Assuntos
Oxigenação por Membrana Extracorpórea , Área Sob a Curva , Criança , Humanos , Recém-Nascido , Ácido Láctico , Curva ROC , Estudos Retrospectivos , Resultado do Tratamento
9.
J Pediatr Intensive Care ; 9(3): 213-215, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32685251

RESUMO

We report two cases of neonates with complex congenital heart disease and volume, catecholamine, and corticosteroid refractory shock treated with arginine-vasopressin. Arginine-vasopressin was able to reverse critical hypotension, but both patients developed severe hyponatremia, which recovered after discontinuation of arginine-vasopressin. Close control and prompt substitution of serum sodium is required in neonates with advanced heart failure on high-dose vasopressin therapy.

10.
Cardiol Young ; 30(2): 213-218, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31948508

RESUMO

BACKGROUND: Congenital heart disease is the most frequent malformation in newborns. The postoperative mortality of these patients can be assessed with the Risk Adjustment in Congenital Heart Surgery-1 (RACHS-1) score. This study evaluates whether the RACHS-1 score can also be used as a predictor for the length of postoperative ventilation and what is the influence of age. MATERIAL AND METHODS: In a retrospective study over the period from 2007 to 2013, all patient records were evaluated: 598 children with congenital heart disease and cardiac surgery were identified and 39 patients have been excluded because of additional comorbidities. For evaluation of mortality, 559 patients could be analysed, after exclusion of 39 deceased patients, 520 cases remained for analysis of postoperative ventilation. RESULTS: Overall mortality was 7% with a dependency on RACHS-1 categories. The median length of postoperative ventilation rose according to the RACHS-1 categories: RACHS-1 category 1: 9 hours (interquartile range (IQR) 7-13 hours), category 2: 30 hours (IQR 12-85 hours), category 4: 58 hours (IQR 13-135 hours), category 4: 71 hours (IQR 29-165 hours), and category 6: 189 hours (IQR 127-277 hours). Some of the RACHS-1 subgroups differed significantly from the categories, especially the repair of tetralogy of Fallot with a longer ventilation time and strong variability. Younger age was an independent factor for longer postoperative ventilation. CONCLUSION: RACHS-1 is a good predictor for the length of postoperative ventilation after cardiac surgery with the exception of some subgroups. Younger age is another independent factor for longer postoperative ventilation. These data provide better insight into ventilation times and allow better planning of operations in terms of available intensive care beds.


Assuntos
Procedimentos Cirúrgicos Cardíacos/mortalidade , Cardiopatias Congênitas/cirurgia , Respiração Artificial/estatística & dados numéricos , Risco Ajustado , Adolescente , Criança , Pré-Escolar , Feminino , Alemanha , Cardiopatias Congênitas/mortalidade , Mortalidade Hospitalar , Humanos , Lactente , Recém-Nascido , Tempo de Internação , Masculino , Período Pós-Operatório , Modelos de Riscos Proporcionais , Estudos Retrospectivos , Fatores de Risco , Índice de Gravidade de Doença , Centros de Atenção Terciária , Fatores de Tempo
11.
J Craniofac Surg ; 31(4): 1117-1119, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31934963

RESUMO

PURPOSE: Possibilities for the reconstruction of orbital floor fractures have been extensive for years with regard to materials, methods and differential indications and are inconsistent worldwide. With the spread of CAD/CAM techniques, new and mostly time-consuming possibilities for orbital floor reconstructions have been added. METHODS: The simple and time-efficient CT-to-patient-specific implant workflow presented here shows that a "form-box" can be created from a patient's computer tomography data set using planning software and a 3D printer. The box is then used to form a patient-specific implant for orbital floor reconstruction: here polydioxanone foil was used, for which stable thermoplastic deformability has been demonstrated for 3D reconstructions. RESULTS: Patient-specific thermoplastic shaping of polydioxanone is feasible in a theoretical clinical setting, though its thermoplastic shaping is not yet certified for clinical use. However, a flexible adaptation of the "form-box" design to other materials is possible by setting a single planning parameter. CONCLUSIONS: The simple structure of the box and its straightforward planning/fabrication process with widely available low-cost materials offer the possibility that a surgeon without a 3D specialist can produce a "form-box" for next day surgery if needed.


Assuntos
Órbita/diagnóstico por imagem , Procedimentos de Cirurgia Plástica , Humanos , Órbita/cirurgia , Fraturas Orbitárias/cirurgia , Polidioxanona/química , Impressão Tridimensional , Procedimentos de Cirurgia Plástica/métodos , Tomografia Computadorizada por Raios X
12.
Endosc Int Open ; 5(3): E165-E171, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28299351

RESUMO

Background and study aims The optimal approach to small subepithelial tumors (SETs) of the upper gastrointestinal tract remains inconclusive. The aim of this study was to evaluate endoscopic ultrasound-guided fine needle biopsy (EUS-FNB) for less invasive tissue sampling of small SETs of the upper gastrointestinal tract. Patients and methods In this prospective observational study patients with small ( ≤ 3 cm) SETs of the upper gastrointestinal tract were eligible and underwent EUS-FNB with a 22-gauge core biopsy needle. The main outcome measure was the diagnostic yield. The number of obtained core biopsies was also assessed. Results Twenty patients were included. The mean SET size was 16 mm (range 10 - 27 mm). EUS-FNB was technically feasible in all cases and no complications were observed. The diagnostic yield was 75 %. Core biopsy specimens were obtained in only 25 % of cases. Conclusion EUS-FNB with a 22-gauge core biopsy needle of small SETs can achieve a definite diagnosis in the majority of cases. However, because core samples cannot regularly be obtained, EUS-FNB seems not to be convincingly superior to standard EUS-FNA in this setting.

13.
ACS Appl Mater Interfaces ; 8(39): 26392-26399, 2016 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-27668665

RESUMO

The high potential of bottom-up fabrication strategies for realizing sophisticated optical sensors combining the high sensitivity of a surface plasmon resonance with the exceptional properties of stimuli-responsive hydrogel is demonstrated. The sensor is composed of a periodic hole array in a gold film whose holes are filled with gold-capped poly(N-isoproyl-acrylamide) (polyNIPAM) microspheres. The production of this sensor relies on a pure chemical approach enabling simple, time-efficient, and cost-efficient preparation of sensor platforms covering areas of cm2. The transmission spectrum of this plasmonic sensor shows a strong interaction between propagating surface plasmon polaritons at the metal film surface and localized surface plasmon resonance of the gold cap on top of the polyNIPAM microspheres. Computer simulations support this experimental observation. These interactions lead to distinct changes in the transmission spectrum, which allow for the simultaneous, sensitive optical detection of refractive index changes in the surrounding medium and the swelling state of the embedded polyNIPAM microsphere under the gold cap. The volume of the polyNIPAM microsphere located underneath the gold cap can be changed by certain stimuli such as temperature, pH, ionic strength, and distinct molecules bound to the hydrogel matrix facilitating the detection of analytes which do not change the refractive index of the surrounding medium significantly.

14.
Pediatr Crit Care Med ; 17(1): 36-44, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26509814

RESUMO

OBJECTIVES: Despite the increasing use of near-infrared spectroscopy across pediatric cardiac ICUs, there is significant variability and equipoise with no universally accepted management algorithms. We aimed to explore the use of near-infrared spectroscopy in pediatric cardiac ICUs in the United Kingdom, Ireland, Italy, and Germany. DESIGN: A cross-sectional multicenter, multinational electronic survey of one consultant in each pediatric cardiac ICU. SETTING: Pediatric cardiac ICUs in the United Kingdom and Ireland (n = 13), Italy (n = 12), and Germany (n = 33). INTERVENTIONS: Questionnaire targeted to establish use, targets, protocols/thresholds for intervention, and perceived usefulness of near-infrared spectroscopy monitoring. RESULTS: Overall, 42 of 58 pediatric cardiac ICUs (72%) responded: United Kingdom and Ireland, 11 of 13 (84.6%); Italy, 12 of 12 (100%); and Germany, 19 of 33 (57%, included all major centers). Near-infrared spectroscopy usage varied with 35% (15/42) reporting that near-infrared spectroscopy was not used at all (7/42) or occasionally (8/42); near-infrared spectroscopy use was much less common in the United Kingdom (46%) when compared with 78% in Germany and all (100%) in Italy. Only four units had a near-infrared spectroscopy protocol, and 18 specifically used near-infrared spectroscopy in high-risk patients; 37 respondents believed that near-infrared spectroscopy added value to standard monitoring and 23 believed that it gave an earlier indication of deterioration, but only 19 would respond based on near-infrared spectroscopy data alone. Targets for absolute values and critical thresholds for intervention varied widely between units. The reasons cited for not or occasionally using near-infrared spectroscopy were expense (n = 6), limited evidence and uncertainty on how it guides management (n = 4), difficulty in interpretation, and unreliability of data (n = 3). Amongst the regular or occasional near-infrared spectroscopy users (n = 35), 28 (66%) agreed that a multicenter study is warranted to ascertain its use. CONCLUSIONS: Although most responding units used near-infrared spectroscopy for high-risk patients, the majority (31/35 [88%]) did not have any protocols or guidelines for intervention. Target thresholds and intervention algorithms are needed to support the use of near-infrared spectroscopy in pediatric cardiac ICUs; an international multicenter study is warranted.


Assuntos
Procedimentos Cirúrgicos Cardíacos/métodos , Unidades de Terapia Intensiva Pediátrica/organização & administração , Oxigênio/sangue , Assistência Perioperatória/métodos , Espectroscopia de Luz Próxima ao Infravermelho/estatística & dados numéricos , Algoritmos , Encéfalo/irrigação sanguínea , Protocolos Clínicos , Estudos Transversais , Europa (Continente) , Humanos , Oximetria , Medição de Risco
16.
Expert Rev Cardiovasc Ther ; 13(2): 183-92, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25600345

RESUMO

Important advances in the diagnosis and therapy of various arrhythmic disorders have been made in the last two decades. These, in turn, have necessitated a re-examination of current practice guidelines, with a view to deciding on optimal management of young patients with suspected or proven arrhythmia syndromes and in assessing the risk of adverse arrhythmic events during sport participation. There has also been a concomitant emphasis on identifying individuals at risk by nationwide screening programs using the ECG and excluding them from competitive sport. This review identifies some of these issues, looks at the data critically and offers some suggestions for current care and future research.


Assuntos
Arritmias Cardíacas/diagnóstico , Arritmias Cardíacas/terapia , Cardiomiopatias/diagnóstico , Cardiomiopatias/terapia , Eletrocardiografia , Adolescente , Arritmias Cardíacas/fisiopatologia , Criança , Diagnóstico Diferencial , Humanos , Medição de Risco , Síndrome , Adulto Jovem
17.
Nano Lett ; 15(2): 1025-30, 2015 Feb 11.
Artigo em Inglês | MEDLINE | ID: mdl-25584636

RESUMO

Plasmonic nanorings provide the unique advantage of a pronounced plasmonic field enhancement inside their core. If filled with a polarizable medium, it may significantly enhance its optical effects. Here, we demonstrate this proposition by filling gold nanorings with lithium niobate. The generated second harmonic signal is compared to the signal originating from an unpatterned lithium niobate surface. Measurements and simulation confirm an enhancement of about 20. Applications requiring nanoscopic localized light sources like fluorescence spectroscopy or quantum communication will benefit from our findings.

18.
Gastrointest Endosc ; 81(4): 889-95, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25432532

RESUMO

BACKGROUND: In mid-GI bleeding, video capsule endoscopy (VCE) shows the best diagnostic yield for ongoing overt bleeding. To date, the utility of VCE in acute severe GI bleeding has been analyzed rarely. OBJECTIVE: To evaluate the impact of VCE when performed on patients with acute severe GI bleeding immediately after an initial negative upper endoscopy result. DESIGN: Prospective study. SETTING: Tertiary-care center. PATIENTS: Patients with melena, dark-red or maroon stool, hemodynamic instability, drop of hemoglobin level ≥2 g/dL/day, and/or need of transfusion ≥2 units of packed red blood cells per day were included. INTERVENTIONS: After a negative upper endoscopy result, emergency VCE was performed by immediate endoscopic placement of the video capsule into the duodenum. MAIN OUTCOME MEASUREMENTS: Rate of patients in whom emergency VCE correctly guided further diagnostic and therapeutic procedures. RESULTS: Upper endoscopy showed the source of bleeding in 68 of 88 patients (77%). In the remaining 20 patients (23%), emergency VCE was performed, which was feasible in 19 of 20 patients (95%; 95% confidence interval [CI], 75%-99%). Emergency VCE correctly guided further diagnostic and therapeutic procedures in 17 of 20 patients (85%; 95% CI, 62%-97%) and showed a diagnostic yield of 75% (95% CI, 51%-91%). LIMITATIONS: Single-center study, small sample size. CONCLUSION: In patients with acute severe GI bleeding and negative upper endoscopy results, emergency VCE can be useful for the immediate detection of the bleeding site and is able to guide further therapy. (Clinical trial registration number: NCT01584869.)


Assuntos
Endoscopia por Cápsula , Hemorragia Gastrointestinal/etiologia , Doença Aguda , Idoso , Idoso de 80 Anos ou mais , Algoritmos , Pressão Arterial , Transfusão de Sangue , Emergências , Endoscopia Gastrointestinal , Feminino , Hemorragia Gastrointestinal/fisiopatologia , Hemorragia Gastrointestinal/terapia , Hemoglobinas/metabolismo , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Índice de Gravidade de Doença , Fatores de Tempo
19.
Opt Express ; 22(8): 9971-82, 2014 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-24787879

RESUMO

Within the past several years a tremendous progress regarding optical nano-antennas could be witnessed. It is one purpose of optical nano-antennas to resonantly enhance light-matter interactions at the nanoscale, e.g. the interaction of an external illumination with molecules. In this specific, but in almost all schemes that take advantage of resonantly enhanced electromagnetic fields in the vicinity of nano-antennas, the precise knowledge of the spectral position of resonances is of paramount importance to fully exploit their beneficial effects. Thus far, however, many nano-antennas were only optimized with respect to their far-field characteristics, i.e. in terms of their scattering or extinction cross sections. Although being an emerging feature in many numerical simulations, it was only recently fully appreciated that there exists a subtle but very important difference in the spectral position of resonances in the near-and the far-field. With the purpose to quantify this shift, Zuloaga et al. suggested a Lorentzian model to estimate the resonance shift. Here, we devise on fully analytical grounds a strategy to predict the resonance in the near-field directly from that in the far-field and disclose that the issue is involved and multifaceted, in general. We outline the limitations of our theory if more sophisticated optical nano-antennas are considered where higher order multipolar contributions and higher order antenna resonances become increasingly important. Both aspects are highlighted by numerically studying relevant nano-antennas.

20.
Nano Lett ; 13(8): 3482-6, 2013 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-23805879

RESUMO

A metal-insulator-metal (MIM) waveguide is a canonical structure used in many functional plasmonic devices. Recently, research on nanoresonantors made from finite, that is, truncated, MIM waveguides attracted a considerable deal of interest motivated by the promise for many applications. However, most suggested nanoresonators do not reach a deep-subwavelength domain. With ordinary fabrication techniques the dielectric spacers usually remain fairly thick, that is, in the order of tens of nanometers. This prevents the wavevector of the guided surface plasmon polariton to strongly deviate from the light line. Here, we will show that the exploitation of an extreme coupling regime, which appears for only a few nanometers thick dielectric spacer, can lift this limitation. By taking advantage of atomic layer deposition we fabricated and characterized exemplarily deep-subwavelength perfect absorbers. Our results are fully supported by numerical simulations and analytical considerations. Our work provides impetus on many fields of nanoscience and will foster various applications in high-impact areas such as metamaterials, light harvesting, and sensing or the fabrication of quantum-plasmonic devices.

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