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1.
J Chem Theory Comput ; 18(11): 6940-6951, 2022 Nov 08.
Artigo em Inglês | MEDLINE | ID: mdl-36205431

RESUMO

The statistical trajectory matching (STM) method was applied successfully to derive coarse grain (CG) models for bulk properties of homopolymers. The extension of the methodology for building CG models for statistical copolymer systems is much more challenging. We present here the strategy for developing CG models for styrene-butadiene-rubber, and we compare the quality of the resulting CG force fields on the structure and thermodynamics at different chemical compositions. The CG models are used through the use of a genuine mesoscopic method called the dissipative particle dynamics method and compared to high-resolution molecular dynamics simulations. We conclude that the STM method is able to produce coarse-grained potentials that are transferable in composition by using only a few reference systems. Additionally, this methodology can be applied on any copolymer system.

2.
J Assist Reprod Genet ; 35(9): 1657-1664, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29931407

RESUMO

OBJECTIVE: To compare live birth rates (LBRs) and multiple birth rates (MBRs) between elective single-embryo transfer (eSET) and double-embryo transfer (DET) in donor oocyte in vitro fertilization (IVF) treatments in both a cycle-level and clinic-level analysis. METHODS: Donor oocyte IVF treatments performed by US IVF clinics reporting to the Centers for Disease Control and Prevention in 2013-2014 were included in the analysis. Primary outcomes included LBR and MBR. Secondary outcomes included gestational age at delivery (GA) and birth weight (BW) of offspring. These outcomes were evaluated on an individual cycle level as well as on the clinic level. RESULTS: In multivariable models, LBR did not change significantly as clinics utilized eSET more frequently. MBR decreased significantly as utilization of eSET increased, from 39% MBR in clinics that utilized eSET 0-9% of the time to 7% MBR in clinics that used eSET 70% of the time (P < .0001). Mean BW and GA of IVF-conceived offspring both increased as clinics utilized eSET more frequently (2778 to 3185 g [P < .0001] and 37.5 to 38.5 weeks [P = .02] for clinics with the lowest and highest eSET utilization, respectively). CONCLUSIONS: US IVF clinics utilizing eSET with higher frequencies have clinically comparable LBRs and significantly lower MBRs than clinics with lower-frequency eSET utilization. Mean offspring BW and GA increased with higher eSET utilization, further confirming the improved safety of this practice.


Assuntos
Fertilização in vitro/tendências , Infertilidade/epidemiologia , Doação de Oócitos/tendências , Oócitos/crescimento & desenvolvimento , Adulto , Criopreservação , Transferência Embrionária , Feminino , Humanos , Infertilidade/fisiopatologia , Nascido Vivo , Idade Materna , Gravidez , Resultado da Gravidez , Taxa de Gravidez , Gravidez Múltipla , Transferência de Embrião Único , Estados Unidos
3.
Knee ; 23(6): 1121-1132, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27717626

RESUMO

BACKGROUND: This study evaluates sports ability, rotational laxity and potential growth changes in children after transphyseal ACL reconstruction with metaphyseal fixation technique, considering physis biology by placing drill holes vertically in the femoral anatomic origin in order to reduce volumetric injury to the physis. METHODS: In this retrospective trial of 42 patients data were collected. Thirty-seven were reviewed measuring rotational laxity and anteroposterior tibial translation using the Laxitester (ORTEMA Sport Protection, Markgroeningen, Germany) and the KT1000. Clinical examination was evaluated with the IKDC 2000 knee examination form. Leg axis was determined with digital photography and leg length was assessed clinically. Sports ability was assessed with questionnaires including subjective IKDC, Tegner Activity Scale, Activity Rating Scale and a questionnaire on sports and level of sports. RESULTS: Mean follow-up was 24.9months. Mean age at surgery was 13.2years in boys and 13.1years in girls. IKDC 2000 grading was A or B in 28 patients and C in nine patients. Significant increased anterior tibial translation was observed in neutral position and in external tibia rotation. No growth abnormalities were seen. Fifty-seven percent of the patients were able to participate in competitive sports at follow-up. CONCLUSION: Transphyseal ACL reconstruction with metaphyseal fixation in children with open growth plates can be done with low risk of growth changes. Return to competitive sports is possible although low rotational laxity still exists. LEVEL OF EVIDENCE: IV.


Assuntos
Lesões do Ligamento Cruzado Anterior/cirurgia , Reconstrução do Ligamento Cruzado Anterior , Lâmina de Crescimento , Adolescente , Fatores Etários , Criança , Feminino , Humanos , Articulação do Joelho/fisiopatologia , Masculino , Amplitude de Movimento Articular , Recuperação de Função Fisiológica , Estudos Retrospectivos , Volta ao Esporte , Resultado do Tratamento
4.
Cerebrovasc Dis ; 32(4): 361-9, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21921600

RESUMO

BACKGROUND: The best revascularization strategy for moyamoya disease (MMD) remains unknown. Our aim was to characterize angiographic revascularization effects of a bilateral standardized revascularization approach, consisting of superficial temporal artery (STA)-middle cerebral artery (MCA) bypass and encephalomyosynangiosis (EMS) on one hemisphere and single EMS on the contralateral hemisphere of each patient, and to compare the effects of both revascularization strategies on cerebral hemodynamics. METHODS: In 30 patients (18 females/12 males, age 8-63 years), standardized revascularization was performed. Digital subtraction angiography was performed preoperatively and at 7 days, 6 months and 12 months postoperatively. STA-MCA and EMS functions were graded I (poor), II (medium) or III (extensive) according to angiographic aspects. In 20 patients, cerebrovascular reserve capacity (CVRC) was assessed pre- and postoperatively (at 12 months) using xenon CT. RESULTS: After 12 months, STA-MCA/EMS function was grade 1 in 40/40%, grade 2 in 27/26%, and grade 3 in 27/10% of hemispheres, respectively. Twelve months after surgery, single EMS showed grade I in 37%, grade II in 27%, and grade III in 20% of hemispheres. Combined revascularization improved CVRC significantly compared to preoperative measurement (preoperative: 16.5 ± 34.6% vs. postoperative: 60.8 ± 64.22%; p < 0.05). Single EMS did not improve CVRC significantly (preoperative: 21.8 ± 35.9% vs. postoperative: 34.8 ± 63.0%; p < 0.05). CONCLUSIONS: Combined and indirect revascularization may be successfully applied in a bilateral standardized approach. STA-MCA/EMS is superior to single EMS in restoring CVRC in adult MMD patients.


Assuntos
Revascularização Cerebral/métodos , Doença de Moyamoya/diagnóstico por imagem , Doença de Moyamoya/cirurgia , Adolescente , Adulto , Angiografia Digital , Criança , Europa (Continente) , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Artéria Cerebral Média/cirurgia , Estudos Retrospectivos , Artérias Temporais/cirurgia , Fatores de Tempo , Tomografia Computadorizada por Raios X , Resultado do Tratamento , Adulto Jovem
5.
Water Sci Technol ; 59(8): 1541-50, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19403967

RESUMO

Hotels in arid coastal areas use mainly desalinated water for their domestic water demands, and treated wastewater for irrigating green areas. Private water companies supply these hotels with their domestic water needs. There is normally a contractual agreement stating a minimum requirement that has to be supplied by the water company and that the hotel management has to pay for regardless of its actual consumption ("contracted-for water supply"). This paper describes a model to determine what value a hotel should choose for its contracted-for water supply in order to minimize its total annual water costs. An example from an arid coastal tourism-dominated city is presented: Sharm El Sheikh, Egypt.The managers of hotels with expected high occupancy rates (74% and above) can contract for more than 80%. On the other hand, hotels with expected lower occupancy rates (60% and less) can contract for less than 70% of the peak daily domestic water demand. With a green area ratio of 40 m(2)/room or less, an on-site wastewater treatment plant can satisfy the required irrigation demand for an occupancy rate as low as 42%. Increasing the ratio of green irrigated area to 100 m(2)/room does not affect the contracted-for water supply at occupancy rates above 72%; at lower occupancy rates, however, on-site treated wastewater is insufficient for irrigating the green areas. Increasing the green irrigated area to 120 m(2)/room increases the need for additional water, either from externally sourced treated wastewater or potable water. The cost of the former is much lower than the latter (0.58 versus 1.52 to 2.14 US$/m(3) in the case study area).


Assuntos
Modelos Econômicos , Purificação da Água/economia , Abastecimento de Água/economia , Clima Desértico , Egito , Recreação/economia , Viagem
6.
Science ; 322(5907): 1516-20, 2008 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-19056979

RESUMO

The notion of mimicking natural structures in the synthesis of new structural materials has generated enormous interest but has yielded few practical advances. Natural composites achieve strength and toughness through complex hierarchical designs that are extremely difficult to replicate synthetically. We emulate nature's toughening mechanisms by combining two ordinary compounds, aluminum oxide and polymethyl methacrylate, into ice-templated structures whose toughness can be more than 300 times (in energy terms) that of their constituents. The final product is a bulk hybrid ceramic-based material whose high yield strength and fracture toughness [ approximately 200 megapascals (MPa) and approximately 30 MPa.m(1/2)] represent specific properties comparable to those of aluminum alloys. These model materials can be used to identify the key microstructural features that should guide the synthesis of bio-inspired ceramic-based composites with unique strength and toughness.


Assuntos
Óxido de Alumínio/química , Cerâmica/química , Polimetil Metacrilato/química , Animais , Carbonato de Cálcio/química , Elasticidade , Congelamento , Gastrópodes/química , Teste de Materiais , Fenômenos Mecânicos
7.
Acta Neurochir (Wien) ; 149(9): 911-8; discussion 918, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17700991

RESUMO

OBJECTIVE: To study the effects of clazosentan, a new selective endothelin receptor subtype A antagonist, on cerebral perfusion and cerebral oxygenation following severe aneurysmal subarachnoid haemorrhage (aSAH). METHODS: All 12 patients treated at our institution in the context of a phase IIa, multicenter, randomized trial on clazosentan's safety and efficacy in reducing the incidence of angiographic cerebral vasospasm were included in this substudy. The phase IIa study (n = 34) consisted of two parts: a double-blind, randomized Part A (clazosentan 0.2 mg/kg/h versus placebo) and an open-label Part B (clazosentan 0.4 mg/kg/h for 12 h followed by 0.2 mg/kg/h) for patients with established vasospasm. In parallel to the phase IIa study protocol, which included assessment of vasospasm by angiography and transcranial Doppler sonography, we determined regional cerebral blood flow (rCBF), cerebrovascular resistance, and regional tissue oxygenation. RESULTS: Cerebral perfusion was comparable between treatment groups during the early post-bleeding period (rCBF placebo, 22.6 +/- 3.5 ml/100 g/min versus rCBF clazosentan, 23.9 +/- 1.1 ml/100 g/min). By the time of control angiography (day 8 after aSAH), rCBF decreased by 50% in the placebo group (11.3 +/- 6.7 ml/ 100 g/min) while it remained stable in the clazosentan group (23.5 +/- 12.9 ml/100 g/min). During Part B of the study, all 3 patients who developed haemodynamically relevant vasospasm during placebo treatment, showed a sustained improvement in rCBF upon conversion to clazosentan. CONCLUSIONS: These preliminary data suggest that clazosentan reduces the extent of vasospasm-associated impairment of cerebral perfusion following aSAH. Furthermore, clazosentan may exert beneficial actions on overt vasospasm-associated hypoperfusion.


Assuntos
Encéfalo/metabolismo , Circulação Cerebrovascular/efeitos dos fármacos , Dioxanos/efeitos adversos , Dioxanos/uso terapêutico , Oxigênio/metabolismo , Piridinas/efeitos adversos , Piridinas/uso terapêutico , Pirimidinas/efeitos adversos , Pirimidinas/uso terapêutico , Hemorragia Subaracnóidea/complicações , Sulfonamidas/efeitos adversos , Sulfonamidas/uso terapêutico , Tetrazóis/efeitos adversos , Tetrazóis/uso terapêutico , Vasoespasmo Intracraniano/tratamento farmacológico , Vasoespasmo Intracraniano/fisiopatologia , Adulto , Angiografia Cerebral , Método Duplo-Cego , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos , Antagonistas do Receptor de Endotelina A , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Índice de Gravidade de Doença , Hemorragia Subaracnóidea/fisiopatologia , Ultrassonografia Doppler Transcraniana , Resistência Vascular , Vasoespasmo Intracraniano/diagnóstico , Vasoespasmo Intracraniano/etiologia
8.
Water Sci Technol ; 55(1-2): 469-75, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17305172

RESUMO

Many cities in developing countries are experiencing high population growth, which is generating chaotic and unplanned development, reducing land areas available for agriculture, and polluting surface and groundwater. Consequently, the reuse of untreated or partially treated wastewater for agricultural irrigation is increasing in arid and semi-arid regions in developing countries. Cochabamba city in Bolivia also has a high population growth. The climatic characteristics and the lack of clean water sources in this city are forcing the agriculture sector to use treated and untreated wastewater for irrigation. We investigated the effluent quality of the Alba Rancho Wastewater Treatment Plant (WWTP) in Cochabamba, Bolivia, and the existing effluent reuse practices for irrigation of fodder crops in the surrounding agricultural land (La Mayca area). The plant uses primary and secondary facultative ponds, and does not achieve the required effluent quality (according to Bolivian environmental law) for effluent BOD, COD, TDS and faecal coliforms. This paper also includes a brief comparison of guidelines for wastewater reuse in agriculture from several developing and developed countries, comparing the parameters measured as pollution indicators. It appears that for developed countries, the main concern is the health risk that reuse can cause to the farmers and consumers. For developing countries on the other hand, pollution reduction is currently the major aim in their guidelines and standards.


Assuntos
Agricultura , Conservação dos Recursos Naturais , Eliminação de Resíduos Líquidos/normas , Bolívia , Países em Desenvolvimento , Guias como Assunto , Esgotos/química , Esgotos/microbiologia
9.
Ugeskr Laeger ; 163(44): 6131-3, 2001 Oct 29.
Artigo em Dinamarquês | MEDLINE | ID: mdl-11715157

RESUMO

INTRODUCTION: The aim of this study was to evaluate the accuracy of death certificates over a one-year period, where asthma was given as the cause of death. METHODS: All medical information available was collected on 218 patients by reviewing hospital records, records from general practitioners, and sometimes by interviewing close relatives. A panel of four pulmonologists each examined the information and independently assessed the cause of death. RESULTS: Thirty-nine were excluded, as the cause of death could not be validated. In 16 (9%) of the subjects, asthma was judged to be the definite cause of death and in 12 (7%) a possible cause. Of 151 non-asthma deaths, but registered as asthma, 109 were judged to have suffered or died from COPD and 14 from heart disease. DISCUSSION: The accuracy of Danish death certification in asthma deaths is poor, especially in the elderly, where COPD is often classified as asthma. We conclude that the true mortality from asthma in Denmark is substantially lower than that officially recorded.


Assuntos
Asma/mortalidade , Causas de Morte , Atestado de Óbito , Prontuários Médicos/normas , Adulto , Idoso , Asma/diagnóstico , Dinamarca/epidemiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
10.
Cerebrovasc Dis ; 12(3): 197-202, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11641584

RESUMO

Adequate therapy of vasospasm (VS) in patients suffering from aneurysmal subarachnoid hemorrhage critically depends upon early and reliable diagnosis of cerebral hypoperfusion. The objective of the present study was to evaluate the usefulness of quantitative regional blood flow (rCBF) analysis as an adjunct in noninvasive prediction of VS. Therefore, 33 transcranial Doppler sonography (TCD) studies assuming cerebrovascular VS (TCD flow velocity >120 cm/s) were followed by (s)Xe/CT and cerebral panangiography (PA). TCD plus (s)Xe/CT significantly increased the predictability of VS from 34 to 91%, proving that a combination of TCD and rCBF studies improves the noninvasive detection of VS and might help to prevent unnecessary angiographic examinations.


Assuntos
Circulação Cerebrovascular , Aneurisma Intracraniano/complicações , Hemorragia Subaracnóidea/complicações , Vasoespasmo Intracraniano/diagnóstico , Vasoespasmo Intracraniano/etiologia , Adulto , Idoso , Angiografia Cerebral , Estabilidade de Medicamentos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Tomografia Computadorizada por Raios X , Ultrassonografia Doppler Transcraniana , Xenônio
11.
Crit Care Med ; 29(5): 976-81, 2001 May.
Artigo em Inglês | MEDLINE | ID: mdl-11378607

RESUMO

OBJECTIVES: To evaluate the effect of controlled lumbar cerebrospinal fluid drainage in adult patients with refractory intracranial hypertension. DESIGN: Prospective, pre- vs. postintervention study. SETTING: Surgical intensive care unit of a university hospital. PATIENTS: Twenty-three patients with severe traumatic brain injury or delayed ischemia after subarachnoid hemorrhage with intracranial hypertension refractory to aggressive treatment, including repeated applications of tromethamine, hypertonic saline solution, barbiturate coma, and decompressive craniectomy. Patients were considered for controlled lumbar cerebrospinal fluid drainage if basal cisterns on computerized tomography scan were discernible. INTERVENTIONS: After institution of a lumbar drain, cerebrospinal fluid was gradually aspirated, and then, continuous cerebrospinal fluid drainage was maintained under control of intracranial pressure (ICP) and pupillary status. MEASUREMENTS AND MAIN RESULTS: ICP and cerebral perfusion pressure before and after initiation of lumbar cerebrospinal fluid drainage and related complications were documented. The neurologic outcome of the patients was assessed according to the Glasgow Outcome Scale 6 months after injury. As a result of lumbar cerebrospinal fluid drainage, all patients demonstrated an immediate and lasting decrease of ICP and a concomitant increase of cerebral perfusion pressure. Two patients temporarily showed a unilateral fixed and dilated pupil 6 and 8 hrs after onset of lumbar cerebrospinal fluid drainage, respectively. Ten patients showed a favorable outcome, four patients survived with a severe permanent neurologic deficit, one patient remained in a persistent vegetative state, and eight patients died. CONCLUSIONS: Controlled lumbar cerebrospinal fluid drainage significantly reduces refractory intracranial hypertension. The danger of transtentorial or tonsillar herniation is minimized by considering lumbar drainage in the presence of discernible basilar cisterns only.


Assuntos
Lesões Encefálicas/complicações , Líquido Cefalorraquidiano , Drenagem/métodos , Hipertensão Maligna/terapia , Adolescente , Adulto , Idoso , Feminino , Escala de Coma de Glasgow , Humanos , Hipertensão Maligna/etiologia , Unidades de Terapia Intensiva , Pressão Intracraniana , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Punção Espinal , Tomografia Computadorizada por Raios X , Resultado do Tratamento
12.
Water Res ; 35(1): 151-9, 2001 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-11257869

RESUMO

Enhanced biological phosphorus removal wastewater treatment plants that use anaerobic digesters for sludge treatment, have high phosphorus concentrations in the sidestreams from their sludge dewatering equipment. To remove phosphorus from such sidestreams controlled struvite crystallisation can be used. Struvite (or MAP) is a naturally occurring crystal of magnesium, ammonium and phosphate. We present operational results obtained with a continuously operated pilot-scale MAP reactor. The pilot-scale reactor (143 l) was an air agitated column reactor with a reaction and a settling zone, based on the Phosnix process of Unitika Ltd., Japan. The influent to the MAP reactor was centrate from the centrifuge that dewaters anaerobically digested sludge at the Oxley Creek wastewater treatment plant in Brisbane. We used a 60% magnesium hydroxide slurry to add the required magnesium to the process and to obtain the alkaline pH value required. The pilot-scale MAP process achieved an ortho-P removal ratio of 94% from an average influent ortho-P concentration of 61 mg/l. The reactor was operated at a pH of around 8.5. Insufficient dosing of magnesium reduced the P removal performance. There was no influence of the hydraulic residence time on the process in the range of 1-8 h. The dry MAP product had cadmium, lead and mercury concentrations well below the legal limits for fertilisers in Queensland, Australia and can be reused as a valuable slow-release fertiliser.


Assuntos
Compostos de Magnésio , Fosfatos , Fósforo/isolamento & purificação , Poluentes Químicos da Água/análise , Purificação da Água/métodos , Amônia , Anaerobiose , Austrália , Cádmio/análise , Cristalização , Desenho de Equipamento , Fertilizantes/análise , Concentração de Íons de Hidrogênio , Chumbo/análise , Mercúrio/análise , Projetos Piloto , Estruvita , Purificação da Água/instrumentação
13.
Stroke ; 32(2): 498-505, 2001 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11157189

RESUMO

BACKGROUND AND PURPOSE: It remains controversial whether the intra-arterial administration of papaverine (IAP) is effective in reversing vasospasm-associated cerebral hypoperfusion after aneurysmal subarachnoid hemorrhage. The aim of the present study was to continuously assess regional cerebral blood flow (rCBF) during and after IAP with the use of quantitative, bedside thermal diffusion flowmetry. METHODS: Eight patients with cerebral vasospasm after subarachnoid hemorrhage (mean flow velocity >120 cm/s; angiographic vessel constriction >33%; hemispheric cerebral blood flow [CBF] <32 mL/100 g per minute) were prospectively entered into the study. Before IAP, thermal diffusion microprobes were implanted into the white matter of each affected vascular territory (n=10) for rCBF monitoring. During and after IAP (300 mg papaverine/50 mL saline over 1 hour), mean arterial blood pressure, intracranial pressure, cerebral perfusion pressure, thermal diffusion rCBF (TD-rCBF), and cerebrovascular resistance (CVR) were recorded continuously. RESULTS: IAP significantly increased TD-rCBF from 7.3+/-1.6 to 37.9+/-6.6 mL/100 g per minute (mean+/-SEM), indicating reversal of cerebral hypoperfusion. This TD-rCBF response was dependent on the degree of cerebral vasospasm and reduced perfusion within the vascular territory. Long-term analysis of TD-rCBF, however, demonstrated that this beneficial effect of IAP on cerebral hypoperfusion was only transient: within 3 hours after treatment, TD-rCBF and CVR returned to baseline values. Furthermore, a lack of correlation between transcranial Doppler sonography and thermal diffusion flowmetry suggested that transcranial Doppler sonography is not suited for CBF-based neuromonitoring after IAP. CONCLUSIONS: IAP is not effective in permanently reversing cerebral hypoperfusion in patients with cerebral vasospasm. The need to validate alternative therapeutic strategies that seek to improve cerebral perfusion in vasospasm warrants continued development of CBF-based neuromonitoring strategies.


Assuntos
Circulação Cerebrovascular/efeitos dos fármacos , Papaverina/administração & dosagem , Vasodilatadores/administração & dosagem , Vasoespasmo Intracraniano/tratamento farmacológico , Adulto , Idoso , Velocidade do Fluxo Sanguíneo/efeitos dos fármacos , Pressão Sanguínea/efeitos dos fármacos , Eletrodos Implantados , Feminino , Humanos , Injeções Intra-Arteriais , Masculino , Microcirculação/diagnóstico por imagem , Microcirculação/efeitos dos fármacos , Pessoa de Meia-Idade , Estudos Prospectivos , Reprodutibilidade dos Testes , Reologia , Hemorragia Subaracnóidea/complicações , Hemorragia Subaracnóidea/diagnóstico por imagem , Hemorragia Subaracnóidea/fisiopatologia , Falha de Tratamento , Ultrassonografia Doppler Transcraniana , Resistência Vascular/efeitos dos fármacos , Vasoespasmo Intracraniano/complicações , Vasoespasmo Intracraniano/fisiopatologia
14.
Neurosurgery ; 47(2): 315-22; discussion 322-3, 2000 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-10942004

RESUMO

OBJECTIVE: The beneficial effect of decompressive craniectomy in the treatment of head trauma patients is controversial. The aim of our study was to assess the value of unilateral decompressive craniectomy in patients with severe traumatic brain injury. METHODS: We retrospectively investigated 49 patients who underwent decompressive craniectomy. Intracranial pressure, cerebral perfusion pressure, therapy intensity level, and cranial computed tomographic scan features (midline shift, visibility of ventricles, gyral pattern, and mesencephalic cisterns) were evaluated before and after craniectomy. The gain of intracranial space was calculated from cranial computed tomographic scans. Patient outcome was graded using the Glasgow Outcome Scale. RESULTS: Thirty-one patients (63.3%) underwent rapid surgical decompression within 4.5 +/- 3.8 hours after trauma; in 18 patients (36.7%), delayed surgical decompression was performed 56.2 +/- 57.0 hours after injury. Patients younger than 50 years or patients who underwent rapid surgical decompression had a significantly better outcome than older patients or patients who underwent delayed surgical decompression. Craniectomy significantly decreased midline shift and improved visibility of the mesencephalic cisterns. The state of the mesencephalic cisterns correlated with the distance of the lower border of the craniectomy to the temporal cranial base. Alterations in intracranial pressure, cerebral perfusion pressure, and therapy intensity level were not significant. The overall mortality of the patients corresponded to the reports of the Traumatic Coma Data Bank (1991). CONCLUSION: Although there was a significant decrease in midline shift after craniectomy, this did not translate into decompressive craniectomy demonstrating a beneficial effect on patient outcome.


Assuntos
Lesões Encefálicas/cirurgia , Craniotomia , Descompressão Cirúrgica , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Lesões Encefálicas/diagnóstico por imagem , Lesões Encefálicas/mortalidade , Feminino , Escala de Resultado de Glasgow , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Fatores de Tempo , Tomografia Computadorizada por Raios X
15.
Respir Med ; 94(4): 373-7, 2000 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-10845437

RESUMO

Many studies of asthma mortality rely on official registration. The aim of this study was to evaluate the accuracy of death certificates, where asthma was coded as cause of death. In a 12-month period, medical information on all subjects with asthma officially coded as the underlying cause of death in Denmark, was obtained by reviewing hospital records, contacting general practitioners and sometimes close relatives. A panel of four pulmonologists each examined the obtained information and independently assessed the cause of death. Of a total of 218 death certificates, 39 were excluded as the cause of death could not be validated. In 16 (9%) of the subjects death from asthma was judged to be the definite cause of death and in 12 (7%) death from asthma was possible. Of 151 non-asthma deaths coded as due to asthma, 109 were judged to have suffered or died from COPD and 14 from heart disease. The accuracy of Danish death certification in asthma deaths is poor, especially in the elderly, where COPD is often classified as asthma. We conclude that the true asthma mortality in Denmark is substantially lower than officially recorded.


Assuntos
Asma/mortalidade , Atestado de Óbito , Adulto , Distribuição por Idade , Idoso , Idoso de 80 Anos ou mais , Causas de Morte , Dinamarca/epidemiologia , Feminino , Humanos , Pneumopatias Obstrutivas/classificação , Pneumopatias Obstrutivas/mortalidade , Masculino , Pessoa de Meia-Idade , Sensibilidade e Especificidade
16.
Neurol Res ; 21(8): 758-64, 1999 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-10596385

RESUMO

Critically elevated intracranial pressure (ICP) represents the most important cause of morbidity and mortality in patients suffering from severe traumatic brain injury (TBI) and is a serious complication after subarachnoid hemorrhage (SAH). Thus new strategies for the control of ICP are required. Based on the evidence available hypertonic saline solution (HSS) may be a promising approach. It was therefore the aim of the present study to evaluate in a prospective manner the effects of HSS on ICP and cerebral perfusion pressure (CPP) in patients with therapy-resistant elevation of ICP. A total of 48 bolus infusions of HSS (7.5%, 2 ml kg-1 b.w.; infusion rate 20 ml min-1) were given intravenously (range 1-15 per patient) to 10 patients (age 41 +/- 6 years) with TBI and SAH. Only patients with ICP > 25 mmHg not responding to standard ICP-management protocol and plasma sodium (Na+) concentration < 150 mmol l-1 were included in the study. Within the first hour after HSS application, ICP decreased from 33 +/- 9 mmHg to 19 +/- 6 mmHg (p < 0.05) and further to 18 +/- 5 mmHg at the time of maximum effect (98 +/- 11 min post bolus). Decrease of ICP was accompanied by a rise of CPP from 68 +/- 11 mmHg to 79 +/- 11 mmHg (p < 0.05) after 1 h and further to 81 +/- 11 mmHg at the time of maximum effect. Plasma Na+ concentration was 141 +/- 6 mmol l-1 before and 143 +/- 5 mmol l-1 1 h after HSS bolus. Corresponding values for plasma osmolality were 302 +/- 11 and 308 +/- 12 mOsm l-1. When the ICP lowering effect was transient, subsequent HSS bolus was necessary 163 +/- 54 min after previous dosing. The present results indicate that repeated bolus application of HSS (7.5% NaCl, 2 ml kg-1 b.w.) is an effective measure to decrease ICP which is otherwise refractory to standard therapeutic approaches. Whether or not the therapy scheme is also suited as primary measure for the control of ICP remains to be established.


Assuntos
Barbitúricos/administração & dosagem , Diuréticos Osmóticos/administração & dosagem , Soluções Hipertônicas/administração & dosagem , Hipertensão Intracraniana/tratamento farmacológico , Manitol/administração & dosagem , Adulto , Edema Encefálico/tratamento farmacológico , Edema Encefálico/etiologia , Lesões Encefálicas/complicações , Lesões Encefálicas/tratamento farmacológico , Feminino , Humanos , Hipertensão Intracraniana/etiologia , Masculino , Pessoa de Meia-Idade , Concentração Osmolar , Pulsoterapia , Sódio/sangue , Hemorragia Subaracnóidea/complicações , Hemorragia Subaracnóidea/tratamento farmacológico , Falha de Tratamento
17.
Clin Neurol Neurosurg ; 101(3): 175-81, 1999 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-10536903

RESUMO

Our current neurosurgical understanding of civilian penetrating craniocerebral injuries is based on US metropolitan series. It is unknown whether all principles applied to these patients are relevant in the Mid-European setting with its distinct epidemiology. The objective of this study was to characterize our patients with penetrating craniocerebral injuries, to analyze their outcome, and to identify relevant prognostic factors. Thirty-two patients with penetrating craniocerebral injuries were entered into the study. Patient evaluation comprised neurological, laboratory and radiographic analyses. Motivating factors were suicide (75%), assault (13%), and accident (9%). Initial GCS score, coagulopathy on admission, and radiographic extent of injury could be identified as outcome predictors (P < 0.001). An aggressive therapeutic approach to patients with GCS 3-7 reduced mortality when compared to a conservative management (67 vs. 91%). Due to major differences in epidemiology and outcome of our penetrating craniocerebral injury patients when compared to major US metropolitan series, current therapeutic strategies applied to this patient population in mid-Europe should be reconsidered. The results of our study justify an aggressive neurosurgical approach even in those patients that are thought to have a deleterious prognosis. Predictive variables identified in this study and a novel CT-grading algorithm may help in decision making.


Assuntos
Traumatismos Cranianos Penetrantes/epidemiologia , Adolescente , Adulto , Idoso , Comparação Transcultural , Feminino , Alemanha/epidemiologia , Escala de Coma de Glasgow , Traumatismos Cranianos Penetrantes/diagnóstico por imagem , Traumatismos Cranianos Penetrantes/mortalidade , Traumatismos Cranianos Penetrantes/terapia , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Vigilância da População , Radiografia , Taxa de Sobrevida , Resultado do Tratamento , Estados Unidos/epidemiologia
18.
Acta Neurochir (Wien) ; 140(11): 1113-9; discussion 1119-20, 1998.
Artigo em Inglês | MEDLINE | ID: mdl-9870055

RESUMO

Intracranial pressure monitoring has a key role in the management of patients developing increased intracranial pressure (ICP). We adopted the Camino fiberoptic system for intracranial pressure measurement in 1993 in our neurosurgical department. The aim of this study was to investigate reliability, handling characteristics and complication rate of the Camino intracranial pressure device. In an eighteen month period, we prospectively investigated 118 patients with intracranial pathology undergoing Camino fiberoptic intraparenchymal or intraventricular ICP monitoring. The assessment of reliability of ICP monitoring according to patients clinical condition, to cranial computed tomography (CCT) findings and ICP waveform was carried out. Position of the probe and intracranial bleeding complications related to probe insertion were confirmed by CCT. Technical complications, as well as infections due to the device, were documented. In vivo recalibration was performed in 22 patients. At the end of the measuring period the drift of the probe was evaluated and the accuracy of the fiberoptic device was measured by performing a two point calibration. Recordings of intracranial pressure were carried out with 136 Camino devices (104 parenchymal, 32 ventricular) in 118 patients with an average measuring time of 94.1 +/- 79.1 hrs. One hundred and fifteen Camino intracranial pressure devices (85.2%) demonstrated reliability according to the predetermined clinical parameters. The actual mean drift after removal of the devices was 3.4 mmHg +/- 3.2 with an actual daily drift of 3.2 +/- 17.2 mmHg. Recorded complications included infection (0.7%), intraparenchymal haematoma (5.1%), and a high complication rate (23.5%) with regard to technical aspects. The Camino intracranial pressure system offers reliable ICP measurements in an acceptable percentage of devices, and the advantage of in vivo recalibration. The high incidence of technical complications identifies a need for improvement in the fiberoptic cable and the fixation system.


Assuntos
Tecnologia de Fibra Óptica/instrumentação , Hipertensão Intracraniana/diagnóstico , Pressão Intracraniana/fisiologia , Monitorização Fisiológica/instrumentação , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Cateteres de Demora , Criança , Desenho de Equipamento , Análise de Falha de Equipamento , Feminino , Humanos , Hipertensão Intracraniana/fisiopatologia , Hipertensão Intracraniana/terapia , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Reprodutibilidade dos Testes , Tomografia Computadorizada por Raios X
19.
Respir Med ; 92(1): 40-3, 1998 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-9519223

RESUMO

Fibre-optic bronchoscopy was performed in local anaesthesia using lignocaine. Serum concentrations of lignocaine and its active metabolite monoethylglycinexylidide (MEGX) were measured in 16 patients at regular intervals up to 120 min after administration. Lignocaine was administered as an aerosol in the upper respiratory tract and as a solution in the bronchial tree. The total dose of lignocaine ranged from 243 to 608 mg (2.4-8.0 mg kg-1 body weight). The dose of lignocaine given as an aerosol ranged from 163 to 508 mg (1.6-6.6 mg kg-1) and the dose given as a solution ranged from 60 to 180 mg (0.8-2.5 mg kg-1). The highest median serum lignocaine concentration, 10.5 mumol l-1, was measured 20 min after administration. None of the patients had toxic serum lignocaine levels (> 26 mumol l-1) or adverse effects. The highest median serum MEGX concentration, 1.7 mumol l-1, was measured 120 min after administration. The dose of lignocaine, expressed in mg per kg body weight correlated with serum lignocaine and serum MEGX (rs = 0.47 and rs = 0.39, respectively). Lignocaine is a clinically safe, local anaesthetic agent provided the total dose does not exceed 6-7 mg kg-1 body weight.


Assuntos
Anestesia Local , Anestésicos Locais/sangue , Lidocaína/sangue , Idoso , Idoso de 80 Anos ou mais , Anestésicos Locais/farmacocinética , Área Sob a Curva , Peso Corporal , Broncoscopia , Cromatografia Líquida de Alta Pressão , Esquema de Medicação , Feminino , Tecnologia de Fibra Óptica , Humanos , Lidocaína/análogos & derivados , Lidocaína/farmacocinética , Masculino , Pessoa de Meia-Idade
20.
Respir Med ; 92(1): 44-9, 1998 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-9519224

RESUMO

The study objective was to compare the effect of budesonide administered as a nebulized suspension as compared to a spray with a spacer in adult asthmatics. In a double-blind, double-dummy crossover study, 26 adult patients with moderately severe unstable asthma were randomized to three 4-week treatment periods with budesonide 0.8 mg b.i.d. administered by a pressurized metered-dose inhaler (pMDI) with spacer (Nebuhaler) and budesonide 1 mg and 4 mg b.i.d. administered by a Pari Inhalier Boy jet nebulizer. The nebulizer was activated only during inspiration. The total mass output was similar from the two devices but their fraction of small particles differed by a factor of 2 in favour of pMDI. Effect was evaluated from daily home measurements of peak expiratory flow (PEF), need of beta 2-agonist and symptom scores. Plasma cortisol and budesonide levels were measured in a subgroup of 10 patients. A consistent trend showed the nebulizer treatment to be at least as efficient as the pMDI plus spacer treatment. In actual fact, the apparent order of effect was: 4 mg nebulized suspension treatment > or = 1 mg nebulized suspension treatment > or = 0.8 mg pMDI with spacer treatment. Plasma budesonide and plasma cortisol also exhibited dose-related levels independent of device. The adverse effects reported appeared to be related to the dose rather than delivery device. Accordingly, the effect was related to total mass output, rather than to the small particle fraction of the budesonide aerosol. These results attest to the efficiency of jet-nebulized budesonide suspension, and indicate nebulized budesonide to be equipotent to standard budesonide therapy delivered by pMDI with Nebuhaler, provided nebulization is synchronized with inspiration and no loss of aerosol occurs during expiration.


Assuntos
Anti-Inflamatórios/administração & dosagem , Asma/tratamento farmacológico , Budesonida/administração & dosagem , Adulto , Anti-Inflamatórios/sangue , Asma/sangue , Budesonida/sangue , Estudos Cross-Over , Relação Dose-Resposta a Droga , Método Duplo-Cego , Sistemas de Liberação de Medicamentos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Nebulizadores e Vaporizadores
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