Functional Evolution after Percutaneous Endoscopic Lumbar Discectomy, an Earlier Evaluation of 32 Cases / Evolução funcional após discectomia endoscópica lombar, uma avaliação mais precoce de 32 casos

Abstract Objective To determine time period for hospital discharge and pain and function improvement in patients submitted to percutaneous endoscopic lumbar discectomy (PELD). Methods Retrospective evaluation of length of stay and visual analog scale (VAS), Oswestry disability index (ODI), and Roland-Morris questionnaire results in 32 patients undergoing PELD at the preoperative period and at 2 days and 1, 2, 4, 6 and 12 postoperative weeks. Results All patients were discharged in less than 6 hours. There was a statistically significant improvement between the results obtained before the procedure and 2 days postsurgery: the mean VAS for axial pain went from 6.63 to 3.31, the VAS for irradiated pain went from 6.66 to 2.75, the Oswestry score went from 44.59 to 33.17%, and the Roland-Morris score went from 14.03 to 10.34. This difference progressively improved up to 12 weeks in all questionnaires. Regarding the Oswestry score, minimum disability values (19.39%) were observed at 6 weeks. Conclusion All 32 patients were discharged within 6 hours. Pain and function improved significantly after 48 hours, with further significant and progressive improvement until the 3rd month.

Resumo Objetivo Determinar o tempo de alta hospitalar e o período de melhora funcional e da dor dos pacientes submetidos a discectomia endoscópica percutânea lombar (DEPL). Métodos Avaliação retrospectiva do tempo de internação e dos questionários escala visual análoga (EVA), índice de incapacidade Oswestry (IIO), e Roland-Morris de 32 pacientes submetidos a DEPL nos períodos pré-operatório e com 2 dias, e 1, 2, 4, 6, e 12 semanas pós-operatórias. Resultados Todos os pacientes receberam alta em menos de 6 horas houve melhora estatística entre o período pré-operatório e 2 dias pós-operatório , sendo o valor médio do questionário EVA axial de 6,63 para 3,31, do EVA irradiado de 6,66 para 2,75, do IIO de 44,59% para 33,17% e do Roland-Morris de 14,03 para 10,34. Tal diferença apresentou melhora progressiva até 12 semanas em todos os questionários. O IIO atingiu valores de incapacidade mínima (19,39%) com 6 semanas de avaliação. Conclusão Todos os 32 pacientes receberam alta hospitalar em até 6 horas. Houve melhora significativa dos sintomas funcionais e de dor já com 48 horas, apresentando ainda melhora adicional significativa e progressiva até o 3º mês.

Protective mechanical ventilation in suspected influenza infection

Abstract INTRODUCTION: Patients with acute respiratory failure due to influenza require ventilatory support. However, mechanical ventilation itself can exacerbate lung damage and increase mortality. METHODS: The aim of this study was to describe a feasible and protective ventilation protocol, with limitation of the tidal volume to ≤6 mL/kg of the predicted weight and a driving pressure ≤15 cmH2O after application of the alveolar recruitment maneuver and PEEP titration. RESULTS: Initial improvement in oxygenation and respiratory mechanics were observed in the four cases submitted to the proposed protocol. CONCLUSIONS: Our results indicate that the mechanical ventilation strategy applied could be optimized.

Radiation Exposure during Percutaneous Endoscopic Lumbar Discectomy: Interlaminar versus Transforaminal

Objective Percutaneous endoscopic lumbar discectomy (PELD) relies heavily on fluoroscopy guidance; therefore, medical staff exposure to radiation has become an important issue. The purpose of this study was to determine the radiation dose and the amount of time to which the surgeons are exposed during PELD and to compare both parameters in the transforaminal (TF) and interlaminar (IL) approaches. Although they are considerably different, they may be wrongly considered together. Methods A retrospective evaluation of the last 20 PELD performed by the authors is presented. Patients were distributed in 2 groups. Six (1F, 5M) patients were submitted to IL-PELD and 14 (6F, 8M) to TF-PELD. Fluoroscopy reports were obtained from patients' records, all performed with the same C-Arm device and software mode. Groups were compared using unpaired t-test. Results The IL group showed an average radiation exposure of 8.37 4.21 mGy and duration of 11.1 5.45 seconds, while the TF group showed an average radiation exposure of 28.92 7.56 mGy and duration of 42 16.64 seconds. The p-value for radiation was 0.0000036, and for time it was 0.00027. Conclusions Interlaminar PELD requires a lower radiation dose and a shorter amount of exposure than TF-PELD. Studies that concern radiation required for minimallyinvasive spine surgeries should consider the PELD approaches separately.

Evaluation of safety, effectiveness and reproducibility of telemedicine for neurosurgical screening / Avaliação da segurança, da efetividade e da reprodutibilidade na utilização de telemedicina para triagem neurocirúrgica

ABSTRACT Objective: To ascertain the safety, effectiveness and reproducibility of screening potential neurosurgical patients by means of smartphones. Methods: This is a retrospective and multicentric study. Data were collected from the medical records of patients subjected to real emergency neurosurgical evaluations and compared with assessments by neurosurgeons using smartphones to determine the feasibility of identifying changes in cranial computed tomography scans, potentially serious conditions of patients, and the need for transfer to reference centers. Results: We analyzed 232 cases. The main diagnosis was traumatic brain injury, with 119 cases (51.3%). Of this, 105 (45.3%) patients were discharged immediately after the assessment. The telemedicine evaluators presented 95.69% accuracy in the identification of changes in computed tomography scans, with 0.858 concordance. Accuracy in the identification of severity was 95.26%, with 0.858 concordance. As for procedure, the concordance among evaluators was 0.672, increasing to 100% in cases that required surgical treatment. Conclusion: Our study indicated that the use of telemedicine for screening patients with acute neurological disorders was safe, effective and reproducible. Implementation of the method shows a promising potential to improve the patient's outcome by reducing unnecessary transfers and decreasing the time elapsed until a specialist can be consulted.

RESUMO Objetivo: Verificar a segurança, a efetividade e a reprodutibilidade da triagem de pacientes potencialmente neurocirúrgicos feita por smartphones. Métodos: Estudo retrospectivo e multicêntrico. Dados de prontuários dos pacientes submetidos à avaliação neurocirúrgica de urgência foram coletados e comparados com a avaliação realizada por neurocirurgiões por meio de smartphones, determinando a capacidade de identificar alterações na tomografia computadorizada de crânio, pacientes potencialmente graves e necessidade de transferência. Resultados: Foram analisados 232 casos. O principal diagnóstico foi traumatismo crânio encefálico, com 119 casos (51,3%). Destes, 105 (45,3%) tiveram alta após a avaliação. Os avaliadores por telemedicina apresentaram acurácia de 95,69% para identificação de alteração na tomografia computadorizada, com concordância de 0,858. Com relação à identificação de gravidade, a acurácia foi de 95,26%, com concordância de 0,858. Com relação à conduta, os avaliadores apresentaram concordância de 0,672, aumentando para 100% nos casos de tratamento cirúrgico. Conclusão: O uso da telemedicina em nosso estudo foi seguro, efetivo e reprodutível para triagem dos pacientes com afecções neurológicas agudas. A implementação do método tem potencial de impacto na melhora do resultado para o paciente devido à redução das transferências desnecessárias e do tempo até o atendimento.

Experimental model for transforaminal endoscopic spine

Abstract Purpose: To validate the porcine spine as a model for learning and practicing transforaminal percutaneous endoscopic lumbar procedures (TF-PELP). Methods: TF-PELP was performed in three porcine cadaver lumbar spine levels. Anatomical features of the current cadaver were compared to human and porcine spines. Performance and documentation of endoscopic procedures were described. Results: This study shows that this representative animal model reflects anatomical characteristics of the human spine. Transforaminal approaches were successfully completed. Although lower disc heights make disc puncture more difficult, the outside-in technique is feasible and more useful to identify anatomical parameters and to practice different surgical steps and maneuvers. Conclusion: This is an effective and representative model for learning and practicing this procedure. Difficulties of the procedure, as well as the differences compared to the human spine, were described.

Plano de análise estatística para o Alveolar Recruitment for Acute Respiratory Distress Syndrome Trial (ART). Ensaio controlado randomizado / Statistical analysis plan for the Alveolar Recruitment for Acute Respiratory Distress Syndrome Trial (ART). A randomized controlled trial

RESUMO Fundamentação: O estudo Alveolar Recruitment for Acute Respiratory Distress Syndrome Trial (ART) é um ensaio clínico internacional, multicêntrico, randomizado, pragmático e controlado com ocultação da alocação que envolve 120 unidades de terapia intensiva no Brasil, Argentina, Colômbia, Espanha, Itália, Polônia, Portugal, Malásia e Uruguai, com o objetivo primário de determinar se o recrutamento alveolar gradual máximo associado com titulação da pressão positiva expiratória final, ajustada segundo a complacência estática do sistema respiratório (estratégia ART), é capaz de aumentar, quando comparada aos resultados do tratamento convencional (estratégia ARDSNet), a sobrevivência em 28 dias de pacientes com síndrome do desconforto respiratório agudo. Objetivo: Descrever o processo de gerenciamento dos dados e o plano de análise estatística em um ensaio clínico internacional. Métodos: O plano de análise estatística foi delineado pelo comitê executivo e revisado pelo comitê diretivo do ART. Foi oferecida uma visão geral do delineamento do estudo, com foco especial na descrição de desfechos primário (sobrevivência aos 28 dias) e secundários. Foram descritos o processo de gerenciamento dos dados, o comitê de monitoramento de dados, a análise interina e o cálculo do tamanho da amostra. Também foram registrados o plano de análise estatística para os desfechos primário e secundários, e os subgrupos de análise pré-especificados. Detalhes para apresentação dos resultados, inclusive modelos de tabelas para as características basais, adesão ao protocolo e efeito nos desfechos clínicos, foram fornecidos. Conclusão: Em acordo com as melhores práticas em ensaios clínicos, submetemos nossos planos de análise estatística e de gerenciamento de dados para publicação antes do fechamento da base de dados e início das análises. Antecipamos que este documento deve prevenir viés em análises e incrementar a utilidade dos resultados a serem relatados. Registro do estudo: Número no registro ClinicalTrials.gov NCT01374022.

ABSTRACT Background: The Alveolar Recruitment for Acute Respiratory Distress Syndrome Trial (ART) is an international multicenter randomized pragmatic controlled trial with allocation concealment involving 120 intensive care units in Brazil, Argentina, Colombia, Italy, Poland, Portugal, Malaysia, Spain, and Uruguay. The primary objective of ART is to determine whether maximum stepwise alveolar recruitment associated with PEEP titration, adjusted according to the static compliance of the respiratory system (ART strategy), is able to increase 28-day survival in patients with acute respiratory distress syndrome compared to conventional treatment (ARDSNet strategy). Objective: To describe the data management process and statistical analysis plan. Methods: The statistical analysis plan was designed by the trial executive committee and reviewed and approved by the trial steering committee. We provide an overview of the trial design with a special focus on describing the primary (28-day survival) and secondary outcomes. We describe our data management process, data monitoring committee, interim analyses, and sample size calculation. We describe our planned statistical analyses for primary and secondary outcomes as well as pre-specified subgroup analyses. We also provide details for presenting results, including mock tables for baseline characteristics, adherence to the protocol and effect on clinical outcomes. Conclusion: According to best trial practice, we report our statistical analysis plan and data management plan prior to locking the database and beginning analyses. We anticipate that this document will prevent analysis bias and enhance the utility of the reported results. Trial registration: ClinicalTrials.gov number, NCT01374022.

Parameter estimation of an artificial respiratory system under mechanical ventilation following a noisy regime

Abstract Introduction: This work concerns the assessment of a novel system for mechanical ventilation and a parameter estimation method in a bench test. The tested system was based on a commercial mechanical ventilator and a personal computer. A computational routine was developed do drive the mechanical ventilator and a parameter estimation method was utilized to estimate positive end-expiratory pressure, resistance and compliance of the artificial respiratory system. Methods The computational routine was responsible for establishing connections between devices and controlling them. Parameters such as tidal volume, respiratory rate and others can be set for standard and noisy ventilation regimes. Ventilation tests were performed directly varying parameters in the system. Readings from a calibrated measuring device were the basis for analysis. Adopting a first-order linear model, the parameters could be estimated and the outcomes statistically analysed. Results Data acquisition was effective in terms of sample frequency and low noise content. After filtering, cycle detection and estimation took place. Statistics of median, mean and standard deviation were calculated, showing consistent matching with adjusted values. Changes in positive end-expiratory pressure statistically imply changes in compliance, but not the opposite. Conclusion The developed system was satisfactory in terms of clinical parameters. Statistics exhibited consistent relations between adjusted and estimated values, besides precision of the measurements. The system is expected to be used in animals, with a view to better understand the benefits of noisy ventilation, by evaluating the estimated parameters and performing cross relations among blood gas, ultrasonography and electrical impedance tomography.

Cisto aracnóideo intradiploico não traumático ­ Relato de caso / Nontraumatic Intradiploic Arachnoid Cyst ­ Case report

Existem apenas 14 casos descritos de cistos aracnóideos intradiploicos sem traumatismo craniano prévio. O objetivo deste estudo é relatar um caso de cistos aracnóideos intradiploicos e alertar para a possibilidade deste diagnóstico entre as lesões osteolíticas do crânio. Umpacientemasculino de 74 anos, com histórico de adenocarcinoma de próstata, tratado com radioterapia há 2 anos, realizou tomografia de crânio para investigação de tontura. Esta mostrou lesão lítica de 2 cm parietoccipital direita. Não havia história de trauma ou alteração neurológica. A ressonância magnética mostrou tecido isointenso ao parênquima cerebral preenchendo a cavidade óssea. O paciente foi submetido à craniectomia ao redor da lesão e foi identificada herniação de tecido encefálico para dentro da díploe craniana. Ao exame anatomopatológico não foram encontradas células neoplásicas, mas sim a presença de cavidade intraóssea com superfície interna recoberta por faixa de tecido conjuntivo fibrilar frouxo e tecido cerebral com morfologia preservada, estabelecendo o diagnóstico de cisto intradiploico com herniação de tecido cerebral. Cistos aracnóideos intradiploicos são geralmente achados incidentais. A cirurgia é necessária para o diagnóstico, mas pode ser evitada em pacientes assintomáticos e quando não há evidência de neoplasia maligna. Portanto, se o tratamento conservador for escolhido, sugere-se seguimento clínico e imagenológico, já que a história natural é desconhecida.

There are only 14 reported cases of intradiploic arachnoid cysts without prior head injury. The aim of this study is to report a case of intradiploic arachnoid cysts. Neurosurgeons must be aware of this possibility among osteolytic lesions of the skull. A male patient, 74 years old, with a history of prostate adenocarcinoma treated with radiotherapy for two years, held cranial tomography for investigation of dizziness. This showed a 2 cm parietal-occipital osteolytic lesion. There was no history of trauma or neurological disorder. The magnetic resonance imaging showed tissue filling the bone cavity that was isointense to brain parenchyma. The patient underwent craniectomy around the lesion, and brain tissue herniation was identified into the cranial diploe. Histopathology did not demonstrate neoplastic cells; the inner surface of the bone cavity was covered by loose fibrillar connective tissue and brain tissue with preserved morphology, establishing the diagnosis of IAC with brain tissue herniation. Intradiploic arachnoid cysts are usually incidental findings. Surgery is required for diagnosis, but it can be avoided in asymptomatic patients when there is no evidence of malignancy. Therefore, if conservative treatment is chosen, close clinical and imaging follow-up is advised, since IAC natural history is unknown.

Recomendações brasileiras de ventilação mecânica 2013. Parte 2 / Brazilian recommendations of mechanical ventilation 2013. Part 2

O suporte ventilatório artificial invasivo e não invasivo ao paciente grave tem evoluído e inúmeras evidências têm surgido, podendo ter impacto na melhora da sobrevida e da qualidade do atendimento oferecido nas unidades de terapia intensiva no Brasil. Isto posto, a Associação de Medicina Intensiva Brasileira (AMIB) e a Sociedade Brasileira de Pneumologia e Tisiologia (SBPT) - representadas por seu Comitê de Ventilação Mecânica e sua Comissão de Terapia Intensiva, respectivamente, decidiram revisar a literatura e preparar recomendações sobre ventilação mecânica, objetivando oferecer aos associados um documento orientador das melhores práticas da ventilação mecânica na beira do leito, com base nas evidências existentes, sobre os 29 subtemas selecionados como mais relevantes no assunto. O projeto envolveu etapas que visaram distribuir os subtemas relevantes ao assunto entre experts indicados por ambas as sociedades, que tivessem publicações recentes no assunto e/ou atividades relevantes em ensino e pesquisa no Brasil, na área de ventilação mecânica. Esses profissionais, divididos por subtemas em duplas, responsabilizaram-se por fazer uma extensa revisão da literatura mundial. Reuniram-se todos no Fórum de Ventilação Mecânica, na sede da AMIB, na cidade de São Paulo (SP), em 3 e 4 de agosto de 2013, para finalização conjunta do texto de cada subtema e apresentação, apreciação, discussão e aprovação em plenária pelos 58 participantes, permitindo a elaboração de um documento final.

Perspectives on invasive and noninvasive ventilatory support for critically ill patients are evolving, as much evidence indicates that ventilation may have positive effects on patient survival and the quality of the care provided in intensive care units in Brazil. For those reasons, the Brazilian Association of Intensive Care Medicine (Associação de Medicina Intensiva Brasileira - AMIB) and the Brazilian Thoracic Society (Sociedade Brasileira de Pneumologia e Tisiologia - SBPT), represented by the Mechanical Ventilation Committee and the Commission of Intensive Therapy, respectively, decided to review the literature and draft recommendations for mechanical ventilation with the goal of creating a document for bedside guidance as to the best practices on mechanical ventilation available to their members. The document was based on the available evidence regarding 29 subtopics selected as the most relevant for the subject of interest. The project was developed in several stages, during which the selected topics were distributed among experts recommended by both societies with recent publications on the subject of interest and/or significant teaching and research activity in the field of mechanical ventilation in Brazil. The experts were divided into pairs that were charged with performing a thorough review of the international literature on each topic. All the experts met at the Forum on Mechanical Ventilation, which was held at the headquarters of AMIB in São Paulo on August 3 and 4, 2013, to collaboratively draft the final text corresponding to each sub-topic, which was presented to, appraised, discussed and approved in a plenary session that included all 58 participants and aimed to create the final document.

Recomendações brasileiras de ventilação mecânica 2013. Parte I / Brazilian recommendations of mechanical ventilation 2013. Part I

O suporte ventilatório artificial invasivo e não invasivo ao paciente crítico tem evoluído e inúmeras evidências têm surgido, podendo ter impacto na melhora da sobrevida e da qualidade do atendimento oferecido nas unidades de terapia intensiva no Brasil. Isto posto, a Associação de Medicina Intensiva Brasileira (AMIB) e a Sociedade Brasileira de Pneumonia e Tisiologia (SBPT) - representadas pelo seus Comitê de Ventilação Mecânica e Comissão de Terapia Intensiva, respectivamente, decidiram revisar a literatura e preparar recomendações sobre ventilação mecânica objetivando oferecer aos associados um documento orientador das melhores práticas da ventilação mecânica na beira do leito, baseado nas evidencias existentes, sobre os 29 subtemas selecionados como mais relevantes no assunto. O projeto envolveu etapas visando distribuir os subtemas relevantes ao assunto entre experts indicados por ambas as sociedades que tivessem publicações recentes no assunto e/ou atividades relevantes em ensino e pesquisa no Brasil na área de ventilação mecânica. Esses profissionais, divididos por subtemas em duplas, responsabilizaram-se por fazer revisão extensa da literatura mundial sobre cada subtema. Reuniram-se todos no Forum de Ventilação Mecânica na sede da AMIB em São Paulo, em 03 e 04 de agosto de 2013 para finalização conjunta do texto de cada subtema e apresentação, apreciação, discussão e aprovação em plenária pelos 58 participantes, permitindo a elaboração de um documento final.

Perspectives on invasive and noninvasive ventilatory support for critically ill patients are evolving, as much evidence indicates that ventilation may have positive effects on patient survival and the quality of the care provided in intensive care units in Brazil. For those reasons, the Brazilian Association of Intensive Care Medicine (Associação de Medicina Intensiva Brasileira - AMIB) and the Brazilian Thoracic Society (Sociedade Brasileira de Pneumonia e Tisiologia - SBPT), represented by the Mechanical Ventilation Committee and the Commission of Intensive Therapy, respectively, decided to review the literature and draft recommendations for mechanical ventilation with the goal of creating a document for bedside guidance as to the best practices on mechanical ventilation available to their members. The document was based on the available evidence regarding 29 subtopics selected as the most relevant for the subject of interest. The project was developed in several stages, during which the selected topics were distributed among experts recommended by both societies with recent publications on the subject of interest and/or significant teaching and research activity in the field of mechanical ventilation in Brazil. The experts were divided into pairs that were charged with performing a thorough review of the international literature on each topic. All the experts met at the Forum on Mechanical Ventilation, which was held at the headquarters of AMIB in São Paulo on August 3 and 4, 2013, to collaboratively draft the final text corresponding to each sub-topic, which was presented to, appraised, discussed and approved in a plenary session that included all 58 participants and aimed to create the final document.

Assessment of regional lung ventilation by electrical impedance tomography in a patient with unilateral bronchial stenosis and a history of tuberculosis / Avaliacao da ventilacao pulmonar regional por tomografia de impedancia eletrica em paciente com estenose bronquica unilateral pos-tuberculose

Bronchial stenosis can impair regional lung ventilation by causing abnormal, asymmetric airflow limitation. Electrical impedance tomography (EIT) is an imaging technique that allows the assessment of regional lung ventilation and therefore complements the functional assessment of the lungs. We report the case of a patient with left unilateral bronchial stenosis and a history of tuberculosis, in whom regional lung ventilation was assessed by EIT. The EIT results were compared with those obtained by ventilation/perfusion radionuclide imaging. The patient was using nasal continuous positive airway pressure (CPAP) for the treatment of obstructive sleep apnea syndrome. Therefore, we studied the effects of postural changes and of the use of nasal CPAP. The EIT revealed heterogeneous distribution of regional lung ventilation, the ventilation being higher in the right lung, and this distribution was influenced by postural changes and CPAP use. The EIT assessment of regional lung ventilation produced results similar to those obtained with the radionuclide imaging technique and had the advantage of providing a dynamic evaluation without radiation exposure.

A estenose brônquica pode comprometer a ventilação pulmonar regional devido a limitações anormais e assimétricas ao fluxo aéreo. A tomografia de impedância elétrica (TIE) é uma técnica que possibilita a avaliação da ventilação pulmonar regional por imagem e, portanto, pode complementar a avaliação funcional dos pulmões. Relatamos o caso de uma paciente com estenose brônquica unilateral à esquerda, pós-tuberculose, em que se avaliou a ventilação pulmonar regional através da TIE, relacionando-a com a cintilografia de ventilação/perfusão. Foram estudados os efeitos das mudanças posturais e da aplicação de continuous positive airway pressure (CPAP, pressão positiva contínua nas vias aéreas) nasal, uma vez que a paciente usava esse tratamento para síndrome da apneia obstrutiva do sono. A TIE demonstrou distribuição heterogênea da ventilação pulmonar regional com maior ventilação no pulmão direito, sendo essa distribuição influenciada pelas mudanças de decúbitos e pela aplicação de CPAP. A análise da ventilação pulmonar regional pela TIE se mostrou similar aos achados da cintilografia pulmonar de ventilação com a vantagem de possibilitar uma avaliação dinâmica e sem exposição à radiação.

Evaluation of manual resuscitators used in ICUs in Brazil / Avaliação de reanimadores manuais utilizados em UTIs brasileiras

OBJECTIVE: To evaluate the performance of manual resuscitators (MRs) used in Brazil in accordance with international standards. METHODS: Using a respiratory system simulator, four volunteer physiotherapists employed eight MRs (five produced in Brazil and three produced abroad), which were tested for inspiratory and expiratory resistance of the patient valve; functioning of the pressure-limiting valve; and tidal volume (VT) generated when the one-handed and two-handed techniques were used. The tests were performed and analyzed in accordance with the American Society for Testing and Materials (ASTM) F920-93 criteria. RESULTS: Expiratory resistance was greater than 6 cmH2O . L−1 . s−1 in only one MR. The pressure-limiting valve, a feature of five of the MRs, opened at low pressures (< 17 cmH2O), and the maximal pressure was 32.0-55.9 cmH2O. Mean VT varied greatly among the MRs tested. The mean VT values generated with the one-handed technique were lower than the 600 mL recommended by the ASTM. In the situations studied, mean VT was generally lower from the Brazilian-made MRs that had a pressure-limiting valve. CONCLUSIONS: The resistances imposed by the patient valve met the ASTM criteria in all but one of the MRs tested. The pressure-limiting valves of the Brazilian-made MRs usually opened at low pressures, providing lower VT values in the situations studied, especially when the one-handed technique was used, suggesting that both hands should be used and that the pressure-limiting valve should be closed whenever possible. .

OBJETIVO: Avaliar o desempenho de reanimadores manuais (RMs) utilizados no Brasil conforme critérios definidos por uma norma internacional. MÉTODOS: Utilizando um simulador do sistema respiratório, oito RMs manuais (cinco produzidos no Brasil e três importados) foram avaliados em relação a resistência inspiratória e expiratória da válvula para o paciente; funcionamento da válvula limitadora de pressão; e volume corrente (VT) gerado por quatro fisioterapeutas voluntários, utilizando uma ou duas mãos. Para a realização e análise dos testes, foram utilizados critérios sugeridos pela norma da American Society for Testing and Materials (ASTM) F920-93. RESULTADOS: A resistência expiratória foi superior a 6 cmH2O . L−1 . s−1 em apenas um dos RMs testados. A válvula limitadora de pressão, presente em cinco RMs, abriu em baixas pressões (< 17 cmH2O), e a pressão máxima variou de 32,0-55,9 cmH2O. Houve grande variação da média de VT obtido pelos diferentes RMs. Os valores médios de VT utilizando uma mão foram inferiores ao sugerido pela ASTM (600 mL). O VT médio, nas situações estudadas, foi geralmente menor nos RMs nacionais com válvula limitadora de pressão. CONCLUSÕES: As resistências impostas pela válvula do paciente estão de acordo com os critérios da ASTM, com exceção de um RM. As válvulas limitadoras de pressão dos RMs nacionais geralmente abrem em baixas pressões, determinando o fornecimento de um menor VT nas situações estudadas, principalmente com o uso de uma mão, o que sugere que a ventilação deva ser feita com as duas mãos e a válvula limitadora de pressão deva ser fechada sempre que possível. .

Estudo experimental sobre a eficiência e segurança da manobra de hiperinsuflação manual como técnica de remoção de secreção / Experimental study on the efficiency and safety of the manual hyperinflation maneuver as a secretion clearance technique

OBJETIVO: Avaliar, em um modelo pulmonar simulando um paciente sob ventilação mecânica, a eficiência e a segurança da manobra de hiperinsuflação manual (HM) com o intuito de remover secreção pulmonar. MÉTODOS: Oito fisioterapeutas utilizaram um ressuscitador manual autoinflável para realizar HM com o objetivo de remover secreções, em duas condições: conforme rotineiramente aplicada durante sua prática clínica, e após receberem instruções verbais baseadas em recomendações de especialistas. Três cenários clínicos foram simulados: função pulmonar normal, doença pulmonar restritiva e doença pulmonar obstrutiva. RESULTADOS: Antes da instrução, o uso de duas compressões sequenciais do ressuscitador era comum, e a pressão proximal (Pprox) foi mais alta em relação à obtida após a instrução. Entretanto, a pressão alveolar (Palv) nunca excedeu 42,5 cmH2O (mediana, 16,1; intervalo interquartil [IQ], 11,7-24,5), mesmo com valores de Pprox de até 96,6 cmH2O (mediana, 36,7; IQ, 22,9-49,4). O volume corrente (VC) gerado foi relativamente pequeno (mediana, 640 mL; IQ, 505-735) e o pico de fluxo inspiratório (PFI) geralmente excedeu o pico de fluxo expiratório (PFE): 1,37 L/s (IQ, 0,99-1,90) e 1,01 L/s (IQ, 0,55-1,28), respectivamente. Uma relação PFI/PFE < 0,9 (que teoricamente favorece a migração do muco em direção às vias aéreas centrais) foi obtida em somente 16,7% das manobras. CONCLUSÕES: Nas condições testadas, a HM gerou valores seguros de Palv mesmo com altas Pprox. Entretanto, a HM foi comumente realizada de um modo que não favorecia a remoção de secreção (PFI excedendo PFE) mesmo após a instrução. A relação PFI/PFE desfavorável foi explicada pelas insuflações rápidas e o baixo VC.

OBJECTIVE: To evaluate, in a lung model simulating a mechanically ventilated patient, the efficiency and safety of the manual hyperinflation (MH) maneuver as a means of removing pulmonary secretions. METHODS: Eight respiratory therapists (RTs) were asked to use a self-inflating manual resuscitator on a lung model to perform MH as if to remove secretions, under two conditions: as routinely applied during their clinical practice; and after receiving verbal instructions based on expert recommendations. In both conditions, three clinical scenarios were simulated: normal lung function, restrictive lung disease, and obstructive lung disease. RESULTS: Before instruction, it was common for an RT to compress the resuscitator bag two times, in rapid succession. Proximal pressure (Pprox) was higher before instruction than after. However, alveolar pressure (Palv) never exceeded 42.5 cmH2O (median, 16.1; interquartile range [IQR], 11.7-24.5), despite Pprox values as high as 96.6 cmH2O (median, 36.7; IQR, 22.9-49.4). The tidal volume (VT) generated was relatively low (median, 640 mL; IQR, 505-735), and peak inspiratory flow (PIF) often exceeded peak expiratory flow (PEF), the median values being 1.37 L/s (IQR, 0.99-1.90) and 1.01 L/s (IQR, 0.55-1.28), respectively. A PIF/PEF ratio < 0.9 (which theoretically favors mucus migration toward the central airways) was achieved in only 16.7% of the maneuvers. CONCLUSIONS: Under the conditions tested, MH produced safe Palv levels despite high Pprox. However, the MH maneuver was often performed in a way that did not favor secretion removal (PIF exceeding PEF), even after instruction. The unfavorable PIF/ PEF ratio was attributable to overly rapid inflations and low V T.

Intracranial cavernous malformation in children: a single-centered experience with 30 consecutive cases / Angiomas cavernosos intracranianos em crianças: experiência de um único centro em 30 casos consecutivos

Objectives: To determine the clinical presentation and treatment outcome of pediatric intracranial cavernous malformation (CM) in a single-centered institution. Methods: Clinical data review of 30 patients under 18 years-old who had undergone surgery for cavernous malformation from January 1993 to December 2011. Results: The Study Group included 18 males and 12 females (mean age: 8.7 years-old). Symptoms at presentation were seizures (16/30, 53.3%), headache (15/30, 50.0%), and focal neurological deficits (11/30, 36.6%). Multiple cavernous malformations were found in 5/30 (16.6%). According to location, patients were classified in groups: (G1) brain-steam in 5/30 (16.6%), (G2) cerebellum in 2/30 (6.6%), (G3) supratentorial associated with seizures in 16/30 (53.3%), and (G4) supratentorial without seizures in 7/30 (23.3%). Surgical resection was performed in 26 out of 30 (86.6%) patients. The mean follow-up period was 4.1 years. Of 15 children followed-up with preoperative seizures, all were rendered seizure-free after surgery. Conclusions: For symptomatic solitary cavernous malformation, the treatment of choice is complete microsurgical excision preceded by careful anatomical and functional evaluation. For multiple cavernous malformation or asymptomatic patients, the treatment modalities must be cautiously considered. .

Objetivos: Determinar a apresentação clínica e o acompanhamento do tratamento em crianças com angioma cavernoso intracraniano numa única instituição. Métodos: Revisão de dados clínicos de 30 pacientes menores de 18 anos com que passaram por uma cirurgia de angioma cavernoso intracraniano entre janeiro de 1993 a dezembro de 2011. Resultados: O grupo de estudo incluiu 18 sujeitos masculinos e 12 femininos (idade média: 8,7 anos). Os sintomas iniciais eram convulsões (16/30, 53,3%), cefaleia (15/30, 50,0%) e déficits neurológicos focais (11/30, 36,6%). Havia angiomas cavernosos intracranianos múltiplos em 5 de 30 (16.6%). A classificação foi feita em grupos de acordo com a localização: (G1) tronco cerebral em 5/30 (16,6%); (G2) cerebelo em 2/30 (6,6%); (G3) supratentoriais associados a convulsões em 16/30 (53,3%) e (G4) supratentoriais sem convulsões em 7/30 (23,3%). Ressecção cirúrgica foi realizada em 26 de 30 (86,6%) pacientes, com seguimento médio de 4,1 anos. De 15 crianças com convulsões pré-operatórias, todas ficaram livres das crises após a cirurgia. Conclusões: Para angioma cavernoso intracraniano solitário e sintomático, o tratamento de escolha é excisão microcirúrgica total precedida de avaliação funcional e anatômica meticulosa. Para angiomas cavernosos intracranianos múltiplos ou pacientes assintomáticos, as modalidades terapêuticas devem ser consideradas cautelosamente. .

First-year experience of a Brazilian tertiary medical center in supporting severely ill patients using extracorporeal membrane oxygenation

OBJECTIVES: The aim of this manuscript is to describe the first year of our experience using extracorporeal membrane oxygenation support. METHODS: Ten patients with severe refractory hypoxemia, two with associated severe cardiovascular failure, were supported using venous-venous extracorporeal membrane oxygenation (eight patients) or veno-arterial extracorporeal membrane oxygenation (two patients). RESULTS: The median age of the patients was 31 yr (range 14-71 yr). Their median simplified acute physiological score three (SAPS3) was 94 (range 84-118), and they had a median expected mortality of 95% (range 87-99%). Community-acquired pneumonia was the most common diagnosis (50%), followed by P. jiroveci pneumonia in two patients with AIDS (20%). Six patients were transferred from other ICUs during extracorporeal membrane oxygenation support, three of whom were transferred between ICUs within the hospital (30%), two by ambulance (20%) and one by helicopter (10%). Only one patient (10%) was anticoagulated with heparin throughout extracorporeal membrane oxygenation support. Eighty percent of patients required continuous venous-venous hemofiltration. Three patients (30%) developed persistent hypoxemia, which was corrected using higher positive end-expiratory pressure, higher inspired oxygen fractions, recruitment maneuvers, and nitric oxide. The median time on extracorporeal membrane oxygenation support was five (range 3-32) days. The median length of the hospital stay was 31 (range 3-97) days. Four patients (40%) survived to 60 days, and they were free from renal replacement therapy and oxygen support. CONCLUSIONS: The use of extracorporeal membrane oxygenation support in severely ill patients is possible in the presence of a structured team. Efforts must be made to recognize the necessity of extracorporeal respiratory support at an early stage and to prompt activation of the extracorporeal membrane oxygenation team.

Linfoma primario de hueso con afectación multicéntrica / Primary bone lymphoma with multicentric involvement

El linfoma primario de hueso es una enfermedad infrecuente, que tiene una presentación y evolución diferente a los linfomas de otras localizaciones. Se presenta un caso de linfoma primario de hueso de localización craneana y esternal de rápido crecimiento. En su evolución, realizada la exéresis de la lesión primaria de calota, presentó aparición de nuevas lesiones de rápido crecimiento a nivel craneano y fémur y progresión de lesión preesternal que, con anatomía patológica de linfoma no Hodgkin difuso de células grandes B, inició R-CHOPP (ciclofosfamida, doxorrubicina, vincristina, prednisona y rituximab) con rápida disminución de todas las lesiones sin evidencia de progresión al cabo de los seis ciclos.

Primary bone lymphoma is a rare disease, which usually has a different presentation and evolution than lymphomas of other locations. We are presenting a case of primary bone lymphoma of rapid growth, in cranial and sternal locations. In its evolution, once the excision of the primary lesion of the skull was performed, the patient presented new lesions of rapid growth at the skull and femur level, and progression of pre-sternal lesion. With large B-cell diffuse non-Hodgkin lymphoma pathology, the patient initiated R-CHOPP (cyclophosphamide, doxorubicin, vincristine, prednisone and rituximab) with rapid reduction of all lesions without evidence of progression after the six cycles.

Extra and intradural spinal Hemangioblastoma / Hemangioblastoma espinhal extra e intradural / Hemangioblastoma espinal extra e intradural

Hemangioblastomas of the central nervous system (CNS) are low-grade highly vascularized tumors that may be sporadic or associated with Von Hippel-Lindau disease. Extradural hemangioblastomas are uncommon and those located extra and intradurally are even rarer. This study uses an illustrative case and literature review to discuss the difficulties to consider the correct diagnosis and to select the best surgical approach. A 57 years-old white male patient presented with myelopathy and right C5 radiculopathy. The images showed a lobulated, hourglass shaped, highly enhanced extra/intradural lesion that occupied the spinal canal and widened the C4-C5 right intervertebral foramen. Total resection of the intradural lesion was achieved through a posterior approach, but the extradural part could only be partially removed. Complete improvement was observed after four months of follow-up and the residual tumor has been followed up clinically and radiologically. Even though the preoperative impression was of a spinal schwannoma, the histopathological examination revealed grade I hemangioblastoma as per WHO. Despite their rarity, current complementary exams allow considering the diagnosis of hemangioblastoma preoperatively. That is essential to a better surgical planning in view of the particular surgical features of this lesion.

Hemangioblastomas do sistema nervoso central são lesões de baixo grau de malignidade, altamente vascularizadas, que podem se apresentar esporadicamente ou associadas com a doença de Von Hippel-Lindau. Hemangioblastomas extradurais são incomuns e os extra e intradurais são ainda mais raros. Este estudo usa um caso ilustrativo e revisão da literatura para discutir as dificuldades de considerar o diagnóstico correto e selecionar a melhor abordagem cirúrgica. Um paciente do sexo masculino, branco, com 57 anos de idade apresentou-se com mielopatia e radiculopatia de C5 à direita. As imagens mostraram lesão extra-intradural lobulada, em forma de ampulheta, com alta impregnação após contraste, que ocupava o canal vertebral e estreitava o forame intervertebral de C4-C5 à direita. A ressecção total da lesão intradural foi alcançada através de abordagem posterior, mas a porção extradural só pôde ser parcialmente removida. Melhora total dos sintomas foi observada após quatro meses e o tumor residual tem sido seguido clínica e radiologicamente. Embora a impressão pré-operatória tenha sido de um schwannoma espinal, o exame histopatológico revelou hemangioblastoma grau I, segundo a OMS. Apesar de sua raridade, exames complementares atuais permitem o correto diagnóstico pré-operatório. Isto é essencial para melhor programação cirúrgica, tendo em vista as características particulares desta lesão.

Hemangioblastomas del sistema nervioso central (SNC) son tumores altamente vascularizados, de grado bajo, que pueden ser esporádicos o vinculados a la enfermedad de Von Hippel-Lindau. Hemangioblastomas extradurales no son comunes, y aquellos localizados extra e intraduralmente son aún más raros. Este estudio usa un caso ilustrativo y la revisión de la literatura para analizar las dificultades cuanto a considerar el diagnóstico correcto y para seleccionar el mejor abordaje quirúrgico. Un paciente, hombre blanco de 57 años de edad, presentaba mielopatía con radiculopatía C5 derecha. Las imágenes mostraban lesión extra/intradural, muy acrecentada, con forma de ampolla y lobulada, la cual ocupaba el conducto espinal y ensanchaba el agujero intervertebral derecho C4-C5. La resección de la lesión intradural fue conseguida mediante un abordaje posterior, pero la parte extradural solamente pudo ser removida parcialmente. La mejoría completa fue observada después de cuatro meses de seguimiento y el tumor residual ha sido acompañado clínica y radiológicamente. Aunque la impresión preoperatoria era de schwannoma espinal, el examen histopatológico reveló hemangioblastoma grado I según la Organización Mundial de la Salud. A pesar de su rareza, los actuales exámenes complementarios permiten considerar, preoperativamente, el diagnóstico de hemangioblastoma. Esto es esencial para hacer un mejor planeamiento quirúrgico, teniendo en cuenta los aspectos quirúrgicos peculiares de esta lesión.

Effects of arterial oxygen tension and cardiac output on venous saturation: a mathematical modeling approach

OBJECTIVES: Hemodynamic support is aimed at providing adequate O2 delivery to the tissues; most interventions target O2 delivery increase. Mixed venous O2 saturation is a frequently used parameter to evaluate the adequacy of O2 delivery. METHODS: We describe a mathematical model to compare the effects of increasing O2 delivery on venous oxygen saturation through increases in the inspired O2 fraction versus increases in cardiac output. The model was created based on the lungs, which were divided into shunted and non-shunted areas, and on seven peripheral compartments, each with normal values of perfusion, optimal oxygen consumption, and critical O2 extraction rate. O2 delivery was increased by changing the inspired fraction of oxygen from 0.21 to 1.0 in steps of 0.1 under conditions of low (2.0 L.min-1) or normal (6.5 L.min-1) cardiac output. The same O2 delivery values were also obtained by maintaining a fixed O2 inspired fraction value of 0.21 while changing cardiac output. RESULTS: Venous oxygen saturation was higher when produced through increases in inspired O2 fraction versus increases in cardiac output, even at the same O2 delivery and consumption values. Specifically, at high inspired O2 fractions, the measured O2 saturation values failed to detect conditions of low oxygen supply. CONCLUSIONS: The mode of O2 delivery optimization, specifically increases in the fraction of inspired oxygen versus increases in cardiac output, can compromise the capability of the "venous O2 saturation" parameter to measure the adequacy of oxygen supply. Consequently, venous saturation at high inspired O2 fractions should be interpreted with caution.

Oxigenação extracorpórea por membrana na hipoxemia grave: hora de revermos nossos conceitos? / Extracorporeal membrane oxygenation in severe hypoxemia: time for reappraisal?

Em 2009, muitos casos de infecção pulmonar com hipoxemia grave refratária às estratégias ventilatórias habitualmente utilizadas e às manobras de resgate para a síndrome do desconforto respiratório agudo foram relatados durante a epidemia por influenza A (H1N1). Em muitos desses pacientes, o uso de extracorporeal membrane oxygenation (ECMO, oxigenação extracorpórea por membrana) foi necessário, fato que fez reacender o interesse na ECMO globalmente. O Grupo De Estudos em Suporte Extracorpóreo foi criado visando a aprender a técnica e a utilizar ECMO no tratamento de pacientes com hipoxemia grave. Neste artigo, são discutidas as indicações de ECMO e é relatado o caso de uma paciente com hipoxemia refratária que foi tratada através de ECMO de forma bem sucedida.

In 2009, during the influenza A (H1N1) epidemic, there were many reported cases of pulmonary infection with severe hypoxemia that was refractory to the ventilatory strategies and rescue therapies commonly used to treat patients with severe acute respiratory distress syndrome. Many of those cases were treated with extracorporeal membrane oxygenation (ECMO), which renewed international interest in the technique. The Extracorporeal Support Study Group was created in order to practice ECMO and to employ it in the treatment of patients with severe hypoxemia. In this article, we discuss the indications for using ECMO and report the case of a patient with refractory hypoxemia who was successfully treated with ECMO.

Follow-up after acute respiratory distress syndrome caused by influenza a (H1N1) virus infection

BACKGROUND: There are no reports on the long-term follow-up of patients with swine-origin influenza A virus infection that progressed to acute respiratory distress syndrome. METHODS: Four patients were prospectively followed up with pulmonary function tests and high-resolution computed tomography for six months after admission to an intensive care unit. RESULTS: Pulmonary function test results assessed two months after admission to the intensive care unit showed reduced forced vital capacity in all patients and low diffusion capacity for carbon monoxide in two patients. At six months, pulmonary function test results were available for three patients. Two patients continued to have a restrictive pattern, and none of the patients presented with abnormal diffusion capacity for carbon monoxide. All of them had a diffuse ground-glass pattern on high-resolution computed tomography that improved after six months. CONCLUSIONS: Despite the marked severity of lung disease at admission, patients with acute respiratory distress syndrome caused by swine-origin influenza A virus infection presented a late but substantial recovery over six months of follow-up.