Fundamento: A ventilação mecânica (VM) é um dos suportes de vida utilizados durante a internação em unidade de terapia intensiva. Entretanto, a alteração no mecanismo fisiológico de depuração mucociliar é um dos efeitos deletérios causados pela VM e pela prótese endotraqueal. Dessa forma, a fisioterapia respiratória objetiva manter as vias aéreas pérvias e as unidades alveolares expandidas, facilitando a ventilação pulmonar e para isso podem ser utilizadas manobras como hiperinsuflação manual (HM) ou hiperinsuflação com ventilador mecânico (HVM). Objetivo: Revisar sistematicamente os efeitos da HVM comparado com a HM no volume de secreção depurado, pneumonia associada à VM e tempo de VM em pacientes adultos em VM invasiva; e secundariamente, determinar os efeitos HVM nas variáveis respiratórias e hemodinâmicas. Métodos: Foi realizada uma busca sistemática nas bases de dados Cochrane CENTRAL, MEDLINE, Lilacs, PEDro e Embase, além de busca manual em referências de estudos publicados até agosto de 2016. Foram incluídos ensaios clínicos randomizados (ECRs) com pacientes adultos em VM que foram submetidos à manobra HVM comparando com manobra HM. Dois revisores independentes realizaram a seleção dos estudos, a extração dos dados e a avaliação da qualidade metodológica. Resultados: Do total de 3.949 artigos, três ECRs foram incluídos, totalizando 96 indivíduos. Foi observado que ambas as intervenções melhoram as variáveis respiratórias: volume de secreção (0,08g; IC95%: -0,70 a 0,85), complacência estática (1,01ml/cmH2O; IC95%: -5,80 a 7,83), complacência dinâmica (1,47 cmH2O; IC95%: - 3,43 a 6,36), relação PaO2/FiO2 (11,18; IC 95%: -26,28 a 48,65) e pressão arterial de dióxido de carbono (-0,38 mmHg; IC 95%: -2,78 a 2,03), sem diferença entre HVM e HM. Nenhum dos estudos incluídos avaliou as variáveis pneumonia associada à VM e tempo de VM. Conclusões: Esta revisão sistemática com metanálise, demonstrou que ambas as intervenções, melhoram os desfechos volume de secreção, complacência estática, complacência dinâmica, relação PaO2/FiO2 e pressão arterial de dióxido de carbono e que não existe diferença entre as mesmas, entretanto, devido as limitações dos estudos incluídos, novos estudos são necessários para confirmação dos achados. / Background: Mechanical ventilation (MV) is one of the supports used during intensive care unit admission. However, the change in the physiological mechanism of mucociliary clearance is one of the deleterious effects caused by MV and endotracheal prosthesis. Thus, respiratory physiotherapy aims to maintain the patent airways and expanded alveolar units, facilitating pulmonary ventilation and for this can be used maneuvers such as manual hyperinflation (HM) or hyperinflation with mechanical ventilator (HVM). Objective: To systematically review the effects of HVM compared with HM on the volume of depurated secretion, MV-associated pneumonia and MV time in adult patients in invasive MV; and secondarily to determine HVM effects on respiratory and hemodynamic variables. Methods: A systematic search was performed in the Cochrane CENTRAL, MEDLINE, Lilacs, PEDro and Embase databases, as well as a manual search in references of studies published up to August 2016. Randomized clinical trials (RCTs) were included, with adult patients in MV, that were submitted to the HVM maneuver comparing with HM maneuver. Two independent reviewers selected the studies, extracted data and assessed the methodological quality. Results: Of the total of 3,949 articles, three RCTs were included, totaling 96 individuals. It was observed that both interventions improved the respiratory variables: volume of secretion (0.08g, 95% CI: -0.70 to 0.85), static compliance (1.01ml / cmH2O, 95% CI: -5.80 to 7 , 83%), dynamic compliance (1.47 cmH2O, 95% CI: -3.43 to 6.36), PaO2 / FiO2 ratio (11.18; 95% CI: -26.28 to 48.65), and blood pressure Of carbon dioxide (-0.38 mmHg, 95% CI: -2.78 to 2.03), with no difference between HVM and HM. None of the included studies evaluated the variables pneumonia associated with MV and time of MV. Conclusions: This systematic review with meta-analysis has shown that both interventions improve the secretion volume, static compliance, dynamic compliance, PaO2 / FiO2 ratio and blood pressure of carbon dioxide and that there is no difference between them, however, due to limitations of the included studies, further studies are needed to confirm the findings.

Fundamento: A ventilação mecânica (VM) é um dos suportes de vida utilizados durante a internação em unidade de terapia intensiva. Entretanto, a alteração no mecanismo fisiológico de depuração mucociliar é um dos efeitos deletérios causados pela VM e pela prótese endotraqueal. Dessa forma, a fisioterapia respiratória objetiva manter as vias aéreas pérvias e as unidades alveolares expandidas, facilitando a ventilação pulmonar e para isso podem ser utilizadas manobras como hiperinsuflação manual (HM) ou hiperinsuflação com ventilador mecânico (HVM). Objetivo: Revisar sistematicamente os efeitos da HVM comparado com a HM no volume de secreção depurado, pneumonia associada à VM e tempo de VM em pacientes adultos em VM invasiva; e secundariamente, determinar os efeitos HVM nas variáveis respiratórias e hemodinâmicas. Métodos: Foi realizada uma busca sistemática nas bases de dados Cochrane CENTRAL, MEDLINE, Lilacs, PEDro e Embase, além de busca manual em referências de estudos publicados até agosto de 2016. Foram incluídos ensaios clínicos randomizados (ECRs) com pacientes adultos em VM que foram submetidos à manobra HVM comparando com manobra HM. Dois revisores independentes realizaram a seleção dos estudos, a extração dos dados e a avaliação da qualidade metodológica. Resultados: Do total de 3.949 artigos, três ECRs foram incluídos, totalizando 96 indivíduos. Foi observado que ambas as intervenções melhoram as variáveis respiratórias: volume de secreção (0,08g; IC95%: -0,70 a 0,85), complacência estática (1,01ml/cmH2O; IC95%: -5,80 a 7,83), complacência dinâmica (1,47 cmH2O; IC95%: - 3,43 a 6,36), relação PaO2/FiO2 (11,18; IC 95%: -26,28 a 48,65) e pressão arterial de dióxido de carbono (-0,38 mmHg; IC 95%: -2,78 a 2,03), sem diferença entre HVM e HM. Nenhum dos estudos incluídos avaliou as variáveis pneumonia associada à VM e tempo de VM. Conclusões: Esta revisão sistemática com metanálise, demonstrou que ambas as intervenções, melhoram os desfechos volume de secreção, complacência estática, complacência dinâmica, relação PaO2/FiO2 e pressão arterial de dióxido de carbono e que não existe diferença entre as mesmas, entretanto, devido as limitações dos estudos incluídos, novos estudos são necessários para confirmação dos achados. / Background: Mechanical ventilation (MV) is one of the supports used during intensive care unit admission. However, the change in the physiological mechanism of mucociliary clearance is one of the deleterious effects caused by MV and endotracheal prosthesis. Thus, respiratory physiotherapy aims to maintain the patent airways and expanded alveolar units, facilitating pulmonary ventilation and for this can be used maneuvers such as manual hyperinflation (HM) or hyperinflation with mechanical ventilator (HVM). Objective: To systematically review the effects of HVM compared with HM on the volume of depurated secretion, MV-associated pneumonia and MV time in adult patients in invasive MV; and secondarily to determine HVM effects on respiratory and hemodynamic variables. Methods: A systematic search was performed in the Cochrane CENTRAL, MEDLINE, Lilacs, PEDro and Embase databases, as well as a manual search in references of studies published up to August 2016. Randomized clinical trials (RCTs) were included, with adult patients in MV, that were submitted to the HVM maneuver comparing with HM maneuver. Two independent reviewers selected the studies, extracted data and assessed the methodological quality. Results: Of the total of 3,949 articles, three RCTs were included, totaling 96 individuals. It was observed that both interventions improved the respiratory variables: volume of secretion (0.08g, 95% CI: -0.70 to 0.85), static compliance (1.01ml / cmH2O, 95% CI: -5.80 to 7 , 83%), dynamic compliance (1.47 cmH2O, 95% CI: -3.43 to 6.36), PaO2 / FiO2 ratio (11.18; 95% CI: -26.28 to 48.65), and blood pressure Of carbon dioxide (-0.38 mmHg, 95% CI: -2.78 to 2.03), with no difference between HVM and HM. None of the included studies evaluated the variables pneumonia associated with MV and time of MV. Conclusions: This systematic review with meta-analysis has shown that both interventions improve the secretion volume, static compliance, dynamic compliance, PaO2 / FiO2 ratio and blood pressure of carbon dioxide and that there is no difference between them, however, due to limitations of the included studies, further studies are needed to confirm the findings.

The development and implementation of technologies that improves Heating Ventilation & Air Conditioning (HVAC) system efficiency, including unique waste heat recovery methods, are sought while considering financial constraints and benefits. Recent studies have found that through the use of advanced waste heat recovery systems, it is possible to reduce building’s energy consumption by 30%. Oscillating heat pipes (OHP) exists as a serpentine-arranged capillary tube, possesses a desirable aerodynamic form factor, and provides for relatively high heat transfer rates via cyclic evaporation and condensation of an encapsulated working fluid with no internal wicking structure required. In last two decade, it has been extensively investigated for its potential application in thermal management of electronic devices. This dissertation focuses on the application of OHP in waste heat recovery systems. To achieve the goal, first a feasibility study is conducted by experimentally assessing a nine turn copper-made bare tube OHP in a typical HVAC ducting system with adjacent air streams at different temperatures. Second, for a prescribed temperature difference and volumetric flow rate of air, a multi-row finned OHP based Heat Recovery Ventilator (OHP-HRV) is designed and analyzed for the task of pre-conditioning the intake air. Additionally, the energy and cost savings analysis is performed specifically for the designed OHP-HRV system and potential cost benefits are demonstrated for various geographical regions within the United States. Finally, an atypically long finned OHP is experimentally investigated (F-OHP) under above prescribed operating condition. Helical fins are added to capillary size OHP tubes at a rate of 12 fins per inch (12 FPI), thereby increasing the heat transfer area by 433%. The coupled effect of fins and oscillation on the thermal performance of F-OHP is examined. Also, F-OHP’s thermal performance is compared with that of bare tube OHP of similar dimension and operating under similar condition. It was determined that OHP can be an effective waste heat recovery device in terms of operational cost, manufacturability, thermal and aerodynamic performance. Moreover, it was also determined that OHP-HRV can significantly reduce energy consumption of a commercial building, especially in the winter operation.

No description available.

INTRODUÇÃO: O sucesso da terapia com ventilação não invasiva com pressão positiva (VNIPP) está associada com a escolha adequada da interface. A máscara Total face® (TF) é considerada mais confortável, porém possui grande espaço morto (875 ml) e vazamento constante elevado. Os ventiladores próprios para ventilação mecânica invasiva (convencionais) têm sido utilizados, habitualmente, para ventilação não invasiva em ambiente de UTI. OBJETIVOS: Avaliar o desempenho de nove ventiladores convencionais com uso da máscara TF e compará-los com um ventilador próprio para VNIPP (Respironics BiPAP Vision). MÉTODOS: Utilizou-se um modelo com dois simuladores mecânicos do sistema respiratório conectados a uma cabeça de manequim onde foi adaptada a máscara TF que foi conectada aos ventiladores testados. O esforço inspiratório foi simulado utilizando-se o modo pressão controlada. Os ventiladores foram testados na modalidade espontânea ventilação com pressão suporte sendo ajustados dois valores de PEEP (5 e 10cmH2O) e 3 valores de pressão suporte (5, 10 e 15 cmH2O). Foi testado se os ventiladores funcionavam com a máscara TF e seu desempenho em relação à compensação de vazamento, pressurização, pico de fluxo atingido, atrasos inspiratório e expiratório. RESULTADOS: O ventilador Vision funcionou em todas as situações. Quatro ventiladores convencionais funcionaram (Horus, Vela, E500 e Servo i). O principal problema com os ventiladores que não funcionaram foi o autodisparo e o desligamento do fluxo inspiratório. O pico de vazamento medido foi maior que 1L/s, em média, e o pico de fluxo gerado, muitas vezes, atingia a capacidade máxima em alguns ventiladores. A capacidade de compensar vazamento foi variável entre os ventiladores, mas aqueles com maior dificuldade (E500 e Horus) foram os que mantiveram os menores valores de PEEP e, também, maiores atrasos no disparo, os demais ventiladores, apresentaram atrasos iniciais menores que 100ms. A ciclagem ocorreu por critérios de segurança nos ventiladores Horus, Vela e E500 em algumas medidas. A capacidade de pressurização foi avaliada pelo cálculo do PTP com 500ms e com 1 segundo. A área de pressurização com 1 segundo ficou abaixo de 50% da área esperada para todos os ventiladores, inclusive para o Vision, específico para VNIPP, sendo que o pior desempenho foi do ventilador Horus. CONCLUSÕES: Entre nove ventiladores convencionais testados, apenas quatro funcionaram com a TF. O desempenho entre os ventiladores foi variável, sendo que, alguns deles não se mostraram adequado para uso com VNIPP usando a máscara TF. A maior dificuldade para o funcionamento dos ventiladores convencionais foi lidar com o grande vazamento, com ocorrência de autodisparos ou desligamento do fluxo de ar do ventilador, acusando desconexão. O vazamento de ar pelos orifícios da máscara é elevado. Os ventiladores Horus e E500 tiveram atrasos maiores que 100ms no disparo; e a ciclagem ocorreu por critérios de segurança em todos ventiladores convencionais, em algumas medidas, exceto o Servo i / BACKGROUND: The success of therapy with noninvasive ventilation with positive pressure (VNIPP) is associated with interface choice. The Total face® mask (TFM) is an interface considered more comfortable than other, but it has a large dead space (875 ml) and constant high leakage. However, intensive care ventilators have been usually used for noninvasive ventilation in the ICU environment, their ability to operate with high air leakage is not known. OBJECTIVES: To evaluate the performance of nine ICU ventilators using TFM and compare them with a VNIPP mode only ventilator (Respironics BiPAP Vision). METHODS: a mechanical respiratory system simulator with two compartments was adapted to TFM what was connected to tested ventilators. The inspiratory effort was simulated using pressure control mode in Newport E500 ventilator. The ventilators were tested in spontaneous mode being adjusted at two values of PEEP (5 and 10cmH2O) and 3 values of pressure support (5, 10 and 15 cmH2O). It was tested if ventilators worked properly with TFM and its performance to compensation for leakage, its pressurization, the capability to reach peak flow target, and trigger and cycling delays. RESULTS: The Vision ventilator worked properly in all situations. Four conventional ventilators (Horus, Vela, E500 and Servo) worked. The main problem with failed ventilator was auto triggering and inspiratory flow turning off. Among worked ventilators, peak inspiratory leakage average was greater than 1L / s , generated peak flow reached maximum capacity in some settings with NIV mode only ventilator. The ability to compensate for leak was variable between ventilators, but those with greater difficulty (E500 and Horus) maintained the lowest values of PEEP and also had great trigger delays, the other ventilators showed trigger delays smaller than 100ms. The cycling occurred by security criteria on Horus, Vela and E500 ventilators in some settings. The ability of pressurization was evaluated by calculating the PTP with 500ms and 1 second. The area of pressurization with 1 second remained below 50% of target area for all ventilators, including for Vision, specifically for VNIPP. Horus ventilator has the worst pressurization performance. CONCLUSIONS: Among nine conventional tested ventilators, only four worked with the TFM. The performance among the ventilators was variable; as a result some of them were not suitable for use with NIV using TFM. The greatest difficulty for conventional ventilator operation was dealing with the large leakage, occurring auto triggering or inspiratory flow turning off, alarming disconnection. The air leakage through the mask holes (exhalation port) was high. Horus and E500 ventilators had trigger delays greater than 100ms and cycling occurred by security criteria for all conventional ventilators, except the Servo, in some setting

Thesis (M.N.)--Memorial University of Newfoundland, 2004. / Bibliography: leaves 104-108.

INTRODUÇÃO: O sucesso da terapia com ventilação não invasiva com pressão positiva (VNIPP) está associada com a escolha adequada da interface. A máscara Total face® (TF) é considerada mais confortável, porém possui grande espaço morto (875 ml) e vazamento constante elevado. Os ventiladores próprios para ventilação mecânica invasiva (convencionais) têm sido utilizados, habitualmente, para ventilação não invasiva em ambiente de UTI. OBJETIVOS: Avaliar o desempenho de nove ventiladores convencionais com uso da máscara TF e compará-los com um ventilador próprio para VNIPP (Respironics BiPAP Vision). MÉTODOS: Utilizou-se um modelo com dois simuladores mecânicos do sistema respiratório conectados a uma cabeça de manequim onde foi adaptada a máscara TF que foi conectada aos ventiladores testados. O esforço inspiratório foi simulado utilizando-se o modo pressão controlada. Os ventiladores foram testados na modalidade espontânea ventilação com pressão suporte sendo ajustados dois valores de PEEP (5 e 10cmH2O) e 3 valores de pressão suporte (5, 10 e 15 cmH2O). Foi testado se os ventiladores funcionavam com a máscara TF e seu desempenho em relação à compensação de vazamento, pressurização, pico de fluxo atingido, atrasos inspiratório e expiratório. RESULTADOS: O ventilador Vision funcionou em todas as situações. Quatro ventiladores convencionais funcionaram (Horus, Vela, E500 e Servo i). O principal problema com os ventiladores que não funcionaram foi o autodisparo e o desligamento do fluxo inspiratório. O pico de vazamento medido foi maior que 1L/s, em média, e o pico de fluxo gerado, muitas vezes, atingia a capacidade máxima em alguns ventiladores. A capacidade de compensar vazamento foi variável entre os ventiladores, mas aqueles com maior dificuldade (E500 e Horus) foram os que mantiveram os menores valores de PEEP e, também, maiores atrasos no disparo, os demais ventiladores, apresentaram atrasos iniciais menores que 100ms. A ciclagem ocorreu por critérios de segurança nos ventiladores Horus, Vela e E500 em algumas medidas. A capacidade de pressurização foi avaliada pelo cálculo do PTP com 500ms e com 1 segundo. A área de pressurização com 1 segundo ficou abaixo de 50% da área esperada para todos os ventiladores, inclusive para o Vision, específico para VNIPP, sendo que o pior desempenho foi do ventilador Horus. CONCLUSÕES: Entre nove ventiladores convencionais testados, apenas quatro funcionaram com a TF. O desempenho entre os ventiladores foi variável, sendo que, alguns deles não se mostraram adequado para uso com VNIPP usando a máscara TF. A maior dificuldade para o funcionamento dos ventiladores convencionais foi lidar com o grande vazamento, com ocorrência de autodisparos ou desligamento do fluxo de ar do ventilador, acusando desconexão. O vazamento de ar pelos orifícios da máscara é elevado. Os ventiladores Horus e E500 tiveram atrasos maiores que 100ms no disparo; e a ciclagem ocorreu por critérios de segurança em todos ventiladores convencionais, em algumas medidas, exceto o Servo i / BACKGROUND: The success of therapy with noninvasive ventilation with positive pressure (VNIPP) is associated with interface choice. The Total face® mask (TFM) is an interface considered more comfortable than other, but it has a large dead space (875 ml) and constant high leakage. However, intensive care ventilators have been usually used for noninvasive ventilation in the ICU environment, their ability to operate with high air leakage is not known. OBJECTIVES: To evaluate the performance of nine ICU ventilators using TFM and compare them with a VNIPP mode only ventilator (Respironics BiPAP Vision). METHODS: a mechanical respiratory system simulator with two compartments was adapted to TFM what was connected to tested ventilators. The inspiratory effort was simulated using pressure control mode in Newport E500 ventilator. The ventilators were tested in spontaneous mode being adjusted at two values of PEEP (5 and 10cmH2O) and 3 values of pressure support (5, 10 and 15 cmH2O). It was tested if ventilators worked properly with TFM and its performance to compensation for leakage, its pressurization, the capability to reach peak flow target, and trigger and cycling delays. RESULTS: The Vision ventilator worked properly in all situations. Four conventional ventilators (Horus, Vela, E500 and Servo) worked. The main problem with failed ventilator was auto triggering and inspiratory flow turning off. Among worked ventilators, peak inspiratory leakage average was greater than 1L / s , generated peak flow reached maximum capacity in some settings with NIV mode only ventilator. The ability to compensate for leak was variable between ventilators, but those with greater difficulty (E500 and Horus) maintained the lowest values of PEEP and also had great trigger delays, the other ventilators showed trigger delays smaller than 100ms. The cycling occurred by security criteria on Horus, Vela and E500 ventilators in some settings. The ability of pressurization was evaluated by calculating the PTP with 500ms and 1 second. The area of pressurization with 1 second remained below 50% of target area for all ventilators, including for Vision, specifically for VNIPP. Horus ventilator has the worst pressurization performance. CONCLUSIONS: Among nine conventional tested ventilators, only four worked with the TFM. The performance among the ventilators was variable; as a result some of them were not suitable for use with NIV using TFM. The greatest difficulty for conventional ventilator operation was dealing with the large leakage, occurring auto triggering or inspiratory flow turning off, alarming disconnection. The air leakage through the mask holes (exhalation port) was high. Horus and E500 ventilators had trigger delays greater than 100ms and cycling occurred by security criteria for all conventional ventilators, except the Servo, in some setting

Introdução: a hipótese deste estudo é de que a Pressão inspiratória máxima, Pressão de oclusão traqueal e sua razão podem predizer a evolução do desmame da ventilação mecânica em uma população mista de Terapia Intensiva. Métodos: A Pi Max , P 0.1 e a razão P 0.1 / Pi Max foram mensuradas em setenta pacientes consecutivos , intubados ou traqueostomizados, e ventilados mecanicamente, que preencheram os critérios para desmame da ventilação mecânica. Após a mensuração da Pi Max, P 0.1 e ainda da freqüência respiratória e volume corrente em litros com o cálculo da relação FR/VC e do produto P 0.1 x FR/VC, os pacientes foram submetidos a um teste de respiração espontânea. Os pacientes que toleraram o teste de respiração espontânea e não precisaram retornar para a ventilação mecânica no período de 24 horas foram considerados desmamados. A sensibilidade, especificidade, valor preditivo positivo, valor preditivo negativo, diagnóstico de acurácia e a área sob a curva ROC (receiver operating characteristic curve) foram calculadas. Resultados: Os valores médios da P 0.1 , Pi Max, P 0.1 / Pi Max, FR / VC e P 0.1 x FR /VC foram de 2,49±1,2, -34,6±13, 0,07±0,01, 75,4±33 e 184,6±123 respectivamente para os pacientes desmamados e 4,36± 2,0, -32,1±11,0 , 0,15± 0,09, 148,4± 42 e 652,9± 358 para os não desmamados da ventilação mecânica. Todos os índices distinguiram entre os pacientes desmamados e não desmamados, à exceção da Pi Max. A sensibilidade para a P 0.1 , Pi Max, P 0.1 / Pi Max, FR / VC e P 0.1 x FR /VC foi de 78,85, 65,38, 80,77, 82,69, 88,46 respectivamente. A especificidade para a P 0.1 , Pi Max, P 0.1 / Pi Max, FR / VC e P 0.1 x FR /VC foi de 72,2, 38,8, 72,2, 83,3, 72,2 respectivamente. Os valores preditivos positivos para a P 0.1 , Pi Max, P 0.1 / Pi Max, FR / VC e P 0.1 x FR /VC foram respectivamente 89,1, 75,5, 89,3, 93,4 e 90,2. Os valores preditivos negativos para a P 0.1 , Pi Max, P 0.1 / Pi Max, FR / VC e P 0.1 x FR /VC foram respectivamente de 54,1, 28,0, 56,5, 62,5 e 68,4. O diagnóstico de acurácia para a P 0.1 , Pi Max, P 0.1 / Pi Max, FR / VC e P 0.1 x FR /VC foi respectivamente de 77,1, 58,5, 78,5, 82,8 e 84,2. As áreas abaixo da curva ROC para a P 0.1 , Pi Max, P 0.1 / Pi Max, FR / VC e P 0.1 x FR /VC foram respectivamente 0,76± 0,06, 0,52±0,08 , 0,78±0,06, 0,90±0,04 e 0,84±0,05. A comparação da áreas abaixo da curva ROC mostrou que os melhores índices foram a relação FR/VC, o produto P 0.1 x FR/VC e a relação P 0.1 / Pi Max não havendo diferença estatística entre eles. A pior área abaixo da curva ROC foi do índice Pi Max. Os índices de desmame da ventilação mecânica P 0.1, Pi Max e P 0.1/ Pi Max não foram diferentes estatisticamente entre os pacientes intubados e traqueostomizados. Conclusão: os melhores índices foram a relação FR/VC, o produto P 0.1 x FR/VC e a relação P 0.1 / Pi Max não havendo diferença estatística entre eles. / Introduction: We hypothesized that maximal inspiratory pressure (Pi Max), airway tracheal occlusion pressure (P 0.1) and its ratio (P 0.1/Pi Max) can be used to predict weaning outcome in a mixed ICU mechanically ventilated patients. Methods: Pi Max, P 0.1 and P 0.1 / Pi Max ratio were measured in seventy consecutive intubated or tracheostomized, mechanically ventilated patients, who fulfilled weaning criteria. After these measurements of Pi Max, P0.1, respiratory rate and expiratory tidal volume (L) with the calculation of f / Vt ratio and the product P0.1x f / Vt , the patients were submitted to a spontaneous breathing trial (SBT) . Those who were able to sustain the SBT and had no need to return to mechanical ventilation in the following 24 hours were considered weaned. The sensitivity, specificity, positive predictive value, negative predictive value, diagnostic accuracy and Receiver- operating-characteristics (ROC) curves for this population were calculated. Results: The mean value of P 0.1 , Pi Max, P 0.1 / Pi Max, FR / VC e P 0.1 x FR /VC were 2,49 ±1,2, -34,6± 13, 0,07± 0,01, 75,4±33 and 184,6±123 respectively for the weaned patients and 4,36± 2,0, -32,1±11,0 , 0,15± 0,09, 148,4± 42 e 652,9± 358 for the not weaned patients. All the indexes distinguished between the weaned and not weaned patient, except for the Pi Max. The sensitivity for the P 0.1 , Pi Max, P 0.1 / Pi Max, FR / VC and P 0.1 x FR /VC were respectively 78,85, 65,38, 80,77, 82,69, 88,46. The specificity for P 0.1 , Pi Max, P 0.1 / Pi Max, FR / VC and P 0.1 x FR /VC were 72,2, 38,8, 72,2, 83,3, 72,2 respectively. The positive predictive value for P 0.1 , Pi Max, P 0.1 / Pi Max, FR / VC and P 0.1 x FR /VC were respectively 89,1, 75,5, 89,3, 93,4 e 90,2. The negative predictive value for P 0.1 , Pi Max, P 0.1 / Pi Max, FR / VC and P 0.1 x FR /VC were respectively 54,1, 28,0, 56,5, 62,5 e 68,4. The diagnostic accuracy for P 0.1 , Pi Max, P 0.1 / Pi Max, FR / VC and P 0.1 x FR /VC were respectively 77,1, 58,5, 78,5, 82,8 e 84,2. The area under the ROC curves for P 0.1 , Pi Max, P 0.1 / Pi Max, FR / VC and P 0.1 x FR /VC were respectively 0,76± 0,06, 0,52±0,08 , 0,78±0,06, 0,90±0,04 e 0,84±0,05. The comparison among the areas under the ROC curves showed that the best weaning indexes were f / Vt ratio, the product P 0.1 x f / Vt and the P0.1/ Pi Max ratio with no statistic differences among them. The Pi Max presented the smaller area under the ROC curve. The weaning indexes P 0.1, Pi Max e P 0.1/ Pi Max were not statistically different between intubated or tracheostomized patients. Conclusion: The best weaning indexes were f/Vt ratio , the product P 0.1 x f/Vt and the P 0.1 / Pi Max ratio with no statistically difference among them.

Introdução: a hipótese deste estudo é de que a Pressão inspiratória máxima, Pressão de oclusão traqueal e sua razão podem predizer a evolução do desmame da ventilação mecânica em uma população mista de Terapia Intensiva. Métodos: A Pi Max , P 0.1 e a razão P 0.1 / Pi Max foram mensuradas em setenta pacientes consecutivos , intubados ou traqueostomizados, e ventilados mecanicamente, que preencheram os critérios para desmame da ventilação mecânica. Após a mensuração da Pi Max, P 0.1 e ainda da freqüência respiratória e volume corrente em litros com o cálculo da relação FR/VC e do produto P 0.1 x FR/VC, os pacientes foram submetidos a um teste de respiração espontânea. Os pacientes que toleraram o teste de respiração espontânea e não precisaram retornar para a ventilação mecânica no período de 24 horas foram considerados desmamados. A sensibilidade, especificidade, valor preditivo positivo, valor preditivo negativo, diagnóstico de acurácia e a área sob a curva ROC (receiver operating characteristic curve) foram calculadas. Resultados: Os valores médios da P 0.1 , Pi Max, P 0.1 / Pi Max, FR / VC e P 0.1 x FR /VC foram de 2,49±1,2, -34,6±13, 0,07±0,01, 75,4±33 e 184,6±123 respectivamente para os pacientes desmamados e 4,36± 2,0, -32,1±11,0 , 0,15± 0,09, 148,4± 42 e 652,9± 358 para os não desmamados da ventilação mecânica. Todos os índices distinguiram entre os pacientes desmamados e não desmamados, à exceção da Pi Max. A sensibilidade para a P 0.1 , Pi Max, P 0.1 / Pi Max, FR / VC e P 0.1 x FR /VC foi de 78,85, 65,38, 80,77, 82,69, 88,46 respectivamente. A especificidade para a P 0.1 , Pi Max, P 0.1 / Pi Max, FR / VC e P 0.1 x FR /VC foi de 72,2, 38,8, 72,2, 83,3, 72,2 respectivamente. Os valores preditivos positivos para a P 0.1 , Pi Max, P 0.1 / Pi Max, FR / VC e P 0.1 x FR /VC foram respectivamente 89,1, 75,5, 89,3, 93,4 e 90,2. Os valores preditivos negativos para a P 0.1 , Pi Max, P 0.1 / Pi Max, FR / VC e P 0.1 x FR /VC foram respectivamente de 54,1, 28,0, 56,5, 62,5 e 68,4. O diagnóstico de acurácia para a P 0.1 , Pi Max, P 0.1 / Pi Max, FR / VC e P 0.1 x FR /VC foi respectivamente de 77,1, 58,5, 78,5, 82,8 e 84,2. As áreas abaixo da curva ROC para a P 0.1 , Pi Max, P 0.1 / Pi Max, FR / VC e P 0.1 x FR /VC foram respectivamente 0,76± 0,06, 0,52±0,08 , 0,78±0,06, 0,90±0,04 e 0,84±0,05. A comparação da áreas abaixo da curva ROC mostrou que os melhores índices foram a relação FR/VC, o produto P 0.1 x FR/VC e a relação P 0.1 / Pi Max não havendo diferença estatística entre eles. A pior área abaixo da curva ROC foi do índice Pi Max. Os índices de desmame da ventilação mecânica P 0.1, Pi Max e P 0.1/ Pi Max não foram diferentes estatisticamente entre os pacientes intubados e traqueostomizados. Conclusão: os melhores índices foram a relação FR/VC, o produto P 0.1 x FR/VC e a relação P 0.1 / Pi Max não havendo diferença estatística entre eles. / Introduction: We hypothesized that maximal inspiratory pressure (Pi Max), airway tracheal occlusion pressure (P 0.1) and its ratio (P 0.1/Pi Max) can be used to predict weaning outcome in a mixed ICU mechanically ventilated patients. Methods: Pi Max, P 0.1 and P 0.1 / Pi Max ratio were measured in seventy consecutive intubated or tracheostomized, mechanically ventilated patients, who fulfilled weaning criteria. After these measurements of Pi Max, P0.1, respiratory rate and expiratory tidal volume (L) with the calculation of f / Vt ratio and the product P0.1x f / Vt , the patients were submitted to a spontaneous breathing trial (SBT) . Those who were able to sustain the SBT and had no need to return to mechanical ventilation in the following 24 hours were considered weaned. The sensitivity, specificity, positive predictive value, negative predictive value, diagnostic accuracy and Receiver- operating-characteristics (ROC) curves for this population were calculated. Results: The mean value of P 0.1 , Pi Max, P 0.1 / Pi Max, FR / VC e P 0.1 x FR /VC were 2,49 ±1,2, -34,6± 13, 0,07± 0,01, 75,4±33 and 184,6±123 respectively for the weaned patients and 4,36± 2,0, -32,1±11,0 , 0,15± 0,09, 148,4± 42 e 652,9± 358 for the not weaned patients. All the indexes distinguished between the weaned and not weaned patient, except for the Pi Max. The sensitivity for the P 0.1 , Pi Max, P 0.1 / Pi Max, FR / VC and P 0.1 x FR /VC were respectively 78,85, 65,38, 80,77, 82,69, 88,46. The specificity for P 0.1 , Pi Max, P 0.1 / Pi Max, FR / VC and P 0.1 x FR /VC were 72,2, 38,8, 72,2, 83,3, 72,2 respectively. The positive predictive value for P 0.1 , Pi Max, P 0.1 / Pi Max, FR / VC and P 0.1 x FR /VC were respectively 89,1, 75,5, 89,3, 93,4 e 90,2. The negative predictive value for P 0.1 , Pi Max, P 0.1 / Pi Max, FR / VC and P 0.1 x FR /VC were respectively 54,1, 28,0, 56,5, 62,5 e 68,4. The diagnostic accuracy for P 0.1 , Pi Max, P 0.1 / Pi Max, FR / VC and P 0.1 x FR /VC were respectively 77,1, 58,5, 78,5, 82,8 e 84,2. The area under the ROC curves for P 0.1 , Pi Max, P 0.1 / Pi Max, FR / VC and P 0.1 x FR /VC were respectively 0,76± 0,06, 0,52±0,08 , 0,78±0,06, 0,90±0,04 e 0,84±0,05. The comparison among the areas under the ROC curves showed that the best weaning indexes were f / Vt ratio, the product P 0.1 x f / Vt and the P0.1/ Pi Max ratio with no statistic differences among them. The Pi Max presented the smaller area under the ROC curve. The weaning indexes P 0.1, Pi Max e P 0.1/ Pi Max were not statistically different between intubated or tracheostomized patients. Conclusion: The best weaning indexes were f/Vt ratio , the product P 0.1 x f/Vt and the P 0.1 / Pi Max ratio with no statistically difference among them.

This research study explored the meanings former patients attributed to being on long-term mechanical ventilation in a critical care unit (CCU). An interpretive phenomenological-ontological perspective informed by the philosophical tenets of Heidegger (1927/1962) was used to examine the lived experience of a group of people who had previously been hospitalised in one of three critical care units in southeast Queensland, Australia, during which time they were on a mechanical ventilator for a period of seven days or more. Data were collected using 14 unstructured audio-taped interviews from participants, who had indicated that they were willing and able to recall aspects of their critical care experience. The data were analysed using the method developed by van Manen (1990). A total of nine people participated in the study, of which six were male and three female. Their ages ranged from 21 to 69 years. Thematic analysis of the data revealed four themes: Being thrown into an uneveryday world; Existing in an uneveryday world; Reclaiming the everyday world; and Reframing the experience. Throughout the description of these themes, excerpts from the interviews with the participants are provided to demonstrate, and bring to light the meaning and interpretations constructed. From this thematic analysis, a phenomenological description drawing on Heidegger's tenets of Being was constructed. Titled Being at its most elusive, this description showed that participants experienced momentary lapses of: situation, engagement, concern and care, temporality, and the ability to self-interpret. These findings highlight and affirm the relevance of Heidegger's ontological tenets to reveal Being. The findings of this study served as a basis for a number of recommendations relating to nursing practice, education and research. Recommendations relating to practice include: constructing a more patient-friendly critical care environment, increased involvement of patients and their families in decision making and patient care activities; ensuring adequate critical care nursing staff levels; ensuring and maintaining appropriate skill level of critical care nurses; enhancing methods of communication with patients; planning for effective patient discharge and adoption of a designated nurse position for discharge planning; providing opportunities for follow up contact of patients once they are discharged from CCU; and promoting the establishment of follow up services for former CCU patients, and their families. Recommendations relating to critical care education include: incorporating more in-depth information of the psychological and social aspects of patient and family care into care planning; incorporating communication and counselling education and training to assist nurses caring for mechanically ventilated patients, and their families; further education regarding the role and responsibilities of patient discharge planning from CCU; incorporating more advanced research skills training and utilisation of research findings into practice; and the provision of appropriate and ongoing training and education in areas such as manual handling and communication skills for all health care staff involved in the direct care of CCU patients. This study also recommended that further research be undertaken to: examine and compare different sedative and analgesic protocols and their effects on the incidence of nightmares and hallucinations reported by CCU patients; replicate this study in a group of patients from different cultural or ethnic backgrounds; evaluate the efficacy of current methods for communicating with intubated and mechanically ventilated patients in the CCU; develop, test and evaluate the efficacy of new methods for communicating with intubated and mechanically ventilated patients in the CCU; examine CCU patients' perceived level of control and power; explore the extent and type of involvement patients would like to have in their care whilst in the CCU; investigate the extent and type of problems experienced by CCU patients after discharge; explore the usefulness and appropriateness of personal diaries for individual patients as an aid to assist in understanding and resolving their CCU experience; and examine the value of follow up contacts by CCU staff to former patients and their families. In summary, the findings from this study add substantial knowledge to critical care nurses' understanding and knowledge about what it means to be on long-term mechanical ventilation in a critical care unit. Findings will help inform future critical care nursing practice and education, and the provision of holistic and evidenced-based care.