Patient-v entilator asynchrony (PVA) is a mismatch between the patient, regarding time, flow, volume, or pressure demands of the patient respiratory system, and the ventilator, which supplies such demands, during mechanical ventilation (MV). It is a common phenomenon, with incidence rates ranging from 10% to 85%. PVA might be due to factors related to the patient, to the ventilator, or both. The most common PVA types are those related to triggering, such as ineffective effort, auto-triggering, and double triggering; those related to premature or delayed cycling; and those related to insufficient or excessive flow. Each of these types can be detected by visual inspection of volume, flow, and pressure waveforms on the mechanical ventilator display. Specific ventilatory strategies can be used in combination with clinical management, such as controlling patient pain, anxiety, fever, etc. Deep sedation should be avoided whenever possible. PVA has been associated with unwanted outcomes, such as discomfort, dyspnea, worsening of pulmonary gas exchange, increased work of breathing, diaphragmatic injury, sleep impairment, and increased use of sedation or neuromuscular blockade, as well as increases in the duration of MV, weaning time, and mortality. Proportional assist ventilation and neurally adjusted ventilatory assist are modalities of partial ventilatory support that reduce PVA and have shown promise. This article reviews the literature on the types and causes of PVA, as well as the methods used in its evaluation, its potential implications in the recovery process of critically ill patients, and strategies for its resolution.

BACKGROUND: Pressure support ventilation (PSV) is often associated with patient-ventilator asynchrony. Proportional assist ventilation (PAV) offers inspiratory assistance proportional to patient effort, minimizing patient-ventilator asynchrony. The objective of this study was to evaluate the influence of respiratory mechanics and patient effort on patient-ventilator asynchrony during PSV and PAV plus (PAV+). METHODS: We used a mechanical lung simulator and studied 3 respiratory mechanics profiles (normal, obstructive, and restrictive), with variations in the duration of inspiratory effort: 0.5, 1.0, 1.5, and 2.0 s. The Auto-Trak system was studied in ventilators when available. Outcome measures included inspiratory trigger delay, expiratory trigger asynchrony, and tidal volume (V _T ). RESULTS: Inspiratory trigger delay was greater in the obstructive respiratory mechanics profile and greatest with a effort of 2.0 s (160 ms); cycling asynchrony, particularly delayed cycling, was common in the obstructive profile, whereas the restrictive profile was associated with premature cycling. In comparison with PSV, PAV+ improved patient-ventilator synchrony, with a shorter triggering delay (28 ms vs 116 ms) and no cycling asynchrony in the restrictive profile. V _T was lower with PAV+ than with PSV (630 mL vs 837 mL), as it was with the single-limb circuit ventilator (570 mL vs 837 mL). PAV+ mode was associated with longer cycling delays than were the other ventilation modes, especially for the obstructive profile and higher effort values. Auto-Trak eliminated automatic triggering. CONCLUSIONS: Mechanical ventilation asynchrony was influenced by effort, respiratory mechanics, ventilator type, and ventilation mode. In PSV mode, delayed cycling was associated with shorter effort in obstructive respiratory mechanics profiles, whereas premature cycling was more common with longer effort and a restrictive profile. PAV+ prevented premature cycling but not delayed cycling, especially in obstructive respiratory mechanics profiles, and it was associated with a lower V _T .

Background: Noninvasive ventilation (NIV) provides positive pressure through different interfaces. A multifunctional full-face mask prototype was developed to provide NIV from three sources: ICU ventilators, portable ventilators, and high-flow medical gas pipeline systems. This study aimed to evaluate the usability of this prototype mask. Methods: This was a quantitative experimental study, conducted in two phases: the development of a full-face mask prototype NIV interface, and the evaluation of its usability by health professionals (evaluators) using a heuristic approach. The Wolf Mask prototype is a multifunctional full-face mask that makes it possible to deliver positive pressure from three different sources: microprocessor-controlled ICU ventilators, portable ventilators with single-limb circuits, and high-flow medical gas. The evaluation was conducted in three stages: presentation of the prototype to the evaluators; skills testing via simulation in a clinical environment; and a review of skills. Results: The prototype was developed by a multidisciplinary team and patented in Brazil. The evaluators were 10 health professionals specializing in NIV. Seven skills related to handling the prototype were evaluated. Three of the ten evaluators called for (non-urgent) changes to improve recognition of the components of the prototype. Only one evaluator called for (non-urgent) changes to improve recognition of the pieces, assembly, and checking the mask. Conclusions: The newly developed multifunctional full-face mask prototype demonstrated excellent usability for providing noninvasive ventilation from multiple sources. Minor modifications may further improve the design.

OBJETIVO: Analisar a qualidade de vida (QV) e a escala de sonolência dos pacientes com síndrome da apneia obstrutiva do sono (SAOS) em tratamento com pressão positiva contínua nas vias aéreas (CPAP). MÉTODOS: Realizou-se um estudo transversal, no Centro do Estudo do Sono de Fortaleza (CESF), de agosto de 2011 a abril de 2012. Participaram 33 usuários de CPAP com SAOS, independentes do sexo, e adultos ou idosos. Aplicaram-se três instrumentos de coleta: questionário sobre a QV; dados demográficos e clínicos e a escala de sonolência de Epworth (ESE). RESULTADOS: Os participantes tinham idade média de 58,03 ± 11,83 anos, dos quais 19 (69,21%) acima de 60 anos; 25 (75,8%) do sexo masculino; e 27 (81,8%) com alguma comorbidade. Sobre o CPAP, 19 (57,6%) utilizaram por mais de 12 meses; 31 (93,9%) faziam uso do automático; e com média de pressão de 11,40 ± 3,48 cmH₂O. Na QV, todos os domínios tiveram pontuações acima de 70, com maiores escores para aspecto social e a limitação por aspecto físico. Na ESE foi encontrado pontuação de 7,64 ± 3,81. O sexo masculino e a faixa etária abaixo de 60 anos apresentaram maiores pontuações da QV e menor pontuação na sonolência diurna (ESE), porém não se constatou influência do tempo de uso do CPAP. CONCLUSÕES: Diante desses achados, ressalta-se a importância da prescrição e aplicação do CPAP para melhoria das condições clínicas da SAOS, como a sonolência diurna, e as repercussões benéficas na QV desses pacientes.

Objectives: To conduct a systematic review of the literature on the outcomes of a physical rehabilitation program on functionality and identify possible impacts on quality of life in patients after liver transplantation. Methods: Controlled clinical trials and observational studies were selected from the PubMed, SciELO, and BIREME databases that "t the PICO (P – population; I – intervention; C – comparison; O – outcomes) question “what are the bene"ts of a physical rehabilitation program on functionality and quality of life outcomes in patients undergoing liver transplantation?” Studies written in English, Portuguese, and Spanish, published in the last 10 years were selected. After selection, the Physiotherapy Evidence Database (PEDro) scale was used to perform the methodological evaluation of the studies. Results and Discussion: A total of "ve interventionist articles were selected, most of which had good methodological quality. Only one study did not associate resistance training with aerobic exercises, but all had signi"cant results regarding increased functional capacity and reduced perception of fatigue after liver transplantation. Conclusion: !e studies indicated that the association of a resistance training program associated with aerobic training is bene"cial in terms of muscle strength gain, exercise capacity, and perception of fatigue.

Objetivos: Realizar uma revisão sistemática da literatura acerca dos desfechos de um programa de reabilitação física sobre a funcionalidade e identificar possíveis impactos na qualidade de vida em pacientes no pós-transplante hepático (TxH). Métodos: Foram selecionados ensaios clínicos controlados e estudos observacionais das bases de dados PubMed, SciELO e BIREME que se encaixassem na estratégia PICO (P – population; I – intervention; C – comparison; O – outcomes) guiando a elaboração da pergunta norteadora: “quais os benefícios de um programa de reabilitação física sobre os desfechos de funcionalidade e qualidade de vida em pacientes submetidos ao transplante hepático?” Foram selecionados estudos escritos em inglês, português e espanhol, publicados nos últimos 10 anos. Após a seleção, a escala Physiotherapy Evidence Database (PEDro) foi utilizada para realizar a avaliação metodológica dos estudos. Resultados e Discussão: Foram selecionados cinco artigos intervencionistas, a maioria com boa qualidade metodológica. Apenas um estudo não associou o treino resistido a exercícios aeróbicos, porém todos tiveram resultados significativos quanto ao aumento da capacidade funcional e redução da percepção de fadiga no pós-TxH. Conclusão: Os estudos indicaram que a associação de um programa de treinamento resistido com treino aeróbico é benéfica quanto ao ganho de força muscular, capacidade de exercício e percepção de fadiga.