A ventilação mecânica pulmonar é a substituição da respiração espontânea de um paciente quando este não realiza ou realiza parcialmente esta tarefa. Esta ventilação é de extrema importância para o tratamento de pacientes em estado crítico em unidades de terapia intensiva e para a manutenção da oxigenação sanguínea durante cirurgias. A ventilação mecânica pulmonar consiste em empurrar os gases para dentro do pulmão de forma controlada, mantendo uma pressão inspiratória ou um volume inspiratório determinado. Além disso, controla o nível de pressão durante a expiração do paciente para manter os alvéolos abertos e dificultar lesões internas. Este trabalho se propõe a caracterizar uma especificação de engenharia para os sistemas de controle de ventilação, se baseando em características fisiológicas do sistema respiratório do paciente saudável e também com patologias conhecidas. São apresentados modelos matemáticos para os sistemas mecânicos responsáveis pela atuação na inspiração e na expiração do paciente, bem como um modelo matemático para o sistema respiratório. Foram desenvolvidos sistemas de controle, baseados no controlador PID, para os principais tipos de modalidades ventilatórias. Os sistemas controlados foram simulados e os resultados são apresentados neste trabalho. Os controles propostos foram implementados em equipamentos de anestesia e UTI projetados na K. Takaoka Ind. Com. Prod. Hosp. LTDA. entre 2008 e 2010 no Brasil, e estão sendo usados hoje nas salas de cirurgia e centros de terapia intensiva pelo Brasil e em alguns países da América do Sul e do Oriente médio. / The mechanical ventilation is the replacement of spontaneous breathing of a patient when it does not perform or partially perform this task. This ventilation is extremely important for the treatment of critically ill patients in intensive care units and for the maintenance of blood oxygenation during surgery. The mechanical ventilation consists in pushing the gas into the lungs in a controlled manner, maintaining a determined inspiratory pressure or inspiratory volume. In addition, it has to control the pressure level during the patients exhalation to keep the alveoli opened and prevent internal injuries. This work aims to characterize an engineering specification for the control systems of ventilation, relying on physiological characteristics of the patient\'s respiratory system on healthy subjects and also subjects with known diseases. Here are presented mathematical models for the mechanical systems responsible for acting on the inspiration and expiration of the patient, as well as a mathematical model for the respiratory system. There were developed control systems, based on the PID controller for the main types of ventilation modes. Controlled systems were simulated and the results are presented in this dissertation. The proposed controls were implemented in anesthesia and intensive care equipments designed in K. Takaoka Ind. Com Prod. Hosp. LTD. between 2008 and 2010 in Brazil, and are being used today in the operating rooms and intensive care centers in Brazil and some countries in South America and the Middle East.

INTRODUÇÃO: O desmame da ventilação mecânica é um processo complexo que requer avaliação e interpretação de parâmetros clínicos objetivos e subjetivos. O atraso no processo de desmame pode expor o paciente a um desconforto desnecessário, aumentar o risco de complicações e custos. Os modos de desmame automatizados podem acelerar a extubação e diminuir a carga de trabalho da equipe da UTI. Há diversos modos automatizados de desmame disponíveis que foram avaliados, separadamente, em populações selecionadas, com resultados divergentes em relação ao desmame convencional. No entanto, os modos automáticos desmame não foram comparados entre si, nem sistematicamente avaliados, em condições específicas, mas comuns, como a ansiedade extrema ou esforços inspiratórios inefetivos. OBJETIVOS: Comparar os modos Smartcare®, ASV® e MRV® quanto a eficácia no desmame da ventilação mecânica. MÉTODOS: Estudo de bancada para avaliar os três diferentes modos de desmame automatizado: adaptive support ventilation (ASV®), mandatory rate ventilation (MRV®) and Smartcare®. Nós simulamos os pacientes usando um simulador pulmonar programável (ASL 5000 - Ingmar Medical) com o padrão respiratório, mecânica respiratória e CO2 arterial de derivados de artigos publicados em periódicos médicos para criar duas condições: 1.extubação provável: mecânica pulmonar normal, ansiedade extrema, idosos normais, padrão de respiração irregular extrema (Cheyne-Stokes), doença pulmonar restritiva; 2. extubação improvável: mecânica pulmonar alterada, com e sem esforços inspiratórios ineficazes. RESULTADOS: Os pacientes com extubação possível, ansiedade extrema, o padrão de respiração irregular moderada e extubação impossível foram diagnosticados corretamente por todos os modos. Os pacientes com Cheyne-Stokes foram diagnosticados impropiamennte por todos os modos, mas o modo Smartcare® diagnosticou corretamente quando a opção de distúrbio neurológico foi ativado. Apenas o Smartcare® diagnosticou corretamente o paciente com respiração rápida e superficial, devido à doença pulmonar restritiva. Somente o modo MRV® diagnosticou impropriamente o paciente com esforços inspiratórios ineficazes. O nível de estabilização da pressão de suporte variou para cada modo. ASV® e MRV® atingiram nível de pressão de suporte estável mais rápido do que Smartcare®. No entanto, especialmente para ASV®, não houve estabilização da pressão de suporte, mas oscilação da pressão ao longo de um grande intervalo. CONCLUSÃO: Os três modos de desmame automatizada tiveram desempenho correto na maioria dos pacientes, mesmo em condições adversas, como a ansiedade extrema. Pacientes com respiração rápida e superficial, devido à doença pulmonar restritiva, esforços inspiratórios ineficazes e Cheyne Stokes, foram impropriamente diagnosticados, dependendo do modo. ASV® e MRV® tem respostas mais rápidas, mas apresentaram grande variação do nível da pressão de suporte, especialmente de modo a ASV® / INTRODUCTION: Weaning from mechanical ventilation is a complex process requiring assessment and interpretation of both objective and subjective clinical parameters. Delay in weaning process may expose the patient to unnecessary discomfort and increased risk of complications, and increasing the cost of care. Automated weaning modes could quicken the extubation and decrease the ICU team workload. Many automated weaning modes were now available. They were separately evaluated in selected populations with divergent results when compared to conventional weaning. However the automated weaning modes were not compared among them, neither systematically evaluated in challenging but common conditions, as extreme anxiety or ineffective inspiratory efforts. OBJECTIVES: Compare Smartcare®, ASV® and MRV® effectiveness in weaning of mechanical ventilation. METHODS: Bench study to evaluate three different automated weaning modes: adaptive support ventilation (ASV®), mandatory rate ventilation (MRV®) and Smartcare®. We simulated the patients using a programmable lung simulator (ASL 5000 Ingmar Medical) with the breathing pattern, respiratory mechanics and arterial CO2 derived from published medical journals articles to create two conditions: 1. Successful extubation: normal lung mechanic, extreme anxiety; old normal adult, extreme irregular breathing pattern (Cheyne-Stokes), restrictive lung disease; 2. Unsuccessful extubation: altered pulmonary mechanics with and without ineffective inspiratory efforts. RESULTS: Patients with successful extubation, extreme anxiety, moderate irregular breathing pattern and unsuccessful extubation were properly diagnosed by all modes. Patients with Cheyne-Stokes were improperly diagnosed by all modes, but the Smartcare® mode properly diagnosed when the neurologic disorder option was activated. Only Smartcare® properly diagnosed the patient with rapid shallow breathing due to restrictive lung disease. Only MRV improperly diagnosed the patient with ineffective inspiratory efforts. The pressure support level that each mode stabilized varied. ASV® and MRV® reached a stable pressure support level faster than Smartcare®. However, especially for ASV®, there was not stabilization oscillation of the pressure support level over a large range. CONCLUSIONS: The three automated weaning modes performed properly in most patients, even in challenging conditions, as extreme anxiety. Patients with rapid shallow breathing due to restrictive lung disease, ineffective inspiratory efforts and Cheyne-Stokes were improperly diagnosed depending on the mode. ASV® and MRV® have faster responses, but they presented large pressure support level variation, especially the ASV® mode

Objetivo: Avaliar os efeitos do uso de dois diferentes níveis de pressão expiratória final positiva (PEEP) em porcos submetidos a transplante pulmonar unilateral através de troca gasosa [pressão parcial de oxigênio (PaO2) e pressão parcial de dióxido de carbono (PaCO2)], hemodinâmica [freqüência cardíaca (FC), pressão arterial média (PAM) e pressão da artéria pulmonar (PAP)], parâmetros ventilatórios [pressão media das vias aéreas (Pmédia); complacência estática (Cst) e resistência das vias aéreas (Rest)], resposta inflamatória [interleuina 8 (IL-8)] e estresse oxidativo [substância reativa ao ácido tiobarbitúrico (TBARS) and superóxido dismutase (SOD)]. Material e Métodos: Doze porcos pesando aproximadamente 30kg foram submetidos a transplante pulmonar esquerdo. Os animais foram randomizados em dois grupos de diferentes valores de PEEP: Grupo 1 (PEEP=5cmH2O) e Grupo 2 (PEEP=10cmH2O). Dados hemodinâmicos, troca gasosa e mecânica respiratória foram medidos em diferentes tempos após o transplante durante 210 minutos. Foi realizada análise histológica, de IL-8 e estresse oxidativo no tecido pulmonar. Resultados: O grupo 2 apresentou aumento significativo da FC (p=0,006) e Cst (p=0.001), diminuição da PAM (p=0.003) e Rest (p=0.001). Não houve diferença entre os grupos na concentração de TBARS, SOD e IL-8. Contudo, após o período de observação, o grupo 2 mostrou um aumento da concentração de TBARS (p=0,001) e IL-8 (p=0,05) e o grupo 1 um aumento da SOD (p=0,05) comparado com os valores iniciais. Conclusão: O uso de altos níveis de PEEP, após o transplante pulmonar unilateral, não resultou em melhora da troca gasosa. Embora apresentasse uma melhora da mecânica respiratória, a PEEP de 10 cmH2O teve impacto negativo nos parâmetros hemodinâmicos, e provocou um aumento da resposta inflamatória e estresse oxidativo. / Objective: Evaluate the effects of two different levels of positive end expiratory pressure (PEEP) on pigs submitted to unilateral lung transplantation through blood gas exchange [partial oxygen arterial pressure (PaO2) and partial carbon dioxide arterial pressure (PaCO2)], hemodynamics [heart rate (HR), mean arterial pressure (MAP) and pulmonary arterial pressure (PAP)], ventilatory parameters [mean airway pressure (P(aw)); static compliance (Cst) and airway resistance (Rest)], inflammatory response [interleukin 8 (IL-8)] and oxidative stress [thiobarbituric acid reactive substances (TBARS) and superoxide dismutase (SOD)]. Material and Methods: Twelve pigs were submitted to left lung transplantation. The animals were randomized into two groups of different PEEP levels: Group 1 (PEEP = 5cmH2O) and Group 2 (PEEP = 10cmH2O). Hemodynamics, gas exchange and respiratory mechanics were measured prior and after surgery for 210 minutes. Cytokines, oxidative stress and histological score were assessed in lung tissue. Results: Group 2 had significantly higher HR (p=0.006), Cst (p=0.001) and lower MAP (p=0.003) and Rest (p=0.001). There were no differences between both groups in TBARS, SOD and IL-8, concentration after transplant. However, at the end of the observation period, group 2 showed higher TBARS (p=0.001) and IL-8 (p=0.05) concentration and group 1 presented higher SOD (p=0.05) when compared to baseline. Conclusion: After unilateral lung transplantation, higher PEEP levels had no effect on gas exchange. Although, 10 cmH2O PEEP improved respiratory mechanics, it had a negative impact on hemodynamics and stimulated a high inflammatory response and production of reactive oxygen species.

L’atteinte neuromusculaire, responsable notamment d’une dégradation des muscles, entraine une insuffisance respiratoire sévère. Cette dernière constitue la composante majeure de la maladie, tant en termes de pronostic que de prise en charge. A ce jour, seule la ventilation mécanique permet de compenser l’affection respiratoire. Elle s’impose donc comme indication thérapeutique incontournable et son efficacité n’est plus à prouver. En effet, l’utilisation de la ventilation mécanique a permis l’impact de l’atteinte respiratoire très tôt le pronostic vital. En 40 ans, ce traitement a permis d’allonger considérablement l’espérance de vie des malades, passant pour par exemple les myopathies de Duchenne de Boulogne de 15 ans à plus de 30 ans à l’heure actuelle.Aujourd’hui, pour ces personnes dont la durée de vie a pu être allongée, se pose l’inévitable question de leur Qualité de vie, d’autant plus que cet allongement de vie s’accompagne d’une aggravation de la déficience musculaire et donc des dysfonctions motrices. De plus, il apparaît que la ventilation mécanique, si elle assure un confort respiratoire indispensable, accroît considérablement le niveau de dépendance des malades et fait émerger chez eux de nouvelles problématiques identitaires, psychosociales ou même économiques. Il s’avère essentiel d’identifier les conséquences de la maladie et du Handicap qu’elle entraine. Il convient ensuite d’analyser l’impact direct de la ventilation mécanique sur la qualité de vie des malades et notamment son effet délétère sur la communication et la déglutition des patients. L’objectif principal de ce travail est de proposer en réponse à notre problématique des alternatives visant à améliorer la qualité de vie des patients en optimisant les deux grandes fonctions physiologiques que sont la parole et la déglutition / Neuromuscular diseases responsible of a wasting of the muscles, may involve severe respiratory failure. It is a major component of the disease, both in terms of prognosis and management. Up to now, only mechanical ventilation can compensate the respiratory disease. It is therefore required as an essential therapeutic indication and its effectiveness is already proven. Indeed, mechanical ventilation has allowed a significant increase of life expectancy. Over the past 40 years, this treatment has considerably increased the life expectancy of patients; for instance patients with Duchenne who passed away in their late teens survive now over their 30’s. Nowadays, for those people whose life has been extended, the question of their quality of life is unavoidable, especially as this longer life is accompanied by a worsening of muscle impairment and of motor disorder. Moreover, it appears that mechanical ventilation, if it provides breathing comfort, increases the level of dependency of patients and leads to the emerging psychological and even economical problems. It is essential to identify the consequences of the disease and the disability that it involves. It is then necessary to analyze the direct impact of mechanical ventilation on the quality of life of patients and especially its deleterious effects on communication and swallowing

Introdução: O grande desafio da descontinuação da VM esta em identificar corretamente os pacientes aptos a extubação com sucesso. O índice de respiração rápida e superficial (IRRS) tem sido o mais utilizado dentro desse processo em pacientes de unidade de terapia intensiva (UTI). Objetivos: O objetivo deste estudo foi avaliar o desempenho do ponto de corte, medidas seriadas e melhor método de obtenção do IRRS em predizer o insucesso de extubação para pacientes graves sob VM prolongada com fatores de risco para falha de extubação. Métodos: Estudo prospectivo, incluindo pacientes com 72h ou mais de ventilação mecânica (VM), prontos para o desmame, de acordo com critérios clínicos. O IRRS foi obtido diariamente, a partir do primeiro dia de desmame, com o paciente recebendo suporte ventilatório (IRRS_MIN) (PS 5cmH2O e PEEP 5cmH2O) e pelo ventilômetro em respiração espontânea (IRRS_ESP). Para os pacientes que passaram pelo processo de desmame com sucesso e foi indicada a extubação, o IRRS foi obtido anteriormente ao teste de respiração espontânea (TRE) através do ventilômetro (IRRS_PRE_TUBO_T), e em seguida colocado em TRE por 30 min. Após 30 min se o paciente não apresentou sinais de intolerância a desconexão da VM, o IRRS foi obtido em respiração espontânea (IRRS_PÓS_TUBO_T) e o paciente foi prontamente extubado. Os resultados foram analisados agrupando os pacientes de acordo com o desfecho do desmame: Grupo traqueostomia (GT); Grupo insucesso de extubação (GI), Grupo sucesso de extubação (GS). Resultados: 45 pacientes finalizaram o estudo, sendo 15 (33%) do GT, 11 (37%) do GI e 19 (63%) do GS. Fatores como tempo de intubação, tempo para iniciar o desmame e tempo de desmame foram maiores nos grupos GT e GI (p<0,05). Um novo ponto de corte foi calculado para essa população ( 74 ciclos/min/L), com especificidade de (0,64) e valor preditivo negativo de (0,54), que melhor identificou os pacientes com falha de extubação (FE). Quanto ao método de obtenção, em todos os grupos, o IRRS_MIN foi menor (GT=68,60 ± 35,16; GI=38,64 ± 12,31; GS=34,79 ±14,67) quando comparado ao IRRS_ESP (GT=141,60 ± 70,13; GI=80,09 ± 20,71; GS=60,95 ± 24,64) (p<0,05). As medidas diárias do IRRS apresentaram oscilações no GT, enquanto que nos GS e GI houve uma tendência de melhora. O IRRS_POS_TUBO_T quando comparado a IRRS_PRE_TUBO_T aumentou no GS e GI (GS: 60.95±24.64 e 69.79±22.67; GI: 80.09±20,71 e 87,09±13,28), com valores menores para o GS (p<0,5). As medidas obtidas em respiração espontânea, com o novo ponto de corte e após 30 minutos de TRE identificaram a FE em 90% dos pacientes. Conclusão: Em pacientes graves, as medidas do IRRS em respiração espontânea, com ponto de corte 74 ciclos/min/L e após o TRE melhora a identificação dos pacientes que poderão evoluir com falha de extubação. / Introduction: One of the challenges in the discontinuation of mechanical ventilation (MV) is ability to correctly identify patients able for a successfully extubation. The Rapid Shallow Breathing Index (IRRS) has been widely used in this process in patients of intensive care unit (ICU). Objectives: The aim of this study was to evaluate the performance of the cutting point, serial measurements and best method of obtaining the IRRS in predicting extubation failure in critically ill patients for prolonged MV and with risk factors for extubation failure. Methods: Prospective study, including patients with 72h or more of MV, ready for weaning according to clinical criteria. The IRRS was daily obtained since the first day of weaning, with the patient receiving ventilatory support (IRRS_MIN) (PS 5cmH2O 5cmH2O and PEEP) and spontaneous breathing in the spirometer (IRRS_ESP). For patients who have gone successfully through the process of weaning and the extubation was indicated, the IRRS was obtained prior to the Spontaneous Breathing Test (SBT) through the spirometer (IRRS_PRE_TUBO_T) and then placed on SBT for 30 min. After 30 minutes, if the patient showed no signs of intolerance to disconnect the VM, the IRRS was obtained in spontaneous breathing (IRRS_PÓS_TUBO_T) and the patient was readily extubated. The results were analyzed by grouping patients according to the outcome of weaning, Tracheostomy Group (TG), Unsuccess Extubation Group (UEG), Success Extubation Group (SEG). Results: 45 patients finished the study, 15 (33%) of TG, 11 (37%) of UEG and 19 (63%) of SEG. Factors such as intubation time, time to start weaning and weaning time were higher in UEG and TG groups (p <0.05). A new cut-off point was calculated for this population ( 74 breaths/min/L), with a specificity of 0.64 and negative predictive value of 0.54, which best identified patients with extubation failure (EF). Regarding the method for obtaining the IRRS, IRRS_MIN was lower (TG=68,60 ± 35,16; UEG=38,64 ± 12,31; SEG=34,79 ±14,67) compared to IRRS_ESP) (TG=141,60 ± 70,13; UEG=80,09 ± 20,71; SEG=60,95 ± 24,64) (p<0,05) in all groups. The daily measurements of the IRRS showed oscillations in UEG, while there was a trend decrease in the SEG and SEG. The IRRS_POS_TUBO_T increased in the SEG and UEG compared to IRRS_PRE_TUBO_T (SEG: 60.95 ± 24.64 and 69.79 ± 22.67, UEG 80.09 ± 20.71 and 87.09 ± 13.28), with lower values for UEG (p <0.5). The measurements obtained in spontaneous breathing identified the EF in 90% of patients when using the new cut-off point and after 30 minutes of SBT. Conclusion: In critically ill patients, the measures of IRRS in spontaneous breathing, with a cutoff 74 breaths/min/L and after SBT improves the identification of patients who may evolve with extubation failure.

Submitted by PPG Medicina e Ci?ncias da Sa?de (medicina-pg@pucrs.br) on 2018-12-11T13:17:23Z No. of bitstreams: 1 FERNANDA DALLAZEN.pdf: 1913250 bytes, checksum: 643c26e233052ab4843690b459dd637d (MD5) / Approved for entry into archive by Sheila Dias (sheila.dias@pucrs.br) on 2018-12-13T12:27:07Z (GMT) No. of bitstreams: 1 FERNANDA DALLAZEN.pdf: 1913250 bytes, checksum: 643c26e233052ab4843690b459dd637d (MD5) / Made available in DSpace on 2018-12-13T12:40:00Z (GMT). No. of bitstreams: 1 FERNANDA DALLAZEN.pdf: 1913250 bytes, checksum: 643c26e233052ab4843690b459dd637d (MD5) Previous issue date: 2018-10-05 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / Objective: To construct a risk score model for prolonged mechanical ventilation (PMV) in patients undergoing coronary after bypass grafting (CABG). Methods: An observational, retrospective and historical cohort study, with 4.165 patients submitted to coronary artery bypass grafting, between January 1996 and December 2016. The duration of ?12 hours on mechanical ventilation defined as prolonged. The multiple logistic regression was used to evaluate the predictor variables. The modeling database, divided in 2/3 of the sample (2.746 patients) generated the preliminary model and its performance was tested in the validation database, divided in 1/3 of the sample (1.419 patients). The final risk score was validated in the total database and the accuracy of the model was tested by performance statistics. Results: The incidence of PMV was 18.8% (783). The variables associated with prolonged PMV were: age ?65 years (OR=1.91; [CI95%=1.62-2.24]; p<0.001); urgent/emergency surgery (OR=2.79; [CI95%=2.09-3.73]; p<0,001); obesity (OR=1.49; [CI95%= 1.21-1.84]; p<0.001); chronic renal failure (OR=1.98; [CI95%=1.61-2.44]; p<0.001); chronic obstructive pulmonary disease (OR=1.43; [CI95%=1.16-1.76];p<0,001) and extracorporeal circulation time ?120 minutes (OR=1.75; [IC95%=1.42-2.16]; p<0.001). The area under de the ROC curve was 0.66 (IC95%=0.64-0.68), the chi-square was 3.38 and the correlation coefficient of r=0.99 (p<0.000). Conclusion: The preoperative predictor variables (age ?65 years, urgent/emergency surgery, obesity, chronic renal failure and chronic obstructive pulmonary disease) and perioperative (extracorporeal circulation time ?120 minutes) were associated with PMV and allowed the constructed of risk score classified in low, medium, high and very high. / Objetivo: Construir um modelo de escore de risco para ventila??o mec?nica prolongada (VMP) em pacientes p?s-cirurgia de revasculariza??o mioc?rdica (CRM). M?todos: Estudo observacional, retrospectivo e de coorte hist?rica, com 4.165 pacientes submetidos ? CRM, entre janeiro de 1996 a dezembro de 2016. A perman?ncia >12 horas em ventila??o mec?nica foi definida como prolongada. A regress?o log?stica m?ltipla foi utilizada para avaliar as vari?veis preditoras. O banco de dados modelagem, dividido em 2/3 da amostra (2.746 pacientes) gerou o modelo preliminar e seu desempenho foi testado no banco valida??o, dividido em 1/3 da amostra (1.419 pacientes). O escore final foi validado no banco total e a acur?cia do modelo foi testada pelas estat?sticas de desempenho. Resultados: A incid?ncia de VMP foi de 18,8% (783). As vari?veis associadas ? VMP foram: idade ?65 anos (OR=1,91; [IC95%=1,62-2,24]; p<0,001); cirurgia de urg?ncia/emerg?ncia (OR=2,79; [IC95%=2,09-3,73]; p<0,001); obesidade (OR=1,49; [IC95%= 1,21-1,84]; p<0,001); insufici?ncia renal cr?nica (OR=1,98; [IC95%=1,61-2,44]; p<0,001); doen?a pulmonar obstrutiva cr?nica (OR=1,43; [IC95%=1,16-1,76]; p<0,001) e tempo de circula??o extracorp?rea ?120 minutos (OR=1,75; [IC95%=1,42-2,16]; p<0,001). A ?rea sob a curva ROC foi 0,66 (IC95%=0,64-0,68), o qui-quadrado de 3,38 (p=0,642) e o coeficiente de correla??o de r=0,99 (p<0,000). Conclus?o: As vari?veis preditoras pr?-operat?rias (idade ?65 anos, cirurgia de urg?ncia/emerg?ncia, obesidade, insufici?ncia renal cr?nica e doen?a pulmonar obstrutiva cr?nica) e perioperat?ria (tempo de circula??o extracorp?rea ?120 minutos) estiveram associadas com a VMP e permitiram a constru??o do escore de risco classificado em baixo, m?dio, alto e muito alto.

The primary, descriptive aim of this dissertation was to describe the nighttime sleep quality of previously mechanically ventilated older adult patients within 24-48 hours of transfer out of the intensive care unit (ICU) to a medical-surgical floor. The secondary, exploratory aim was to examine the relationships between post-ICU sleep efficiency (SE) and wake after sleep onset (WASO) with grip strength in previously mechanically ventilated older adult patients within 24-48 hours of transfer out of the ICU. The study included 30 adults ages 65 and older (11 women, 19 men; age 71.37 ± 5.35, range 65-86 years), who were functionally independent at home prior to hospitalization, mechanically ventilated during their ICU stay, and were within 24-48 hours of transfer out of ICU to a medical-surgical floor at Tampa General Hospital, a level 1 trauma center. Subjects wore an actigraph monitor on the dominant wrist (Actiwatch Spectrum) to monitor sleep over two consecutive nights. Parameters of post-ICU sleep quality included total sleep time (TST), sleep efficiency (SE), wake after sleep onset (WASO), sleep latency (SL), and number of awakenings (NA). The outcome measure of motor function was dominant hand grip strength, assessed by the National Institutes of Health Toolbox Motor Battery Grip Strength Test. Sleep data collected between nighttime hours (9:00 PM to 9:00 AM) on both nights were analyzed. For the descriptive aim, means for each sleep parameter and clinical characteristics were reported. For the exploratory aims, multiple regression analyses examined the individual associations between mean sleep parameters (SE and WASO) and grip strength. Study subjects had a mean SE of 63.24 ± 3.88% and spent 135.39 ± 9.94 minutes awake after sleep onset. The mean TST among subjects was 7.55 ± 2.52 hours, ranging from 2.02 to 10.84 hours of sleep, out of the 12 hours of total time in bed. A total of 6 (20%) subjects slept less than 5 hours each night, and a total of 6 (20%) subjects slept greater than 10 hours each night. The mean SL among study subjects was 42.57 minutes, and ranged from 0.0 to 237.75 minutes. Overall, subjects’ average NA was 78.28 ± 26.39, ranging from 35 to 136 awakenings. In multiple regression analysis, SE was significantly and negatively associated with grip strength, after adjusting for potential confounding factors. The model predictors explained 80.8% of the variance in grip strength, [R2 = .808, F(10, 15) = 6.324, p = .001]. Higher SE independently predicted worse grip strength (β = -0.326, p = .036). Further, among the tertiles of subjects with moderate or high TST (sleep duration ≥ 6 hours, n = 23), there remained a significant, negative association between SE and grip strength. The predictors explained 73.7% of the variance in grip strength, [R2 = .737, F(5, 15) = 8.416, p = .001]. Higher SE independently predicted worse grip strength among the subset of subjects with moderate or high sleep duration (β = -0.296, p = .046). Among the two quartiles of subjects with moderate-high or high WASO (≥ 120 minutes spent awake after sleep onset, n = 16), there was a significant, negative association between WASO and grip strength, after adjusting for covariates. The model indicated that the predictors explained 91.4% of the variance in grip strength [R2 = .914, F(6, 8) = 14.134, p = .001]. Greater WASO independently predicted worse grip strength (β = -0.276, p = .04). Finally, the effects of sex and preexisting obstructive sleep apnea (OSA) on grip strength were individually examined. Higher SE independently predicted worse grip strength among male subjects (β = -0.353, p = .039), as did preexisting OSA (β = -0.493, p = .033). In summary, objectively measured sleep quality was disturbed among previously mechanically ventilated, hospitalized older adults, even after transfer out of ICU to a medical-surgical floor. Longer TST and greater SE predicted worse grip strength among these frail patients who were previously independent, community dwelling older adults. Among the subjects with more severely fragmented sleep, WASO also independently predicted weaker grip strength. As poor grip strength is an indicator of ICU-acquired weakness, optimal sleep duration and less sleep disturbances may be crucial in prevention of worse functional outcomes and new institutionalization. Additional research is needed to discern the temporality of associations between sleep quality and motor function among older adult survivors of critical illness.

Introduction: Several problems arise when HMEs are used while giving aerosolized medication including increased airway resistance (Raw) or the need to open the ventilator circuit. Recently, heat and moisture exchangers designed to allow aerosol delivery (HME-AD) have been developed to solve this problem, but no tests have been performed to confirm their effectiveness. The purpose of this study is to evaluate the effect of HME-ADs on aerosol deposition and Raw. Methods: An in-vitro lung model consisting of an 8.0 mm ID endotracheal tube (ETT) connected to a standard ventilator circuit and ventilator was connected to a rubber test lung via cascade humidifier set to deliver 37˚C and 100% relative humidity. The ventilator settings were as follows: Vt 450 ml, RR 20/min, PIF 50 L/min, PEEP 5 cm H2O, and I:E ratio 1:2. HME-ADs used in this study include Circuvent HME/HCH bypass (Smiths-Medical, Keene, NH), Gibeck Humid-Flo HME (Hudson RCI, Arlington Heights, IL), and Airlife BHME (Carefusion, San Diego, CA). As a control, albuterol sulfate (2.5 mg/3mL) was delivered with a vibrating mesh nebulizer (Aeroneb Solo, Aerogen Inc) placed at the wye without any HME-AD in the circuit. Then, the aerosol and HME configurations of each HME-AD were tested by measuring pre-post Raw and aerosol deposition at the end of each run. Each condition was repeated in triplicate (n=3). Aerosol deposition between the aerosol and HME configurations of each HME-AD was compared with a series of student t-tests. Then, differences both in aerosol deposition and in airway resistance among the HME-ADs were analyzed using one-way analysis of variance (ANOVA). Significance was determined as p<0.05. Results: Raw increased after each albuterol treatment with every HME-AD. In the aerosol configuration, the Circuvent and Humid-Flo delivered significantly less aerosol compared to the control (p=.004 and p=.002, respectively), while there was no significant difference on aerosol delivery between the Airlife and the control (p=.084). The Airlife gave the highest aerosol deposition which was not significantly different than control (p=.084). When aerosol delivery between the HME and aerosol configurations in each HME-AD was compared, aerosol deposition with the Humid-Flo was not significantly different (p=.078) but both the Airlife and the Circuvent showed a statistically significant reduction in aerosol deposition with the HME configuration (p=.002 and p=.005). Conclusions: Aerosol delivery and Raw with each HME-AD differ in simulated mechanically ventilated patients. Further studies are needed to determine the effectiveness of these devices over time and with different aerosol generating devices.

The present work consists of two parts: experimental study of natural ventilation in a model room and the flow associated with a source-sink pair. The first part describes the natural ventilation of a model room of size 300mmx 300mm x 300mm with water as the fluid medium. It is insulated by air gaps on the four sides and at the top. A constant heat flux of 3148W/m2 has been maintained on the bottom surface of the room. This ‘room’ is surrounded by a large exterior tank containing water. The changes in temperature of the bottom, the interior and the exterior have been measured using T-type thermocouples. There are three openings each on two opposing sides of the model room. For any experiment, only one opening on each side is kept open. Fluid enters or leaves these openings and the flow is driven entirely by buoyancy forces. Three configurations have been studied: (1) The bottom opening at the inlet side and the top opening at the outlet side are open, (2) the bottom opening at the inlet side and the middle opening at the outlet side are open, and (3) the middle opening at the inlet side and the top opening at the outlet side are open. Shadowgraph technique is used for visualization. The buoyancy causes flow to enter through the bottom opening and leave through the top opening. At the openings, buoyant jets are observed and which have higher or lower relative densities. The buoyant jet at the inlet interacts with the plumes on the heated bottom plate. From these visualizations, it appears that free convection at bottom plate will be affected by the buoyant jets at the openings and the degree to which it is affected depends on the position and size of openings and distance between inlet and outlet. The flow rate due to the natural ventilation depends on the bottom surface heat flux and the height difference between the openings. The temperatures of the floor, the interior and the exterior are calculated using a simple mathematical model (Hunt and Linden [1999]). The mathematical model assumes well mixed conditions within the room and accounts for losses at the openings. The values of temperatures obtained in the experiments are reasonably well predicted by the mathematical model. The second part of the work is concerned with the interaction of a source -sink pair. The source consists of fluid issuing out of a nozzle in the form of a jet and the sink is a pipe that is kept some distance from the source pipe. Such source -sink pairs are observed in many situations including data centers, and collection of fresh water from a large reservoir that has also a discharge of pollutants. The main parameters of the problem are source and sink flow rates, the axial and lateral separations of the source and sink, and the angle between the axes of source and sink. Of concern is the percentage of source fluid that enters the sink as a function of these parameters. The experiments have been carried in a large glass water tank. The source nozzle diameter is 6mm and the sink pipe diameter is either 10mm or 20mm. The horizontal and vertical separations and angles between these source and sink pipes are adjustable. The Reynolds numbers of the source jet is about 3200. Experiments were done with the sink flow rate equal to, lower or higher than the source flow rate. The flow was visualized using KMnO4 dye and planar Laser Induced Fluorescence (LIF). The velocity fields for some cases were obtained using Particle Image Velocitymetry (PIV). To obtain the efficiency (that is percentage of source fluid entering the sink pipe), titration method is used. A small amount of hydrochloric acid (HCL) is added in the jet fluid through the overhead tank and the fluid collected at the sink is titrated with the Sodium hydroxide (NaOH) as base and Phenolphthalein as the pH indicator. The main characteristics of the jet, without a sink, were measured using PIV. The velocity profiles, jet widths and volume flow rates at various axial locations were obtained and compared with results reported in the literature for similar Reynolds number jets. For 100%, 70%, 50% and 25% efficiencies or removals and for zero lateral separations, the sink flow rate is about 1.5 times the flow rate predicted on the basis of jet properties at that point in the absence of a sink. The sink flow rate to obtain a certain efficiency increase dramatically with lateral separation; for example, when the lateral separation is about one half jet width, the required sink flow rate to obtain a certain efficiency increases by about five times. The sink diameter and the angle between source and the sink axes don’t influence efficiencies as much as the lateral separation. Data from our all experiments have been consolidated in the form of correlations that can be used for design of appropriate sinks for removal of heat and pollutants.

Bakgrund: Sedering av respiratorbehandlade patienter är ofta en nödvändighet för komfort och för att kunna utföra optimal behandling. Trenderna inom sedering har på senaste tid gått från djup till lätt sedering. Tidigare forskning indikerar att detta är fysiologiskt gynnsamt för patienterna och att det upplevs som positivt av både patienter och anhöriga. Dock är det föga utforskat hur detta nya arbetssätt upplevs av sjuksökterskorna och hur det påverkar deras arbetssituation. Syfte: Att beskriva sjuksköterskors upplevelser av att vårda lätt sederade patienter i respirator. Metod: Studien genomfördes med en kvalitativ design och datainsamlingen skedde genom fem intervjuer med semistrukturerade frågor. Intervjutexten analyserades via induktiv innehållsanalys, vilket resulterade i formulering av tre huvudkategorier och åtta subkategorier. Resultat: Sjuksköterskornas upplevelser av att vårda lätt sederade patienter i respirator beskrivs genom tre huvudkategorier: En upplevelse av samspel, en upplevelse av att inte räcka till och en upplevelse av teamarbetets betydelse. Slutsats: Lätt sedering bidrar till en möjlighet att etablera en relation till patienten genom ett samspel av kommunikation, delaktighet och information. Men att vårda lätt sederade patienter upplevdes som utmanande och krävande av sjuksköterskorna, vilket ledde till känslor av otillräcklighet och stress. Det krävs kunskap, erfarenhet och ett multiprofessionellt teamarbete för att lyckas ta tillvara på de positiva effekterna av sänkt sederingsdjup. Därför är det viktigt att utbilda intensivvårdspersonal om fördelarna med lätt sedering och om hur de bör kommunicera med patienterna. / Background: Sedation of mechanically ventilated patients is often necessary for comfort and for implementing the best possible treatment. The trends in sedation have gone from deep to light sedation. Previous research indicates that this is beneficial physiologically for patients and is perceived as positive by both patients and relatives. However, there is little research on how this new approach is experienced by nurses and how it affects their work situation. Purpose: To describe nurses' experiences of caring for lightly sedated patients during mechanical ventilation. Method: The study was conducted with a qualitative design and data was collected through five interviews with semi-structured questions. The data was analysed with inductive content analysis, resulting in the fomulation of three main categories and eight sub-categories. Result: The nurses' experiences of caring for lightly sedated patients during mechanical ventilation was described in three main categories: An experience of interplay, an experience of being insufficient and an experience of the importance of team work. Conclusion: Light sedation contributes to an opportunity to establish a relationship with the patient through an interplay of communication, participation and information. But caring for lightly sedated patients was experienced as challenging and difficult for nurses, leading to feelings of inadequacy and stress. It takes knowledge, experience and a multidisciplinary teamwork to successfully take advanage of the positive effects of reduced sedation depth. Therefore it is important to educate critical care staff about the benefits of light sedation and about how they should communicate with the patients