Performance of Invasive Mode in Different Heated Humidification Systems With High-Flow Nasal Cannula.

BACKGROUND: Oxygen therapy via high-flow nasal cannula generates physiologic changes that impact ventilatory variables of patients. However, we know that there are detrimental effects on airway mucosa related to inhalation of gases. The objective of this study was to evaluate the performance in terms of absolute humidity, relative humidity, and temperature of different brands of heated humidifiers and circuits in the invasive mode during the use of high-flow oxygen therapy in flows between 30 and 100 L/min. METHODS: A prospective observational study conducted at the Sanatorio Anchorena equipment analysis laboratory; September 5 to October 20, 2019. RESULTS: A statistically significant interaction was found among the programmed flows and the different combinations of devices and circuits for the delivery of absolute humidity (P < .001). An effect of flow on delivered absolute humidity was found, regardless of the equipment and circuit combination (P < .001). However, in the invasive mode, the combination of the Fisher&Paykel MR850 heated humidifier with the Medtronic-Dar circuit, the Intersurgical circuit, and the AquaVENT circuit always reached or achieved absolute humidity values > 33 mg/L, even at flows up to 100 L/min. The combination of the Flexicare FL9000 heated humidifier with the Fisher&Paykel RT202 circuit, the Fisher&Paykel Evaqua 2 circuit, the Flexicare circuit, the AquaVENT circuit, and the GGM circuit achieved similar results. The mean (SD) of absolute humidity delivered in the invasive mode (36.2 ± 5.9 mg/L) was higher compared with the noninvasive mode (26.8 ± 7.2 mg/L) (P < .001), regardless of circuit and programmed flows. CONCLUSIONS: When heated humidifiers were used in the invasive mode for high-flow oxygen therapy, absolute humidity depended not only on the heated humidifiers and the combination of circuits but also on the programmed flow, especially at flows > 50 L/min. Moreover, the heated humidifiers exhibited different behaviors, in some cases inefficient, in delivering adequate humidification. However, some equipment improved performance when set to the invasive mode.

Performance of Different Active Humidification Systems in High-Flow Oxygen Therapy.

BACKGROUND: We sought to evaluate the performance in terms of absolute humidity (AH), relative humidity (RH), and temperature of different heated humidifiers (HH) and circuits that are commonly used to deliver high-flow oxygen therapy in conventional ranges (30-60 L/min) and unconventional ranges (70-100 L/min). METHODS: In this prospective, observational study, an electronic thermohygrometer was used to obtain the required measurements. A mechanical ventilator was used as a source for high-flow nasal cannula oxygen therapy. For active humidification, the following equipment was used: a HH with standard disposable water trap circuit, 3 servo-controlled HH, and 7 circuits with a heated wire. Data on environmental conditions (ie, temperature, RH, AH) were collected from the laboratory during each measurement; the temperature, RH, and AH resulting from the application of 8 flows (30-100 L/min) were also recorded. Variables were compared with analysis of variance for repeated measurements with Tukey post hoc tests. A value of P < .05 was assumed to be significant. RESULTS: During the study, a statistically significant difference was found in the average AH for each flow for the different devices (P < .005). The highest AH values were recorded with the Fisher & Paykel MR850 and the Medtronic-DAR circuit (AH = 40.8 mg/L with flow of 50 L/min, P < .005), and the lowest AH values were recorded with the Flexicare FL9000 HH and the Flexicare circuit (AH = 11.4 mg/L with 100 L/min flow, P < .005). For flows > 50 L/min, the best performance for all flows in terms of AH was found with the Fisher & Paykel MR850 HH, regardless of the circuit used. CONCLUSIONS: During oxygen therapy with very high gas flows, HH devices behave differently and in many cases are inefficient in delivering adequate humidification, even at conventional flows. Caution is therefore recommended when selecting the device and flow settings for the implementation of high-flow nasal cannula oxygen therapy.

Heated Humidifier versus Heat-and-Moisture Exchanger During Positive Pressure Ventilation With a T-Piece Resuscitator in Rabbits.

BACKGROUND: There are many proven benefits of the use of conditioned gases in mechanically ventilated patients. In spite of this, its use in the delivery room is limited, perhaps because of known difficulties with heated humidifiers (HH); moreover, there is no evidence regarding the use of heat-and-moisture exchangers (HME) in a delivery room setting. We sought to asess the airway's absolute humidity level using three diferents strategies: HH, HME and unconditioned gases. METHODS: We conducted an experimental study in 12 intubated rabbits ventilated with a T-piece resuscitator. Absolute humidity levels in inspired gases were measured at baseline and at 5, 10, 15, and 20 min while using HH, HME, or no conditioning method (ie, unconditioned). The animals were initially randomized to one of the 3 interventions, and each animal underwent the other methods with at least 24 h between each test. RESULTS: There were no differences in vital signs at baseline or at the end of the procedures. Mean absolute humidity at the end of the tests was 38.2 ± 1.7 g/m3 for HH, 28.9 ± 4.7 g/m3 for HME, and 13.9 ± 5.1 g/m3 for unconditioned gas (P = .003). CONCLUSIONS: During ventilation with a T-piece resuscitator, the absolute humidity was the highest with HH. The absolute humidity with HME was lower, but it was still significantly more than that with unconditioned gas. Therefore, the use of a T-piece resuscitator with HME could be a good alternative to HH given that positive-pressure ventilation is used ideally for short periods of time in the delivery room.

Análise do processo de dessalinização solar com ênfase no método de umidificação e desumidificação / Analysis of the process of solar desalination with emphasis in the humidification and dehumidification method

RESUMO A falta de água é um problema que afeta muitas regiões do nosso planeta, especialmente ilhas e locais de clima muito seco. Especialistas dizem que essa situação irá se agravar e que, em 2025, cerca de 1,8 bilhão de pessoas sofrerão com essa escassez. Embora métodos tradicionais de dessalinização sejam alternativas bem conhecidas e implantadas para obtenção de água potável, eles não são sustentáveis ambientalmente, porque são geralmente supridos por combustíveis não renováveis, cuja queima intensifica o efeito estufa, trazendo desequilíbrios ao meio ambiente. Outra opção que vem sendo desenvolvida ao longo dos anos é a dessalinização por energia solar. Como se trata de uma forma de energia limpa, abundante e renovável, esse método já é muito indicado em regiões isoladas, de baixa e média demanda. Algumas técnicas são apresentadas neste trabalho, que foca o método de dessalinização por umidificação e desumidificação (DSUD). Essa técnica tem se mostrado a mais eficiente, devido ao seu reaproveitamento de energia. Há ainda muito o que melhorar para viabilizar a sua implantação em grande escala, principalmente em termos de produção de água, energia específica requerida e custo específico de produção de água. Entretanto, a DSUD já se mostrou uma técnica sustentável, promissora, de custo razoável e funcionamento simples. Dessa forma, os autores incentivam maiores investimentos em pesquisas no Brasil na área de dessalinização solar e aproveitamento dos rejeitos do processo, visando à produção de água purificada nas regiões brasileiras que têm deficiência em água potável.

ABSTRACT The lack of water is a problem that affects many regions in our planet, specially in very dry places and isles. Experts say that this situation will worsen, and that by 2025 about 1.8 billion people will suffer with water scarcity. Although traditional desalination methods are well-known and implemented alternatives to obtain fresh drinking water, they are not environmentally sustainable, because they are generally supplied by non-renewable fuels, whose combustion intensifies the greenhouse effect, causing disequilibrium to the environment. Another option that has been developed along the years is the desalination by solar energy. Since it is a clean, abundant and renewable type of energy, it is already a good option to isolated regions, whose demand is low or medium. Some technics are shown in this work, which focuses on the humidification-dehumidification desalination method. This technique has shown to be the most efficient one, due to its energy reuse. There is still a long way to go in order to make it viable in large scale, especially in terms of water production, specific energy requirement and specific cost of water production. However, solar desalination by humidification-dehumidification has proven to be a sustainable, promising technic which is reasonably costly and simple to operate. Therefore, the authors encourage more investments in researches in Brazil in the area of solar desalination and use of its rejects, aiming at the production of fresh water in Brazilian regions lacking it.

Acondicionamiento del gas inhalado en pacientes con vía aérea artificial. Revisión narrativa / Humidification and heating of inhaled gas in patients with artificial airway. A narrative review

RESUMEN La instrumentación de la vía aérea del paciente crítico (tubo endotraqueal o cánula de traqueostomía) impide que ésta pueda cumplir con su función de calentar y humidificar el gas inhalado. Sumado a ello la administración de gases medicinales fríos y secos, y los altos flujos a los que se someten los pacientes en ventilación mecánica invasiva o no invasiva, generan una condición aún más desfavorable. Debido a esto es imperativo utilizar algún dispositivo para acondicionar los gases entregados incluso en tratamientos de corta duración con el fin de evitar los daños potenciales sobre la estructura y función del epitelio respiratorio. En el ámbito de terapia intensiva es habitual para esto el uso de intercambiadores de calor y humedad, como así también el uso de sistemas de humidificación activa. Para su correcta utilización es necesario poseer el conocimiento necesario sobre las especificaciones técnicas, ventajas y desventajas de cada uno de estos dispositivos ya que el acondicionamiento de los gases inspirados representa una intervención clave en pacientes con vía aérea artificial y se ha transformado en un cuidado estándar. La selección incorrecta del dispositivo o la configuración inapropiada pueden impactar negativamente en los resultados clínicos. Los integrantes del Capítulo de Kinesiología Intensivista de la Sociedad Argentina de Terapia Intensiva realizaron una revisión narrativa con el objetivo de exponer la evidencia disponible en relación al acondicionamiento del gas inhalado en pacientes con vía aérea artificial, profundizando sobre los conceptos relacionados a los principios de funcionamiento de cada uno.

ABSTRACT Instrumentation of the airways in critical patients (endotracheal tube or tracheostomy cannula) prevents them from performing their function of humidify and heating the inhaled gas. In addition, the administration of cold and dry medical gases and the high flows that patients experience during invasive and non-invasive mechanical ventilation generate an even worse condition. For this reason, a device for gas conditioning is needed, even in short-term treatments, to avoid potential damage to the structure and function of the respiratory epithelium. In the field of intensive therapy, the use of heat and moisture exchangers is common for this purpose, as is the use of active humidification systems. Acquiring knowledge about technical specifications and the advantages and disadvantages of each device is needed for proper use since the conditioning of inspired gases is a key intervention in patients with artificial airway and has become routine care. Incorrect selection or inappropriate configuration of a device can have a negative impact on clinical outcomes. The members of the Capítulo de Kinesiología Intensivista of the Sociedad Argentina de Terapia Intensiva conducted a narrative review aiming to show the available evidence regarding conditioning of inhaled gas in patients with artificial airways, going into detail on concepts related to the working principles of each one.

A Randomized Trial of Conditioned or Unconditioned Gases for Stabilizing Preterm Infants at Birth.

OBJECTIVE: To determine whether the use of heated-humidified gases for respiratory support during the stabilization of infants <30 weeks of gestational age (GA) in the delivery room reduces rates of hypothermia on admission to the neonatal intensive care unit (NICU). STUDY DESIGN: A multicenter, unblinded, randomized trial was conducted in Melbourne, Australia, between February 2013 and June 2015. Infants <30 weeks of GA were randomly assigned to receive either heated-humidified gases or unconditioned gases during stabilization in the delivery room and during transport to NICU. Infants born to mothers with pyrexia >38°C were excluded. Primary outcome was rate of hypothermia on NICU admission (rectal temperature <36.5°C). RESULTS: A total of 273 infants were enrolled. Fewer infants in the heated-humidified group were hypothermic on admission to NICU (36/132 [27%]) compared with controls (61/141 [43%], P < .01). There was no difference in rates of hyperthermia (>37.5°C); 20% (27/132) in the heated-humidified group compared with 16% (22/141) in the controls (P = .30). There were no differences in mortality or respiratory outcomes. CONCLUSIONS: The use of heated-humidified gases in the delivery room significantly reduces hypothermia on admission to NICU in preterm infants, without increased risk of hyperthermia. CLINICAL TRIAL REGISTRATION: Australian and New Zealand Clinical Trials Register (www.anzctr.org.au) ACTRN12613000093785.

Humidification on Ventilated Patients: Heated Humidifications or Heat and Moisture Exchangers?

The normal physiology of conditioning of inspired gases is altered when the patient requires an artificial airway access and an invasive mechanical ventilation (IMV). The endotracheal tube (ETT) removes the natural mechanisms of filtration, humidification and warming of inspired air. Despite the noninvasive ventilation (NIMV) in the upper airways, humidification of inspired gas may not be optimal mainly due to the high flow that is being created by the leakage compensation, among other aspects. Any moisture and heating deficit is compensated by the large airways of the tracheobronchial tree, these are poorly suited for this task, which alters mucociliary function, quality of secretions, and homeostasis gas exchange system. To avoid the occurrence of these events, external devices that provide humidification, heating and filtration have been developed, with different degrees of evidence that support their use.

Mudanças funcionais de farinha de arroz torrada com micro-ondas em função do teor de umidade e do tempo de processamento / Functional changes of rice flour roasted with microwave as a function of moisture content and processing time

O Brasil está entre os dez maiores produtores de arroz do mundo. Devido ao beneficiamento, boa parte dos grãos é quebrada, gerando um subproduto de baixo valor comercial. A farinha de arroz normalmente é produzida a partir de grãos quebrados e é utilizada em produtos manufaturados devido a suas propriedades funcionais. Visando à obtenção de farinhas com propriedades funcionais diferenciadas e assim ampliar sua utilização como ingrediente em diferentes aplicações na indústria de alimentos, o objetivo deste trabalho foi avaliar o efeito da umidade e do tempo de torra (variáveis independentes), em micro-ondas, sobre as características funcionais de farinhas de arroz da cultivar 'IRGA 417'. Utilizou-se delineamento experimental composto central. A variação do teor de amilose (TA) entre as farinhas de arroz torradas foi de 16-30g (100g)-1, sendo que nos menores tempos de torra (até 13,3min) e umidade acima de 18,5g (100g)-1 observaram-se os maiores TA. Ocorreu elevação do índice de absorção de água (IAA) à medida que aumentou o tempo de torra das farinhas de arroz. Os valores mais elevados de índice de solubilidade em água (ISA) (25%) foram encontrados para as farinhas de arroz com umidade acima de 22g (100g)-1. Com o aumento do tempo de torra, ocorreu diminuição do pico de viscosidade, viscosidade final e de tendência a retrogradação das farinhas torradas. O contrário foi observado para a quebra de viscosidade. Conclui-se que a torração em micro-ondas pode ampliar as aplicações da farinha de arroz na indústria de alimentos em função das mudanças funcionais resultantes.

Brazil is among the ten largest producers of rice in the world. Due to processing, most of the grains is broken, causing a by-product of low commercial value. Rice flour is usually produced from broken grains and used in manufactured products because of their functional properties. Aiming to obtain flours with different functional properties and thus extend its use as an ingredient in different applications in the food industry, the objective was to evaluate the effect of moisture content and roasting time (independent variables), in the microwave, on the functional characteristics of flour from rice variety 'IRGA 417'. We used central composite rotational experimental design. The variation of amylose content (TA) between the roasted rice flour was 16-30g (100g)-1, and roasting in the shortest times (until 13.3min) and humidity above 18.5g (100g)-1, we observed the highest TA. An elevation of the water absorption index (WAI) increased as the roasting time of rice flours. The highest values of water solubility index (WSI) (25%) were found for rice flour with humidity above 22g (100g)-1. With increased roasting time diminished the peak viscosity, final viscosity and setback of roasted flour. On the contrary was observed for the breakdown of viscosity. It is concluded that roasting in a microwave can expand the applications of rice flour in the food industry according to the functional changes that result.

Mudanças funcionais de farinha de arroz torrada com micro-ondas em função do teor de umidade e do tempo de processamento

Brazil is among the ten largest producers of rice in the world. Due to processing, most of the grains is broken, causing a by-product of low commercial value. Rice flour is usually produced from broken grains and used in manufactured products because of their functional properties. Aiming to obtain flours with different functional properties and thus extend its use as an ingredient in different applications in the food industry, the objective was to evaluate the effect of moisture content and roasting time (independent variables), in the microwave, on the functional characteristics of flour from rice variety 'IRGA 417'. We used central composite rotational experimental design. The variation of amylose content (TA) between the roasted rice flour was 16-30g (100g)-1, and roasting in the shortest times (until 13.3min) and humidity above 18.5g (100g)-1, we observed the highest TA. An elevation of the water absorption index (WAI) increased as the roasting time of rice flours. The highest values of water solubility index (WSI) (25%) were found for rice flour with humidity above 22g (100g)-1. With increased roasting time diminished the peak viscosity, final viscosity and setback of roasted flour. On the contrary was observed for the breakdown of viscosity. It is concluded that roasting in a microwave can expand the applications of rice flour in the food industry according to the functional changes that result.

O Brasil está entre os dez maiores produtores de arroz do mundo. Devido ao beneficiamento, boa parte dos grãos é quebrada, gerando um subproduto de baixo valor comercial. A farinha de arroz normalmente é produzida a partir de grãos quebrados e é utilizada em produtos manufaturados devido a suas propriedades funcionais. Visando à obtenção de farinhas com propriedades funcionais diferenciadas e assim ampliar sua utilização como ingrediente em diferentes aplicações na indústria de alimentos, o objetivo deste trabalho foi avaliar o efeito da umidade e do tempo de torra (variáveis independentes), em micro-ondas, sobre as características funcionais de farinhas de arroz da cultivar 'IRGA 417'. Utilizou-se delineamento experimental composto central. A variação do teor de amilose (TA) entre as farinhas de arroz torradas foi de 16-30g (100g)-1, sendo que nos menores tempos de torra (até 13,3min) e umidade acima de 18,5g (100g)-1 observaram-se os maiores TA. Ocorreu elevação do índice de absorção de água (IAA) à medida que aumentou o tempo de torra das farinhas de arroz. Os valores mais elevados de índice de solubilidade em água (ISA) (25%) foram encontrados para as farinhas de arroz com umidade acima de 22g (100g)-1. Com o aumento do tempo de torra, ocorreu diminuição do pico de viscosidade, viscosidade final e de tendência a retrogradação das farinhas torradas. O contrário foi observado para a quebra de viscosidade. Conclui-se que a torração em micro-ondas pode ampliar as aplicações da farinha de arroz na indústria de alimentos em função das mudanças funcionais resultantes.

Mudanças funcionais de farinha de arroz torrada com micro-ondas em função do teor de umidade e do tempo de processamento

Brazil is among the ten largest producers of rice in the world. Due to processing, most of the grains is broken, causing a by-product of low commercial value. Rice flour is usually produced from broken grains and used in manufactured products because of their functional properties. Aiming to obtain flours with different functional properties and thus extend its use as an ingredient in different applications in the food industry, the objective was to evaluate the effect of moisture content and roasting time (independent variables), in the microwave, on the functional characteristics of flour from rice variety 'IRGA 417'. We used central composite rotational experimental design. The variation of amylose content (TA) between the roasted rice flour was 16-30g (100g)-1, and roasting in the shortest times (until 13.3min) and humidity above 18.5g (100g)-1, we observed the highest TA. An elevation of the water absorption index (WAI) increased as the roasting time of rice flours. The highest values of water solubility index (WSI) (25%) were found for rice flour with humidity above 22g (100g)-1. With increased roasting time diminished the peak viscosity, final viscosity and setback of roasted flour. On the contrary was observed for the breakdown of viscosity. It is concluded that roasting in a microwave can expand the applications of rice flour in the food industry according to the functional changes that result.

O Brasil está entre os dez maiores produtores de arroz do mundo. Devido ao beneficiamento, boa parte dos grãos é quebrada, gerando um subproduto de baixo valor comercial. A farinha de arroz normalmente é produzida a partir de grãos quebrados e é utilizada em produtos manufaturados devido a suas propriedades funcionais. Visando à obtenção de farinhas com propriedades funcionais diferenciadas e assim ampliar sua utilização como ingrediente em diferentes aplicações na indústria de alimentos, o objetivo deste trabalho foi avaliar o efeito da umidade e do tempo de torra (variáveis independentes), em micro-ondas, sobre as características funcionais de farinhas de arroz da cultivar 'IRGA 417'. Utilizou-se delineamento experimental composto central. A variação do teor de amilose (TA) entre as farinhas de arroz torradas foi de 16-30g (100g)-1, sendo que nos menores tempos de torra (até 13,3min) e umidade acima de 18,5g (100g)-1 observaram-se os maiores TA. Ocorreu elevação do índice de absorção de água (IAA) à medida que aumentou o tempo de torra das farinhas de arroz. Os valores mais elevados de índice de solubilidade em água (ISA) (25%) foram encontrados para as farinhas de arroz com umidade acima de 22g (100g)-1. Com o aumento do tempo de torra, ocorreu diminuição do pico de viscosidade, viscosidade final e de tendência a retrogradação das farinhas torradas. O contrário foi observado para a quebra de viscosidade. Conclui-se que a torração em micro-ondas pode ampliar as aplicações da farinha de arroz na indústria de alimentos em função das mudanças funcionais resultantes.

El frasco humidificador como sistema de humidificación del gas inspirado no cumple con las recomendaciones. Evaluación y comparación de tres sistemas de humidificación. Estudio de laboratorio / The humidifier bottle as humidification system of the inspired gas does not meet with the recommendations. Evaluation and comparison of three humidification systems. Laboratory study

Objetivos. Demostrar que el frasco humidificador (FH), como sistema de humidificación del gas inspirado, no alcanza los valores mínimos de humedad relativa (HR), humedad absoluta (HA) y temperatura (Tº) recomendados por la literatura. Secundariamente, comparar el rendimiento del FH y dos sistemas activos de humidificación (SAH). Materiales y métodos. Las variables principales fueron T° del agua, HR, Tº y HA del gas entregado. Se realizaron mediciones a diferentes niveles de Tº, volumen de agua y flujos. Resultados. El FH no alcanzó los valores recomendados de HR 100%, HA 30 mg/l y Tº 31ºC. El SAH sin circuito calefaccionado alcanzó valores recomendados en el NIVEL III con flujos de 20-60lpm, y en el NIVEL II con flujos de 20-30lpm. El SAH con circuito calefaccionado logró valores sugeridos en los NIVELES II y III (20-60lpm). Se encontró diferencia significativa (p<0,001 Global) para flujo, Tº y tipo de humidificador. El modelo ANOVA arrojó significación estadística (p<0,001) del término interacción de flujo y tipo de humidificador en cada nivel de Tº. Conclusiones. El FH no acondiciona el gas de acuerdo a lo recomendado. El mejor rendimiento fue con 300 ml y flujo de 1 lpm: Tº 23,92(±0,69), HR 74,02%(±6,53) y HA 16,02 mg/l (±1,86), estos valores apenas superan el 50% de lo mínimo sugerido en la literatura. Los SAH acondicionaron el gas adecuadamente. El modelo ANOVA arroja que existen otros factores involucrados en mantener la HA y que la significación varía en cada tipo de humidificador a cada nivel de flujo(AU)

Objetive. To demonstrate that humidifier bottle (HB) as inspired gas humidification system does not attain the minimum values of relative humidity (RH), absolute humidity (AH) and temperature (Tº) as recommended by the literature. Furthermore, to compare the HB performance with two active humidification systems (AHS). Materials and Methods. Main variables were: water Tº, RH, Tº and AH of delivered gas. Measurements were made at different levels of Tº, water and flows volume. Results. Recommended values of RH 100%, AH 30 mg/l and Tº 31º C were not reached by the HB. AHS without heating circuit reached recommended values in LEVEL III with flows of 20-60 lpm, and in LEVEL II with flows of 20-30lpm. AHS with heating circuit obtained recommended values in LEVELS II and III (20-60lpm). A significant difference (p<0.001 Global) for flow, Tº and humidifier type was found. ANOVA model showed statistical evidence (p<0.001) of interaction between flow and type of humidifier in each Tº level. Conclusions. The HB does not condition gas in accordance with recommended values. The best performance was with 300ml and 1lpm flow: Tº 23.92 (±0.69), RH 74.02% (±6.53) and AH 16.02 mg/l (±1.86) and these values hardly exceed the 50% of minimum recommended by literature. AHS conditioned gas in a proper way. ANOVA model shows that there exist other factors involved to maintain AH and that there are important differences between each type of humidifier and each flow level.(AU)