Comparação do impacto imediato das técnicas de oscilação oral de alta frequência sonorizada e sopro sonorizado com tubo de ressonância em idosas vocalmente saudáveis / Comparison of the immediate effect of voiced oral high-frequency oscillation and flow phonation with resonance tube in vocally-healthy elderly women

RESUMO Objetivo Verificar e comparar os efeitos imediatos da técnica de oscilação oral de alta frequência sonorizada (OOAFS) e sopro sonorizado com tubo de ressonância na autopercepção de sintomas vocais/laríngeos e na qualidade vocal de idosas. Método Participaram 14 mulheres idosas que realizaram as técnicas OOAFS e sopro sonorizado com tubo de ressonância de silicone, com wash-out de uma semana. Todas responderam questões sobre frequência e intensidade dos sintomas vocais/laríngeos; foram submetidas à gravação da vogal sustentada /a/ e contagem de números, para análise perceptivo-auditiva e acústica vocal. Foram extraídos os tempos máximos de fonação (TMF). Em seguida, sorteou-se a técnica a ser realizada: OOAFS ou tubo de ressonância, por três minutos em tom habitual. Após exercício, os mesmos procedimentos da avaliação inicial foram repetidos e as idosas responderam a um questionário de autoavaliação sobre os efeitos das técnicas. Os dados foram comparados antes e após aplicação das técnicas por meio dos testes ANOVA, Wilcoxon e Mann-Whitney; para as sensações vocais após técnicas, aplicou-se teste Quiquadrado(p<0,05). Resultados Ao comparar as técnicas, verificou-se diminuição da rugosidade e melhora da ressonância na contagem dos números após tubo de ressonância e manutenção dos resultados após OOAFS. Não houve mais diferenças significantes para as demais variáveis estudadas entre os grupos. Conclusão O sopro sonorizado com tubo de ressonância melhora a qualidade vocal de mulheres idosas. Além disso, ambos os exercícios apresentaram semelhanças na autopercepção dos sintomas vocais/laríngeos e sensações, sugerindo que a OOAFS é segura e pode ser empregada na terapia de voz nesta população.

ABSTRACT Purpose To verify and compare the immediate effects of the voiced oral high-frequency oscillation (VOHFO) technique and the phonation into a silicone resonance tube in the elderly self-perception of vocal and laryngeal symptoms and in their voice quality. Methods 14 elderly women, over 60 years old, performed the VOHFO and phonation into a resonance tube technique (35cm in length and 9mm in diameter) with one-week interval between both to avoid carry-over effect. Initially, all participants answered questions regarding the frequency and intensity of their vocal/laryngeal symptoms. Recordings of the sustained vowel /a/ and counting numbers were performed for posterior perceptual and acoustic analyses of the voice quality. The maximum phonation time (MPT) for /a/, /s/, /z/ and counting numbers were also obtained. After that, a draw lot established which technique (VOHFO or resonance tube) would be initially applied for three minutes. After the exercise performance the same procedures were carried out and the elderly women answered a self-assessment questionnaire about the effect of the techniques in her voice, larynx, breathing and articulation. Comparison pre and post each technique were analyzed using ANOVA, Wilcoxon and Mann-Whitney tests. The sensations after the techniques were assessed using the Chi-square test (p<0.05). Results The comparison of both techniques showed decrease in roughness and improvement in resonance for counting numbers after the resonance tube and same outcomes post VOHFO. There were no significant differences for the other analyzed variables between groups. Conclusion The phonation into a resonance tube exercise improves the vocal quality of elderly women. In addition, both exercises are similar regarding self-perception of vocal / laryngeal symptoms and sensations post three minutes of the technique, suggesting that VOHFO can be safely applied in voice therapy for this population.

Management of acute respiratory distress syndrome in a child with adenovirus pneumonia: case report and literature review / Manejo da síndrome do desconforto respiratório agudo em criança com pneumonia por adenovírus: relato de caso e revisão da literatura

ABSTRACT Objective: To report the case of a child who developed acute respiratory distress syndrome (ARDS) from a pulmonary infection by adenovirus. Case description: A female patient aged 2 years and 6 months, weighting 10,295 grams developed fever, productive cough and vomiting, later on progressing to ARDS despite initial therapy in accordance with the institutional protocol for ARDS treatment. The child evolved to refractory hypoxemia and hypercapnia, requiring high parameters of mechanical pulmonary ventilation and use of vasoactive agents. In the treatment escalation, the patient received steroids, inhaled nitric oxide (iNO), was submitted to the prone position, started oscillatory high-frequency ventilation (HFOV) and extracorporeal membrane oxygenation (ECMO) was indicated due to severe refractory hypoxemia. During this time, the patient's clinical response was favorable to HFOV, improving oxygenation index and hypercapnia, allowing the reduction of vasoactive medications and mechanical ventilation parameters, and then the indication of ECMO was suspended. The patient was discharged after 26 days of hospital stay without respiratory or neurological sequelae. Comments: Adenovirus infections occur mainly in infants and children under 5 years of age and represent 2 to 5% of respiratory diseases among pediatric patients. Although most children with adenovirus develop a mild upper respiratory tract disease, more severe cases can occur. ARDS is a serious pulmonary inflammatory process with alveolar damage and hypoxemic respiratory failure; Adenovirus pneumonia in children may manifest as severe pulmonary morbidity and respiratory failure that may require prolonged mechanical ventilation. Exclusive pulmonary recruitment and HFOV are advantageous therapeutic options.

RESUMO Objetivo: Descrever paciente que evoluiu com síndrome do desconforto respiratório agudo (SDRA) a partir de infecção pulmonar por adenovírus. Descrição do caso: Paciente de dois anos e seis meses, sexo feminino, peso de 10295 g, que apresentou com quadro de febre, tosse produtiva e vômitos, evoluindo para SDRA. Apesar da terapêutica inicial em conformidade com o protocolo institucional de tratamento da SDRA, a criança evoluiu para hipoxemia e hipercapnia refratárias, necessitando de elevados parâmetros de ventilação pulmonar mecânica e utilização de agentes vasoativos. No escalonamento da terapêutica, a paciente recebeu terapias adjuvantes, foi iniciada ventilação oscilatória de alta frequência (VOAF) e indicada oxigenação por membrana extracorpórea (OMEC) pela hipoxemia grave refratária. Nesse ínterim, a paciente apresentou resposta clínica favorável à VOAF, melhorando do quadro ventilatório e possibilitando a redução das medicações vasoativas e dos parâmetros de ventilação mecânica. A paciente recebeu alta hospitalar após 26 dias de internação, sem sequelas respiratórias ou neurológicas. Comentários: As infecções por adenovírus ocorrem principalmente em lactentes e crianças com menos de cinco anos de idade e representam de 2 a 5% das doenças respiratórias entre os pacientes pediátricos. Embora a maioria das crianças com infecção por adenovírus desenvolva doença leve do trato respiratório superior, casos mais graves podem ocorrer com comprometimento do trato respiratório inferior. A pneumonia por adenovírus em crianças pode se manifestar com morbidade pulmonar grave e insuficiência respiratória com risco de vida, o que resulta na necessidade de suporte mecânico prolongado. O recrutamento pulmonar exclusivo pela VOAF pode ser uma opção terapêutica útil.

Inflammatory lung injury in rabbits: effects of high-frequency oscillatory ventilation in the prone position / Lesão inflamatória pulmonar em coelhos: efeitos da ventilação oscilatória de alta frequência em posição prona

ABSTRACT Objective: To compare the effects that prone and supine positioning during high-frequency oscillatory ventilation (HFOV) have on oxygenation and lung inflammation, histological injury, and oxidative stress in a rabbit model of acute lung injury (ALI). Methods: Thirty male Norfolk white rabbits were induced to ALI by tracheal saline lavage (30 mL/kg, 38°C). The injury was induced during conventional mechanical ventilation, and ALI was considered confirmed when a PaO2/FiO2 ratio < 100 mmHg was reached. Rabbits were randomly divided into two groups: HFOV in the supine position (SP group, n = 15); and HFOV with prone positioning (PP group, n = 15). For HFOV, the mean airway pressure was initially set at 16 cmH2O. At 30, 60, and 90 min after the start of the HFOV protocol, the mean airway pressure was reduced to 14, 12, and 10 cmH2O, respectively. At 120 min, the animals were returned to or remained in the supine position for an extra 30 min. We evaluated oxygenation indices and histological lung injury scores, as well as TNF-α levels in BAL fluid and lung tissue. Results: After ALI induction, all of the animals showed significant hypoxemia, decreased respiratory system compliance, decreased oxygenation, and increased mean airway pressure in comparison with the baseline values. There were no statistically significant differences between the two groups, at any of the time points evaluated, in terms of the PaO2 or oxygenation index. However, TNF-α levels in BAL fluid were significantly lower in the PP group than in the SP group, as were histological lung injury scores. Conclusions: Prone positioning appears to attenuate inflammatory and histological lung injury during HFOV in rabbits with ALI.

RESUMO Objetivo: Comparar os efeitos das posições prona e supina durante ventilação oscilatória de alta frequência (VOAF) sobre oxigenação e inflamação pulmonar, lesão histológica e estresse oxidativo em um modelo de lesão pulmonar aguda (LPA) em coelhos. Métodos: Trinta coelhos Norfolk machos brancos foram submetidos à LPA por meio de lavagem traqueal com salina (30 ml/kg, 38°C). A lesão foi induzida durante a ventilação mecânica convencional, e a LPA foi considerada confirmada na presença de relação PaO2/FiO2 < 100 mmHg. Os coelhos foram aleatoriamente divididos em dois grupos: VOAF em posição supina (grupo PS, n = 15); e VOAF em posição prona (grupo PP, n = 15). Para a VOAF, a pressão média das vias aéreas foi inicialmente estabelecida em 16 cmH2O. No 30º, 60º e 90º min após o início do protocolo de VOAF, a pressão média das vias aéreas foi reduzida para 14, 12 e 10 cmH2O, respectivamente. No 120º min, os animais foram recolocados ou permaneceram na posição supina por mais 30 min. Foram avaliados os índices de oxigenação e escores histológicos de lesão pulmonar, bem como os níveis de TNF-α em lavado broncoalveolar e tecido pulmonar. Resultados: Após a indução da LPA, todos os animais apresentaram hipoxemia significativa, diminuição da complacência do sistema respiratório, diminuição da oxigenação e aumento da pressão média das vias aéreas em comparação aos valores basais. Não houve diferenças estatisticamente significativas entre os dois grupos, em nenhum dos momentos avaliados, quanto a PaO2 e índice de oxigenação. Entretanto, os níveis de TNF-α no lavado broncoalveolar foram significativamente menores no grupo PP que no grupo PS, assim como os escores histológicos de lesão pulmonar. Conclusões: A posição prona parece atenuar a lesão pulmonar inflamatória e histológica durante a VOAF em coelhos com LPA.

Comparação entre ventilação mecânica convencional protetora e ventilação oscilatória de alta frequência associada à posição prona / Comparison between conventional protective mechanical ventilation and high-frequency oscillatory ventilation associated with the prone position

RESUMO Objetivo: Comparar os efeitos da ventilação oscilatória de alta frequência e da ventilação mecânica convencional protetora associadas à posição prona quanto à oxigenação, à histologia e ao dano oxidativo pulmonar em modelo experimental de lesão pulmonar aguda. Métodos: Foram instrumentados com traqueostomia, acessos vasculares e ventilados mecanicamente 45 coelhos. A lesão pulmonar aguda foi induzida por infusão traqueal de salina aquecida. Foram formados três grupos experimentais: animais sadios + ventilação mecânica convencional protetora, em posição supina (Grupo Controle; n = 15); animais com lesão pulmonar aguda + ventilação mecânica convencional protetora, posição prona (GVMC; n = 15); animais com lesão pulmonar aguda + ventilação oscilatória de alta frequência, posição prona (GVAF; n = 15). Após 10 minutos do início da ventilação específica de cada grupo, foi coletada gasometria arterial, sendo este momento denominado tempo zero, após o qual o animal foi colocado em posição prona, permanecendo assim por 4 horas. O estresse oxidativo foi avaliado pelo método de capacidade antioxidante total. A lesão tecidual pulmonar foi determinada por escore histopatológico. O nível de significância adotado foi de 5%. Resultados: Ambos os grupos com lesão pulmonar aguda apresentaram piora da oxigenação após a indução da lesão comparados ao Grupo Controle. Após 4 horas, houve melhora significante da oxigenação no grupo GVAF comparado ao GVMC. A análise da capacidade antioxidante total no plasma mostrou maior proteção no GVAF. O GVAF apresentou menor escore de lesão histopatológica no tecido pulmonar que o GVMC. Conclusão: A ventilação oscilatória de alta frequência, associada à posição prona, melhora a oxigenação, e atenua o dano oxidativo e a lesão pulmonar histopatológica, comparada com ventilação mecânica convencional protetora.

ABSTRACT Objective: To compare the effects of high-frequency oscillatory ventilation and conventional protective mechanical ventilation associated with the prone position on oxygenation, histology and pulmonary oxidative damage in an experimental model of acute lung injury. Methods: Forty-five rabbits with tracheostomy and vascular access were underwent mechanical ventilation. Acute lung injury was induced by tracheal infusion of warm saline. Three experimental groups were formed: healthy animals + conventional protective mechanical ventilation, supine position (Control Group; n = 15); animals with acute lung injury + conventional protective mechanical ventilation, prone position (CMVG; n = 15); and animals with acute lung injury + high-frequency oscillatory ventilation, prone position (HFOG; n = 15). Ten minutes after the beginning of the specific ventilation of each group, arterial gasometry was collected, with this timepoint being called time zero, after which the animal was placed in prone position and remained in this position for 4 hours. Oxidative stress was evaluated by the total antioxidant performance assay. Pulmonary tissue injury was determined by histopathological score. The level of significance was 5%. Results: Both groups with acute lung injury showed worsening of oxygenation after induction of injury compared with the Control Group. After 4 hours, there was a significant improvement in oxygenation in the HFOG group compared with CMVG. Analysis of total antioxidant performance in plasma showed greater protection in HFOG. HFOG had a lower histopathological lesion score in lung tissue than CMVG. Conclusion: High-frequency oscillatory ventilation, associated with prone position, improves oxygenation and attenuates oxidative damage and histopathological lung injury compared with conventional protective mechanical ventilation.

The value of high-flow nasal cannula oxygen therapy after extubation in patients with acute respiratory failure

OBJECTIVE: To investigate the value of high-flow nasal cannula oxygen therapy after extubation in patients with acute respiratory failure. METHODS: A single-center, prospective, randomized, controlled pilot trial was conducted between January 2013 and December 2014. Sixty enrolled patients were randomized immediately after extubation into either a high-flow nasal cannula group (n=30) or an air entrainment mask group (n=30) at a fixed inspired oxygen fraction (40%). The success rate of oxygen therapy, respiratory and hemodynamic parameters and subjective discomfort (using a visual analogue scale) were assessed at 24h after extubation. RESULTS: The two groups were comparable at extubation. A total of 46 patients were successfully treated including 27 patients in the high-flow nasal cannula group and 19 patients in the air entrainment mask group. Compared to the air entrainment mask group, the success rate of oxygen therapy and the partial pressure of arterial oxygen were significantly higher and the respiratory rate was lower in the high-flow nasal cannula group. In addition, less discomfort related to interface displacement and airway dryness was observed in the high-flow nasal cannula group than in the air entrainment mask group. CONCLUSIONS: At a fixed inspired oxygen fraction, the application of a high-flow nasal cannula after extubation achieves a higher success rate of oxygen therapy and less discomfort at 24h than an air entrainment mask in patients with acute respiratory failure.

Ventilación de alta frecuencia oscilatoria en pediatría / High frequency oscillatory ventilation in pediatrics

Mechanical ventilation (MV) is a usual therapy for the management of critically ill children. However its inappropriate use can produce lung injury. Today, the evidence recommends protective ventilation such as strategie low tidal volumes (VT) that minimize injury and thus, high frequency oscillatory ventilation (HFOV) would have a theoretical role. HFOV allows gas exchange using low tidal volumes (1 – 2 ml/kg) and supraphysiologic respiratory frequencies. In pediatrics it comprises 3 – 30 percent of mechanically ventilated patients, most of the time as a rescue therapy in refractory respiratory failure cases where conventional mechanical ventilation fails. Many aspects of HFVO in children remain unclear, theoretical benefits has no solid clinical basis, when is the best time to initiate (early vs rescue mode), which are the optimal settings, and how to monitor lung mechanics. This review examines HFVO theoretical bases, suggest recommendations for its use and considers the available evidence to understand the aspects that are still unclear.

La ventilación mecánica (VM) constituye un apoyo frecuente en el manejo de niños críticamente enfermos, quienes pueden requerirla por diferentes etiologías, entre ellas el síndrome de dificultad respiratoria aguda (SDRA). Sabemos que a pesar de ser un soporte vital, su uso inapropiado puede producir daño inducido por ventilación mecánica (DIVM). En la actualidad, la evidencia recomienda las estrategias de “ventilación protectora”, bajos volúmenes corrientes, que minimicen este daño y es ahí donde la ventilación de alta frecuencia oscilatoria (VAFO) tendría un rol teórico. La VAFO permite el intercambio gaseoso usando pequeños volúmenes corrientes (VT) 1-2 ml /kg y frecuencias respiratorias supra fisiológicas, con la consiguiente disminución del riesgo de atelectrauma, manteniendo el “pulmón abierto” y en la zona de seguridad de la curva presión-volumen. Su uso en pediatría oscila entre el 3 y el 30 por ciento de los pacientes ventilados, la mayoría de las veces como terapia de rescate frente a la falla de la ventilación convencional (VMC) en insuficiencia respiratoria refractaria. Muchos aspectos de la VAFO en pediatría no han sido totalmente esclarecidos; su efecto protector teórico permanece aún sin bases sólidas en el escenario clínico, quienes se benefician de su uso, cuál es el mejor momento para iniciarla (temprana o rescate), cuales son los valores óptimos del oscilador y como monitorear la mecánica pulmonar en VAFO. La presente revisión pretende repasar los conceptos teóricos de la VAFO, formular recomendaciones para su uso y considerar la evidencia disponible que nos permitan dilucidar las interrogantes antes mencionadas.

Ventilación neonatal en Cuba, modalidades más utilizadas y sobrevida durante el período 2002-2011 / Neonatal ventilation in Cuba, the most used modalities and the survival rates in the 2002-2011 period

Introducción: la asistencia respiratoria es un marcador de la evolución de la Neonatología. Objetivo: describir el comportamiento de las modalidades ventilatorias y su sobrevida en Cuba. Métodos: se realizó un estudio descriptivo, multicéntrico nacional en 14 377 recién nacidos ventilados, durante el período 2002-2011. Se calculó el índice de ventilados, los porcentajes de las modalidades con presión positiva intermitente, presión positiva continua y alta frecuencia oscilatoria, y el porcentaje de sobrevida de cada una de ellas. Resultados: aumentó el índice de ventilación a 2 por ciento, el uso de presión positiva continua a 29 por ciento y con alta frecuencia oscilatoria a 7,2 por ciento, disminuyó la utilización de presión positiva intermitente a 64 por ciento. La sobrevida aumentó en todas las modalidades. Conclusiones: hubo un incremento de la ventilación con presión positiva continua, acompañado de una disminución de la ventilación con presión positiva intermitente. La sobrevida se incrementó en todas las modalidades empleadas

Introduction: The assisted ventilation is a development marker of neonatology. Objective: To describe the behavior of ventilation modalities and their survival rates in Cuba. Methods: A national multicenter descriptive study was conducted in 14 377 ventilated newborns in the period of 2002 through 2011. The index of ventilated patients, the percentages of modalities with intermittent positive pressure, continuous positive pressure and high oscillatory frequency, and the survival percentages of each of them were all estimated. Results: The ventilation index rose to 2 percent, the use of continuous positive pressure to 29 percent and the high oscillatory frequency to 7.2 percent but the use of intermittent positive pressure decreased to 64 percent. The survival rates increased in all the modalities. Conclusions: There was increase of continuous positive pressure ventilation and in turn a reduction of intermittent positive pressure ventilation. The survival rate increased in all the modalities

Oscillation mechanics of the respiratory system in never-smoking patients with silicosis: pathophysiological study and evaluation of diagnostic accuracy

OBJECTIVES: Silicosis is a chronic and incurable occupational disease that can progress even after the cessation of exposure. Recent studies suggest that the forced oscillation technique may help to clarify the changes in lung mechanics resulting from silicosis as well as the detection of these changes. We investigated the effects of airway obstruction in silicosis on respiratory impedance and evaluated the diagnostic efficacy of the forced oscillation technique in these patients. METHODS: Spirometry was used to classify the airway obstruction, which resulted in four subject categories: controls (n=21), patients with a normal exam (n=12), patients with mild obstruction (n=22), and patients with moderate-to-severe obstruction (n=12). Resistive data were interpreted using the zero-intercept resistance (R0), the resistance at 4 Hz (Rrs4), and the mean resistance. We also analyzed the mean reactance (Xm) and the dynamic compliance. The total mechanical load was evaluated using the absolute value of the respiratory impedance (Z4Hz). The diagnostic potential was evaluated by investigating the area under the receiver operating characteristic curve. ClinicalTrials.gov: NCT01725971. RESULTS: We observed significant (p<0.0002) increases in R0, Rrs4, Rm, and Z4Hz and significant reductions in Crs,dyn (p<0.0002) and Xm (p<0.0001). R0, Rrs4, Rm, and Z4Hz performed adequately in the diagnosis of mild obstruction (area under the curve>0.80) and highly accurately in the detection of moderate-to-severe obstruction (area under the curve>0.90). CONCLUSIONS: The forced oscillation technique may contribute to the study of the pathophysiology of silicosis and may improve the treatment offered to these patients, thus representing an alternative and/or complementary tool for evaluating respiratory mechanics. .

Ventilación de alta frecuencia en infección respiratoria grave por VRS / High frequency oscillatory ventilation in severe RSV infection

High frequency oscillatory (HFOV) has been progressively useful in children with severe hypoxemic and Iry-percapnic respiratory insufficiency, at Pediatric Intensive Care Units. Objectives: To describe our experience in treatment of children with severe RSV infection unresponsive to conventional ventilation (CV), to describe effectiveness in gas exchange and to evaluate the safety of the method. A descriptive and prospective study set at two paediatric intensive care units, in Hospital Roberto del Río and Clínica Santa María of Santiago, Chile between January 2001 and December 2004. Results: 36 patients between 0.5 and 10 months of age with severe RSV infection and respiratory failure unresponsive to mechanical ventilation were connected to HFOV after an average time of conventional ventilation of 2.6 days. Arterial pH improved during the first hour in HFOV from 7.18 to > 7.3. Initial PaO2/FiO2 in average was 104.8, there was a slow and progressive improvement until 72 hours (138). FiO2 diminished since an average of 74 percent till 63.6 percent at 72 hours pCO2 went down from an average of 88 mm de Hg pre HFOV to 50 mmHg at 12 hours, remaining low. Oxygenation Index, preHFOV, was in average 18 and it maintained in 17 at 72 hours, with a FiO2 < 60 percent. Patients were hold in HFOV between 2-18 days. 3/36 patients died after 1.5, 4 and 18 days of HFOV. 8,3 percent presented air leak. One of these patients is oxygen dependent after 12 months of following. Conclusions: High frequency oscillatory ventilation is a useful method in the management of acute respiratory failure in children with severe infection for RSV unresponsive to conventional ventilation. It can improve gas exchange slowly and progressively with a low risk of air leak, secuelae and death.

La ventilación de alta frecuencia oscilatoria (VAFO) es un modo ventilatorio cada vez más utilizado en el manejo del paciente pediátrico con insuficiencia respiratoria grave, tanto hipoxémica como hipercápnica, en unidades de paciente crítico. Objetivos. Describir nuestra experiencia en el uso de VAFO en niños con infección respiratoria aguda grave por Virus Respiratorio Sincicial (VRS), su efectividad en el intercambio gaseoso y la seguridad del método. Método: Estudio descriptivo, retrospectivo, realizado en unidades de cuidado intensivo pediátricos de Hospital Roberto del Río y Clínica Santa María de Santiago, Chile, entre los meses de Enero 2001 y Diciembre 2004. Resultados: Se conectaron a VAFO 36 pacientes de 0,5 a 10 meses de edad con falla respiratoria aguda por infección por VRS y sin respuesta a VMC, luego de un promedio de 2,6 días. El pH arterial mejora durante la primera hora en VAFO, de 7,18 a 7,3. PaO2/FiO2 inicial promedio fue de 104,8, se observó una lenta y progresiva mejoría hasta las 72 horas (138). FiO2 disminuyó de 74 por ciento hasta 63,6 por ciento en las primeras 72 horas. La PCO2fue disminuyendo desde un promedio en VMC de 88 a 50 mmHg a las 12 horas, permaneciendo luego en rangos bajos. El índice de oxigenación pre VAFO, fue en promedio 18 y se mantuvo en 17 a las 72 horas de conexión, con una FiO2 < 60 por ciento. El tiempo de VAFO fue de 2-18 días. 3/36 pacientes fallecieron a los 1,5, 4 y 18 días de VAFO, 8,3 por ciento presentaron escape aéreo. 1/36 paciente es oxígeno dependiente luego de 12 meses de seguimiento. Conclusiones: VAFO se constituyó en un método eficaz en el manejo de la falla respiratoria aguda en niños con una infección grave por VRS, que no respondieron a la VMC. Podría mejorar rápidamente la hipercapnia, y la oxigenación lenta y progresivamente, con un bajo riesgo de escape aéreo, secuelas y mortalidad.

Ventilación de alta frecuencia: una opción terapéutica del síndrome de distrés respiratorio del adulto: [revisión] / High-frequency ventilation: a therapeutic option of adult respiratory distress syndrome: [review]

El síndrome de Distrés Respiratorio del Adulto es una de las enfermedades nosológicas de mayor gravedad en los pacientes ingresados en las unidades de cuidados intensivos. Se realiza una revisión del uso de la ventilación de alta frecuencia como una opción terapéutica para estos pacientes. Desde hace aproximadamente una década se están utilizando diferentes estrategias ventilatorias en el tratamiento del distrés, como el uso de la presión positiva al final de la espiración y las maniobras de reclutamiento alveolar. La ventilación de alta frecuencia surge como alternativa en el tratamiento de aquellos pacientes donde la ventilación mecánica convencional ha fallado; es una modalidad de ventilación donde se aplican bajo volúmenes tidales y altas frecuencias respiratorias, para lo cual es necesario la utilización de un tipo especial de máquina de ventilación capaz de garantizar altas frecuencias respiratorias. Actualmente la más utilizada es la ventilación oscilatoria de alta frecuencia, sus ventajas principales son requerir menos volumen tidal, niveles de presión. Se puede combinar con técnicas de ventilación prona para lograr mayor efectividad, la mortalidad es menor y se produce menos lesión asociada a la ventilación mecánica. Las complicaciones más frecuentes son el neumotórax, el incremento de los niveles de presión venosa central y de oclusión de la arteria pulmonar con ligera disminución del gasto cardíaco.

Adult respiratory distress syndrome is one of the nosologic diseases most seriousness in patients admitted at intensive care units. A review on the use of high-frequency ventilation as a therapeutic option for these patients was conducted. For approximately one decade different ventilatory strategies are using in the treatment of distress, as the use of positive pressure to the end of the expiration and the maneuvers of alveolar recruitment. High-frequency ventilation arises as alternative in the treatment of those patients where conventional mechanical ventilation has failed; it is a ventilation mode where low tidal volumes and high respiratory frequencies are applied, for which is necessary the use of a special type of ventilation machine able to guarantee high respiratory frequencies. Nowadays the most used is the oscillatory ventilation of high frequency, its main advantages are to require less tidal volume, levels of pressure. It may combine with prone ventilation technique to achieve bigger effectiveness, mortality is smaller and less associated lesion to the mechanical ventilation takes place. The most frequent complications are the pneumothorax, the increment of central venous pressure and occlusion levels of the pulmonary artery with slight decrease of heart output.

High-frequency oscillatory ventilation for acute respiratory distress syndrome.

Objective. To evaluate the effectiveness of HFOV in pediatric patients with acute respiratory distress syndrome. Methods. In this retrospective study, we reviewed all 20 pediatric patients, who were consecutively ventilated with HFOV in the pediatric intensive care unit of a tertiary medical center, from January 2006 to February 2007. Results. A total of 20 patients were enrolled. The median age of the subjects was 70 (3-168) months; 10 were male. All patients received conventional ventilation before HFOV. After initiation of HFOV, there was an immediate and sustained increase in PaO2/FiO2 ratio. The PaO2/FiO2 ratio was elevated and OI was decreased significantly after 10-20 minutes and maintained for at least 48 hours (p= 0.03, both). Thirteen of the 20 patients were successfully weaned. No significant change in the mean arterial pressure and heart rate was noted after HFOV. Overall survival rate was 65%. Of 20 patients, 11 patients suffered from extrapulmonary ARDS (ARDSexp) and 9 from pulmonary ARDS (ARDSp). When HFOV was initiated, there was significant increase in PaO2/FiO2 and decrease in OI in ARDSexp compared to ARDSp (p= 0.03, both). Also mortality rate was significantly lower in patients with ARDSexp (9% vs.66%), (p= 0.01). Conclusion. In our study, HFOV was effective in oxygenation and seems to be safe for pediatric ARDS patients. HFOV affected ARDSp and ARDSexp paediatric patients differently. However prospective, randomized controlled trials are needed to identify its benefits over conventional modes of mechanical ventilation.

Tratamiento de la Hipertensión Pulmonar Persistente Neonatal / Neonatal Persistent Pulmonary Hypertension Treatment

La Hipertensión Pulmonar Persistente Neonatal se caracteriza por el mantenimiento de una presión arterial anormalmente elevada en la circulación pulmonar después del nacimiento, cuya consecuencia más importante es el cortocircuito de derecha a izquierda por el agujero oval y el conducto arterioso que provoca inestabilidad y disminución intensa y progresiva de la paO 2, con una hipoxia severa que puede asociarse a pCO 2 normal o elevada. Se realizó una revisión bibliográfica acerca de algunos aspectos del tratamiento utilizado en estos casos, las ventajas de unos procederes sobre otros y las experiencias de especialistas en el manejo de esta grave afección neonatal. Dentro de las técnicas más ventajosas se reportan la ventilación de Alta Frecuencia Oscilatoria, el uso del Óxido Nítrico, la oxigenación por Membrana Extracorpórea y la Ventilación Líquida con Perfluorocarbonos.

The Neonatal Persistent Pulmonary Hypertension is characterized by maintaining the arterial pressure abnormally high in pulmonary circulation after birth; its more important consequence is the right-to-left shortcut by the oval hole and the arterial conduct, provoking instability and paO 2 progressive and intense diminishing, with a severe hypoxia that can be associated to a normal or elevated pCO 2 . We made a bibliographic review on some aspects of the treatment used in these cases, the advantages of some procedures over others and the specialists´ experience in the management of this serious neonatal disorder. Among the most advantageous techniques are reported the High Frequency Oscillatory ventilation, the Nitric Oxide usage, the Extracorporeal Membrane oxygenation and the liquid ventilation with perfluorocarbonates.

Beneficio de la asistencia ventilatoria de alta frecuencia en el recién nacido / Benefits of the high frequency ventilatory support in the newborn

La ventilación de alta frecuencia es una nueva modalidad de terapia ventilatoria muy útil en los servicios de neonatología que reporta numerosas ventajas para el recién nacido con complicaciones complejas. Se realizó un estudio retrospectivo de 17 neonatos que fueron asistidos con esta modalidad en el servicio de cuidados intensivos neonatales del Hospital Ginecoobstétrico Ramón González Coro, durante el período del 2002 al 2004. Se estimó como universo a todos los RN que fueron ventilados en el período en que se realizó la investigación. Se conformó la muestra con los 17 neonatos que fueron asistidos con ventilación de alta frecuencia por presentar problemas respiratorios graves. El objetivo de este estudio fue divulgar los beneficios de este nuevo proceder. La ventilación de alta frecuencia se aplicó con mayor reiteración en los recién nacidos pretérminos, los diagnósticos médicos que más repeticiones tuvieron para su indicación fueron la enfermedad de la membrana hialina en el 49,1 por ciento y el bloqueo aéreo en el 41,2 pòr ciento; la bronconeumonía adquirida, presente en el 17,6 por ciento de la muestra, fue la complicación que más se registró. La supervivencia de niños relacionado con este soporte ventilatorio representó el 70,6 por ciento. Se demostró que la ventilación de alta frecuencia constituye una alternativa de ventilación segura y muy efectiva cuando se indica correctamente y se aplican estrictamente los cuidados de enfermería(AU)

The ventilation of high frequency is a new modality of therapy very useful ventilatoria in the neonatología services that it reports numerous advantages for the recently born with complex complications. Was he/she carried out a retrospective study of 17 neonatos that you/they were attended with this modality in the service of cares intensive neonatales of the Hospital Ginecoobstétrico Ramón González Choir, during the period of the 2002 at the 2004. He/she was considered as universe to all the RN that were ventilated in the period in that he/she was carried out the investigation. He/she conformed to the sample with the 17 neonatos that were attended with ventilation of high frequency to present serious breathing problems. The objective of this study was to disclose the benefits of this new one to proceed. The ventilation of high frequency was applied with more reiteration in the recently born pretérminos, the medical diagnoses that more repetitions had for its indication were the illness of the membrane hialina in 49,1 percent and the air blockade in the 41,2 pòr hundred; the acquired bronchopneumonia, present by 17,6 percent of the sample, it was the complication that more he/she registered. The survival of children related with this support ventilatorio represented 70,6 percent. It was demonstrated that the ventilation of high frequency constitutes a sure and very effective ventilation alternative when it is indicated correctly and they are applied the infirmary cares strictly(AU)

El aporte de la cirugía bariátrica en el tratamiento del síndrome de Pickwick / Contribution of bariatric surgery in the treatment of Pickwick syndrome

El conjunto de alteraciones respiratorias que sufren los obesos mórbidos y que llevan a la hipoxemia e hipercapnia crónica, con poliglobulia compensatoria y falla cardíaca derecha secundaria es conocida desde hace tiempo como Síndrome de Pickwick. Su tratamiento médico es complejo y poco efectivo, siendo en la actualidad la cirugía bariátrica la que mejores resultados obtiene. En una serie de seis pacientes, con este cuadro, operados desde 1980 por el autor principal, sus resultados han sido muy satisfactorios al corregir rápida y efectivamente las graves alteraciones respiratorias presentes, corroborando lo descrito por la literatura mundial

Uso de ventilación de alta frecuencia oscilatoria en pacientes pediátricos / The use of oscillating high frequency ventilation in paedriatrics

Introducción: el enfoque ventilatorio actualmente sugerido en pacientes con Síndrome de Distress Respiratorio Agudo (SDRA) es lograr el reclutamiento y mantención del volumen pulmonar óptimo. La ventilación de alta frecuencia oscilatoria (VAFO) es una modalidad que emplea pequeños volúmenes corrientes con rápidas frecuencias respiratorias, reduciendo las presiones pico y el riesgo de volutrauma. Objetivo: describir los resultados en nuestra Unidad de Cuidados Intensivos con la VAFO como terapia de la Falla Respiratoria Hipoxémica Aguda. Diseño: un estudio clínico prospectivo no controlado de series de casos. Pacientes y métodos: se incluyeron pacientes menores de 16 años de edad, con diagnóstico de Falla Respiratoria Hipoxémica Aguda (PaO2/FiO2 < 200) frente a fracaso de Ventilación Mecánica Convencional (VMC), es decir, con índice de oxigenación (IO) >16. Resultados: se presentan un total de 31 episodios de empleo de VAFO en 29 pacientes cuyo diagnóstico fue SDRA en 90 por ciento, con edad de 5 meses (1 día a 104 meses) y peso de 6 kilogramos (2,8 a 60 kg). La duración de la VMC previo ala VAFO fue de 33 horas (0-740). El IO al momento de iniciarse la VAFO fue de 27. La presión media vía aérea (PMVA) fue fijada en promedio 10 cmH2O sobre el valor en VMC. La duración promedio de la VAFO fue de 85 horas por paciente. Tanto en los pacientes vivos como fallecidos se observó un descenso del índice de oxigenación (OI) durante las primeras 48 horas, sin una diferencia estadística entre ambos grupos. El efecto adverso más frecuente fue la hipotensión transitoria (13 episodios). Diez 24 por ciento (7/29). Conclusión: la VAFO es una terapia eficaz en dar soporte ventilatorio ante el fracaso de las modalidades ventilatorias convencionales

Ventilaçao de alta frequencia por oscilaçao comparada a ventilaçao mecânica convencional associada a reposicao de surfactante em coelhos / High frequency oscillation ventilation compared to conventional mechanical ventilation plus exogenous surfactant replacement in rabbits

Objetivos: a) avaliar o efeito na oxigenacao e ventilacao de coelhos artificialmente depletados de surfactante quando submetidos a ventilacao mecanica convencional associada a reposicao parcial de surfactante exógeno; b) comparar a evolucao deste grupo com outro grupo submetido a ventilacao de alta frequencia pos oscilacao (HFO) sem reposicao associada de surfactante. Métodos: vinte coelhos brancos da raca New Zealand, peso de +- 3 kg, foram anestesiados e artificialmente induzidos a deplecao de surfactante endógeno através de sucessivas lavagens pulmonares con alíquotas (25 ml/kg) de solucao fisiológica, até atingir uma PaO2 menor que 100 mmHg, quando ventilados vía traqueostomía no modo de pressao controlada objetivando um volume corrente de 10 ml/kg, com PEEP de 5 cm H2O, FiO2 de 100 por cento, frequencia respiratoria de 30 mpm, e tempo inspiratorio de 0,65 s. Posteriormente, os coelhos foram divididos em (a) grupo CMV+S, submetido a ventilacao convencional associada com reposicao parcial de surfactante exógeno; (b) grupo HFO submetido a ventilacao de alta frequencia por oscilacao. Gasometrías arteials foram coletadas antes da lavagem pulmonar, após a lavagem pulmonar, 15, 60 e 120 minutos após iniciado o tratamento. Os grupos foram comparados utilizando-se o teste 1 de Student. Resultados: em ambos grupos a PaO2 (pós lavagem pulmonar) era inferior a 50 mmHg (p=0,154), subindo aos 15 minutos de tratamento para 254 mmHg (CMV+S) e 288 mmHg (HFO, p=0,626). Aos 60 e 120 minutos, a PaO2 foi maior (p=0,001) no grupo HFO (431 e 431 mmHg) quando comparado com o grupo CMV+S, que apresentou queda progressiva (148 e 126 mmHg). Aos 60 minutos a PaCO2 era significativamente menor no grupo do CMV+S (29 versus 41 mmHg). Conclusoes: em modelo animal com SARA a estratégia de ventilacao protetora como a HFO, isoladamente, promove uma rápida e persistente melhora na oxigenacao, inclusive, com niveis superiores aos obtidos pelos animais submetidos a ventilacao mecánica convencional associada a reposicao de surfactante

Empleo de ventilación oscilatoria de alta frecuencia en el tratamiento del síndrome de distress respiratorio agudo en niños: descripción clínica y actualización de condiciones asociadas para una visión kinésica integral / Use of high frequency oscilltory ventilation in the treatment of the acute respiratory distress syndrome in children: clinical description and update of conditions associated for integral kinesic vision

Introducción: El síndrome de Distress Respiratorio Agudo (SDRA) presenta nuevas opciones terapéuticas en nuestra realidad, una de ella es la ventilación de alta frecuencia oscilatoria (VAFO), la cual es una modalidad que emplea pequeños volúmenes corrientes, con bajos cambios bifásicos de presión a frecuencias suprafisiológicas. Se presenta la experiencia en la instauración de la VAFO en el tratamiento del SDRA. Del mismo modo se revisa desde un aspecto teórico la asociación con el uso de decúbito prono (DP), como también la inmovilización prolongada y neuro-miopatía de paciente crítico, hallazgos frecuentes de observar en esta entidad clínica. Pacientes y Métodos: Se incluyeron los pacientes menores de 16 años que ingresaron con diagnóstico de Falla Respiratoria Hipoxémica Aguda (PaO2/FiO2<200) refractaria a Ventilación Mecánica Convencional. Un estudio clínico prospectivo investigó las características clínicas, parámetros ventilatorios empleados y la respuesta de indicadores de oxigenación. Resultados: Se presenta un total de 31 conexiones de VAFO en 29 pacientes, cuyo diagnóstico fue SDRA en el 90 por ciento. Tanto en los pacientes vivos y fallecidos hubo un descenso del índice de oxigenación (10) durante las primeras 48 horas, pero no se observó diferencia estadística entre ambos grupos. El 10 al momento de iniciarse la VAFO fue de 27. La PMVA fue fijada en promedio 10 cmH2O sobre el valor en VM convencional. La duración de la VAFO tuvo una mediana de 85 horas. En el 71 por ciento de los pacientes se asoció a DP. Hubo un 19 por ciento de barotrauma. Ocurrió un caso de neuro-miopatía de paciente crítico. Diez pacientes fallecieron (7 por causa pulmonar), dando una letalidad de 34 por ciento para este grupo. Conclusiones: Si se reúnen ciertas condiciones, la VAFO parece ser un modo efectivo de ventilación en falla respiratoria pediátrica. El kinesiológo debe estar atento a las manifestaciones de las condiciones asociadas con los diversos modos de tratamiento a los cuales es sometido el niño con falla respiratoria aguda

The use of L-arginine [correction of F-arginine] and phosphodiesterase inhibitor (dipyridamole) to wean from inhaled nitric oxide.

A full-term, female neonate developed acute hypoxemic respiratory failure complicated by persistent pulmonary hypertension of the newborn (PPHN), and responded to high-frequency oscillatory ventilation (HFOV) and inhaled nitric oxide (iNO). Discontinuation of iNO was attempted three times and was followed by severe desaturation due to right-to-left shunt through the patent ductus arteriosus and patent foramen ovale. As a result of iNO dependency state and rebound pulmonary hypertension, the neonate was maintained on iNO therapy for dipyridamole alone was unsuccessful. However, successful discontinuation of iNO therapy was achieved by combination of L-Arginine and dipyridamole. Exogeous NO may lead to down regulation of endogenous NO production, and further lead to rapid hydrolization of cyclic guanosine 3', 5' monophosphate (cGMP), the smooth muscle relaxant, by the enzyme phosphodiesterase. Moreover L-Arginine, the precursor for the formation of endogenous NO, has been found to be deficient in neonates with PPHN, so we speculated that by inhibiting phosphodiesterase and administrating L-Arginine smooth muscle relaxation occurred, and consequent weaning from iNO was achieved.

High frequency ventilation: basic concepts and clinical application.

High frequency ventilation (HFV) is a mode of therapy that improves gas exchange with pressure fluctuations much lower than that required for conventional ventilation. HFV is efficacious in the "rescue" management of infants with respiratory failure. Although each HFV system has functional characteristics that are design related, it now appears that when used with similar treatment strategies and within functional limitations, similar outcomes can be achieved. Ideally, the clinician or the operator should be familiar with the basic concepts of different high frequency ventilators to achieve maximal benefits from using these devices in infants with respiratory failure.