Estimación de Distensibilidad Dinámica Toraco-pulmonar en Modelos Neonatales de Ventilación Mecánica de Alta Frecuencia / Estimation of dynamic thoracopulmonary compliance in neonatal high-frequency mechanical ventilation models

Introducción. La ventilación de alta frecuencia (VAF) es utilizada en pacientes graves neonatales con un uso cercano al 10% del total de usuarios en ventilación mecánica (VM). Actualmente estos equipos miden volumen corriente de manera precisa, continua y rutinaria, sin embargo no hay estimaciones del comportamiento mecánico del sistema respiratorio del usuario, como lo es la distensibilidad toracopulmonar, durante el ciclo ventilatorio que sean reportadas por las pantallas de los equipos. Objetivo. Estimar distensibilidad dinámica toracopulmonar en modelos neonatales de VAF. Métodos. Estudio cuantitativo, observacional, descriptivo, y "wench work", donde se midió distensibilidad en VM convencional y volumen corriente (Vt) en VAF con equipo Acutronics Fabian® por 4 evaluadores independientes, en 5 tipos de pulmón de ensayo y bajo diferentes escenarios de parámetros de VAF con ajustes de presión media de la vía aérea (PMVA), amplitud, frecuencia respiratoria, tiempo inspiratorio, volumen garantizado, y tipo de circuito. Mediante suavización de regresiones locales por estimación mínima cuadrática (LOWESS) y análisis de regresión multivariada se obtuvieron los valores asociados a distensibilidad, con los que se construyeron ecuaciones de estimación de distensibilidad en VAF. Resultados. Se realizaron en total 46080 mediciones, con correlación intra e interevaluador > 0.99. La distensibilidad mediana (percentil 25; 75) de los 5 modelos pulmonares fue de 0.455 (0.3; 0.98). Se asociaron a distensibilidad, mediante modelos de regresión lineal múltiple de manera significativa, todas las variables evaluadas, salvo PMVA. Se establecieron asociaciones multivariantes crudas (R2=.311), de distensibilidad predicha por LOWESS (R2=.744) y distensibilidad predicha y variables independientes predichas por regresión lineal simple (R2=.973). Conclusiones. La distensibilidad en VAF esta determinada en pulmones de ensayos por los parámetros programados de: tipo de circuito, uso de volumen garantizado, tiempo inspiratorio, frecuencia respiratoria y amplitud, además del Vt medido. Se reporta ecuación explicativa de distensibilidad en VAF.

Background. Background: High frequency mechanical ventilation (HFV) is used in severe neonatal subjects nearly 10% of total mechanically ventilated (MV) users. Currently, this MV's mode allow to measure tidal volumen in an accurately, continuous and routinarie way in HFV, however there are non estimation to assess mechanical behavior of respiratory system during ventilatory cycle, like thoraco-pulmonary compliance, who be report in the equipment display. Objetive. To estimate thoraco-pulmonary compliance in artificial neonatal lung models in HFV. Methods. Quantitative, observational, descriptive, and wench work study, where distensibility was measured in conventional MV and tidal volume (TV) in HFV with Acutronics Fabian® equipment by 4 independent evaluators, in 5 types of test lung and under different scenarios of HFV parameters with adjustments of mean airway pressure (MAP), amplitude, respiratory rate, inspiratory time, guaranteed volume, and type of circuit. By smoothing local regressions by least quadratic estimation (LOWESS) and multivariate regression analysis, the values associated with distensibility were obtained, with this measures, equations for estimating compliance in VAF were constructed. Results. A total of 46080 measurements were made, with intra and inter-evaluator correlation coefficent > 0.99. The median compliance (25th percentile; 75) of the 5 lung models was 0.455 (0.3; 0.98). All variables evaluated, except MAP, were associated with compliance, by means of multiple linear regression models. Crude multivariate associations (R2 = .311), predicted compliance by LOWESS (R2 = .744) and predicted compliance and independent variables predicted by simple linear regression (R2 = .973) were established to estimate thoraco-pulmonary compliance. Conclusions. Compliance in VAF is determined in test lungs by the programmed parameters of: type of circuit, use of guaranteed volume, inspiratory time, respiratory frequency and amplitude, in addition to the measured Vt. An explanatory equation for distensibility in VAF is reported.

Efficacy and safety of noninvasive high-frequency oscillatory ventilation in the treatment of respiratory failure in premature infants / 中国基层医药

Objective:To investigate the efficacy and safety of noninvasive high-frequency oscillatory ventilation in the treatment of respiratory failure in premature infants.Methods:Sixty-one premature infants with respiratory failure who received treatment in Neonatal Intensive Care Unit, Wenzhou Central Hospital from June 2019 to June 2020 were included in this study. They were randomly assigned to undergo either noninvasive high-frequency oscillatory ventilation (observation group, n = 31) or transnasal continuous positive airway pressure ventilation (control group, n = 31). Blood gas indicators, including pH value, oxygen partial pressure (PaO 2), partial pressure of carbon dioxide (PaCO 2), oxygenation index (OI), and respiratory index (RI), were determined before ventilation and 2, 8, 12, and 24 hours after ventilation. At the same time, the incidence of complications post-ventilation, including intracranial hemorrhage, bronchopulmonary dysplasia, air leakage, nasal crush injury, retinopathy of prematurity, abdominal distension, and necrotizing enterocolitis, was recorded in each group. Results:There were no significant differences in pH value, PaO 2, PaCO 2, OI, and RI pre-ventilation between observation and control groups ( t = 0.58, 0.64, 0.85, 0.43, 0.70, all P > 0.05). pH value, PaO 2, and OI measured 2, 8, 12 and 24 hours post-ventilation were significantly higher in the observation group than in the control group (pH value: t2 h = 3.20, t8 h = 4.81, t12 h = 6.39, t24 h = 5.22; PaO 2value:t2 h = 5.80, t8 h = 6.31, t12 h = 7.55, t24 h = 6.97; OI value: t2 h = 6.38, t8 h = 8.37, t12 h = 11.30, t24 h = 9.61). PaCO 2 and RI values were significantly lower in the observation group than in the control group (PaCO 2value:t2 h = 4.29, t8 h = 5.09, t12 h = 6.83, t24 h = 8.30; RI value: t2 h = 3.26, t8 h = 5.81, t12 h = 7.36、 t24 h = 6.54) (all P < 0.05). The incidence of complications was significantly lower in the observation group than in the control group [25.81% (8/31) vs. 46.67% (14/30), χ2 = 8.75, P < 0.05]. Conclusion:Compared with transnasal continuous positive airway pressure ventilation, noninvasive high-frequency oscillatory ventilation leads to better ventilation performance and a greater oxygenation ability, exhibits stronger effects on CO 2 clearance and acidosis correction, and has fewer complications in premature infants with respiratory failure. Therefore, noninvasive high-frequency oscillatory ventilation is suitable for clinical application.

Exercise Training Improved Pulmonary Gas Exchange Abnormalities in Pulmonary Hypertension due to Heart Failure: A Case Report

Abstract Heart failure (HF) is the most common cause of pulmonary hypertension (PH), and reduced exercise capacity and exertional dyspnea are the most frequent concerns in patients with PH-HF. Indeed, carbon dioxide end-tidal partial pressure (PETCO 2 ) during exercise is a well-established noninvasive marker of ventilation/perfusion ratio in PH. We aimed to evaluate the effect of aerobic exercise training on PETCO 2 response during exercise in a 59-year-old woman with PH secondary to idiopathic dilated cardiomyopathy. The patient with chronic fatigue and dyspnea at mild-to-moderate efforts was admitted to a cardiorespiratory rehabilitation program and had her cardiorespiratory response to exercise assessed during a cardiopulmonary exercise testing performed before and after three months of a thrice-weekly aerobic exercise training program. Improvements in aerobic capacity (23.9%) and endurance time (37.5%) and reduction in ventilatory inefficiency (-20.2%) was found after intervention. Post-intervention improvements in PETCO 2 at ventilatory anaerobic threshold (23.3%) and change in PETCO 2 kinetics pattern, with progressive increases from rest to peak of exercise, were also found. Patient also improved breathing pattern and timing of ventilation. This case report demonstrated for the first time that aerobic exercise training might be able to improve PETCO 2 response during exercise in a patient with PH-HF.

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.

Clinical application of transnasal high volume oxygen therapy in acute heart failure / 中国基层医药

Objective To explore the clinical value of transnasal high volume oxygen therapy in the treatment of patients with acute heart failure.Methods From January 2016 to January 2018,61 cases with acute heart failure in Huxi Hospital Affiliated to Jining Medical College were selected.The patients were randomly divided into control group and treatment group according to the digital table,31 cases in the control group and 30 cases in the treatment group.The two groups were routinely given control of fluid volume,analgesia,strong heart,diuresis,vasodilator,anti-platelet aggregation,camp support and so on.The control group was given conventional oxygen therapy,and the treatment group was treated with high flow oxygen through nose.Before treatment and 12h,24h,48h,72h after treatment,the left ventricular ejection fraction (LVEF),oxygen index (PaO2/FiO2),serum lactic acid (Lac),B type sodium and titanium (BNP) in serum,and the application rate of non-invasive mechanical ventilation and invasive mechanical ventilation in 7d were observed in the two groups.Results Compared with the control group,the LVEF of the treatment group in each time point increased [(35.58 ± 3.64) ％ vs.(37.77 ± 3.76) ％,(37.87 ± 3.58) ％ vs.(40.07 ±3.36)％,(44.94 ±3.19)％ vs.(46.83 ±3.21)％,(47.55 ±3.45％)％ vs.(40.07 ±3.36％)％,t =-2.308,-2.466,-2.316,-2.487,all P ＜ 0.05].The PaO2/FiO2 of the treatment group increased significantly at each time point after treatment [(177.39 ± 10.62) mmHg vs.(184.17 ± 10.49) mmHg,(188.00 ± 11.72) mmHg vs.(198.57 ± 18.47) mmHg,(204.06 ± 17.69) mmHg vs.(221.40 ± 23.80) mmHg,(265.23 ± 34.51) mmHg vs.(290.37 ± 26.72) mmHg,t =-2.507,-2.678,-3.236,-3.174,all P ＜ 0.05].The BNP level of the treatment group decreased significantly at each time point after treatment [(2 462.90 ± 288.00) ng/mL vs.(2 264.53 ± 366.44) ng/mL,(1 646.61 ± 377.19) ng/mL vs.(1 474.07 ± 214.03) ng/mL,(991.94 ± 242.95) ng/mL vs.(811.90 ±258.67) ng/mL,(653.77 ± 147.671) ng/mL vs.(526.47 ± 127.87) ng/mL,t =2.355,2.187,2.803,3.594,all P ＜ 0.05].The Lac level of the treatment group decreased significantly at 12h and 24h after treatment [(5.05 ± 0.69) mmol/L vs.(4.55 ± 0.80) mmol/L,(3.68 ± 0.89) mmol/L vs.(3.13 ± 0.77) mmol/L,t =2.610,2.601,all P ＜ 0.05],but there were no statistically significant differences between the two groups at 48h and 72h after treatment [(1.62 ± 0.65) mmol/L vs.(1.53 ± 0.65) mmol/L,(1.36 ± 0.64) mmol/L vs.(1.26 ± 0.46) mmol/L,all P ＞ 0.05].In the control group and the treatment group,the incidence rates of non-invasive mechanical ventilation in 7d were 35.48％ (11/31),13.33％ (4/30),respetively,the difference was statistically significant (x2 =4.034,P ＜ 0.05).In the control group and the treatment group,the incidence rates of invasive mechanical ventilation in 7d were 12.90％ (4/31),3.33％ (1/30),respetively,the difference was statistically significant (x2 =4.957,P ＜ 0.05).Conclusion Nasal high flow oxygen therapy has better clinical effect on patients with acute heart failure.It is a more active treatment measure,and is worthy of clinical application.

Clinical application of noninvasive high-frequency ventilation in neonatal respiratory support / 中华实用儿科临床杂志

Noninvasive high-frequency ventilation (NIHFV) is a new form of noninvasive ventilation which distends positive pressure continuously with oscillations superimposed on spontaneous tidal breathing, through a noninvasive interface.NIHFV, which provides the advantages of nasal continuous positive airway pressure and high frequency ventilation, can rapidly improve oxygenation, effectively remove carbon dioxide, and does not require synchronous techno-logy.It is considered as a new and effective noninvasive ventilation mode.In this paper, the application of NIHFV to neonates were reviewed, including mechanics of gas exchange, research advances and approach to the use of NIHFV.

Investigating the mechanism of the high frequency ventilation for the oscillation airflow between left and right lungs / 生物医学工程学杂志

Traditionally, adequate tidal volume is considered to be a necessary condition to support respiratory patient breathing. But the high frequency ventilation (HFV) with a small tidal volume can still support the respiratory patient breathing well. In order to further explore the mechanisms of HFV, the pendelluft ventilation between left and right lungs was proposed in this paper. And a test platform by using two fresh sheep lungs was developed for investigating the pendelluft ventilation between the left and right lungs. Furthermore, considering the viscous resistance ( ), inertance ( ) and lung compliance ( ) in the lung, a second-order lung ventilation model was designed to inspect and evaluate the pendelluft ventilation between left lung and right lungs. On referring to both results of experiments in practice and simulation in MATLAB Simulink, between the left and right lungs, the phase difference in their airflow happens during HFV at some frequencies. And the pendelluft ventilation between the left and right lungs is resulted by the phase difference, even if the total airflow entering a whole lung is 0. Under HFV, the pendelluft ventilation between left and right lungs will benefit the lungs being more adequately ventilated, and will be improve the utilization rate of oxygen in the lungs.

Clinical application of noninvasive high_frequency ventilation in neonatal respiratory support / 中华实用儿科临床杂志

Noninvasive high_frequency ventilation( NIHFV)is a new form of noninvasive ventilation which distends positive pressure continuously with oscillations superimposed on spontaneous tidal breathing,through a nonin_vasive interface. NIHFV,which provides the advantages of nasal continuous positive airway pressure and high frequency ventilation,can rapidly improve oxygenation,effectively remove carbon dioxide,and does not require synchronous techno_logy. It is considered as a new and effective noninvasive ventilation mode. In this paper,the application of NIHFV to neo_nates were reviewed,including mechanics of gas exchange,research advances and approach to the use of NIHFV.

Nursing care for very low birth weight infants with non-invasive high frequency ventilation / 中国实用护理杂志

Objective To summarize the nursing experience of non-invasive high- frequency ventilation in very low birth weight infants. Methods A total of 21 cases in 2017 were retrospectively analyzed. Ensuring effective ventilation, keeping the infants quiet, taking care of complication and strict observation were the key points. Results Sixteen cases had satisfied results, 2 cases were transferred to another hospital, and 3 cases died. Fourteen of the 21-cases successfully withdrawn from the machine, while 33.3％(7/21) of the cases were using invasive respiratory support. Conclusions Careful and meticulous nursing of non-invasive high-frequency ventilation can ensure the effectiveness of the invasive respiratory support, and promote the successful withdrawal, and reduce the intubation rate in very low birth weight infants.

The complications of premature infants receiving high－frequency ventilation vs conventional mechanical ventilation: a systematic review and meta－analysis / 中国新生儿科杂志

Objective To systematically evaluate the incidences of complications of high frequency oscillatory ventilation ( HFOV) and conventional mechanical ventilation ( CMV ) in premature infants. Method Randomized controlled trials of HFOV and CMV in premature infants published in databases including PubMed, Embase, Cochrane Library, CNKI Database, Wanfang Database, Weipu Chinese Sci－Tech Periodical Database were searched.The retrieval time was from the establishment of the databases to January 2018.The quality of the literature were evaluated , and Stata 15.0 statistical software was used for meta－analysis.Result A total of 18 articles and 3 888 premature infants were included in the study , including 1 910 in the HFOV group and 1 978 in the CMV group.No significant differences were found in the incidences of in－hospital mortality, air leakage syndromes , retinopathy of prematurity (ROP),≥grade 3 intraventricular hemorrhage (IVH), periventricular leukomalacia (PVL), necrotizing enterocolitis (NEC) and patent ductus arteriosus ( PDA) requiring medication or surgery ( P ＞0.05 ).The incidences of bronchopulmonary dysplasia (BPD) (RR ＝0.90,95%CI 0.83 ～0.98),≥grade 2 ROP (RR ＝0.78, 95%CI 0.63～0.96) and pulmonary hemorrhage (RR＝0.63, 95%CI 0.47～0.85) in HFOV group was significantly lower than the CMV group (P＜0.05).In the subgroup analysis, the results of the researches in 1980s, 1990s, 2000s, and 2010s showed that no significant differences existed in in－hospital mortality between the HFOV group and the CMV group on ventilator pressure control mode and volume control mode (P＞0.05).Conclusion Current evidences suggested that comparing with CMV , the application of HFOV in preterm infants might reduce the incidences of BPD ,≥grade 2 ROP and pulmonary hemorrhage.

Clinical effect of high frequency oscillatory ventilation combined with dobutamine on persistent pulmonary hypertension in neonates / 中国基层医药

Objective To investigate the clinical effects of high frequency oscillatory ventilation combined with dobutamine in the treatment of neonates with persistent pulmonary hypertension .Methods From April 2015 to April 2017,62 neonates with persistent pulmonary hypertension in the People＇s Hospital of Dongyang were selected. The patients were divided into control group and experimental group according to the single number,with 31 cases in each group.The experimental group was given high -frequency oscillatory ventilation combined with dobutamine treatment.The control group was treated with constant frequency mechanical ventilation combined with dobutamine . The therapeutic effect,blood gas,analytical indicators,biochemical indicators,pulmonary arterial pressure,systemic systolic blood pressure,oxygen inhalation time,ventilator treatment time,and incidence rate of complication were compared between the two group.Results Compared with the control group ( 76.41%),the effective rate (96.77%) was increased in the experimental group (χ2＝5.16,P＝0.02).The SpO2of the experimental group was (93.03 ±14.06)%,which was higher than (82.15 ±13.87)%of the control group (t＝3.06;P＝0.00).The OI in the experimental group was (17.35 ±1.46),which was lower than (57.36 ±15.36) in the control group ( t ＝14.43;P＝0.00).The CRP,BNP,DD,PAP levels in the experimental group were (2.62 ±0.63) mg/L,(6.19 ± 1.06)ng/L,(7.62 ±1.97)mg/L,(27.65 ±5.06)mmHg,respectively,which were lower than those in the control group [(3.69 ±0.72)mg/L,(8.34 ±1.63)ng/L,(15.72 ±2.81)mg/L,(33.52 ±4.62) mmHg](t＝6.22,6.15,13.14,4.76;P＝0.00,0.00,0.00,0.00).SBP in the experimental group was (71.62 ±6.35) mmHg,which was higher than (65.22 ±6.58)mmHg in the control group (t＝5.29,P＝0.00).The oxygen infusion time,ventilator treatment time of the experimental group were (9.96 ±5.63) d,(18.42 ±5.52) d,respectively,which were longer than those in the control group [(7.21 ±3.45)d,(13.65 ±4.12)d](t＝2.23,3.85,P＝0.02,0.00).The incidence rate of complications in the experimental group was 22.58%,which was lower than 6.45% in the control group (χ2＝6.71,P＝0.00).Conclusion High frequency oscillatory ventilation combined with dobutamine in the treatment of neonatal persistent pulmonary hypertension has better effect and is worthy of clinical promotion .

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.

Application of high-frequency nasal ventilation in the treatment of neonatal respiratory failure / 国际儿科学杂志

In order to reduce the complications associated with invasive mechanical ventilation,non-invasive respiratory support is used widely in the clinical work.However,the optimal approach and mode for noninvasive ventilation remains uncertain.As a new mode of non-invasive respiratory support,high-frequency nasal ventilation(HFNV) theoretically should combine the advantages of nasal CPAP and high-frequency ventilation,which is often used in the respiratory support of newborns,particularly in the extremely low birth weight infants.We review the research progress and application of the HFNV in the treatment of neonatal respiratory failure.

Effects of high-frequency oscillatory ventilation on brain injury in preterm infants with respiratory distress syndrome / 中华围产医学杂志

Objective To investigate the association between high-frequency oscillatory ventilation (HFOV) and the incidence of brain injury in premature infants(BIPI) with respiratory distress syndrome (RDS).Methods A total of 136 premature infants who were diagnosed as RDS and treated with mechanical ventilation between January 1,2014 and June 30,2016 were enrolled.Atter stratified by gestational age of 36-34 weeks,33-32 weeks,31-28 weeks and ≤ 27 weeks,the neonates were randomly divided into two groups (68 cases each):conventional mechanical ventilation (CMV) and HFOV groups.Duration of ventilation and changes in blood gas parameters following 24,48 and 72 hours of ventilation were monitored and compared between the two groups.Incidences of BIPI and complications in the two groups were calculated and their associations with gestational age and birth weight were analyzed.Moreover,incidences of cure rates in the two groups were comparatively analyzed.Independent samples t-test,two-way analysis of variance,Chi-square test or Fisher's exact test was used for statistical analysis.Results (1)Significant difference was observed neither in the perinatal factors (prenatal glucocorticoid usage,and incidences of premature rupture of membrane and gestational diabetes mellitus),nor in the severity of RDS between the two groups (all P＞0.05).(2) The average duration of ventilation in the CMV group was higher than that of the HFOV group [(68.44±10.3) vs (64.7±8.5) h,t=2.285,P＜0.05].No significant difference in the values of pH,partial pressure of carbon dioxide (PaCO2) or partial pressure of oxygen (PaO2) before and after 24,48 or 72 hours of ventilation treatment was found between the two groups (all P＞0.05).(3) Neither the incidence of hemorrhagic brain injury nor that of non-hemorrhagic brain injury showed any significant difference between the CMV and HFOV groups [36.8％ (25/68) vs 39.7％ (27/68);16.2％ (11/68)vs 14.7％ (10/68),both P＞0.05].The total incidence of BIPI showed no significant difference [44.1％(30/68) vs 45.8％(33/68),22=0.266,P=0.606].The smaller gestational age at birth and the lower birth weight,the higher incidence of BIPI,although no significant difference was shown in the incidence of BIPI when compared among different gestational age groups and different birth weight groups (all P＞0.05).(4) The incidence of complications in the CMV group was higher than that in HFOV group [25.0％(17/68) vs 11.8％(8/68),22=3.970,P=0.044],while the cure rate of RDS was similar [94.1％(64/68) vs 95.6％(65/68),x2=0.151,P=0.703].Conclusions HFOV is a safe and reliable therapy for preterm infants with RDS.Compared with CMV,HFOV can shorten the duration of ventilation and reduce the incidence of complications without increasing the risk of BIPI.However,the cure rate of RDS is not increased by HFOV.

Non-invasive high frequency ventilation support in the treatment of neonatal respiratory distress syndrome after extubation / 中国新生儿科杂志

Objective To compare the efficacy and safety of the non-invasive high frequency ventilation (NHFV) and non-invasive intermittent positive pressure ventilation (NIPPV)in neonates with respiratory distress syndrome (RDS) after extubation.Method Neonates with RDS from January 2015 to January 2016,who required high frequency ventilation after birth and were extubated after treatment were retrospectively studied.The enrolled patients were divided into NHFV group and NIPPV group to compare the rate of successful extubation within 7 days,non-invasive respiratory ventilation support time and complication incidence.Result In total 42 neonates were included,NHFV group were 21 cases and NIPPV group were 21 cases.The rates of successful extubation were not statistically different (71.4％ vs.80.9％,P ＞ 0.05);Compared with NIPPV group,NHFV group had shorter ventilation time [3.5 (2.2,4.1) d vs.4.6 (2.8,5.3)];the incidence of bronchopulmonary dysplasia,pneumothorax,intraventricular hemorrhage,periventricular leukomalacia,retinopathy of premature and necrotizing enterocolitis between groups were not statistically different (P ＞ 0.05).Conclusion NHFV is a new safe and efficient ventilation support method for extubated neonates,and needs further research.

The clinical application of high frequency oscillatory ventilation in children / 中国小儿急救医学

High-frequency ventilation ( HFV) is theoretically an ideal ventilatory mode for lung pro-tection. It also delivers extremely small tidal volumes near to or less than the anatomically invalid cavity (about 2ml/kg) at very high respiratory frequencies (recognized ventilation frequency about 4 times more than the normal range) . Compared to the conventional mechanical ventilation,HFV makes use of lung-open mode,with low tidal volume, low airway pressure, low thoracic pressure and end-exhaling pressure effect, which can avoid recruitment/derecruitment of alveoli to reduce pressure injuries on lung tissue and airway. Nowadays,more and more critical care practitioners implement this ventilation mode. We reviewed the princi-ples,classification,parameters,and clinical indications of HFV in this article.

Clinical study of high-frequency oscillatory ventilation in the treatment of pulmonary hemorrhage in newborn infants / 中国基层医药

Objective To investigate the effects of high frequency oscillatory ventilation in the treatment of neonatal pulmonary hemorrhage curative.Methods 56 neonates with pulmonary hemorrhage were selected,28 cases in high frequency mechanical ventilation(HFOV) group and 28 cases in conventional mechanical ventilation(CMV)group.On the basis of conventional treatment,the HFOV group received high-frequency mechanical ventilation therapy,the CMV group treated with conventional ventilation.The breathing machine parameters of the two groups were observed and recorded,calculated oxygenation index (OI) and arterial/alveolar oxygen partial pressure ratio (a/APaO2) The duration of pulmonary hemorrhage,the duration of mechanical ventilation,the length of hospital stay,and the duration of oxygen therapy were compared between the two groups.Results Before treatment,there were no statistically differences of in OI and a/APaO2 between the two groups (t1 =0.28,P1 =0.78;t2 =0.47,P2 =0.64),1h treatment later,declining value of the OI and the rising of a/APaO2 in surviving children,and the therapeutic effect of the HFOV group were more obvious than those of the CMV group (t1'=2.14,P1'=0.04;t2'=2.26,P2'=0.03).In the HFOV group,23 cases cured(82.1％),5 cases died(17.9％).And in CMV group,15 cases cured(53.6％),13 cases died (46.4％).The duration of pulmonary hemorrhage,the duration of mechanical ventilation,the length of the hospital stay,and the duration of oxygen therapy of the HFOV group were significantly lower than those of CMV group,the differences were statistically significant (P =0.046,0.044,0.048,0.035).Conclusion HFOV can better improve oxygenation function in infants with pulmonary hemorrhage,shorten the course of the disease and improve the cure rate,recommend the application and clinical treatment.

Use of noninvasive high-frequency oscillatory ventilation in very low birth weight infants / 中华儿科杂志

Objective@#To evaluate the effectiveness and safety of the use of noninvasive high-frequency oscillation ventilation (nHFOV) in very low birth weight infants.@*Method@#A total of 36 cases received nHFOV between January 2016 and October 2016 in Children′s Hospital, Zhejiang University School of Medicine, including 24 males and 12 females, with the gestational age of (27.5±2.5) weeks and birth weight of(980±318)g. The data of the ventilator settings, side effects, and changes of the respiratory function before and after nHFOV were collected and analyzed retrospectively. Nonparametric tests or t tests or χ2 tests were used.@*Result@#Thirty-two (89%) out of the 36 cases successfully avoided intubation or re-intubation after using of nHFOV. nHFOV was used as the rescue treatment after failure of other noninvasive ventilation in 17 cases, and as the prophylactical treatment preventing re-intubation after extubation in the remaining 19 cases. There were significant decreases in the incidences of apnea and desaturation(SpO2<0.85), the level of PaCO2, and the FiO2 24 h after the initiation of the nHFOV as the rescue therapy((1.2±1.1)vs.(6.3±2.1)episodes , (1.1±1.2) vs.(4.3±1.5) episodes, (43±8) vs.(56±10) mmHg, 0.30±0.07 vs. 0.39±0.11, respectively; 1 mmHg=0.133 kPa, t=7.562, 8.913, 4.179, 3.437 respectively, all P<0.01). No significant changes were found in FiO2 and PaCO2 levels 24 h after initiation of nHFOV as the prophylactical therapy after extubation (0.42±0.12 vs.0.40±0.10, (49±8)vs.(48±7)mmHg, t=0.872 and 0.501 respectively, both P>0.05), except for the significant decreases in the mean airway pressure ((7.9±2.6)vs.(9.6±1.6)cmH2O, 1 cmH20=0.098 kPa, t=2.198, P=0.041). There were 4 cases suffered from nasal septum injury, while no other nHFOV related complications were noted.@*Conclusion@#nHFOV can be applied in preterm infants as a rescue treatment after the failure of other noninvasive ventilation, or prophylactically used in patients who have high risk of re-intubation.

Actualización en ventilación de alta frecuencia oscilatoria en pacientes pediátricos con insuficiencia respiratoria aguda / Ventilation update high oscillatory frequency in pediatric patients with Severe respiratory insufficiency

Recientemente un grupo de expertos estableció la definición del síndrome de dificultad respiratoria aguda en niños y las recomendaciones relativas a su tratamiento. La ventilación de alta frecuencia oscilatoria es considerada por este consenso como una alternativa válida a la ventilación mecánica convencional en pacientes con este síndrome e hipoxemia resistente. La incorporación de la ventilación de alta frecuencia oscilatoria en el ámbito clínico data de la década de 1970, su utilización se sustenta en que este modo ventilatorio respeta los objetivos fisiológicos de reclutamiento y protección pulmonar. La literatura alberga numerosas publicaciones referidas a la ventilación de alta frecuencia oscilatoria en niños con síndrome de dificultad respiratoria aguda y su comparación con la ventilación mecánica convencional, la mayoría de los trabajos con diseños limitados, a excepción de dos estudios controlados y aleatorizados que objetivan menor daño inducido y menor enfermedad pulmonar crónica en los pacientes tratados con ventilación de alta frecuencia oscilatoria. A la luz de la evidencia analizada, esta ventilación en pacientes con síndrome de dificultad respiratoria aguda pediátrico sería una terapia aceptable ante el fracaso de las medidas convencionales(AU)

Recently, a group of experts established the definition of pediatric acute respiratory distress syndrome and the recommendations regarding its treatment. High-frequency oscillatory ventilation is considered by this consensus as a valid alternative to conventional mechanical ventilation in children with acute respiratory distress syndrome and refractory hypoxemia. There are numerous publications about high-frequency oscillatory ventilation in pediatric patients with this syndrome and its comparison with the conventional mechanical ventilation, most of the studies with limited designs, except for two randomized controlled studies that reported less induced injury and less chronic lung disease in patients treated with high-frequency oscillatory ventilation. Incorporation of this type of ventilation in the clinical setting dates back to the 70s, its use is supported by the fact that this ventilation mode respects the physiological aims of recruitment and lung protection. In light of the analyzed evidence, high-frequency oscillatory ventilation in children with acute respiratory distress syndrome would be an acceptable therapy when conventional measures fail.(AU)