Prospects and developments in the technologies of high frequency oscillatory ventilation / 生物医学工程学杂志

The high frequency oscillatory ventilation (HFOV) is characterized with low tidal volume and low mean airway pressure, and can well support the breathing of the patients with respiratory diseases. Since the HFOV was proposed, it has been widely concerned by medical and scientific researchers. About the HFOV, this paper discussed its current research status and prospected its future development in technologies. The research status of ventilation model, mechanisms and ventilation mode were introduced in detail. In the next years, the technologies in developing HFOV will be focused on: to develop the branched high-order nonlinear or volume-depended resistance-inertance-compliance (RIC) ventilation model, to fully understand the mechanisms of HFOV and to achieve the noninvasive HFOV. The development in technologies of HFOV will be beneficial to the patients with respiratory diseases who failed with conventional mechanical ventilation as one of considerable ventilation methods.

Clinical Curative Effects of High Frequency Oscillatory Ventilation on Acute Respiratory Distress Syndrome Caused by Smoke Inhalation Injury in the Lungs / 昆明医科大学学报

Objective To study the curative effect of high frequency oscillatory ventilation on acute respiratory distress syndrome (ARDS) caused by smoke inhalation injury in the lungs. Methods Fifty ARDS patients with lung injury caused by smoke inhalation were selected from 2010 to 2015. Patients were randomly divided into two groups, respectively choosing conventional mechanical ventilation or high frequency oscillatory ventilation. Results PaO2, PaCO2, and PaO2/FiO2were improved in both groups after the treatment (P＜0.05) . Patients in the treatment group improved significantly compared to those in the control group (P＜0.05) . The ventilation time and length of hospital stay reduced significantly in the treatment group (P＜0.05) . No significant difference was found in mortality and complication rates in both groups within 30 days (P＞ 0.05) . Conclusion High frequency oscillatory ventilation can effectively alleviate symptoms of ARDS caused by smoke inhalation injury in the lungs by improving oxygenation index. No obvious improvement is found in prognosis.

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.

Effections of different ways of mechanical ventilation with pulmonary surfactant on respiratory mechanics of patients with neonatal acute respiratory distress syndrome / 实用医学杂志

Objective To investigate the respiratory mechanics and treatment outcomes of different types of mechanical ventilation for patients with neonatal acute respiratory distress syndrome(ARDS):the high frequency oscillation ventilation + pulmonary surfactant (HFOV+PS),conventional mechanical ventilation + pulmonary surfactant(CMV+PS),conventional mechanical ventilation(CMV). Methods Seventy-five cases with neonatal ARDS,25 cases in the HFOV+PS group,30 cases in the CMV+PS group,20 cases in the CMV group. Patients in the former two groups received 70 mg/kg PS at a time. PaO2,PaCO2,PaO2/FiO2,oxygenation index(OI)and respiratory index(RI)were detected at 0 h,12 h,24 h,48 h,72 h post-mechanical ventilation. Results At 12, 24,and 48 hours post-mechanical ventilation,patients in the HFOV+PS group had a significantly higher level of PaO2 and a significantly lower level of PaCO2 than those of patients in the CMV+PS group and the CMV group(P<0.05). At 12,24,48,and 72 hours post-mechanical ventilation,patients in the HFOV+PS group had a significantly higher level of PaO2/FiO2 and significantly lower level of OI and RI than those of patients in the CMV+PS group and the CMV group (P < 0.05,respectively). Patients in the HFOV+PS group also had significantly shorter durations of mechanical ventilation and oxygen usage than those of patients in the CMV+PS group and the CMV group (P < 0.05). No significant differences were observed in Gas leak,the incidence of intracerebral haemorrhage and cure rate among the three groups. Conclusions Application of HFOV with PS therapy for patients with neonatal ARDS can timely improve the oxygenation,shorten the time of mechanical ventilation and the usage of oxygen,without increasing complications.

Current status and recognition of high frequency ventilation in acute respiratory distress syndrome / 中华实用儿科临床杂志

Acute respiratory distress syndrome(ARDS) is a common critical disease in pediatric patients,and mechanical ventilation is one of the most important methods for respiratory support.High frequency oscillation ventilation,which has these characteristics of low tidal volume,low airway pressure,and low alveolar injury,is a safe and effective treatment of ARDS.This article will elaborate about current status and recognition of high frequency ventilation in ARDS.

The effects of high frequency oscillation ventilation on patients with acute respiratory distress syndrome:a Meta-analysis and sequential analysis of trial / 中华危重病急救医学

ObjectiveTo evaluate the effect of high frequency oscillation ventilation (HFOV) vs. conventional mechanical ventilation (CV) on the treatment and prognosis of adult patients with acute respiratory distress syndrome (ARDS).Methods Published articles concerning randomized controlled trials (RCTs) about the effect of HFOV vs. CV on the prognosis of adult patients with ARDS published before May 2014 were retrieved from PubMed, EMBase, Cochrane central registry of controlled trials, CNKI and Wanfang Data. The mortality and data of physiological parameters were analyzed with STATA 12.0, and the mortality rate was also analyzed by trial sequential analysis with TSA 0.9, and the line chart was drawn with Microsoft Office Excel 2003.Results Seven trials with 1 731 patients met the criteria, all of them recorded the physiological parameters data, and mortality rate was mentioned in 6 trials (1 705 patients). Compared with CV, HFOV did not show any statistically significant beneficial effects on mortality [relative risk (RR) = 0.93, 95% confidence interval (95%CI) = 0.70-1.24,P = 0.63], and other clinical outcomes, including survival without mechanical ventilation (RR = 1.05, 95%CI = 0.72-1.54,P = 0.80), survival on mechanical ventilation (RR = 1.23, 95%CI = 0.65-2.35,P = 0.52), or treatment failure (RR = 0.89, 95%CI = 0.50-1.56,P = 0.67). The risk factors of adverse events including hypotension (RR = 0.89, 95%CI = 0.07-10.99,P =0.93), acidosis (RR = 1.05, 95%CI = 0.43-2.56,P = 0.91), and air leakage from ventilator (RR = 0.74, 95%CI = 0.31-1.80,P =0.51) were similar. But the physiologic parameters of patients and parameters of ventilator in HFOV group, including oxygenation index, positive end-expiratory pressure, tidal volume, mean airway pressure, arterial pH, partial pressure of arterial carbon dioxide, fraction of inspired oxygen, ratio of partial pressure of arterial oxygen to fraction of inspired oxygen, were better than those in the CV group. Methods adapted from formal interim monitoring boundaries applied to cumulative Meta-analysis showed that the evidence failed by a considerable degree to meet the standards for forgoing studies, and the necessary sample was 3 874 patients. Trial sequential analysis also showed that the accumulatedZ-score did not cross the traditional boundary (P = 0.05) and interim monitoring boundaries. This result indicated that there was no significant difference between CV and HFOV on mortality before the number of needed sample reached (3 874 cases). We could not get a definitive conclusion with current evidences.ConclusionsCompared with CV, the use of HFOV in ARDS was not associated with a significant reduction in mortality. But the physiologic parameters of patients in HFOV group were better than those in the CV group. More RCTs are needed to draw a definitive conclusion.

Effectiveness of high frequency oscillation ventilation combined with Sildenafil treatment on newborns with persistent pulmonary hypertension / 中华实用儿科临床杂志

Objective To explore the effectiveness and adverse effect of high frequency oscillation ventilation (HFOV) combined with Sildenafil (SIL) treatment on newborns with persistent pulmonary hypertension (PPHN).Methods A total of 89 cases of PPHN infants collected from Chengdu Women and Children's Central Hospital from Sep.2010 to Sep.2012 were randomly divided into HFOV group,constant mechanical ventilation (CMV) group,HFOV combined SIL group (HFOV + SIL group) and CMV combined with SIL group (CMV + SIL group).The arterial blood gas,pulmonary artery pressure (PAP) and adverse reactions were monitored before and 3 days after treatment.SNK multiple comparison method andx2 test were performed for data before and after treatment among groups for continuous variables and categorical variables,respectively.Results The levels of pa (O2) [(79.1 ± 13.7) mmHg (1 mmHg =0.133 kPa),(77.9 ±14.6) mmHg,(85.4 ±15.2) mmHg],Sa(O2) [(87.8 ±13.4)％,(88.4±15.6)％,(96.1±15.9)％],pa(CO2)[(42.5±11.3) mmHg,(40.2 ±10.5) mmHg,(35.6 ±8.7) mmHg] and PAP [(31.1 ± 8.1) mmHg,(30.4 ± 9.5) mmHg,(25.8 ± 7.3) mmHg] were all improved significantly in CMV + SIL group,HFOV group and HFOV + SIL group compared with those in CMV group[(69.9 ± 12.3) mmHg,(81.1 ± 14.9)％,(48.1 ±9.5) mmHg,(35.6 ±8.9) mmHg] (F =4.629 3,3.673 2,5.865 3,4.849 5,P ＜0.05),especially for HFOV + SIL group(P ＜ 0.05).No significant difference in such indicators was observed between CMV + SIL group and HFOV group (P ＞ 0.05).The effective rate in HFOV + SIL group (90％) was the highest among the 4 groups (x2 =7.938,P ＜ 0.05).During the treatment,all neonates have no adverse reaction.Conclusion The combined use of SIL and HFOV might be a more effective and safer method in the treatment of PPHN of neonate.

Effectiveness and safety of high frequency oscillation ventilation in serious pulmonary hemorrhaege after surgical repair of congenital heart disease / 中华胸心血管外科杂志

Objective Experience with high-frequency oscillatory ventilation (HFOV) after congenital cardiac surgery is limited.The aim of the present study was to investigate the effect and safety of high frequency oscillation ventilation for patients with serious pulmonary hemorrhaege after surgical repair of congenital heart disease (CHD).Methods The patients with serious pulmonary hemorrhaege after surgical repair of CHD using conventional mechanical ventilation or high frequency oscillation ventilation were retrospectively analyzed.From January 2010 to July 2012,there were fourteen patients suffered from serious pulmonary hemorrhaege after surgical repair of congenital heart disease in our hospital and all involved in this study.The mean age was (6.5 ± 5.9) months(ranged from 1 to 24 months) and the mean body weight was (5.8 ± 1.7) kg(ranged from 3.7 to 10 kg).Before May 2011 patients with serious pulmonary hemorrhaege after surgical repair of congenital heart disease were treated with conventional mechanical ventilation(CMV group,n =6),and after May 2011 high frequency oscillation ventilation (HFOV group,n =8) instead.The diagnoses were pulmonary atresia with ventricular septal defect and major aortopulmonary collateral arteries 7 cases,tetralogy of Fallot with imbalance pulmonary arterial development 5 cases,and total anomalous pulmonary venous connection 2 cases.Heart rate,arterial blood pressure,central venous pressure(CVP),inostmpic score,the blood gas analysis,the oxygenation index(OI),the outcomes and complications during both mechanical ventilations were all recorded.Results The PaO2,OI and systolic blood pressure of patients in HFOV group were significant higher than those in CMV group after 2 hours ventilation.There was no statistical difference in PCO2,diastolic blood pressure and inostropic score after 1,2,4,8,24 hours ventilation.All cases had no significant changes in hemodynamics.CVP of patients in HFOV group increased slightly(P ＜0.05),but there was no statistical difference in arterial blood pressure.Four patients died in CMV group.The mortality of CMV group and HFOV group was 66.7％ (4/6) and 37.5％ (3/8,one with pulmonary venous obstrution,one with tracheobronchial blocked,the other with re-hemorrhaege) respectively.The mortality of HFOV group was no significantly different from that of CMV group.Conclusion Compared to CMV,using HFOV achieved greater oxygenation function in patients with serious pulmonary hemorrhaege after surgical repair of CHD rapidly,had no significant changes in hemodynamics and rare serious complications.HFOV was effective and safe for patients with serious pulmonary hemorrhaege after surgical repair of congenital heart disease.

Using the High Frequency Ventilation during Neonatal Transport

PURPOSE: To present and evaluate a system of high-frequency oscillatory ventilator (HFOV) during intra-/inter-hospital neonate transport. METHODS: The system includes a charged HFOV (SOPHIE, Fritz Stephan GmbH, Dusseldorf, Germany), an incubator, and E-oxygen/air-cylinders with connections to the HFOV. The test lung was evaluated at the high and medium ventilator settings used for infants to determine the operating time of HFOV. The time required to exhaust the gas supply was checked, and the HFOV was operated until the low-battery alarm sounded to determine the operating time of the batteries. RESULTS: The batteries provided electrical power for at least 60 mins, and the oxygen and air-cylinders lasted at least 20 mins. The system has been used frequently for the intra-hospital transport, from delivery rooms to ICU and from ICU for surgery. The system has been used twice for the inter-hospital transport of infants with bronchopulmonary dysplasia and pulmonary hypertension to another hospital 45 km away (one hour distance). In one case, the ambulance's electrical power supply failed, causing the system failure during the last 5 mins of transport. However, with the complete check and simulation of the system and the ambulance bulk oxygen/electric supply, the second patient was transported successfully in stable condition. CONCLUSION: The system was useful for intra-/inter-hospital transport of the neonates on HFOV. For the transport time of 60 mins, fully charged HFOV, 2 E-oxygen-cylinders, and 3 E-air-cylinders seemed to be sufficient. H-oxygen-cylinder and ambulance electrical power supply should also be provided for safe and efficient transport between hospitals.

Anesthetic Management of Premature Infant with Severe Respiratory Distress Syndrome Who Underwent Surgical Closure of Patent Ductus Arteriosus: A case report / 대한마취과학회지

Premature infants with respiratory distress syndrome may have clinically significant shunting through a patent ductus arteriosus (PDA). Left-to-right shunting through the PDA may lead to left ventricular volume overload and pulmonary edema. We present a case of perioperative management for severe respiratory distress syndrome in a premature infant who underwent surgical closure of PDA. Under general anesthesia, the infant was successfully managed by inhaled nitric oxide, high frequency oscillation ventilation with intermittent mandatory ventilation despite intermittent hypoxia. The operation was performed safely in the neonatal intensive care unit.

High Frequency Oscillation Ventilation for Resection of Congenital Lobar Emphysema: A case report / 대한마취과학회지

Congenital lobar emphysema (CLE) is a rare entity of unknown incidence. The main signs and symptoms are tachypnea, tachycardia, cyanosis, retractions, wheezing, tympanic chest percussion, asymetric breath sounds, or displaced cardiac tones within the first month of life. Occasionally a superimposed pulmonary infection exacerbates the condition, prompting hospital admission and medical treatment of the pneumonia followed by surgical treatment of the CLE. We now report a case of left upper CLE in a 15-day-old infant. Anesthesia was induced with thiopental sodium and maintained with intravenous fentanyl and midazolam. Endotracheal intubation was uneventful. Muscle relaxation was done with rocuronium. Gentle manual ventilation with a Mapleson D circuit was begun and changed to intermittent mandatory ventilation with an infant ventilator. During the left upper lobe resection, we used high frequency oscillation ventilation (HFOV) at FIO2 1.0, 12 Hz frequency, 12 cmH2O amplitude for 25 minutes. The minimal lung movement during HFOV was found to provide excellent operating conditions for the surgeons and adequate oxygenation without cardiovascular compromise. The PaCO2 was increased to 71 mmHg 25 minutes after the start of HFOV, and returned to normal value with intermittent mandatory ventilation. The remainder of the operation and anesthesia were uneventful. The patient was transferred to the neonatal intensive care unit.