Hemodynamic effects of high-frequency oscillatory ventilation in severe pediatric respiratory failure

Objective To assess the hemodynamic effects of high mean proximal airway pressures (Paw) during high-frequency oscillatory ventilation (HFOV) in non-neonatal pediatrics patients with severe respiratory failure.Design Prospective and retrospective study.Setting Pediatric ICU in a university-affiliated hospital.Patients 8 non-neonatal pediatric patients with severe respiratory failure ventilated with HFOV at our institution between July 1991 and February 1994. All patients had a pulmonary artery catheter.Interventions HFOV.Measurements and results Higher Paw was required during HFOV to obtain adequate lung expansion during the first 24 h (median 20.9 cmH₂O, range 16.9–30.0 cmH₂O in CMV, versus median 30.0 cmH₂O, range 21.0–33.0 cmH₂O in HFOV,p=0.008), resulting in improved oxygenation as evaluated by alveolar-arterial oxygen difference (median of 557.2 mmHg, range 360.4–607.8 mmHg in CMV, versus median of 410.5 mmHg, range 282.9–550.2 mmHg after 24 h of HFOV,p=0.03). The only observed effect on the cardiovascular system was a decrease in heart rate (median of 162, range 129–178 in CMV, versus median of 142, range 104–195 after 24 h of HFOV,p=0.03). Oxygen delivery, cardiac index, mean systemic arterial blood pressure, and pulmonary and systemic vascular resistances did not change significantly before and after HFOV in the patients as a group, although in one case a decrease in cardiac index and oxygen delivery was observed.Conclusions High-Paw HFOV must be used cautiously, but seems to have no discernible adverse effects on the cardiovascular system in most patients.     

有创-无创序贯机械通气救治严重呼吸衰竭的护理

目的探讨有创一无创序贯机械通气救治严重呼吸衰竭的护理方法。方法在47例严重呼吸衰竭患者进行有创一无创序贯机械通气治疗过程中,进行认真的观察和有针对性的护理。结果降低了患者的住院病死率、呼吸机相关肺炎（VAP）发生率,缩短了住院时间。结论护士和医生密切配合,根据患者的具体情况,应用专科护理知识,实施正确并具有针对性的护理,能够提高严重呼吸衰竭患者救治的成功率。     

High-frequency percussive ventilation improves oxygenation and ventilation in pediatric patients with acute respiratory failure

Purpose

High-frequency percussive ventilation (HFPV) in pediatrics has been described predominantly in burned patients. We aimed to describe its effectiveness and safety in noninhalational pediatric acute respiratory failure (ARF).

Methods

We conducted an observational study in a tertiary care pediatric intensive care unit on 31 patients with ARF failing conventional ventilation transitioned to HFPV. Demographics, ventilator settings, oxygenation index, oxygen saturation index, oxygen saturation as measured by pulse oximetry/fraction of inspired oxygen (Fio₂), and Pao₂/Fio₂ were recorded before and during HFPV.

Results

Initiation of HFPV was associated with improvements in oxygenation index, oxygen saturation index, Pao₂/Fio₂, and oxygen saturation as measured by pulse oximetry/Fio₂ as early as 12 hours (P < .05), which continued through 48 hours after transition. Improved oxygenation occurred without an increase in mean airway pressures. Reductions in Paco₂ occurred 6 hours after initiation of HFPV and continued through 48 hours (P < .01). Improved gas exchange was accompanied by reduced peak-inflating pressures at all time intervals after initiation of HPFV (P < .01). Vasopressor scores were similar before and after initiation of HFPV in patients requiring vasoactive support. Twenty-six (83.9%) of 31 patients survived to hospital discharge.

Conclusions

In a heterogeneous population of pediatric ARF failing conventional ventilation, HFPV efficiently improves gas exchange in a lung-protective manner.     

Palliative noninvasive ventilation in patients with acute respiratory failure

Over the last two decades, the increasing use of noninvasive ventilation (NIV) has diminished the need for endotracheal ventilation, thus decreasing the rate of ventilation-induced complications. Thus, NIV has decreased both intubation rates and mortality rates in specific subsets of patients with acute respiratory failure (e.g., patients with hypercapnia, cardiogenic pulmonary edema, immune deficiencies, or post-transplantation acute respiratory failure). NIV is also increasingly used as a palliative strategy when endotracheal ventilation is deemed inappropriate. In this context, palliative NIV can either be administered to offer a chance for survival, or to alleviate the symptoms of respiratory distress in dying patients. The literature provides information from 10 studies published between 1992 and 2006, in which 458 patients received palliative NIV. The technique was feasible, usually well tolerated, and half of the patients survived. The objectives of this review article are to define palliative NIV, to delineate the place for palliative NIV among overall indications of NIV, and to define the contribution of NIV to the palliative strategies available for patients with acute respiratory failure. Potential benefits and harm from NIV in patients who are not eligible for endotracheal ventilation are discussed. The appropriateness of palliative NIV should be reported in a study that relies on both quantitative criteria (rate of palliative NIV use and mortality) and qualitative criteria (patient comfort, end-of-life process, family burden, and health-care provider satisfaction).     

高频振动通气在急性呼吸窘迫综合征治疗中的作用

目的　评估高频振动通气 (high frequencypercussiveventilation ,HFPV)在成人ARDS治疗中的有效性和安全性 ,探索ARDS治疗的新途径。方法　临床观察 93例ICU条件下使用HFPV的ARDS病人 ,对常规通气 (conventionalventilation ,CV)和HFPV下的PaO2 /FiO2 、PaCO2 、DO2 、VO2 、Qs/Qt、PEEP/CPAP、PAWP等氧代谢、血流动力学指标和呼吸参数的变化进行统计分析。结果　 93例病人中 ,存活 6 6例 ,死亡2 7例 ,死亡率为 2 9 0 % (除外 7例未死于ICU者 ,实际死亡率为 2 1 5 % )。使用HFPV前后PaO2 /FiO2 、PaC O2 、DO2 、VO2 、Qs/Qt的变化为 (77 6± 2 0 0 )和 (2 0 8 7± 70 8)、 (471 2± 114 7)和 (6 0 1 3± 14 0 9)、(10 7 6± 34 3)和 (14 6 4± 2 3 3)、 (35 7± 2 0 5 )和 (2 4 5± 6 5 ) (P <0 0 5 )。X ray胸片双肺阴影减轻或消失 ,同时可看到病人鼻腔口腔有不等量的混浊液体从呼吸道溢出。结论　HFPV在ARDS治疗中是有效和安全的。临床应用HFPV能明显改善氧代谢 ,提高PaO2 /FIO2 。早期应用和合理化管理能明显降低ARDS的病死率     

Severe combined respiratory and myocardial failure treated with high-frequency ventilation

High levels of positive end-expiratory pressure (PEEP) impair cardiac output. The subsequent lowering of mixed venous oxygenation, when coupled with a significant intrapulmonary shunt, may dramatically depress PaO2. We present a patient whose severe myocardial and respiratory insufficiency was unmanageable on conventional ventilation with high levels of PEEP and maximal inotropic support. High-frequency ventilation superimposed on conventional ventilation lowered peak airway pressure and dramatically improved both cardiac and pulmonary function.     

无创通气治疗慢性阻塞性肺疾病合并呼吸衰竭疗效观察

目的 探讨无创正压通气治疗慢性阻塞性肺疾病合并呼吸衰竭的临床疗效.方法 对25例慢性阻塞性肺疾病合并呼吸衰竭患者,在常规治疗的基础上联合无创正压通气治疗,观察临床疗效.结果 本组患者治疗有效率为80％.结论 无创正压通气治疗慢性阻塞性肺疾病合并呼吸衰竭疗效确切.     

Combined high-frequency ventilation in children with severe adult respiratory distress syndrome

Six children conventionally ventilated for acute pulmonary parenchymal failure developed severe hypoxemia (mean PaO₂ 48±7 mmHg at an FiO₂ of 0.95±0.08) persisting for more than 6 h despite a progressive increase in positive end expiratory pressure (PEEP) to 14.7±1.5 cmH₂O. Combined high-frequency jet ventilation (HFJV, mean rate 225 b/min superimposed on small tidal volume conventional ventilation) resulted in a sustained increase in PaO₂ to 93±21 mmHg,p<0.05 while peak inspiratory pressure decreased from 47±8 to 35±6 cmH₂O and positive end expiratory pressure could be reduced to 5.8±4.5 cmH₂O,p<0.05 and FiO₂ to 0.88±0.10. This improvement occurred without new barotrauma nor deleterious effects on hemodynamic function or diuresis. After a mean of 62 h of combined HFJV, persistant improvement in gas exchange allowed us to resume conventional mechanical ventilation at lower airway pressures in 4 children who continued to improve and survived. The 2 other children maintained satisfactory gas exchange on combined HFJV, but ultimately died from multiple organ failure. We conclude that combined HFJV might prove helpful to relieve profound hypoxemia and possibly decrease the risk of barotrauma in children with catastrophic pulmonary failure.This study was presented in part at the Annual Meeting of the Swiss Society of Intensive Care Medicine, Basel, Switzerland, October 1989.     

无创高频振荡通气对早产儿呼吸窘迫综合征的临床疗效

目的探讨无创高频振荡通气（nHFOV）对早产儿呼吸窘迫综合征（RDS）的临床疗效。 方法将2017年3月至2020年3月诊断为RDS的200例早产儿分为研究组和对照组,每组各100例。研究组给予nHFOV进行治疗,对照组给予经鼻持续气道正压通气（nCPAP）治疗。对比两组患儿治疗后的疗效、初始治疗失败率、早产儿支气管肺发育不良（BPD）发生率、不良事件发生率、血气分析相关指标、振幅整合脑电图（aEEG）评分及血清高迁移族蛋白B1（HMGB1）水平。 结果研究组患儿治疗后的疗效显著优于对照组患儿[93.00%（93/100）vs. 63.0%（63/100）,χ² = 68.923,P < 0.001],且研究组患儿初始治疗失败率[6.00%（6/100）vs. 15.00%（15/100）,χ² = 4.310,P = 0.038]及BPD发生率[1.00%（1/100）vs. 9.00%（9/100）,χ² = 6.737,P = 0.009]均显著低于对照组,而两组患儿气胸/气漏、消化道穿孔、早产儿坏死性小肠结肠炎、早产儿视网膜病、颅内出血、鼻损伤、死亡的发生率比较,差异均无统计学意义（χ² = 2.083、2.909、0.977、1.332、1.047、0.521、2.750,P均> 0.05）。同时,与对照组患儿比较,治疗后研究组患儿的氧分压[（89 ± 28）mmHg vs.（80 ± 29）mmHg,t = 2.151,P = 0.033]、二氧化碳分压[（37 ± 7）mmHg vs.（41 ± 10）mmHg,t = 3.386,P<0.001]及血氧饱和度水平[（97.4 ± 2.1）% vs.（90.6 ± 6.4）%,t = 10.049,P < 0.001]均显著改善,aEEG评分显著升高[（8.5 ± 1.5）分vs.（5.2 ± 1.9）分,t = 13.319,P<0.001],血清HMGB1水平显著降低[（578 ± 71）ng/L vs.（628 ± 72）ng/L,t = 5.071,P<0.001]。 结论nHFOV可有效改善RDS早产儿的脑功能、血气分析及呼吸支持相关指标,降低血清HMGB1水平,提升整体临床疗效。     

Ventilators for noninvasive ventilation to treat acute respiratory failure

The application of noninvasive ventilation (NIV) to treat acute respiratory failure has increased tremendously both inside and outside the intensive care unit. The choice of ventilator is crucial for success of NIV in the acute setting, because poor tolerance and excessive air leaks are significantly correlated with NIV failure. Patient-ventilator asynchrony and discomfort can occur if the physician or respiratory therapist fails to adequately set NIV to respond to the patient's ventilatory demand, so clinicians need to fully understood the ventilator's technical peculiarities (eg, efficiency of trigger and cycle systems, speed of pressurization, air-leak compensation, CO(2) rebreathing, reliability of fraction of inspired oxygen reading, monitoring accuracy). A wide range of ventilators of different complexity have been introduced into clinical practice to noninvasively support patients in acute respiratory failure, but the numerous commercially available ventilators (bi-level, intermediate, and intensive care unit ventilators) have substantial differences that can influence patient comfort, patient-ventilator interaction, and, thus, the chance of NIV clinical success. This report examines the most relevant aspects of the historical evolution, the equipment, and the acute-respiratory-failure clinical application of NIV ventilators.     

Predictors of failure of noninvasive ventilation in patients with severe community-acquired pneumonia

Purpose

The study aimed to investigate cardiorespiratory parameters potentially predictive of failure of noninvasive ventilation (NIV) in severe community-acquired pneumonia (CAP).

Patients and Methods

Sixty-four consecutive patients with severe CAP entered the study and underwent NIV with a helmet. Arterial blood gases, Pao₂/FIo₂, and oxygenation index (OI; mean airway pressure × FIo₂ × 100/Pao₂) were determined before and after a 1-hour trial of NIV.

Results

Noninvasive ventilation succeeded in 28 patients (43%) and failed in 36 patients (56%). Patients who avoided intubation had significantly (P < .05) shorter stays in ICU and lower rates of mortality in ICU and in hospital. Patients who failed NIV had higher Simplified Acute Physiology Score II at ICU admission (33 ± 11 versus 29 ± 9) and lower pH before NIV trial (7.37 versus 7.44). Furthermore, patients who required intubation failed to improve or worsened arterial blood gases during NIV trial and, by the end of the trial, had lower (P < .05) pH (7.34 versus 7.44) and Pao₂/FiO₂ (177 versus 228) and higher OI (8.6 versus 5.0) and respiratory rate (28 versus 23 breaths/min). In a multivariate analysis, post-NIV to pre-NIV deltas of Pao₂/FiO₂ and of OI were independent predictors of NIV failure, with OI delta being significantly more accurate.

Conclusions

Noninvasive ventilation failed in approximately half patients with severe CAP. Posttrial to pretrial deltas of Pao₂/FiO₂ and OI may help to guide decision about endotracheal intubation.     

High-frequency jet ventilation for severe respiratory failure

High-frequency jet ventilation (HFJV) is a newer form of mechanical ventilatory support that has shown promise in the treatment of severe neonatal respiratory distress syndrome. It is now also being studied as a possible treatment for adult respiratory distress syndrome in older children.     

Volume-controlled ventilation for severe neonatal respiratory failure

Volume-controlled ventilation was utilized as a rescue modality in six newborn infants with severe respiratory failure. Infants were switched from time-cycled, pressure-limited ventilation to volume-controlled ventilation at 10-12 mL/kg using the VIP-Bird infant ventilator. All six displayed dramatic improvements in oxygenation with virtually no change in mean airway pressure and with subsequent resolution of the respiratory failure. Preliminary analysis of pulmonary function during volume-controlled ventilation suggests differences in the patterns of delivery of tidal volume and minute ventilation, which are more consistent. This may improve stabilization of lung volume and decrease ventilation-perfusion mismatch.