有创机械通气患儿呼吸评估与治疗进展

机械通气技术的广泛应用使得很多呼吸衰竭患儿得到成功救治。同时,强制通气、肺部正常呼吸生理及呼吸力学的改变会导致呼吸功能减退以及气道廓清能力下降。因此,如何根据儿童自身生理特点进行全面、精准的呼吸功能评估,进行适宜的呼吸功能康复,以尽快拔除气管插管,缩短机械通气时间,是目前儿童重症机械通气有效撤机的研究重点。该文就有创机械通气患儿呼吸功能评估与治疗方法进展进行综述。     

Respiratory support for children in the emergency department

Respiratory support in paediatric emergency settings ranges from oxygen delivery with subnasal oxygen to invasive mechanical ventilation. Recent data suggest that oxygen can cause reperfusion injuries and should be delivered with caution within well‐defined clinical target ranges. Most mild to moderate respiratory distress conditions with an oxygen requirement may benefit from early use of continuous positive airway pressure. High‐flow nasal cannula therapy (HFNC) is an emerging alternative way to support the inspiratory effort combined with oxygen delivery and positive expiratory pressures without the need of complicated equipment or good compliance from the child. Besides a positive pressure support effect, HFNC therapy reduces the physiological dead space with improved CO₂ clearance. A decrease in heart and respiratory rate within the first few hours after initiation of HFNC therapy is likely to identify responders of the treatment. The use of non‐invasive ventilation such as continuous positive airway pressure or the use of bi‐level positive airway pressure ventilation in emergency departments has increased, and it has been recognised that continuous positive airway pressure support for older children with asthma is particularly efficient.     

Non-invasive ventilation in pediatric intensive care

The aims of this paper are: to examine the physiological rationale for noninvasive respiratory support (NRS) in children with acute respiratory failure (ARF); to review clinical available data and to give some practical recommendations to its safe application. NRS is the delivery of ventilatory support without the need of an invasive airway. Two types of NRS are commonly used in the pediatric population: non-invasive continuous positive airway pressure (nCPAP) and non-invasive positive pressure ventilation (nPPV). In general, the evidence to promote the use of NRS in children with ARF is scarce. However, two randomized studies have been recently published suggesting that nPPV ameliorates clinical signs and gas exchange while reducing the need for endotracheal intubation. Moreover, nCPAP and heliox may improve clinical scores and CO2 washout in infants with severe bronchiolitis, without major complications. Data from non controlled studies show that NRS unloads the respiratory muscles and that the helmet can be a valid alternative to facial and/or nasal mask when nCPAP is administered to children in the early stage of ARF.     

Contemporary ventilatory strategies for surgical patients

Respiratory failure affects a significant percentage of critically ill children, necessitating both invasive and non-invasive respiratory support. As the outcomes of these patients have improved, children with higher acuity and more complex respiratory pathophysiology require mechanical ventilation. Despite growing understanding of lung-protective strategies and ventilation induced lung injury, certain patients still require harmful ventilatory settings with conventional mechanical ventilation (CMV). High frequency ventilation, neurally adjusted ventilatory assist, and airway pressure release ventilation offer feasible alternatives to CMV. In addition to minimizing the risk of ventilatory induced lung injury when used appropriately, they provide a unique environment to facilitate operations on certain neonates and older children. Finally, non-invasive ventilation is now commonly employed in children with surgical conditions.     

Noninvasive positive pressure ventilation: five years of experience in a pediatric intensive care unit.

OBJECTIVES: To evaluate the feasibility and outcome of noninvasive positive pressure ventilation (NPPV) in daily clinical practice. DESIGN: Observational retrospective cohort study. SETTING: Pediatric intensive care unit in a university hospital. PATIENTS:: Patients treated by NPPV, regardless of the indication, during five consecutive years (2000-2004). MEASUREMENTS AND RESULTS: A total of 114 patients were included, and 83 of the 114 patients (77%) were successfully treated by NPPV without intubation (NPPV success group). The success rate of NPPV was significantly lower (22%) in the patients with acute respiratory distress syndrome (p < .05) than in the other patients. The Pediatric Risk of Mortality II (p = .003) and Pediatric Logistic Organ Dysfunction scores (p = .002) at admission were significantly higher in patients who were unsuccessfully treated with NPPV (NPPV failure group). Baseline values of Pco2, pulse oximetry, and respiratory rate did not differ between the two groups. A significant decrease in Pco2 and respiratory rate within the first 2 hrs of NPPV was observed in the NPPV success group. Multivariate analysis showed that a diagnosis of acute respiratory distress syndrome (odds ratio, 76.8; 95% confidence interval, 4.4-1342; p = .003) and a high Pediatric Logistic Organ Dysfunction score (odds ratio, 1.09; 95% confidence interval, 1.01-1.17; p = .01) were independent predictive factors for NPPV failure. A total of 11 patients (9.6%), all belonging to the NPPV failure group, died during the study. CONCLUSIONS: This study demonstrates the feasibility and efficacy of NPPV in the daily practice of a pediatric intensive care unit. This ventilatory support could be proposed as a first-line treatment in children with acute respiratory distress, except in those with a diagnosis of acute respiratory distress syndrome.     

Outcome of non-invasive positive pressure ventilation in paediatric neuromuscular disease.

BACKGROUND: Non-invasive positive pressure ventilation (NPPV) has a beneficial effect on nocturnal hypoventilation and hospitalisation rates in adults with static or slowly progressive neuromuscular disease and respiratory failure. Its role in children affected with similar disease processes, however, remains unclear. AIMS: To investigate the impact of NPPV on hospitalisations and sleep related respiratory parameters in children with neuromuscular disease. METHODS: Fifteen children (mean age 11.7, range 3.4-17.8 years) diagnosed with neuromuscular disease who had been started on nocturnal NPPV and had at least one year of follow up since the initiation of such therapy were studied. Patients served as their own controls and comparison was made of the years preceding and following the initiation of NPPV. RESULTS: Children spent 85% fewer days in hospital (mean pre-NPPV 48.0 days, mean post-NPPV 7.0 days) and 68% less days in intensive care after initiation of NPPV (mean pre-NPPV 12.0 days, mean post-NPPV 3.9 days). Sleep study parameters including number of desaturations, apnoea-hypopnoea index and transcutaneous pCO2 levels improved after initiation of NPPV. CONCLUSIONS: NPPV can decrease hospitalisations for children with neuromuscular disease and improves sleep related respiratory parameters. A prospective study is now needed to further delineate the role of NPPV in this population of children.     

Outcome of non-invasive positive pressure ventilation in paediatric neuromuscular disease

Background: Non-invasive positive pressure ventilation (NPPV) has a beneficial effect on nocturnal hypoventilation and hospitalisation rates in adults with static or slowly progressive neuromuscular disease and respiratory failure. Its role in children affected with similar disease processes, however, remains unclear. Aims: To investigate the impact of NPPV on hospitalisations and sleep related respiratory parameters in children with neuromuscular disease. Methods: Fifteen children (mean age 11.7, range 3.4–17.8 years) diagnosed with neuromuscular disease who had been started on nocturnal NPPV and had at least one year of follow up since the initiation of such therapy were studied. Patients served as their own controls and comparison was made of the years preceding and following the initiation of NPPV. Results: Children spent 85% fewer days in hospital (mean pre-NPPV 48.0 days, mean post-NPPV 7.0 days) and 68% less days in intensive care after initiation of NPPV (mean pre-NPPV 12.0 days, mean post-NPPV 3.9 days). Sleep study parameters including number of desaturations, apnoea-hypopnoea index and transcutaneous pCO₂ levels improved after initiation of NPPV. Conclusions: NPPV can decrease hospitalisations for children with neuromuscular disease and improves sleep related respiratory parameters. A prospective study is now needed to further delineate the role of NPPV in this population of children.     

Current methods of non-invasive ventilatory support for neonates

Non-invasive ventilatory support can reduce the adverse effects associated with intubation and mechanical ventilation, such as bronchopulmonary dysplasia, sepsis, and trauma to the upper airways. In the last 4 decades, nasal continuous positive airway pressure (CPAP) has been used to wean preterm infants off mechanical ventilation and, more recently, as a primary mode of respiratory support for preterm infants with respiratory insufficiency. Moreover, new methods of respiratory support have been developed, and the devices used to provide non-invasive ventilation (NIV) have improved technically. Use of NIV is increasing, and a variety of equipment is available in different clinical settings. There is evidence that NIV improves gas exchange and reduces extubation failure after mechanical ventilation in infants. However, more research is needed to identify the most suitable devices for particular conditions; the NIV settings that should be used; and whether to employ synchronized or non-synchronized NIV. Furthermore, the optimal treatment strategy and the best time for initiation of NIV remain to be identified. This article provides an overview of the use of non-invasive ventilation (NIV) in newborn infants, and the clinical applications of NIV.     

Noninvasive Ventilation for the Treatment of Acute Lower Respiratory Tract Diseases in Children

Noninvasive positive-pressure ventilation is a promising therapy for the treatment of acute lower respiratory tract diseases in children. Based on preliminary studies in adults and children, NPPV was well tolerated, was not associated with significant adverse events, and was effective at improving pulmonary function and gas exchange. In addition, NPPV may have a role in patients with severe lower airway obstruction to assist with nebulized gas delivery. However, careful patient selection, staff familiarity with NPPV, and close monitoring of the patient are important for the success of this intervention.     

Non-invasive ventilatory support in neonates: An evidence-based update

Non-invasive ventilatory support (NIV) is considered the gold standard in the care of preterm infants with respiratory distress syndrome (RDS). NIV from birth is superior to mechanical ventilation (MV) for the prevention of death or bronchopulmonary dysplasia (BPD), with a number needed to treat between 25 and 35. Various methods of NIV are available, some of them extensively researched and with well proven efficacy, whilst others are needing further research. Nasal continuous positive airway pressure (nCPAP) has replaced routine invasive mechanical ventilation (MV) for the initial stabilization and the treatment of RDS. Choosing the most suitable form of NIV and the most appropriate patient interface depends on several factors, including gestational age, underlying lung pathophysiology and the local facilities. In this review, we present the currently available evidence on NIV as primary ventilatory support to preventing intubation and for secondary ventilatory support, following extubation. We review nCPAP, nasal high-flow cannula, nasal intermittent positive airway pressure ventilation, bi-level positive airway pressure, nasal high-frequency oscillatory ventilation and nasal neurally adjusted ventilatory assist modes. We also discuss most suitable NIV devices and patient interfaces during resuscitation of the newborn in the delivery room.     

双水平正压通气和持续气道正压通气在早产儿呼吸窘迫综合征中应用的比较

目的：对患有新生儿呼吸窘迫综合征（RDS）的早产儿早期使用双水平正压通气（DuoPAP）和经鼻持续气道正压通气（NCPAP）模式在降低有创呼吸支持率和支气管肺发育不良（BPD）发生率方面进行比较分析。方法：该试验为单中心随机对照试验,将胎龄30~35 周患有RDS生后6 h内的早产儿随机分为早期使用DuoPAP组（n=34）和早期使用 NCPAP组（n=33）,若这两种方式不能维持则使用气管内插管、呼吸机辅助呼吸,肺表面活性物质作为急救药物。观察患儿生后24 h、48 h及72 h内的总插管有创呼吸支持率、支气管肺发育不良（BPD）发生率及使用无创呼吸支持后1、12、24、48、72 h 二氧化碳分压（PaCO2）、氧分压（PaO2）及氧合指数（OI）。结果：DuoPAP组48 h内、72 h内总插管有创呼吸支持率明显低于NCPAP组（P0.05）。DuoPAP组OI无创呼吸支持后1、12、24、48、72 h均高于NCPAP组（均P<0.05）。DuoPAP组PaCO2在无创呼吸支持后1、12、24 h明显小于NCPAP组（P<0.05）;DuoPAP组PaO2在无创呼吸支持后1、12 h 明显大于NCPAP组（P<0.05）。结论：早期使用DuoPAP与NCPAP相比,可明显降低RDS患儿插管有创呼吸支持率,值得推广。     

Congenital central hypoventilation syndrome: not just another rare disorder

Congenital central hypoventilation syndrome (CCHS) is a rare syndrome, present from birth, and is defined as the failure of automatic control of breathing. Patients have absent or negligible ventilatory sensitivity to hypercapnia and hypoxaemia during sleep and wakefulness. Therefore, especially while asleep, children with CCHS experience progressive hypercapnia and hypoxaemia. They lack arousal responses and sensations of dyspnoea to the endogenous challenges of isolated hypercapnia and hypoxaemia and to the combined stimulus of hypercapnia and hypoxaemia. Patients with CCHS do not exhibit signs of respiratory distress when challenged with hypercarbia or hypoxia. The diagnosis is one of exclusion, ruling out any primary pulmonary, cardiac, metabolic or neurologic cause for central hypoventilation. CCHS is associated with other manifestations of autonomic nervous system dysfunction, including Hirschsprung's disease. All patients with CCHS require lifelong ventilatory support during sleep but some will be able to maintain adequate ventilation without assistance while awake once past infancy. However, some CCHS patients require ventilatory support for 24h/day. Modalities of home mechanical-assisted ventilation include positive pressure ventilation via tracheostomy, non-invasive positive pressure ventilation (bi-level ventilation), negative pressure ventilation and diaphragmatic pacers. Supplemental oxygen alone is inadequate treatment. With early diagnosis and adequate ventilatory support, these children can have good outcomes and lead productive lives.     

Gentle ventilation: the new evidence from the SUPPORT, COIN, VON, CURPAP, Colombian Network, and Neocosur Network trials

Many neonates have respiratory disorders requiring oxygen supplementation and respiratory support. Even though advances in respiratory care such as surfactant and new ventilatory techniques have improved outcomes, mortality from respiratory failure and morbidities such as bronchopulmonary dysplasia are still common. In the trials of prophylactic, early, or late surfactant, the control infants received mechanical ventilation. It is possible that the control infants had lung injury secondary to mechanical ventilation. This review will address the recent trials of early continuous positive airway pressure (CPAP) as an alternative to the common practice of surfactant and mechanical ventilation.     

Mechanical ventilation in pediatrics (III). Weaning, complications and other types of ventilation. Noninvasive ventilation

Noninvasive ventilation (NIV), i.e. without tracheal intubation, has been reintroduced for the treatment of respiratory failure to reduce the complications of mechanical ventilation. Nowadays, NIV with positive pressure is the preferred method, applied through a mask held in place by a harness. Several masks can be used (nasal, bucconasal facial) and a variety of means can be used to keep them in place. Many respirators can be selected, ranging from those traditionally used in the intensive care unit(ICU) to specific NV respirators and conventional ICU respirators with specific software for NIV. Many respiratory modalities can be used according to the respirator (biphasic positive airway pressure [BIPAP], proportional assist ventilation, pressure support, synchronized intermittent mandatory ventilation [SIMV], etc.). NIV is mainly indicated in exacerbations of chronic respiratory failure: neuromuscular diseases, pretransplantation cystic fibrosis, and obstructive sleep apnea syndrome. It is also indicated in acute respiratory failure: pneumonia, status asthmaticus, and acute lung edema. The main contraindications are a weakened airway protection reflex(absent cough reflex) and hemodynamic instabiity. The advantages of NIV derive mainly from avoiding the complications associated with invasive ventilation. NIV also presents some disadvantages, especially the greater workload involved to ensure good patient adaptation to the respirator. The most common sequelae of NIV are skin lesions due to pressure on the nasal bridge.     

Newer experience with CPAP

Progress in neonatal intensive care is closely linked to improvements in the management of respiratory failure in small infants. Current modalities of ventilatory assistance range from more benign continuous positive airway pressure (CPAP) to various modes of mechanical ventilation (including high frequency ventilation). The advent of less invasive methods of delivering CPAP has permitted earlier treatment of infants with respiratory distress syndrome and avoided the need for mechanical ventilation. Children's Hospital of New York (Columbia University) places all spontaneously breathing infants on nasal prong CPAP as the first mode of respiratory support. The early initiation of nasal prong CPAP in combination with a tolerance to elevated PCO₂ levels has reduced the incidence of chronic lung disease to <5% in infants weighing less than 1500 g. This report will present an historical review and summarize the experience with CPAP at Columbia and other centres. In addition, it reviews the clinical applications and physiological effects of CPAP in preterm infants with respiratory distress syndrome.     

Recognition of the child at risk of cardiopulmonary arrest

Early treatment is a major factor to improve the outcome of children at risk of cardiopulmonary arrest. That's why it is essential to recognize as soon as possible clinical signs that indicate a respiratory and/or circulatory dysfunction. Immediate systematic assessment and re-assessment of oxygenation, ventilation and organ perfusion status is one of the keys in the prevention of cardiorespiratory arrest in children. Health care staff must assure that a child with signs of acute respiratory and/or circulatory dysfunction is under constant surveillance by a person with ability to interpret signs, identify problems and to initiate emergency treatment, if needed. Respiratory assessment must include respiratory rate, signs of mechanical respiratory failure (nasal flaring, respiratory noises, paradoxical breathing, prolonged expiration) as well as skin-mucous colour. Cardiocirculatory failure assessment includes heart rate, blood pressure, peripheral perfusion (capillary refill time and temperature gradient), level of consciousness and urinary output. In a child with impending signs of cardio-respiratory failure, the priority is to warrant adequate ventilation and oxygenation. If, despite this treatment, there is no improvement in perfusion, treatment of circulatory failure with fluids and vasoactive drugs is necessary.     

重症毛细支气管炎的治疗

毛细支气管炎主要发生于2岁以下婴幼儿,主要由呼吸道病毒尤其是呼吸道合胞病毒感染所致。临床上有自限性,其治疗以对症及支持治疗为主,包括监测病情变化、供氧以及保持水电解质内环境稳定。重症感染患儿在常规吸氧、吸痰及雾化等处理无缓解时,需采取其他措施积极治疗。包括给予肾上腺素、糖皮质激素、高渗盐水雾化吸入及积极抗感染治疗,重症毛细支气管炎患儿无创通气的应用越来越受到重视,早期使用持续气道正压通气可降低有创气管插管率,有效改善呼吸窘迫,减少呼吸做功,缩短住院时间。对具有危险因素的患儿,要密切监测病情变化,并及时处理病情的加重和恶化。     

新生儿呼吸窘迫综合征无创通气治疗的研究进展

新生儿呼吸窘迫综合征(neonatal respiratory distress syndrome,NRDS)是造成新生儿死亡的重要原因.目前治疗方案以肺表面活性物质替代治疗和机械通气为主.为了避免有创通气所带来的严重并发症,目前临床医生越来越倾向于采用无创通气的模式.无创通气模式包括经鼻间歇正压通气、经鼻持续正压通气、加热加湿高流量鼻导管通气等.该文就无创通气在临床应用的研究进展作一综述.     

Respiratory failure: current status of experimental therapies.

A number of advances in the treatment of infants and children with respiratory failure have been investigated in the laboratory with translation to clinical practice. Investigators have recognized that application of high ventilating pressures and failure to apply adequate levels of positive end-expiratory pressure (PEEP) can inflict injury to the already failing lung. Other interventions such as prone positioning and application of new ventilating strategies such as proportional assist ventilation (PAV), inverse ratio ventilation (IRV), high frequency ventilation, liquid ventilation, and intratracheal pulmonary ventilation (ITPV), continue to be developed and explored. Administration of inhaled nitric oxide (iNO) may improve pulmonary physiology and gas exchange in patients with respiratory insufficiency. Finally, the technique of extracorporeal life support (ECLS) is being simplified and refined. This report summarizes the status of these advances and describes the basic science and clinical research that brought them to clinical application.     

Mechanical ventilatory support in preterm infants

A large proportion of premature infants presents with acute respiratory failure after birth and require mechanical ventilatory support. In addition to conventional mechanical ventilation, an increasing number of these infants are currently supported by newer modes including synchronized, volume targeted and noninvasive mechanical ventilation. While these new modes have improved weaning from mechanical ventilation they have not had a consistent impact on respiratory outcome or other morbidities. This is a review of the different modes of invasive and noninvasive mechanical ventilation used to support premature infants with respiratory failure.