A review of non-invasive ventilation support in neonates

Non-invasive ventilation (NIV) is a mode of respiratory support commonly used on the neonatal unit. Since the advent of NIV, it has evolved from being used as a mode of respiratory support to wean infants from mechanical ventilation (MV) to a primary mode of respiratory support. Newer methods of NIV support such as nasal bilevel positive airway pressure (BiPAP) and humidified high flow nasal cannula oxygen therapy (HHFNC) have emerged in attempts to reduce intubation rates and subsequent MV in preterm infants. There is ongoing debate about the role of nasal continuous positive airway pressure (NCPAP) in reducing ventilator induced lung injury, its timing and use as a primary mode of ventilation in the very low birth weight and extreme preterm infants.This review gives an overview of the current understanding and practices of the different modes of NIV in the neonatal unit.     

高流量鼻导管氧疗与早产儿呼吸支持

高流量鼻导管氧疗(high flow nasal cannulae,HFNC)是一种经充分湿化、加温,流量大于1～2 L/min,通过鼻塞外联吸氧管输送高流量混合氧气的无创性呼吸支持模式。在新生儿的应用中,HFNC 产生的扩张压与氧流量呈正相关,与新生儿体型呈负相关,同时沿导管泄露氧气也会对其造成影响。HFNC在提高新生儿潮气量、呼吸功等方面与经鼻持续气道正压通气(nasal continuous positive airway pressure, nCPAP)可能有相似效果,但仅限于流量低于2 L/min 的情况下。HFNC 可替代 CPAP /nCPAP 等各类无创通气方法,但在早产儿中推广普及则缺乏更强有力的证据支持。     

加温湿化高流量经鼻导管氧疗的作用机制及在儿科的应用

加温湿化高流量经鼻导管氧疗(heated humidified high flow nasal cannula oxygen therapy,HFNC)具有改善呼吸做功,产生呼吸末正压效应,操作简单,患者耐受性优良,安全性高的特点.目前已经广泛用于新生儿相关的呼吸支持治疗,但缺乏在婴幼儿和儿童的广泛使用和研究.从HFNC作用机制及儿科生理学角度看,适合用于婴儿病毒性毛细支气管炎、儿童肺炎、哮喘、急性呼吸窘迫综合征以及拔管后呼吸支持治疗.HFNC应该成为儿科首选的常规氧疗模式.     

High-flow nasal cannulae and nasal continuous positive airway pressure use in non-tertiary special care nurseries in Australia and New Zealand

Aim: Non‐tertiary centres (NTCs) in Australia and New Zealand are increasingly providing non‐invasive respiratory support, including high‐flow nasal cannulae (HFNC) and nasal continuous positive airway pressure (nCPAP), to newborn infants. We aimed to determine the proportion of NTCs in these countries treating newborn infants with HFNC and nCPAP, and how these therapies are used. Methods: We surveyed public and private NTCs in Australia and public NTCs in New Zealand. The survey, directed at senior medical and nursing staff, consisted of questions regarding unit demographics, HFNC and nCPAP use. Results: One hundred seventeen responses were received regarding HFNC use, from 88% (80/91) of public hospitals and 64% (37/58) of private hospitals surveyed. Ten (8.5%) responders (nine public and one private) used HFNC; all used the Fisher & Paykel system. HFNC was used for respiratory distress syndrome from birth (9/10 units), as a weaning mode from nCPAP (5/10 units) and as treatment for apnoea (3/10 units). Flow rates used ranged from 1 to 8 L/min, with typical minimum flow of 1 L/min and maximum of 4–6 L/min. The main perceived advantage of HFNC was ‘ease of use’. In the units treating newborn infants with nCPAP, it was used either in an ongoing fashion (43 units), short term or episodically (four units), or only for stabilisation prior to transfer (11 units). Excluding those units using nCPAP only for stabilisation and non‐responders, 47/108 (44%) units were using nCPAP. Conclusions: HFNC is being used in NTCs in Australia and New Zealand, and the use of nCPAP has increased over time.     

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.     

The A-B-C of high-flow nasal oxygen therapy use in a sick child

Heated humidified high flow nasal cannula therapy (HFNC) is a relatively new method of oxygen delivery that came into vogue only a decade ago. The additional physiological benefits it provides make HFNC more than just a fancy oxygen delivery device. Theoretically, Continuous Positive Airway Pressure (CPAP) continues to be the gold standard therapy for moderate to severe respiratory disease. Practically, there are limitations to its use especially in older children outside of an intensive care setting. Initially, thought of as a step-down or step-up from or towards CPAP i.e. halfway between CPAP and nasal oxygen, HFNC has now overtaken CPAP as the respiratory support mechanism of choice. Paediatricians go straight from failure of HFNC to intubation without a trial of CPAP, or extubate children straight onto HFNC. Today, more than a decade later, high quality evidence (FIRST-ABC and Tramontane Trials) is finally available to guide its use. The article summarises the evidence base behind the clinical safety, efficacy, cost-effectiveness and practical use of HFNC in managing sick children on high dependency and intensive care units. We outline what HFNC therapy is, the respiratory physiology underlying its use, currently available devices, practicalities of how to select the flow rate and its role in current paediatric practice with clinical examples.     

Survey of neonatal respiratory support strategies

AIM: To survey current practice regarding neonatal respiratory support strategies to determine whether it reflected evidence from randomised trials. METHODS: A questionnaire (in Supplementary Material online) survey of all U.K. neonatal units was undertaken to determine what modes of ventilation, types of endotracheal tube, lung function monitoring and oxygen saturation levels were used. RESULTS: There was an 80% response rate. Most (73%) units used in prematurely born infants (in the first 24 h) the intermittent positive pressure ventilation, and other respiratory modes included: CPAP (2%), triggered ventilation with or without volume guarantee (22%) and high frequency oscillation (2%). Only 15% of units used assist control mode for weaning; the preferred weaning mode was synchronous intermittent mandatory ventilation (73%). Few units used shouldered endotracheal tubes (3%) or lung function measurements (25%) to aid choice of ventilator settings. Oxygen saturation levels from 80% to 98% were used, levels greater or equal to 95% were used by 11% of units for infants with acute respiratory disease but by 34% of units for BPD infants (p < 0.001). CONCLUSION: Many practitioners do not base their choice of neonatal respiratory support strategies on the results of large randomised trials; more effective methods are required to ensure evidence-based practice.     

Humidified high flow nasal cannulae: current practice in Australasian nurseries, a survey

Aim: Humidified High Flow Nasal Cannula (HHFNC) has been increasingly adopted as a new means of respiratory support throughout the world. However, evidence to support its safety and efficacy is limited. The aim of the present survey was to determine current practices regarding the usage of HHFNC by neonatologists in Australia and New Zealand. Methods: Surveys were sent to all 167 neonatologists identified by the list of centres in the Australia and New Zealand Neonatal Network. Results: A total of 157 surveys were sent to valid email addresses: 111 (71%) responded of which 105 (67%) had completed the questionnaire. HHFNC is used in 17 (63%) of neonatal intensive care units in Australia and New Zealand. It is most commonly used to reduce nasal trauma (91%) and provide continuous positive airways pressure (62%). The main perceived benefits of HHFNC were the easier application and care of the infant (86%), and improved tolerance by the baby (84%). Rain out leading to fluid instillation into the upper airway (59%) was the most common problem. Conclusion: This survey has provided a snapshot of the practice of HHFNC usage in Australia and New Zealand in 2010 and has revealed that HHFNC use is widespread and that clinical practices are diverse. The majority of neonatologists acknowledge that there is limited evidence to support its efficacy and safety, and would be happy to participate in clinical trials to address how best to deliver HHFNC.     

Respiratory support practices in infants born at term in the United Kingdom

Infants born at term requiring mechanical ventilation suffer significant mortality and morbidity, yet few studies have tried to identify the optimum respiratory support for such infants. We, therefore, hypothesised that practice would vary, particularly between different levels of neonatal care provision. The lead clinicians of all 212 UK neonatal units were asked to complete an electronic web-based survey regarding respiratory support practices for term-born infants. Survey questions included the level of neonatal care provided, number of term-born infants ventilated per annum, initial and rescue ventilation modes and whether surfactant or inhaled nitric oxide (NO) were used. The overall response rate was 82?%. A greater proportion of neonatal intensive care units (NICUs) compared to local neonatal units (LNUs) stated that they used volume-targeting, particularly for infants with RDS (p?=?0.0006) or congenital pneumonia (p?=?0.0005). High-frequency oscillatory ventilation was stated as initial mode by a greater proportion of NICUs compared to LNUs and special care units (SCUs), particularly for respiratory distress syndrome (p?<?0.0001) or persistent pulmonary hypertension of the newborn (p?<?0.001). Continuous mandatory ventilation was stated to be the rescue mode by a greater proportion of LNUs/SCUs compared to NICUs (p?<?0.0001). Surfactant was stated to be most commonly given for respiratory distress syndrome (79?% of units) and MAS (61?% of units); surfactant use was lowest in SCUs (p?<?0.0001); inhaled NO was infrequently used by LNUs and SCUs. Conclusions There was considerable variation in respiratory support practices for term-born infants, particularly between different levels of neonatal care provision.     

高流量鼻导管吸氧对比经鼻持续气道正压通气治疗新生儿呼吸窘迫综合征疗效的Meta分析

目的 系统评价高流量鼻导管吸氧（HFNC）对比经鼻持续气道正压通气（nCPAP）治疗新生儿呼吸窘迫综合征（RDS）的有效性和安全性。方法 计算机检索PubMed、Embase、Cochrane Library、Web of Science、中国生物医学文献数据库、万方数据库、中国知网和维普数据库建库至2020年4月1日的文献,收集HFNC对比nCPAP运用于新生儿RDS的随机对照试验（RCT）。采用RevMan5.3软件对符合纳入标准的临床研究进行Meta分析。结果 共纳入12篇RCT文献,包括2 861例新生儿,其中胎龄≥28周2 698例（94.30%）, < 28周163例（5.70%）。在初始呼吸支持中,HFNC组治疗失败率高于nCPAP组（RR=1.86,95% CI：1.53~2.25,P < 0.001）;两组有创机械通气率（P=0.40）、肺表面活性物质使用率（P=0.77）的比较差异无统计学意义。在拔管后呼吸支持中,两组治疗失败率、重新插管率、总用氧时间的比较差异均无统计学意义（P > 0.05）。在初始呼吸支持和拔管后呼吸支持中,HFNC组的鼻损伤发生率均明显低于nCPAP组（P < 0.001）;HFNC组和nCPAP组病死率及气漏综合征、支气管肺发育不良、坏死性小肠结肠炎等并发症的发生率的比较差异均无统计学意义（P > 0.05）。结论 基于现有临床证据,HFNC作为新生儿RDS初始治疗时失败率高于nCPAP,不建议在新生儿RDS初始治疗时使用;在胎龄≥28周RDS新生儿撤机阶段可以考虑使用HFNC作为拔管后辅助呼吸支持。     

Use of nasal cannula to induce positive expiratory pressure in neonatology

A 6 years experience of the use of a CPAP nasal cannula is reported. In children over 1,500 g and Silverman's index less than or equal to 6, the indications for this technique were neonatal idiopathic respiratory distress (excluding stage 4), transitory respiratory distress, cesarean lungs and amniotic inhalation of clear fluid after aspiration and physiotherapy. In children under 1,500 g, it was used only when Silverman's index was less than or equal to 5, and when correct hemodynamic, thermal and metabolic status were present. In 91 treated children, the use of the cannula avoided intubation 75 times and had few complications. The innocuousness of the method makes it a routine technique in all cases at the onset of respiratory distress, reducing the need for intubations. It was found to be an efficient complement for the relay after mechanical ventilation.     

Laryngeal mask airway use during neonatal resuscitation: a survey of practice across newborn intensive care units and neonatal retrieval services in Australian New Zealand Neonatal Network

This is an Australia New Zealand Neonatal Network (ANZNN) wide survey to identify current practice and guide future practice improvement for the use of laryngeal mask airway (LMA) during neonatal resuscitation. An online questionnaire containing 13 questions was sent out to all tertiary neonatal centres (n = 29 units) and neonatal transport units (n = 4) within ANZNN. The non‐tertiary (level‐II) centres were not included. Response from a senior neonatologist at each centre was received and evaluated. Twenty‐two services (67%) had LMA available; of that only, 40% felt the competency of staff to be adequate; and 59% had routine training in LMA use. During neonatal resuscitation, 68% units reported using LMA if endotracheal intubation was unsuccessful after two or more failed intubation attempts and only 18% used it before intubation if face mask ventilation was inadequate. This survey highlighted variations in practice across the tertiary neonatal centres in ANZNN network. One‐third of the units lack LMA availability and the units with LMA, face concerns of underutilisation and lack of skills for its use.     

Neonatal respiratory support strategies in the intensive care unit: an Italian survey

We carried out a survey of current practices of neonatal respiratory support in neonatal intensive care units (NICUs) in Italy with the aim of comparing the current reality with evidence from the literature. We sent a questionnaire by email to the 103 level III neonatal units in Italy. There was a 61 % (73/120) response rate to the questionnaire. We found that synchronized intermittent positive pressure ventilation is mostly used in infants in the acute phase of respiratory distress syndrome (RDS), while the majority of the units prefer volume-targeted ventilation for those in the weaning phase. Nasal continuous positive airway pressure is the most commonly used non-invasive mode of respiratory support, both in the acute and post-extubation phase of RDS. Surfactant is mainly given as rescue treatment. Infants receive caffeine before extubation and analgesia under mechanical ventilation, while post-natal steroids are given after the first week of life in the majority of the units. In conclusion, respiratory support strategies in Italian NICUs are frequently evidence-based. However, since there are areas where this does not occur, we suggest that focused interventions take place on these areas to help improve clinical practice and increase their adherence to evidence-based medical criteria.     

High-flow nasal cannula use for bronchiolitis treatment in French intensive care units: A transversal study

Over the past 10 years, continuous positive airway pressure (CPAP) has revolutionized the prognosis and management of bronchiolitis patients hospitalized in pediatric intensive care units (PICUs). High-flow nasal cannula (HFNC) is emerging as an alternative to CPAP. Despite encouraging results of several clinical and physiological studies, HFNC use remains controversial and its indications heterogeneous. To better define the place of HFNC in severe bronchiolitis respiratory support, we investigated the different ventilation assistance techniques used for severe bronchiolitis over 3 days at the peak of a bronchiolitis epidemic in December 2015. We conducted an observational cross-sectional study in 27 French university hospital PICUs. Fifty-nine patients were included. The results show that HFNC already accounts for nearly half of the respiratory support techniques used for severe bronchiolitis in French PICUs with no significant difference between the CPAP group and the HFNC group of patients.     

Drug treatment for bronchopulmonary dysplasia in Japan: Questionnaire survey

Bronchopulmonary dysplasia (BPD) is one of the most common complications in premature infants. Although several different drugs have been developed for BPD, there is a wide variation in the choice of drug used among facilities. The aim of this study was to carry out a survey of the current drugs used to treat BPD in Japan. Questionnaires regarding the current use of drugs for BPD were sent to tertiary neonatal units. The response rate was 80% (77/96). Most units used antenatal steroids and oral diuretics for the prevention and treatment of BPD, respectively. Only 4% used caffeine for prevention, whereas 88% used systemic corticosteroids for treatment. Few units used inhaled anticholinergics and i.v. vitamins for the prevention and treatment of BPD, respectively. It was found that the drugs used to treat BPD vary greatly among institutions. Further research is required to develop evidence‐based clinical guidelines for BPD in premature infants.     

Hypothermia for neonatal encephalopathy: Nationwide Survey of Clinical Practice in Japan as of August 2010

Background: Therapeutic hypothermia is now recommended as a standard of care for neonatal encephalopathy. Although adherence to standard cooling protocols used in the phase‐III trials is essential, empiric approaches have prevailed in Japan. Aim: To elucidate the gap between the standard cooling methods and the current practice in Japan. Method: In July 2010, a questionnaire regarding the practice of neonatal encephalopathy was mailed to clinical leads of registered neonatal intensive care units. Result: 56.2% of the units were incapable of offering therapeutic hypothermia because of the reasons such as the shortage of human/medical resources (85.1%) and limited number of cases (21.1%). Eighty‐nine centres provided therapeutic hypothermia using either selective‐head cooling (88.8%) or whole‐body cooling (11.2%). Various target temperatures and cooling durations were used; 20.2% of the units cooled infants without using purpose‐built equipments, whereas 14.6% did not continuously monitor the body temperature. Discussion: Only 43.8% of the units provided therapeutic hypothermia. Even in centres where hypothermia was offered, adherence to the standard protocols was extremely poor. To secure the safety and efficacy, further promotion of the standard cooling protocols is required; an efficient cooling centre network has to be established by optimizing the work forth distribution and transportation system.     

早产儿加温湿化高流量经鼻导管通气初始呼吸支持失败的危险因素分析

目的 分析早产儿加温湿化高流量鼻导管通气（heated humidified high-flow nasal cannula,HHHFNC）初始呼吸支持失败的危险因素。 方法 回顾性收集2018年1月至2021年4月收治的生后使用HHHFNC初始呼吸支持的早产儿病例资料,根据治疗后72 h内是否需升级为无创持续气道正压通气或有创机械通气,分为呼吸支持失败组和成功组,采用单因素分析与多因素logistic回归分析HHHFNC呼吸支持失败的危险因素。 结果 共纳入166例早产儿,HHHFNC呼吸支持失败48例（28.9%）。单因素分析结果显示：呼吸支持失败组胎龄、出生体重均低于成功组（n=118）,吸入氧浓度>35%、流量>6 L/min、发生动脉导管未闭（patent ductus arteriosus,PDA）、诊断新生儿呼吸窘迫综合征（respiratory distress syndrome,RDS）、使用肺表面活性物质治疗比例均高于成功组（P<0.05）。多因素logistic回归分析显示：胎龄<32周、PDA >1.5 mm且左心房∶主动脉内径>1.4、吸入氧浓度>35%、流量>6 L/min、RDS是HHHFNC初始呼吸支持失败的危险因素（P<0.05）。 结论 当早产儿胎龄<32周,或有RDS时,早产儿HHHFNC初始呼吸支持失败的风险高;在HHHFNC初始呼吸支持治疗中,当氧浓度>35%和/或流量>6 L/min,或出现PDA时,呼吸支持失败的风险增大,应积极考虑升级呼吸支持方式。 引用格式:     

Limited comparability of classifications of levels of neonatal care in UK units

AIM—To assess whether different classifications of neonatal care or dependency scales are comparable when used in multicentre studies of cost effectiveness.
METHODS—A survey of classifications was used in a nationally representative group of 57 units in 1990-1, with a retrospective study of 10 354 cot days using patient records from a 5% random sample of 1042 admissions. Local and national classifications were correlated with medical and nursing procedures recorded for up to 26 days after each admission.
RESULTS—Classifications varied substantially. Of the 57 units in our sample, 26 used one of two national classifications, sometimes modified; 17 used the Northern Neonatal Network dependency scale; and the other 14 did not record daily levels of care. In each classification, the highest level was having respiratory support by ventilation or continuous distending pressure through an endotracheal tube, nasal prongs, facemask or negative pressure device. This level of care was consistently comparable between classifications; lower levels were not.
CONCLUSIONS—Retrospective comparisons between units with different classifications can only reliably differentiate between days with and without respiratory support. There is a pressing need to develop and validate more appropriate scales for prospective multicentre studies. These should relate activity to costs and outcome.

     

CPAP review

Continuous positive airway pressure (CPAP) is widely used in neonatal units both as a primary mode of respiratory support and following extubation from mechanical ventilation. In this review, the evidence for CPAP use particularly in prematurely born infants is considered. Studies comparing methods of CPAP generation have yielded conflicting results, but meta-analysis of randomised trials has demonstrated that delivering CPAP via short nasal prongs is most effective in preventing re-intubation. At present, there is insufficient evidence to establish the safety or efficacy of high flow nasal cannulae for prematurely born infants. Observational studies highlighted that early CPAP use rather than intubation and ventilation was associated with a lower incidence of bronchopulmonary dysplasia (BPD), but this has not been confirmed in three large randomised trials. Meta-analysis of the results of randomised trials has demonstrated that use of CPAP reduces extubation failure, particularly if a CPAP level of 5?cm H2O or more is used. Nasal injury can occur and is related to the length of time CPAP is used; weaning CPAP by pressure rather than by "time-cycling" reduces the weaning time and may reduce BPD. In conclusion, further studies are required to identify the optimum mode of CPAP generation and it is important that prematurely born infants are weaned from CPAP as soon as possible.     

Current trends in paediatric and neonatal ventilatory care – a nationwide survey

Aim: To assess daily practices in paediatric and neonatal ventilatory care in Finland. Methods: All neonatal and paediatric intensive care units in Finland were sent a questionnaire on ventilatory strategies and were offered a 3‐month prospective survey. Results: A total of 96% of units returned the questionnaire, and clinicians agreed on most of the principles of lung‐protective ventilation. Seventeen hospitals (94%) joined the prospective survey. On average, 2.3 new ventilation episodes were started daily, and totally 211 episodes were monitored. Pulmonary problems (64%) were the main cause of treatment in neonates and postoperative care (68%) in older children. Synchronized intermittent mandatory ventilation with pressure support was the primary mode in 42% of episodes. Hypocapnia was observed repeatedly in all units. In adult intensive care units, children often received high oxygen fraction, leading to hyperoxia, and they were frequently sedated with propofol, which is not licensed for that purpose. A large proportion of children had only light sedation or no sedation at all. Despite the different strategies and practices, most episodes resulted in a favourable outcome. Conclusion: Most of the principles of lung‐protective ventilation have been well accepted by clinicians. More attention should be paid to achieving normocapnia and normoxia and to the correct use of sedatives, especially in units that only occasionally provide paediatric ventilation.