Effort of breathing in children receiving high-flow nasal cannula

High Flow Nasal Cannula Versus Conventional Oxygen Therapy and Incidence of Post-Extubation Airway Obstruction in PICU: An Open-Label Randomized Controlled Trial (HiFloCOT-PICU Trial)

OBJECTIVES

To study the impact of high flow nasal cannula (HFNC) vs. conventional oxygen therapy (COT) (by simple nasal cannula) as respiratory support after extubation on the rates of post-extubation airway obstruction (PEAO) among mechanically ventilated critically ill children.

METHODS

This open-label randomized controlled trial was conducted in pediatric intensive care unit (PICU) of a tertiary care teaching hospital in North India over a period of 7 mo (11 August 2021 to 10 March 2022). Children aged 3 mo to 12 y who required invasive mechanical ventilation for > 72 h and had passed spontaneous breathing trial (ready for extubation) were enrolled and randomized by computer generated block randomization to receive HFNC or COT after extubation. Primary outcome was rate of PEAO (assessed by modified Westley croup score, mWCS) within 48 h of extubation; and secondary outcomes were rate and number of adrenaline nebulization, treatment failure (requiring escalation of respiratory support), extubation failure, adverse events, and length of PICU stay in two groups.

RESULTS

During the study period, 116 children were enrolled (58 each in HFNC and COT groups). There was no difference in rate of PEAO (55% vs. 51.7%, respectively), need of adrenaline nebulization, extubation failure, adverse events, and duration of PICU stay in two groups. However, the HFNC group had significantly lower rates of treatment failure (27.6% vs. 48.3%, p = 0.02).

CONCLUSIONS

The rate of PEAO was similar in HFNC and COT groups. However, HFNC group had significantly lower rate of treatment failure requiring escalation of respiratory support.

The effects of flow settings during high-flow nasal cannula oxygen therapy for neonates and young children

BACKGROUND

During neonatal and paediatric high-flow nasal cannula therapy, optimising the flow setting is crucial for favourable physiological and clinical outcomes. However, considerable variability exists in clinical practice regarding initial flows and subsequent adjustments for these patients. Our review aimed to summarise the impact of various flows during high-flow nasal cannula treatment in neonates and children.

METHODS

Two investigators independently searched PubMed, Embase, Web of Science, Scopus and Cochrane for in vitro and in vivo studies published in English before 30 April 2023. Studies enrolling adults (≥18 years) or those using a single flow setting were excluded. Data extraction and risk of bias assessments were performed independently by two investigators. The study protocol was prospectively registered with PROSPERO (CRD42022345419).

RESULTS

38 406 studies were identified, with 44 included. In vitro studies explored flow settings' effects on airway pressures, humidity and carbon dioxide clearance; all were flow-dependent. Observational clinical studies consistently reported that higher flows led to increased pharyngeal pressure and potentially increased intrathoracic airway pressure (especially among neonates), improved oxygenation, and reduced respiratory rate and work of breathing up to a certain threshold. Three randomised controlled trials found no significant differences in treatment failure among different flow settings. Flow impacts exhibited significant heterogeneity among different patients.

CONCLUSION

Individualising flow settings in neonates and young children requires consideration of the patient's peak inspiratory flow, respiratory rate, heart rate, tolerance, work of breathing and lung aeration for optimal care.

Extubation to High-Flow Nasal Cannula in Infants Following Cardiac Surgery: A Retrospective Cohort Study

High-flow nasal cannula (HFNC) therapy is commonly used in the pediatric intensive care unit (PICU) for postextubation respiratory support. This hypothesis-generating retrospective cohort study aimed to compare postextubation PICU length of stay in infants extubated to HFNC and low flow oxygen (LF) in PICU following cardiac surgery. Of 136 infants (newborn to 1 year) who were intubated and mechanically ventilated in PICU following cardiac surgery, 72 (53%) were extubated to HFNC and 64 (47%) to LF. Compared with patients extubated to LF, those extubated to HFNC had significantly longer durations of cardiopulmonary bypass (152 vs. 109 minutes; p  = 0.002), aortic cross-clamp (90 vs. 63 minutes; p  = 0.003), and invasive mechanical ventilation (3.2 vs. 1.6 days; p  < 0.001), although demographic and preoperative clinical variables were similar. No significant difference was observed in postextubation PICU length of stay between HFNC and LF groups in unadjusted analysis (3.3 vs. 2.6 days, respectively; p  = 0.19) and after controlling for potential confounding variables (F [1,125] = 0.17, p  = 0.68, R 2  = 0.16). Escalation of therapy was similar between HFNC and LF groups (8.3 vs. 14.1%; p  = 0.41). HFNC was effective as rescue therapy for six patients in the LF group requiring escalation of therapy. Need for reintubation was similar between HFNC and LF groups (8.3 vs. 4.7%; p  = 0.5). Although extubation to HFNC was associated with a trend toward longer postextubation PICU length of stay and was successfully used as rescue therapy for several infants extubated to LF, our results must be interpreted with caution given the limitations of our study.

Randomized Trial of Weight-Based Versus Fixed Limit High-Flow Nasal Cannula in Bronchiolitis

BACKGROUND

High flow nasal cannula (HFNC) is increasingly used to treat bronchiolitis. Although lower HFNC rates (≤8 L per minute) are commonly employed, higher weight-based flows more effectively alleviate dyspnea. The impact of higher flows on the need for care escalation is unclear.

METHODS

A randomized clinical trial was performed in a community hospital inpatient pediatric unit. Patients with bronchiolitis on HFNC were randomized to an existing "standard" HFNC protocol (max flow of 8 L per minute), or to a novel weight-based protocol (max flow of 2 L/kg per minute). Weaning of HFNC for the patients in the standard arm was left to provider discretion but was prescribed in the weight-based arm. The primary outcome was interhospital transfer to a PICU. The study was powered to detect a 35% difference in transfer rate.

RESULTS

51 patients were randomized to the weight-based or standard HFNC arms. The interhospital PICU transfer rate did not differ significantly between the standard (41.7%) and weight-based arms (51.9%) P = .47. Hospital length of stay was significantly shorter in the weight-based arm with protocolized weaning (45 h [interquartile range 42.1-63.3] versus 77.6 h [interquartile range 47.3-113.4]); P = .01. There were no significant adverse events in either group.

CONCLUSIONS

Weight-based provision of HFNC did not significantly impact the number of patients with bronchiolitis requiring interhospital transfer from a community hospital to a PICU, though we were underpowered for this outcome. Patients who received weight-based flow with protocolized weaning had a shorter length of stay, which may reflect a clinical impact of weight-based flow or the efficacy of the aggressive weaning pathway.

Efficacy of prophylactic high-flow nasal cannula therapy for postoperative pulmonary complications after pediatric cardiac surgery: a prospective single-arm study

PURPOSE

This study investigated the incidence of postoperative pulmonary complications (PPC) when high-flow nasal cannula therapy (HFNC) is used prophylactically after pediatric cardiac surgery, and evaluated its efficacy.

METHODS

This was a single-arm prospective interventional study that was conducted in a tertiary teaching hospital with eight beds in the pediatric cardiac ICU after approval by the Ethics Committee. One-hundred children under the age of 48 months who were scheduled for cardiac surgery for congenital heart disease were recruited. HFNC was used for 24 h after extubation at a 2 L/kg/min flow rate. The primary outcome was the incidence of PPC within 48 h after extubation. PPC was defined as atelectasis and acute respiratory failure meeting certain criteria. We considered prophylactic HFNC as effective if the prevalence of PPC was < 10%, based on previous reports of reintubation rates of 6%-9% after pediatric cardiac surgery.

RESULTS

A total of 91 patients were finally included in the analysis. The incidence of PPC within 48 h after extubation was 18.7%, whereas atelectasis was observed in 13.2%, and acute respiratory failure in 8.8%. Reintubation rate within 48 h after extubation was 0%.

CONCLUSIONS

We found the incidence of PPC with prophylactic HFNC after planned extubation after pediatric cardiac surgery. However, the incidence was > 10%; therefore, we could not demonstrate its efficacy in this single-arm study. Further studies are needed to investigate whether the HFNC could be adapted as first-line oxygen therapy after pediatric cardiac surgery.

Clinical review of high-flow nasal oxygen therapy in human and veterinary patients

Oxygen therapy is the first-line treatment for hypoxemic acute respiratory failure. In veterinary medicine this has traditionally been provided via mask, low-flow nasal oxygen cannulas, oxygen cages and invasive positive pressure ventilation. Traditional non-invasive modalities are limited by the maximum flow rate and fraction of inspired oxygen (FiO₂) that can be delivered, variability in oxygen delivery and patient compliance. The invasive techniques are able to provide higher FiO₂ in a more predictable manner but are limited by sedation/anesthesia requirements, potential complications and cost. High-flow nasal oxygen therapy (HFNOT) represents an alternative to conventional oxygen therapy. This modality delivers heated and humidified medical gas at adjustable flow rates, up to 60 L/min, and FiO₂, up to 100%, via nasal cannulas. It has been proposed that HFNOT improves pulmonary mechanics and reduces respiratory fatigue via reduction of anatomical dead space, provision of low-level positive end-expiratory pressure (PEEP), provision of constant FiO₂ at rates corresponding to patient requirements and through improved patient tolerance. Investigations into the use of HFNOT in veterinary patients have increased in frequency since its clinical use was first reported in dogs with acute respiratory failure in 2016. Current indications in dogs include acute respiratory failure associated with pulmonary parenchymal disease, upper airway obstruction and carbon monoxide intoxication. The use of HFNOT has also been advocated in certain conditions in cats and foals. HFNOT is also being used with increasing frequency in the treatment of a widening range of conditions in humans. Although there remains conflict regarding its use and efficacy in some patient groups, overall these reports indicate that HFNOT decreases breathing frequency and work of breathing and reduces the need for escalation of respiratory support. In addition, they provide insight into potential future veterinary applications. Complications of HFNOT have been rarely reported in humans and animals. These are usually self-limiting and typically result in lower morbidity and mortality than those associated with invasive ventilation techniques.

Operational Definitions Related to Pediatric Ventilator Liberation

BACKGROUND

Common, operational definitions are crucial to assess interventions and outcomes related to pediatric mechanical ventilation. These definitions can reduce unnecessary variability among research and quality improvement efforts, to ensure findings are generalizable, and can be pooled to establish best practices.

RESEARCH QUESTION

Can we establish operational definitions for key elements related to pediatric ventilator liberation using a combination of detailed literature review and consensus-based approaches?

STUDY DESIGN AND METHODS

A panel of 26 international experts in pediatric ventilator liberation, two methodologists, and two librarians conducted systematic reviews on eight topic areas related to pediatric ventilator liberation. Through a series of virtual meetings, we established draft definitions that were voted upon using an anonymous web-based process. Definitions were revised by incorporating extracted data gathered during the systematic review and discussed in another consensus meeting. A second round of voting was conducted to confirm the final definitions.

RESULTS

In eight topic areas identified by the experts, 16 preliminary definitions were established. Based on initial discussion and the first round of voting, modifications were suggested for 11 of the 16 definitions. There was significant variability in how these items were defined in the literature reviewed. The final round of voting achieved ≥ 80% agreement for all 16 definitions in the following areas: what constitutes respiratory support (invasive mechanical ventilation and noninvasive respiratory support), liberation and failed attempts to liberate from invasive mechanical ventilation, liberation from respiratory support, duration of noninvasive respiratory support, total duration of invasive mechanical ventilation, spontaneous breathing trials, extubation readiness testing, 28 ventilator-free days, and planned vs rescue use of post-extubation noninvasive respiratory support.

INTERPRETATION

We propose that these consensus-based definitions for elements of pediatric ventilator liberation, informed by evidence, be used for future quality improvement initiatives and research studies to improve generalizability and facilitate comparison.

Efficacy of high-flow nasal oxygenation compared with laryngeal mask airway in children undergoing ambulatory oral surgery under deep sedation: A randomized controlled non-inferiority trial

BACKGROUND

High-flow nasal oxygenation (HFNO) has been suggested as an alternative oxygenation method during procedural sedation. This randomized, non-inferiority trial evaluated the safety and efficacy of HFNO compared with laryngeal mask airway (LMA) in pediatric ambulatory oral surgery under deep sedation.

METHODS

In total, 120 children aged 2-7 years (weight: 10-30 kg) were equally assigned into two groups, namely, HFNO with propofol total intravenous anesthesia infusion (HFNO-IV) or LMA with propofol total intravenous anesthesia infusion (LMA-IV). The primary objective was to monitor carbon dioxide (CO2) accumulation during perioperative surgery. Secondary objectives included monitoring transcutaneous oxygen saturation, grade exposure to the surgical field, perioperative adverse events, or other events. The predefined non-inferiority margin was 7 mmHg. During the COVID-19 pandemic, a novel WeChat applet was implemented to gather follow-up data after discharge.

RESULTS

Non-inferiority could be declared for HFNO relative to LMA (mean difference in transcutaneous CO2 (TcCO2) = -1.4 mmHg, 95% CI: -2.9, 0.1 mmHg; P > 0.05). The pre-surgical TcCO2 of the HFNO-IV group (45.4 ± 4.5 mmHg) was similar to that of the LMA-IV group (44.0 ± 3.5 mmHg), within the clinically acceptable normal range. All the children maintained SpO2 levels of >97%. The surgical field exposure score of the HFNO group was significantly better than that of the LMA group. There was no significant difference between the two groups regarding risk or adverse events.

CONCLUSION

HFNO was not inferior to LMA for maintaining oxygenation and ventilation in patients undergoing pediatric ambulatory oral surgery under deep sedation under strict isolation from the oral cavity to the upper airway.

Commentary on High-Flow Nasal Cannula and Continuous Positive Airway Pressure Practices After the First-Line Support for Assistance in Breathing in Children Trials

Continuous positive airway pressure (CPAP) and heated humidified high-flow nasal cannula (HFNC) are commonly used to treat children admitted to the PICU who require more respiratory support than simple oxygen therapy. Much has been published on these two treatment modalities over the past decade, both in Pediatric Critical Care Medicine (PCCM ) and elsewhere. The majority of these studies are observational analyses of clinical, administrative, or quality improvement datasets and, therefore, are only able to establish associations between exposure to treatment and outcomes, not causation. None of the initial randomized clinical trials comparing HFNC and CPAP were definitive due to their relatively small sample sizes with insufficient power for meaningful clinical outcomes (e.g., escalation to bilevel noninvasive ventilation or intubation, duration of PICU-level respiratory support, mortality) and often yielded ambiguous findings or conflicting results. The recent publication of the First-Line Support for Assistance in Breathing in Children (FIRST-ABC) trials represented a major step toward understanding the role of CPAP and HFNC use in critically ill children. These large, pragmatic, randomized clinical trials examined the efficacy of CPAP and HFNC either for "step up" (i.e., escalation in respiratory support) during acute respiratory deterioration or for "step down" (i.e., postextubation need for respiratory support) management. This narrative review examines the body of evidence on HFNC published in PCCM , contextualizes the findings of randomized clinical trials of CPAP and HFNC up to and including the FIRST-ABC trials, provides guidance to PICU clinicians on how to implement the literature in current practice, and discusses remaining knowledge gaps and future research priorities.

Comparison of high flow oxygen therapy versus noninvasive mechanical ventilation for successful weaning from invasive ventilation in children: An observational study

Post-extubation respiratory failure is associated with a poor prognosis due to increased ventilator-associated pneumonia, and longer length of stay in the ICU and hospital. In this study, we aimed to evaluate the efficacy of high-flow nasal cannula (HFNC) and noninvasive mechanical ventilation (NIMV) on extubation success in children. A total of 48 patients, aged between 1 month and 18 years, who were weaned to either NIMV or HFNC were included. Patients who had tracheostomy or were not weaned and underwent unplanned extubation were excluded. Age, gender, anthropometric parameters, Pediatric Risk of Mortality and Pediatric Logistic Organ Dysfunction scores, oxygenation index, mechanical ventilation length of stay (LOS), HFNC/NIMV LOS, Modified Downes-Silverman score (MDS), and venous blood gas parameters, pediatric intensive care unit (PICU) LOS were recorded. 24 patients were extubated to NIMV, and 24 patients to HFNC. HFNC LOS and NIMV LOS were similar (P = .621). The failure rates at the 48th hour of HFNC and NIMV were 33% (n = 8), and 33% respectively (n = 8) (P = 1.0). PICU LOS and mortality rate was also similar (P = .06, P = .312 respectively). MDS decreased significantly in both groups (P < .001, P = .02 respectively). Changes in blood gas parameters and MDS within the first 48-hour of device application were similar between the 2 groups. HFNC is not inferior to NIMV in patients with extubation difficulty or those expected to have such difficulty in terms of treatment success, PICU LOS, and mortality. Therefore, HFNC appears to be a weaning technique alternative to NIMV after extubation.

Indications and outcome of home high-flow nasal therapy in children, a single-center experience

High-flow nasal therapy (HFNT) is a safe and simple way to deliver humidified air and oxygen for respiratory support in infants and children. HFNT is well established in an inpatient setting, but home HFNT lacks evidence. In the current study, we studied characteristics and outcomes of pediatric patients with home HFNT. In a monocentric retrospective analysis of data for 10 years (April 2010-April 2020), patient characteristics from the time point of the first discharge from hospital with home HFNT-treatment and the subsequent course were analyzed. Patients were divided into three HFNT indication groups: (1) bronchopulmonary dysplasia (BPD), (2) upper airway obstruction (UAO), and (3) other indications. Forty patients received home HFNT in the study period. Seventeen patients were treated for BPD, 15 for UAO, and 8 had other indications. Twenty-two patients (55%) were successfully weaned from HFNT (12 [70.6%] BPD, 7 [46.7%] UAO, 3 [37.5%] other), while seven patients (17.5%) died during follow-up (4 BPD, 2 UAO, 1 other). Twenty-three patients (57.5%) required (intermittent) additional oxygen application (14 [82.4%] BPD, 6 [40%] UAO, 4 [50%] other). Weaning success and need for additional oxygen were significantly more probable in BPD patients compared to the UOA group. In conclusion, HFNT plays an increasing role in home treatment of respiratory insufficiency of various etiologies in childhood. It often represents a temporary intervention, especially for children with BPD but might also serve as long-term treatment for children in whom other forms of ventilatory support are not feasible or desired.

High-Flow Nasal Cannula Oxygen Therapy: Physiological Mechanisms and Clinical Applications in Children

High-flow nasal cannula (HFNC) oxygen therapy has rapidly become a popular modality of respiratory support in pediatric care. This is undoubtedly due to its ease of use and safety, which allows it to be used in a wide variety of settings, ranging from pediatric intensive care to patients' homes. HFNC devices make it possible to regulate gas flow and temperature, as well as allowing some nebulized drugs to be administered, features very useful in children, in which the balance between therapeutic effectiveness and adherence to treatment is pivotal. Although the physiological effects of HFNC are still under investigation, their mechanisms of action include delivery of fixed concentration of oxygen, generation of positive end-expiratory pressure, reduction of the work of breathing and clearance of the nasopharyngeal dead space, while providing optimal gas conditioning. Nevertheless, current evidence supports the use of HFNC mainly in moderate-to-severe bronchiolitis, whereas for asthma exacerbations and breath sleeping disorders there is a lack of randomized controlled trials comparing HFNC to continuous positive airway pressure (CPAP) and non-invasive ventilation (NIV), which are essentials for the identification of response and non-response predictors. In this regard, the development of clinical guidelines for HFNC, including flow settings, indications, and contraindications is urgently needed.

Efficacy and safety analysis of high-flow nasal cannula in children with bronchiolitis: a systematic review and meta-analysis

BACKGROUND

Oxygen therapy is one of the most common treatments for bronchiolitis, But traditional standard oxygen therapy is poorly tolerated by patients. Nasal continuous positive airway pressure (nCPAP) also has many contraindications. High-flow nasal cannula (HFNC), as a new method of adjunctive respiratory support, has received extensive attention in oxygen therapy in pediatric. In this meta-analysis, we evaluated the efficacy and safety of HFNC in the treatment of infant bronchiolitis.

METHODS

We searched PubMed, Web of Science, CNKI, GeenMedical, Wanfang, and Weipu using the following keywords: children with respiratory diseases, infant bronchiolitis, bronchiolitis treatment, HFNCs, warming and humidifying high-flow, nasal catheter oxygen inhalation, and conventional oxygen therapy. The publication time was set from the establishment of the database to October 2021. Selected articles were randomized controlled trial (RCT) studies in which the patients were less than 16 years old and the experimental group was treated with HFNCs, and the control group was treated with nCPAP or conventional oxygen. After extracting the data, the study subjects were divided into HFNC treatment and control groups. The Cochrane risk of bias tool was used to assess the quality of the included literature, and RevMan 5.30 was used for meta-analysis.

RESULTS

Seven articles met the inclusion criteria. All articles described random sequence generation, four articles reported on allocation concealment, only two articles reported on the double-blind method. All articles described the complete blinding of outcome evaluation bias, outcome data bias, selective reporting bias, and other risk biases. The HFNC treatment group included 436 children, 405 children treated with nCPAP or standard oxygen therapy were included in the control. The results showed that the failure rate [relative risk (RR) is 0.57, 95% CI: 0.43-0.76], respiratory rate [mean difference (MD) is -7.43, 95% CI: -8.42 to -6.43], and social function (MD is 0.76, 95% CI: -0.32 to 1.83) of HFNC-treated children with bronchiolitis were significantly different to that of the control group patients.

DISCUSSION

HFNC treatment provides the same improvement in arterial oxygen partial pressure as standard oxygen therapy or transnasal positive airway pressure treatment, but it is significantly better at improving the respiratory rate of children with bronchiolitis.

High Flow Nasal Cannula in the Pediatric Intensive Care Unit

INTRODUCTION

The use of high flow nasal cannula (HFNC) has become widely used in pediatric intensive care units (PICUs) throughout the world. The rapid adoption has outpaced the number of studies evaluating the safety and efficacy in a variety of pediatric diseases/conditions.

AREAS COVERED

This scoping review begins with the definition and mechanisms of action of HFNC and then follows with a review of the literature focused on studies performed on critically ill children cared for in the PICU. The Pubmed database was searched with a pediatric filter from the time period 2000 to 2021.

EXPERT OPINION

The rapid adoption of HFNC in PICUs has largely been driven by changes in institutional practices and small observational studies. There is a lack of adequately powered studies evaluating patient-centered outcomes, such as intubation rates, mortality, PICU and hospital length of stay. Given the wide variability in flow rates and clinical indications, more research is needed to better define effective flow rates for different disease states as well as markers of treatment success and failure. One particular entity that is poorly studied is the use of HFNC in those at risk for developing pediatric acute respiratory distress syndrome (PARDS).

Impact of High Flow Nasal Cannula on Resource Utilization in Bronchiolitis

OBJECTIVES

High flow nasal cannula (HFNC) is increasingly used for children hospitalized with bronchiolitis. We aimed to validate identification of HFNC use in a national database, then compare resource utilization among children treated with and without HFNC.

METHODS

In this cross-sectional, multicenter study, we obtained clinical and resource utilization data from the Pediatric Health Information System (PHIS) database for healthy children aged 1 to 24 months admitted for bronchiolitis. We assessed HFNC use based on a combination of billing codes and reviewed charts at 2 hospitals to determine their accuracy. We compared costs, length of stay, and readmissions between the HFNC and no HFNC groups at hospitals utilizing the HFNC codes.

RESULTS

The PHIS codes demonstrated 90.4% sensitivity and 99.3% specificity to detect HFNC use as verified by chart review at 2 hospitals. However, only 24 of 51 PHIS hospitals used these codes for ≥1% of patients with bronchiolitis. Within those hospitals, children treated with HFNC had greater total costs ($7054 vs $4544; P < .001), greater daily costs ($2922 vs $2613; P < .001), and longer length of stay (57.6 vs 41.6 hours; P < .001). Those treated with HFNC were less likely to be readmitted at 3 and 7 days (P < .001), but by 14 days, readmissions were similar in the 2 groups.

CONCLUSIONS

Billing codes for HFNC are inconsistently applied across PHIS hospitals; however, among those hospitals that routinely apply these codes, HFNC was associated with more intense resource utilization. Standardization of billing practices for HFNC would allow future study to more broadly describe the value of HFNC.

High-flow nasal cannula in children with asthma exacerbation: A review of current evidence

Asthma is the commonest obstructive airway disease and the leading cause of morbidity in children. In the pediatric population, acute exacerbations of asthma are a frequent cause of presentations and hospital admissions. An acute asthma exacerbation is potentially life-threatening; it is predominantly treated using conventional oxygen therapy with bronchodilators and systemic corticosteroids. The treatment of those who do not respond to conventional therapy is escalated to noninvasive positive pressure ventilation (NIPPV) before invasive ventilation. Although NIPPV has demonstrated benefits and safety, it still has limitations such as treatment intolerance caused mainly by discomfort and complications. High-flow oxygen therapy administered through a nasal cannula (HFNC) provides respiratory support with adequate airway humidity and has demonstrated safety and benefits in clinical practice. In the present review, we discuss HFNC and variations in HFNC use, focusing on its feasibility and current evidence of using it on children with asthma exacerbations.

Clinical practices related to high-flow nasal cannulas in pediatric critical care in Brazil compared to other countries: a Brazilian survey

Objetivo

Descrever as práticas clínicas atuais relacionadas à utilização de cânula nasal de alto fluxo por intensivistas pediátricos brasileiros e compará-las com as de outros países.

Métodos

Para o estudo principal, foi administrado um questionário a intensivistas pediátricos em países das Américas do Norte e do Sul, Ásia, Europa e Austrália/Nova Zelândia. Comparou-se a coorte brasileira com coortes dos Estados Unidos, Canadá, Reino Unido e Índia.

Resultados

Responderam ao questionário 501 médicos, dos quais 127 eram do Brasil. Apenas 63,8% dos participantes brasileiros tinham disponibilidade de cânula nasal de alto fluxo, em contraste com 100% dos participantes no Reino Unido, no Canadá e nos Estados Unidos. Coube ao médico responsável a decisão de iniciar a utilização de uma cânula nasal de alto fluxo segundo responderam 61,2% dos brasileiros, 95,5% dos localizados no Reino Unido, 96,6% dos participantes dos Estados Unidos, 96,8% dos médicos canadenses e 84,7% dos participantes da Índia; 62% dos participantes do Brasil, 96,3% do Reino Unido, 96,6% dos Estados Unidos, 96,8% do Canadá e 84,7% da Índia relataram que o médico responsável era quem definia o desmame ou modificava as regulagens da cânula nasal de alto fluxo. Quando ocorreu falha da cânula nasal de alto fluxo por desconforto respiratório ou insuficiência respiratória, 82% dos participantes do Brasil considerariam uma tentativa com ventilação não invasiva antes da intubação endotraqueal, em comparação com 93% do Reino Unido, 88% dos Estados Unidos, 91,5% do Canadá e 76,8% da Índia. Mais intensivistas brasileiros (6,5%) do que do Reino Unido, Estados Unidos e Índia (1,6% para todos) afirmaram utilizar sedativos com frequência concomitantemente à cânula nasal de alto fluxo.

Conclusão

A disponibilidade de cânulas nasais de alto fluxo no Brasil ainda não é difundida. Há algumas divergências nas práticas clínicas entre intensivistas brasileiros e seus colegas estrangeiros, principalmente nos processos e nas tomadas de decisão relacionados a iniciar e desmamar o tratamento com cânula nasal de alto fluxo.

Clinical Factors of High-Flow Nasal Cannula Oxygen Success in Children

This study was aimed to evaluate the success rate of high-flow nasal cannula (HFNC) oxygen therapy and factors causing therapy failure. This prospective observational study included 131 children who received HFNC oxygen and followed-up in the pediatric emergency department, pediatric clinics, and pediatric intensive care unit between March 2018 and December 2019. The median age was 23.0 months (interquartile range [IQR]: 9.0-92.0) and 65 patients were male (49.6%). The most common reason for requiring HFNC oxygen therapy was pneumonia ( n  = 75, 57.3%). A complex chronic condition was present in 112 (85.5%) patients. Therapy success was achieved in 116 patients (88.5%). The reason for requiring treatment and the patients' complex chronic condition did not affect the success of the therapy ( p  = 0.294 and 0.091, respectively). In the first 24 hours of treatment, a significant improvement in pulse rate, respiratory rate, pH, and lactate level were observed in successful HFNC oxygen patients ( p  < 0.05). In addition, these patients showed a significant improvement in SpO ₂ and SpO ₂ /FiO ₂ ratio, and a significant decrease in FiO ₂ and flow rate ( p  < 0.05). HFNC oxygen success rate was 95.6% in patients with SpO ₂ /FiO ₂ ≥ 150 at the 24th hour; it was 58.0% in those with SpO ₂ /FiO ₂  < 150 ( p  < 0.001). Caution should be exercised in terms of HFNC oxygen failure in patients with no significant improvement in vital signs and with SpO ₂ /FiO ₂  < 150 during treatment.

Trends in Bronchiolitis ICU Admissions and Ventilation Practices: 2010-2019

OBJECTIVES

To determine the changes in ICU admissions, ventilatory support, length of stay, and cost for patients with bronchiolitis in the United States.

METHODS

Retrospective cross-sectional study of the Pediatric Health Information Systems database. All patients age <2 years admitted with bronchiolitis and discharged between January 1, 2010 and December 31, 2019, were included. Outcomes included proportions of annual ICU admissions, invasive mechanical ventilation (IMV), noninvasive ventilation (NIV), and cost.

RESULTS

Of 203 859 admissions for bronchiolitis, 39 442 (19.3%) were admitted to an ICU, 6751 (3.3%) received IMV, and 9983 (4.9%) received NIV. ICU admissions for bronchiolitis doubled from 11.7% in 2010 to 24.5% in 2019 (P < .001 for trend), whereas ICU admissions for all children in Pediatric Health Information Systems <2 years of age increased from 16.0% to 21.1% during the same period (P < .001 for trend). Use of NIV increased sevenfold from 1.2% in 2010 to 9.5% in 2019 (P < .001 for trend). Use of IMV did not significantly change (3.3% in 2010 to 2.8% in 2019, P = .414 for trend). In mixed-effects multivariable logistic regression, discharge year was a significant predictor of NIV (odds ratio: 1.24; 95% confidence interval [CI]: 1.23-1.24) and ICU admission (odds ratio: 1.09; 95% CI: 1.09-1.09) but not IMV (odds ratio: 1.00; 95% CI: 1.00-1.00).

CONCLUSIONS

The proportions of children with bronchiolitis admitted to an ICU and receiving NIV have substantially increased, whereas the proportion receiving IMV is unchanged over the past decade. Further study is needed to better understand the factors underlying these temporal patterns.

Invasive and noninvasive ventilation strategies for acute respiratory failure in children with coronavirus disease 2019

PURPOSE OF REVIEW

Severe Acute Respiratory Syndrome Coronavirus 2 presents as symptomatic coronavirus disease 2019 (COVID-19) disease in susceptible patients. Severe pediatric COVID-19 disease is rare, limiting potential data accumulation on associated respiratory failure in children. Pediatric intensivists and pulmonologists managing COVID-19 patients look to adult guidelines and pediatric-specific consensus statements to guide management. The purpose of this article is to review the current literature and recommended strategies for the escalation of noninvasive and invasive respiratory support for acute respiratory failure associated with COVID-19 disease in children.

RECENT FINDINGS

There are no prospective studies comparing COVID-19 treatment strategies in children. Adult and pediatric ventilation management interim guidance is based on evidence-based guidelines in non-COVID acute respiratory distress syndrome, with considerations of (1) noninvasive positive pressure ventilation versus high-flow nasal cannula and (2) high versus lower positive end expiratory pressure strategies related to lung compliance and potential lung recruitability.

SUMMARY

Management of acute respiratory failure from COVID-19 requires individualized titration of noninvasive and invasive ventilation modalities with consideration of preserved or compromised pulmonary compliance. Research regarding best practices in the management of pediatric severe COVID-19 with respiratory failure is lacking and is acutely needed as the pandemic surges and vaccination of the pediatric population will be delayed compared to adults.

A pediatric high-flow nasal cannula protocol standardizes initial flow and expedites weaning

OBJECTIVE

Respiratory illnesses compose the most common diagnoses of patients admitted to pediatric intensive care units. In pediatrics, high-flow nasal cannula (HFNC) therapy is an intermediate level of respiratory support with variability in practice. We conducted a pre-post intervention study of patients placed on HFNC therapy before and after the implementation of an HFNC protocol.

METHODS

This was a quality improvement/pre-post intervention study of pediatric patients who received HFNC therapy in our teaching, tertiary care children's hospital between January 2015 and April 2019. Patients were evaluated before and after the implementation of a protocol that promoted initiation of higher flow and rapid weaning. Our primary outcomes were initial flow and rate of weaning pre- and post-protocol; our secondary outcomes were HFNC failure rate (defined as escalation to noninvasive ventilation or mechanical ventilation) and length of hospital stay. Propensity matching was used to account for differences in age and weight pre- and post-protocol.

RESULTS

In total, 584 patients were included, 292 pre-protocol, and 292 post-protocol. The median age was 20 months, and the indication for HFNC therapy was bronchiolitis in 29% of patients. Post-protocol patients compared to pre-protocol patients had significantly a higher initial flow (median 14.5 L/min vs. 10 L/min, p < .001) and a higher weaning rate of flow (median 4.1 L/min/h vs. 2.4 L/min/h, p < .001). Post-protocol patients also had a lower HFNC failure rate (10% vs. 17%, p = .015) and a shorter length of stay (5.97 days vs. 6.80 days, p = .006).

CONCLUSION

Among pediatric patients, the implementation of an HFNC protocol increases initial flow, allows for more rapid weaning, and may decrease the incidence of escalation to noninvasive ventilation or mechanical ventilation.

Association of transcutaneous CO2 with respiratory support: a prospective double blind observational study in children with bronchiolitis and reactive airway disease

The use of clinical scoring to assess for severity of respiratory distress and respiratory failure is challenging due to subjectivity and interrater variability. Transcutaneous Capnography (TcpCO₂) can be used as an objective tool to assess a patient’s ventilatory status. This study was designed to assess for any correlation of continuous monitoring of TcpCO₂ with the respiratory clinical scores and deterioration in children admitted for acute respiratory distress. A prospective observational study over one year on children aged 2 weeks to 5 years admitted with acute respiratory distress or failure secondary to Bronchiolitis and Reactive airway disease was performed. Continuous TcpCO₂ monitoring for upto 48 h was recorded. Investigators, bedside physicians, respiratory therapists, and nurses were blinded from the transcutaneous trends at the time of data collection. Total of 813 TcpCO₂ measurements at standard intervals of 30 min were obtained on 38 subjects. Subjects with abnormal TcpCO₂ (> 45 mmHg) were younger (6.9 ± 5.2 vs. 23.05 ± 17.7 months,) and were more likely to be on higher oxygen flow rate (0.52 L/min/kg vs 0.46 lier/min/kg, p = 0.004) and higher FiO₂ (38.4 vs 33.6, p < 0.001 using heated high flow nasal cannula. No difference was found in bronchiolitis score or PEW score in subjects with normal and abnormal TcpCO₂. A small but statistically significant increase in TcpCO₂ was observed at the escalation of care. Even though odds of escalation of care are higher with abnormal TcpCO₂ (OR 1.92), this difference did not reach statistical significance. pCO₂ can provide additive information for non-invasive clinical monitoring of children requiring varying respiratory support; however, it does not provide predictive value for escalation or de-escalation of care.

High flow in children with respiratory failure: A randomised controlled pilot trial - A paediatric acute respiratory intervention study

AIMS

High-flow is increasingly used in children with acute hypoxaemic respiratory failure (AHRF), despite limited evidence. The primary feasibility endpoint for this pilot-study was the proportion of treatment failure, secondary outcomes being intensive care unit (ICU) admissions and proportion of patients requiring escalation of care. We measured duration of hospital stay, duration of oxygen therapy and rates of ICU admission.

METHODS

An open-labelled randomised controlled trial feasibility design was used in two tertiary children's hospitals in the emergency department and general wards. Children aged 0-16 years with AHRF were randomised (1:1) to either high-flow or standard-oxygen. Children on standard-oxygen received rescue high-flow in general wards if failure criteria were met.

RESULTS

Of 563 randomised, 283 received high-flow and 280 standard-oxygen with no adverse events. The proportion of children who failed treatment and receiving escalation of care was 11.7% (32/283 children) on high-flow and 18.1% (50/280 infants) on standard-oxygen (odds ratio 0.68, 95% confidence interval 0.38-1.00). In children with obstructive airway disease, 9.7% on high-flow and 17.4% on standard-oxygen required escalation (risk-difference -7.7% percentage points; 95% confidence interval -14.3, -1.1); in children with non-obstructive disease no difference was observed. Neither difference in ICU admissions nor any difference in length of hospital stay was observed. Sixty percent of children who failed standard-oxygen responded to rescue high-flow.

CONCLUSION

High-flow outside ICU appears to be feasible in children with AHRF and the required proportion of escalation was lower compared to standard-oxygen. The trial design can be applied in a future large randomised controlled trial.

Update on the Role of High-Flow Nasal Cannula in Infants with Bronchiolitis

Bronchiolitis (BR), a lower respiratory tract infection mainly caused by respiratory syncytial virus (RSV), can be very severe. Presently, adequate nutritional support and oxygen therapy remain the only interventions recommended to treat patients with BR. For years, mild BR cases were treated with noninvasive standard oxygen therapy (SOT), i.e., with cold and poorly or totally non-humidified oxygen delivered by an ambient headbox or low-flow nasal cannula. Children with severe disease were intubated and treated with invasive mechanical ventilation (IMV). To improve SOT and overcome the disadvantages of IMV, new measures of noninvasive and more efficient oxygen administration have been studied. Bi-level positive air way pressure (BiPAP), continuous positive airway pressure (CPAP), and high-flow nasal cannula (HFNC) are among them. For its simplicity, good tolerability and safety, and the good results reported in clinical studies, HFNC has become increasingly popular and is now widely used. However, consistent guidelines for initiation and discontinuation of HFNC are lacking. In this narrative review, the role of HFNC to treat infants with BR is discussed. An analysis of the literature showed that, despite its widespread use, the role of HFNC in preventing respiratory failure in children with BR is not precisely defined. It is not established whether it can offer greater benefits compared to SOT and when and in which infants it can replace CPAP or BiPAP. The analysis of the results clearly indicates the need for multicenter studies and official guidelines. In the meantime, HFNC can be considered a safe and effective method to treat children with mild to moderate BR who do not respond to SOT.

Predicting Failure of Non-Invasive Ventilation With RAM Cannula in Bronchiolitis

INTRODUCTION

In infants hospitalized for bronchiolitis on non-invasive ventilation (NIV) via the RAM cannula nasal interface, variables predicting subsequent intubation, or NIV non-response, are understudied. We sought to identify predictors of NIV non-response.

METHODS

We performed a retrospective cohort study in infants admitted for respiratory failure from bronchiolitis placed on NIV in a quaternary children's hospital. We excluded children with concurrent sepsis, critical congenital heart disease, or with preexisting tracheostomy. The primary outcome was NIV non-response defined as intubation after a trial of NIV. Secondary outcomes were vital sign values before and after NIV initiation, duration of NIV and intubation, and mortality. Primary analyses included Chi-square, Wilcoxon rank-sum, student's t test, paired analyses, and adjusted and unadjusted logistic regression assessing heart rate (HR) and respiratory rate (RR) before and after NIV initiation.

RESULTS

Of 138 infants studied, 34% were non-responders. There were no differences in baseline characteristics of responders and non-responders. HR decreased after NIV initiation in responders (156 [143-156] to149 [141-158], p < 0.01) compared to non-responders (158 [149-166] to 158 [145-171], p = 0.73). RR decreased in responders (50 [43-58] vs 47 [41-54]) and non-responders (52 [48-58] vs 51 [40-55], both p < 0.01). Concurrent bacterial pneumonia (OR 6.06, 95% CI: 2.54-14.51) and persistently elevated HR (OR: 1.04, 95% CI: 1.01-1.07) were associated with NIV non-response.

CONCLUSION

In children with acute bronchiolitis who fail to respond to NIV and require subsequent intubation, we noted associations with persistently elevated HR after NIV initiation and concurrent bacterial pneumonia.

High-Flow Nasal Cannula Therapy in Children With Acute Respiratory Distress With Hypoxia in A Pediatric Intensive Care UnitA Single Center Experience

Aim: High-flow nasal cannulas (HFNCs) show potential in the application of positive pressure, improving gas exchange, and decreasing work of breathing in patients with acute respiratory distress. The aims of this study were to elucidate the indications for HFNC therapy in children of all ages and diagnoses, and to evaluate the efficacy and risk factors for failure of HFNC therapy in children with acute respiratory distress with hypoxia in a pediatric intensive care unit. Methods: We conducted this retrospective cohort study at a tertiary pediatric intensive care unit between January 1, 2018 and December 31, 2020. All children, from 1 month to 18 years of age, with acute respiratory distress with hypoxia and HFNC therapy were eligible. The clinical data were reviewed. Results: One hundred and two children met the eligibility criteria for the study, of whom 57 (55.9%) were male, and the mean age was 7.00 6.79 years. Seventy-eight (76.5%) of the children had underlying disorders. The most common indications for the use of HFNC therapy were pneumonia (40, 39.2%), sepsis-related respiratory distress (17, 16.7%), and bronchiolitis (16, 15.7%). The failure rate was 15.7% (16 of 102 children). Higher initial and maximum fraction of inspiration O2 levels and lower initial and lowest SpO2/FiO2 (S/F) ratio were early and possible signs of failure requiring escalation of respiratory support. Conclusion: In our population, we found that HFNC therapy could be initiated as the first-line therapy for various etiologies of acute respiratory distress with hypoxia in a pediatric intensive care unit and for all age groups.

Nasal high flow therapy introduction lowers reintubation risk in a Peruvian paediatric intensive care unit

AIM

We examined the impact of introducing high-flow nasal oxygen therapy (HFNT) on children under five with post-extubation respiratory failure in a paediatric intensive care unit (PICU) in Peru.

METHODS

This quasi-experimental study compared clinical outcomes before and after initial HFNT deployment in the PICU at Instituto Nacional de Salud del Niño in Lima in June 2016. We compared three groups: 29 received post-extubation HFNT and 17 received continuous positive airway pressure (CPAP) from 2016-17 and 12 historical controls received CPAP from 2012-16. The primary outcome was the need for mechanical ventilation. Adjusted hazard ratios (aHR) and 95% confidence intervals (95% CI) were calculated via survival analysis.

RESULTS

High-flow nasal oxygen therapy and CPAP did not alter the need for mechanical ventilation after extubation (aHR 0.47, 95% CI 0.15-1.48 and 0.96, 95% CI 0.35-2.62, respectively) but did reduce the risk of reintubation (aHR 0.18, 95% CI 0.06-0.57 and 0.14, 95% CI 0.03-0.72, respectively). PICU length of stay was 11, 18 and 37 days for CPAP, HFNT and historical CPAP and mortality was 12%, 7% and 27%, respectively. There was no effect on the duration of sedative infusions.

CONCLUSION

High-flow nasal oxygen therapy provided effective support for some children, but larger studies in resource-constrained settings are needed.

Nasal high flow higher than 60 L/min in patients with acute hypoxemic respiratory failure: a physiological study

Background

Nasal high flow delivered at flow rates higher than 60 L/min in patients with acute hypoxemic respiratory failure might be associated with improved physiological effects. However, poor comfort might limit feasibility of its clinical use.

Methods

We performed a prospective randomized cross-over physiological study on 12 ICU patients with acute hypoxemic respiratory failure. Patients underwent three steps at the following gas flow: 0.5 L/kg PBW/min, 1 L/kg PBW/min, and 1.5 L/kg PBW/min in random order for 20 min. Temperature and FiO₂ remained unchanged. Toward the end of each phase, we collected arterial blood gases, lung volumes, and regional distribution of ventilation assessed by electrical impedance tomography (EIT), and comfort.

Results

In five patients, the etiology was pulmonary; infective disease characterized seven patients; median PaO₂/FiO₂ at enrollment was 213 [IQR 136–232]. The range of flow rate during NHF 1.5 was 75–120 L/min. PaO₂/FiO₂ increased with flow, albeit non significantly (p = 0.064), PaCO₂ and arterial pH remained stable (p = 0.108 and p = 0.105). Respiratory rate decreased at higher flow rates (p = 0.014). Inhomogeneity of ventilation decreased significantly at higher flows (p = 0.004) and lung volume at end-expiration significantly increased (p = 0.007), but mostly in the non-dependent regions. Comfort was significantly poorer during the step performed at the highest flow (p < 0.001).

Conclusions

NHF delivered at rates higher than 60 L/min in critically ill patients with acute hypoxemic respiratory failure is associated with reduced respiratory rate, increased lung homogeneity, and additional positive pressure effect, but also with worse comfort.

Additional work of breathing from trigger errors in mechanically ventilated children

Background

Patient–ventilator asynchrony is associated with increased morbidity and mortality. A direct causative relationship between Patient–ventilator asynchrony and adverse clinical outcome have yet to be demonstrated. It is hypothesized that during trigger errors excessive pleural pressure swings are generated, contributing to increased work-of-breathing and self-inflicted lung injury. The objective of this study was to determine the additional work-of-breathing and pleural pressure swings caused by trigger errors in mechanically ventilated children.

Methods

Prospective observational study in a tertiary paediatric intensive care unit in an university hospital. Patients ventilated > 24 h and < 18 years old were studied. Patients underwent a 5-min recording of the ventilator flow–time, pressure–time and oesophageal pressure–time scalar. Pressure–time–product calculations were made as a proxy for work-of-breathing. Oesophageal pressure swings, as a surrogate for pleural pressure swings, during trigger errors were determined.

Results

Nine-hundred-and-fifty-nine trigger errors in 28 patients were identified. The additional work-of-breathing caused by trigger errors showed great variability among patients. The more asynchronous breaths were present the higher the work-of-breathing of these breaths. A higher spontaneous breath rate led to a lower amount of trigger errors. Patient–ventilator asynchrony was not associated with prolonged duration of mechanical ventilation or paediatric intensive care stay.

Conclusions

The additional work-of-breathing caused by trigger errors in ventilated children can take up to 30–40% of the total work-of-breathing. Trigger errors were less common in patients breathing spontaneously and those able to generate higher pressure–time–product and pressure swings.

Trial registration

Not applicable.

High-flow nasal cannula vs standard respiratory care in pediatric procedural sedation: A randomized controlled pilot trial

INTRODUCTION

Respiratory instability is frequently observed during pediatric procedural sedation. The aim of this trial was to estimate the impact of high-flow nasal cannula (HFNC) therapy on respiratory stability during sedation for upper gastrointestinal tract endoscopy in children.

METHODS

Prospective randomized controlled non-blinded single-center pilot trial. Children were randomly allocated to receive either HFNC (2 L/kg/min) or low-flow nasal oxygen cannula (LFNC, standard care). FiO₂ was titrated to maintain SpO₂ 94% to 98% in both groups. Primary outcome was the number of events of respiratory instability defined by prespecified criteria (hypoxia, hypercapnia, apnea). Secondary outcomes included type and duration of events, number of interventions to regain respiratory stability and cumulative doses of medication.

RESULTS

Fifty children (mean age, 12.3 ± 3.1 years) were enrolled and treated with HFNC (n = 25) or LFNC (n = 25). Patient and intervention characteristics were not different in the two study groups, including total oxygen flow rate. Mean (SD) number of respiratory events in the HFNC group was 2.0 ± 1.9 events compared to 2.0 ± 1.4 events in the LFNC group (P = .65; 95% CI of difference, -1.0 to 1.0). There was no difference for any secondary outcome criteria, percentage of patients for any outcome criteria and no difference in the number of respiratory events or airway management maneuvers per patient between treatment groups.

CONCLUSIONS

HFNC did not increase respiratory stability in sedated children undergoing upper gastrointestinal tract endoscopy compared to LFNC.

A randomised trial of high-flow nasal cannula in infants with moderate bronchiolitis

BACKGROUND

The objective was to determine whether high-flow nasal cannula (HFNC), a promising respiratory support in infant bronchiolitis, could reduce the proportion of treatment failure requiring escalation of care.

METHODS

In this randomised controlled trial, we assigned infants aged <6 months who had moderate bronchiolitis to receive either HFNC at 3 L·kg^-1·min^-1 or standard oxygen therapy. Crossover was not allowed. The primary outcome was the proportion of patients in treatment failure requiring escalation of care (mostly noninvasive ventilation) within 7 days following randomisation. Secondary outcomes included rates of transfer to the paediatric intensive care unit (PICU), oxygen, number of artificial nutritional support-free days and adverse events.

RESULTS

The analyses included 268 patients among the 2621 infants assessed for inclusion during two consecutive seasons in 17 French paediatric emergency departments. The percentage of infants in treatment failure was 14% (19 out of 133) in the study group, compared to 20% (27 out of 135) in the control group (OR 0.66, 95% CI 0.35-1.26; p=0.21). HFNC did not reduce the risk of admission to PICU (21 (15%) out of 133 in the study group versus 26 (19%) out of 135 in the control group) (OR 0.78, 95% CI 0.41-1.41; p=0.45). The main reason for treatment failure was the worsening of modified Wood clinical asthma score (m-WCAS). Short-term assessment of respiratory status showed a significant difference for m-WCAS and respiratory rate in favour of HFNC. Three pneumothoraces were reported in the study group.

CONCLUSIONS

In patients with moderate bronchiolitis, there was no evidence of lower rate of escalating respiratory support among those receiving HFNC therapy.

Intensive Care Unit Utilization After Adoption of a Ward-Based High-Flow Nasal Cannula Protocol

BACKGROUND

Hospitals are increasingly adopting ward-based high-flow nasal cannula (HFNC) protocols that allow HFNC treatment of bronchiolitis outside of the intensive care unit (ICU). Our objective was to determine whether adoption of a ward-based HFNC protocol reduces ICU utilization.

METHODS

We examined a retrospective cohort of infants aged 3 to 24 months hospitalized with bronchiolitis at hospitals in the Pediatric Health Information System database. The study exposure was adoption of a ward-based HFNC protocol, measured by direct contact with pediatric hospital medicine leaders at each hospital. All analyses utilized an interrupted time series approach. The primary analysis compared outcomes three respiratory seasons before and three respiratory seasons after HFNC adoption, among adopting hospitals. Supplementary analysis 1 mirrored the primary analysis with the exception that the first season after adoption was censored. In supplementary analysis 2, effects among nonadopting hospitals were subtracted from effects measured among adopting hospitals.

RESULTS

Of 44 contacted hospitals, 41 replied (93% response rate), of which 18 were categorized as non-adopting hospitals and 12 were categorized as adopting hospitals. Included ward-based HFNC protocols were adopted between the 2010-2011 and 2015-2016 respiratory seasons. The primary analysis included 26,253 bronchiolitis encounters and measured immediate increases in the proportion of patients admitted to the ICU (absolute difference, 3.1%; 95% CI, 2.8%-3.4%) and ICU length of stay (absolute difference, 9.1 days per 100 patients; 95% CI, 5.1-13.2). Both supplementary analyses yielded similar findings.

CONCLUSION

Early protocols for ward-based HFNC were paradoxically associated with increased ICU utilization.

Monitoring of Respiratory Muscle Function in Critically Ill Children

OBJECTIVES

This review discusses the different techniques used at the bedside to assess respiratory muscle function in critically ill children and their clinical applications.

DATA SOURCES

A scoping review of the medical literature on respiratory muscle function assessment in critically ill children was conducted using the PubMed search engine.

STUDY SELECTION

We included all scientific, peer-reviewed studies about respiratory muscle function assessment in critically ill children, as well as some key adult studies.

DATA EXTRACTION

Data extracted included findings or comments about techniques used to assess respiratory muscle function.

DATA SYNTHESIS

Various promising physiologic techniques are available to assess respiratory muscle function at the bedside of critically ill children throughout the disease process. During the acute phase, this assessment allows a better understanding of the pathophysiological mechanisms of the disease and an optimization of the ventilatory support to increase its effectiveness and limit its potential complications. During the weaning process, these physiologic techniques may help predict extubation success and therefore optimize ventilator weaning.

CONCLUSIONS

Physiologic techniques are useful to precisely assess respiratory muscle function and to individualize and optimize the management of mechanical ventilation in children. Among all the available techniques, the measurements of esophageal pressure and electrical activity of the diaphragm appear particularly helpful in the era of individualized ventilatory management.

High-flow nasal cannula oxygen therapy in children: a clinical review

High-flow nasal cannula (HFNC) is a relatively safe and effective noninvasive ventilation method that was recently accepted as a treatment option for acute respiratory support before endotracheal intubation or invasive ventilation. The action mechanism of HFNC includes a decrease in nasopharyngeal resistance, washout of dead space, reduction in inflow of ambient air, and an increase in airway pressure. In preterm infants, HFNC can be used to prevent reintubation and initial noninvasive respiratory support after birth. In children, flow level adjustments are crucial considering their maximal efficacy and complications. Randomized controlled studies suggest that HFNC can be used in cases of moderate to severe bronchiolitis upon initial low-flow oxygen failure. HFNC can also reduce intubation and mechanical ventilation in children with respiratory failure. Several observational studies have shown that HFNC can be beneficial in acute asthma and other respiratory distress. Multicenter randomized studies are warranted to determine the feasibility and adherence of HFNC and continuous positive airway pressure in pediatric intensive care units. The development of clinical guidelines for HFNC, including flow settings, indications, and contraindications, device management, efficacy identification, and safety issues are needed, particularly in children.

Multicentre, randomised trial to investigate early nasal high-flow therapy in paediatric acute hypoxaemic respiratory failure: a protocol for a randomised controlled trial-a Paediatric Acute respiratory Intervention Study (PARIS 2)

INTRODUCTION

Acute hypoxaemic respiratory failure (AHRF) in children is the most frequent reason for non-elective hospital admission. During the initial phase, AHRF is a clinical syndrome defined for the purpose of this study by an oxygen requirement and caused by pneumonia, lower respiratory tract infections, asthma or bronchiolitis. Up to 20% of these children with AHRF can rapidly deteriorate requiring non-invasive or invasive ventilation. Nasal high-flow (NHF) therapy has been used by clinicians for oxygen therapy outside intensive care settings to prevent escalation of care. A recent randomised trial in infants with bronchiolitis has shown that NHF therapy reduces the need to escalate therapy. No similar data is available in the older children presenting with AHRF. In this study we aim to investigate in children aged 1 to 4 years presenting with AHRF if early NHF therapy compared with standard-oxygen therapy reduces hospital length of stay and if this is cost-effective compared with standard treatment.

METHODS AND ANALYSIS

The study design is an open-labelled randomised multicentre trial comparing early NHF and standard-oxygen therapy and will be stratified by sites and into obstructive and non-obstructive groups. Children aged 1 to 4 years (n=1512) presenting with AHRF to one of the participating emergency departments will be randomly allocated to NHF or standard-oxygen therapy once the eligibility criteria have been met (oxygen requirement with transcutaneous saturation <92%/90% (dependant on hospital standard threshold), diagnosis of AHRF, admission to hospital and tachypnoea ≥35 breaths/min). Children in the standard-oxygen group can receive rescue NHF therapy if escalation is required. The primary outcome is hospital length of stay. Secondary outcomes will include length of oxygen therapy, proportion of intensive care admissions, healthcare resource utilisation and associated costs. Analyses will be conducted on an intention-to-treat basis.

ETHICS AND DISSEMINATION

Ethics approval has been obtained in Australia (HREC/15/QRCH/159) and New Zealand (HDEC 17/NTA/135). The trial commenced recruitment in December 2017. The study findings will be submitted for publication in a peer-reviewed journal and presented at relevant conferences. Authorship of all publications will be decided by mutual consensus of the research team.

TRIAL REGISTRATION NUMBER

ACTRN12618000210279.

Effect of randomization of nasal high flow rate in preterm infants

OBJECTIVE

To assess the effect of nasal high flow (NHF) cannula on end-expiratory level (EEL), continuous distending pressure (CDP) and regional ventilation distribution in preterm infants.

DESIGN

A prospective observational clinical study with randomly applied NHF rates.

PATIENTS AND SETTING

Preterm infants requiring continuous positive airway pressure (CPAP) respiratory support in a Neonatal Intensive Care Unit.

INTERVENTIONS

Infants were measured on randomly applied flow rates at 2, 4, and 6 L/min of NHF and compared with bubble CPAP.

MEASUREMENTS AND RESULTS

Regional ventilation distribution and EEL were measured using electrical impedance tomography (EIT) and respiratory inductance plethysmography (RIP) in 24 preterm infants (31.19 ± 1.17 weeks corrected age). Changes in CDP were measured from the esophagus via the nasogastric tube. Physiological variables were also recorded. There were no differences in ventilation distribution, EEL or CDP between CPAP and NHF (P > .05). However, the physiological variables of FiO₂ (P = .01) and SpO₂ /FiO₂ (P < .01) were improved on CPAP compared with NHF.

CONCLUSION

NHF applied in random order with flow rates between 2 to 6 L/min was equally as good as CPAP in maintaining EEL and ventilation distribution in stable preterm infants. Overall oxygenation was better on CPAP compared to NHF.

Comparison of high flow nasal cannula oxygen administration to traditional nasal cannula oxygen therapy in healthy dogs

OBJECTIVE

To determine the feasibility, degree of respiratory support, and safety of high flow nasal cannula (HFNC) oxygen therapy in sedated and awake healthy dogs, when compared to traditional nasal cannula (TNC) oxygen administration.

DESIGN

Randomized experimental crossover study.

SETTING

University research facility.

ANIMALS

Eight healthy dogs.

INTERVENTIONS

Variable flow rates (L/kg/min) were assessed, TNC: 0.1, 0.2, and 0.4 and HFNC: 0.4, 1.0, 2.0, and 2.5. HFNC was assessed in sedated and awake dogs.

MEASUREMENTS

Variables measured included: inspiratory/expiratory airway pressures, fraction of inspired oxygen (FiO₂ ), end-tidal oxygen (ETO₂ ), end-tidal carbon dioxide (ETCO₂ ), partial pressure of oxygen (PaO₂ ), partial pressure of carbon dioxide (PaCO₂ ), temperature, heart/respiratory rate, arterial blood pressure, and pulse oximetry. Sedation status, complications, and predefined tolerance and respiratory scores were recorded.

MAIN RESULTS

Using HFNC, continuous positive airway pressure (CPAP) was achieved at 1 and 2 L/kg/min. CPAP was not higher at 2.5 than 2 L/kg/min, with worse tolerance scores. Expiratory airway pressures were increased when sedated (P = 0.006). FiO₂ at 0.4 L/kg/min for both methods was 72%. FiO₂ with TNC 0.1 L/kg/min was 27% and not different from room air. The FiO₂ at all HFNC flow rates ≥1 L/kg/min was 95%. PaO₂ for HFNC 0.4 L/kg/min was lower than at other flow rates (P = 0.005). The only noted complication was aerophagia. PaCO₂ was increased with sedation and use of HFNC when compared to baseline (P = 0.006; P < 0.01).

CONCLUSIONS

Use of HFNC in dogs is feasible and safe, provides predictable oxygen support and provides CPAP, but may cause a mild increase in PaCO₂ . Flow rates of 1-2 L/kg/min are recommended. If using TNC, flow rates above 0.1 L/kg/min may attain higher FiO₂ .

Nasal High Flow in Room Air for Hypoxemic Bronchiolitis Infants

Background: Bronchiolitis is the most common reason for hospital admission in infants, with one third requiring oxygen therapy due to hypoxemia. It is unknown what proportion of hypoxemic infants with bronchiolitis can be managed with nasal high-flow in room air and their resulting outcomes. Objectives and Settings: To assess the effect of nasal high-flow in room air in a subgroup of infants with bronchiolitis allocated to high-flow therapy in a recent multicenter randomized controlled trial. Patients and Interventions: Infants allocated to the high-flow arm of the trial were initially treated with room air high-flow if saturations were ≥85%. Subsequently, if oxygen saturations did not increase to ≥92%, oxygen was added and FiO₂ was titrated to increase the oxygen saturations. In this planned sub-study, infants treated during their entire hospital stay with high-flow room air only were compared to infants receiving either standard-oxygen or high-flow with oxygen. Baseline characteristics, hospital length of stay and length of oxygen therapy were compared. Findings: In the per protocol analysis 64 (10%) of 630 infants commenced on high-flow room air remained in room air only during the entire stay in hospital. These infants on high-flow room air were on average older and presented with moderate hypoxemia at presentation to hospital. Their length of respiratory support and length of stay was also significantly shorter. No pre-enrolment factors could be identified in a multivariable analysis. Conclusions: In a small sub-group of hypoxemic infants with bronchiolitis hypoxemia can be reversed with the application of high-flow in room air only. Trial registration: ACTRN12615001305516.

Using high-flow nasal cannulas for infants with bronchiolitis admitted to paediatric wards is safe and feasible

AIM

Using a high-flow nasal cannula (HFNC) for infant bronchiolitis is increasingly common, but insufficiently studied. In this retrospective study, we examined the outcomes of HFNC and compared infants who did and did not respond to this oxygen delivery method.

METHODS

This 2012-2015 study of six Finnish hospitals focused on 88 infants under 12 months who received HFNC: 53 on paediatric wards and 35 in paediatric intensive care units (PICUs). We reviewed patient files for underlying factors, clinical parameters and HFNC treatment. The treatment failed if the patient was transferred to another respiratory support.

RESULTS

We found HFNC treatment was successful in 76 (86%) infants, including all 53 on the paediatric wards and 23/35 PICU patients. The responders' heart rates were significantly lower, and their oxygen saturation was significantly higher at 60 minutes after HFNC treatment started and then stayed relatively constant. Their respiratory rate was only significantly lower after 360 minutes. In non-responders, the respiratory rate initially decreased but was higher at 180 and 360 minutes after the start of HFNC.

CONCLUSION

We found preliminary evidence that oxygen support needs and heart rate were useful early predictors of HFNC therapy success in infants hospitalised with bronchiolitis, but respiratory rate was not.

HIGH-FLOW NASAL CANNULA POST-TRACHEAL EXTUBATION IN A CHILD WITH UPPER AIRWAY OBSTRUCTION: CASE REPORT

OBJECTIVE

To report a case of a patient who required tracheal intubation in a pediatric emergency department due to acute laryngitis and that, after the planned extubation, has successfully used the high-flow nasal cannula, which possibly prevented extubation failure.

CASE DESCRIPTION

A male 8-month-old child was admitted to the pediatric emergency room with acute respiratory distress due to a high airway obstruction secondary to severe acute laryngitis. He was immediately intubated and referred to the pediatric intensive care unit. He presented extubation failure due to a significant laryngeal edema evidenced by bronchoscopy. In the second attempt to extubate, he presented respiratory distress, but, after the use of the high-flow nasal cannula, he became stable, reducing the heart and respiratory frequencies, and the extubation was successful.

COMMENTS

The use of the high-flow nasal cannula was effective and presented good response in this patient with acute laryngitis, suggesting that it is a possible adjuvant for the treatment, avoiding worsening respiratory conditions and the need for reintubation.

FIRST-line support for Assistance in Breathing in Children (FIRST-ABC): a multicentre pilot randomised controlled trial of high-flow nasal cannula therapy versus continuous positive airway pressure in paediatric critical care

BACKGROUND

Although high-flow nasal cannula therapy (HFNC) has become a popular mode of non-invasive respiratory support (NRS) in critically ill children, there are no randomised controlled trials (RCTs) comparing it with continuous positive airway pressure (CPAP). We performed a pilot RCT to explore the feasibility, and inform the design and conduct, of a future large pragmatic RCT comparing HFNC and CPAP in paediatric critical care.

METHODS

In this multi-centre pilot RCT, eligible patients were recruited to either Group A (step-up NRS) or Group B (step-down NRS). Participants were randomised (1:1) using sealed opaque envelopes to either CPAP or HFNC as their first-line mode of NRS. Consent was sought after randomisation in emergency situations. The primary study outcomes were related to feasibility (number of eligible patients in each group, proportion of eligible patients randomised, consent rate, and measures of adherence to study algorithms). Data were collected on safety and a range of patient outcomes in order to inform the choice of a primary outcome measure for the future RCT.

RESULTS

Overall, 121/254 eligible patients (47.6%) were randomised (Group A 60%, Group B 44.2%) over a 10-month period (recruitment rate for Group A, 1 patient/site/month; Group B, 2.8 patients/site/month). In Group A, consent was obtained in 29/33 parents/guardians approached (87.9%), while in Group B 84/118 consented (71.2%). Intention-to-treat analysis included 113 patients (HFNC 59, CPAP 54). Most reported adverse events were mild/moderate (HFNC 8/59, CPAP 9/54). More patients switched treatment from HFNC to CPAP (Group A: 7/16, 44%; Group B: 9/43, 21%) than from CPAP to HFNC (Group A: 3/13, 23%; Group B: 5/41, 12%). Intubation occurred within 72 h in 15/59 (25.4%) of HFNC patients and 10/54 (18.5%) of CPAP patients (p = 0.38). HFNC patients experienced fewer ventilator-free days at day 28 (Group A: 19.6 vs. 23.5; Group B: 21.8 vs. 22.2).

CONCLUSIONS

Our pilot trial confirms that, following minor changes to consent procedures and treatment algorithms, it is feasible to conduct a large national RCT of non-invasive respiratory support in the paediatric critical care setting in both step-up and step-down NRS patients.

TRIAL REGISTRATION

clinicaltrials.gov, NCT02612415 . Registered on 23 November 2015.

Modelling nasal high flow therapy effects on upper airway resistance and resistive work of breathing

AIM

The goal of this paper is to quantify upper airway resistance with and without nasal high flow (NHF) therapy. For adults, NHF therapy feeds 30-60 L/min of warm humidified air into the nose through short cannulas which do not seal the nostril. NHF therapy has been reported to increase airway pressure, increase tidal volume (V_t) and decrease respiratory rate (RR), but it is unclear how these findings affect the work done to overcome airway resistance to air flow during expiration. Also, there is little information on how the choice of nasal cannula size may affect work of breathing. In this paper, estimates of airway resistance without and with different NHF flow (applied via different cannula sizes) were made. The breathing efforts required to overcome airway resistance under these conditions were quantified.

METHOD

NHF was applied via three different cannula sizes to a 3-D printed human upper airway. Pressure drop and flow rate were measured and used to estimate inspiratory and expiratory upper airway resistances. The resistance information was used to compute the muscular work required to overcome the resistance of the upper airway to flow.

RESULTS

NHF raises expiratory resistance relative to spontaneous breathing if the breathing pattern does not change but reduces work of breathing if peak expiratory flow falls. Of the cannula sizes used, the large cannula produced the greatest resistance and the small cannula produced the least. The work required to cause tracheal flow through the upper airway was reduced if the RR and minute volume are reduced by NHF. NHF has been observed to do so in COPD patients (Bräunlich et al., 2013). A reduction in I:E ratio due to therapy was found to reduce work of breathing if the peak inspiratory flow is less than the flow below which no inspiratory effort is required to overcome upper airway resistance.

CONCLUSION

NHF raises expiratory resistance but it can reduce the work required to overcome upper airway resistance via a fall in inspiratory work of breathing, RR and minute volume.

National high-flow nasal cannula and bronchiolitis survey highlights need for further research and evidence-based guidelines

AIM

High-flow nasal cannula (HFNC) therapy provides noninvasive respiratory support for infant bronchiolitis and its use has increased following good clinical experiences. This national study describes HFNC use in Finland during a severe respiratory syncytial virus (RSV) epidemic.

METHODS

A questionnaire on using HFNC for infant bronchiolitis during the 2015-2016 RSV epidemic was sent to the head physicians of 18 Finnish children's hospitals providing inpatient care for infants: 17 hospitals answered, covering 77.5% of the infants born in Finland in 2015.

RESULTS

Most (85%) HFNC was given on paediatric wards. The mean incidence for bronchiolitis treated with HFNC in infants under the age of one in 15 of 17 hospitals was 3.8 per 1000 per year (range: 1.4-8.1): one hospital did not supply the relevant data and one supplied a figure of 34.1 due to a different treatment policy. Instructions on how to start and wean HFNC therapy were present in 71% and 61% of the hospitals, respectively, weighted to the population. Providing weaning instructions was associated with shorter weaning times.

CONCLUSION

High-flow nasal cannula was actively used for infants with bronchiolitis, with no substantial overuse. Randomised controlled studies are needed before any evidence-based guidelines can be constructed for using HFNC in infant bronchiolitis.

The use of high-flow nasal cannula in the pediatric emergency department

OBJECTIVES

To summarize the current literature describing high-flow nasal cannula use in children, the components and mechanisms of action of a high-flow nasal cannula system, the appropriate clinical applications, and its role in the pediatric emergency department.

SOURCES

A computer-based search of PubMed/MEDLINE and Google Scholar for literature on high-flow nasal cannula use in children was performed.

DATA SUMMARY

High-flow nasal cannula, a non-invasive respiratory support modality, provides heated and fully humidified gas mixtures to patients via a nasal cannula interface. High-flow nasal cannula likely supports respiration though reduced inspiratory resistance, washout of the nasopharyngeal dead space, reduced metabolic work related to gas conditioning, improved airway conductance and mucociliary clearance, and provision of low levels of positive airway pressure. Most data describing high-flow nasal cannula use in children focuses on those with bronchiolitis, although high-flow nasal cannula has been used in children with other respiratory diseases. Introduction of high-flow nasal cannula into clinical practice, including in the emergency department, has been associated with decreased rates of endotracheal intubation. Limited prospective interventional data suggest that high-flow nasal cannula may be similarly efficacious as continuous positive airway pressure and more efficacious than standard oxygen therapy for some patients. Patient characteristics, such as improved tachycardia and tachypnea, have been associated with a lack of progression to endotracheal intubation. Reported adverse effects are rare.

CONCLUSIONS

High-flow nasal cannula should be considered for pediatric emergency department patients with respiratory distress not requiring immediate endotracheal intubation; prospective, pediatric emergency department-specific trials are needed to better determine responsive patient populations, ideal high-flow nasal cannula settings, and comparative efficacy vs. other respiratory support modalities.