Nasal high flow therapy: a novel treatment rather than a more expensive oxygen device

Tools used to assess comfort among patients undergoing high flow nasal cannula: A scoping review

OBJECTIVE

The aims were twofold: (a) to map tools documented in the literature to evaluate comfort among patients undergoing high flow nasal cannula (HFNC) treatment; and (b) to assess if the retrieved tools have been validated for this purpose.

METHODS

A scoping review, following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for scoping reviews (PRISMA-ScR). In July 2023, PubMed, Scopus, CINAHL and Cochrane Library were consulted. Studies assessing comfort in adult, paediatric, and neonatal patients undergoing HFNC were included.

RESULTS

Seventy-four articles were included, among which nine (12.2 %) investigated comfort as the primary aim. Twenty-five different tools were found, classifiable into 14 types, mostly unidimensional and originating from those measuring pain. The most widely used was the Visual Analogic Scale (n = 27, 35.6 %) followed by the Numerical Rating Scale (n = 11, 14.5 %) and less defined generic tools (n = 10, 13.2 %) with different metrics (e.g. 0-5, 0-10, 0-100). Only the General Comfort Questionnaire and the Comfort Scale were specifically validated for the assessment of comfort among adults and children, respectively.

CONCLUSION

Although the comfort of patients undergoing HFNC is widely investigated in the literature, there is a scarcity of tools specifically validated in this field. Those used have been validated mainly to assess pain, suggesting the need to inform patients to prevent confusion while measuring comfort during HFNC and to develop more research in the field.

IMPLICATIONS FOR CLINICAL PRACTICE

Comfort assessment is an important aspect of nursing care. Given the lack of validation studies in the field, efforts in research are recommended.

Clinical Practice of High-Flow Nasal Cannula Therapy in ARDS Patients: A Cross-Sectional Survey of Respiratory Therapists

Background

High-flow nasal cannula (HFNC) is an essential non-invasive oxygen therapy in acute respiratory distress syndrome (ARDS) patients. Despite its wide use, research assessing the knowledge, practice, and barriers to using HFNC among respiratory therapists (RT) is lacking.

Methods

A cross-sectional questionnaire was conducted among RTs in Saudi Arabia between December 19, 2022, and July 15, 2023. Data were analyzed as means and standard deviation or frequency and percentages. A Chi-square test was used to compare the differences between groups.

Results

A total of 1001 RTs completed the online survey. Two-thirds of the respondents 659 (65.8%) had received training in using HFNC and 785 (78.4%) had used HFNC in clinical settings. The top conditions for HFNC indication were COVID-19 (78%), post-extubation (65%), and do-not-intubate patients (64%). Participants strongly agreed that helping maintain conversation and eating abilities (32.95%) and improving shortness of breath (34.1%) were advantages of HFNC. Surprisingly, 568 (57%) of RT staff did not follow a protocol for HFNC with ARDS patients. When starting HFNC, 40.2% of the participants started with FiO2 of 61% to 80%. Additionally, high percentages of RT staff started with a flow rate between 30 L/minute and 40 L/minute (40.6%) and a temperature of 37°C (57.7%). When weaning ARDS patients, 482 (48.1%) recommended first reducing gas flow by 5-10 L/minute every two to four hours. Moreover, 549 (54.8%) believed that ARDS patients could be disconnected from HFNC if they achieved a flow rate of <20 L/minute and FiO2 of <35%. Lack of knowledge was the most common challenge concerning HFNC implementation.

Conclusion

The findings revealed nuanced applications marked by significant endorsement in certain clinical scenarios and a lack of protocol adherence, underscoring the need for uniform, evidence-based guidelines and enhanced training for RTs. Addressing these challenges is pivotal to optimizing the benefits of HFNC across varied clinical contexts.

High-Flow Nasal Cannula Therapy as an Adjuvant Therapy for Respiratory Support during Endoscopic Techniques: A Narrative Review

High-flow nasal cannula (HFNC) is a respiratory support technique that delivers a controlled concentration of oxygen with high flow, heat, and humidity via the nasal pathway. As it has many physiological effects, its use has increased for a variety of clinical indications; however, there is limited guidance on using HFNC as a respiratory support tool during endoscopic procedures. We conducted a narrative review to evaluate the effect of HFNC as an adjuvant tool during fiberoptic bronchoscopy (FOB), upper gastrointestinal tract endoscopy, and surgical procedures in adults. A search of the PubMed and Cochrane databases were performed. Approximately 384 publications were retrieved, and 99 were selected (93 original works and 6 case reports with a literature review). In patients who underwent FOB, HFNC appears to be superior to conventional oxygen therapy (COT) in preventing hypoxaemia. In contrast, for gastrointestinal endoscopy, the current evidence is insufficient to recommend HFNC over COT in a cost-effective manner. Finally, in surgical procedures such as laryngeal microsurgery or thoracic surgery, HFNC has been shown to be a safe and effective alternative to orotracheal intubation. As the results are heterogeneous, we advocate for the need for more quality studies to understand the effectiveness of HFNC during endoscopic procedures.

Synergic Difficulties in an Anticipated Physiologically and Anatomically Difficult Airway in a Trauma Patient: A Case Report

The American Society of Anesthesiologists (ASA) defines a difficult airway as a clinical situation in which a physician who is trained in anesthesiology experiences difficulty or fails in either face mask ventilation, laryngoscopy, using a supraglottic airway, tracheal intubation, extubation, or front-of-neck airway. Classically, this has been defined in relation to anatomic factors, but the concept of a physiologically difficult airway has been growing in relevance, in which physiologic factors, such as hypoxemia and hypercapnia, act to reduce safe apnea times. The case reports on a trauma patient with an unstable thoracic vertebral fracture requiring correction via the posterior approach. Our patient had multiple anatomical difficult airway predictors, namely, a short neck, greatly limited neck mobility, and a Mallampati class IV airway, among others, and multiple physiological difficult airway predictors, such as a baseline hypoxemic respiratory failure and severe sleep apnea, in addition to the restrictions on mobility imposed by the fracture itself. We describe a successful perioxygenation strategy, using high-flow nasal oxygen (HFNO) during the preoxygenation, intubation, extubation, and post-anesthesia care phases, and with an awake fiberoptic intubation technique for securing the airway.

Monitoring the Efficacy of High-Flow Nasal Cannula Oxygen Therapy in Patients with Acute Hypoxemic Respiratory Failure in the General Respiratory Ward: A Prospective Observational Study

High-flow nasal cannula (HFNC) is widely used to treat hypoxemic respiratory failure. The effectiveness of HFNC treatment and the methods for monitoring its efficacy in the general ward remain unclear. This prospective observational study enrolled 42 patients who had acute hypoxemic respiratory failure requiring HFNC oxygen therapy in the general adult respiratory ward. The primary outcome was the all-cause in-hospital mortality. Secondary outcomes included the association between initial blood test results and HFNC outcomes. Regional ventilation distributions were monitored in 24 patients using electrical impedance tomography (EIT) after HFNC initiation. Patients with successful HFNC treatment had better in-hospital survival (94%) compared to those with failed HFNC treatment (0%, p < 0.001). Neutrophil-to-lymphocyte ratios of ≥9 were more common in patients with failed HFNC (70%) compared to those with successful HFNC (52%, p = 0.070), and these patients had shorter hospital survival rates after HFNC treatment (p = 0.046, Tarone-Ware test). Patients with successful HFNC treatment had a more central ventilation distribution compared to those with failed HFNC treatment (p < 0.05). Similarly, patients who survived HFNC treatment had a more central distribution compared to those who did not survive (p < 0.001). We concluded that HFNC in the general respiratory ward may be a potential rescue therapy for patients with respiratory failure. EIT can potentially monitor patients receiving HFNC therapy.

Effect of noninvasive respiratory support on interstitial lung disease with acute respiratory failure: A systematic review and meta-analysis

Background

Primary studies have demonstrated the effectiveness of noninvasive respiratory supports, including noninvasive positive pressure ventilation (NIPPV) and high flow nasal cannula (HFNC), for improving oxygenation and ventilation in patients with interstitial lung diseases (ILDs) and acute respiratory failure (ARF). These studies have not been synthesized and are not included in current practice guidelines. This systematic review with meta-analysis synthesizes studies that compared the effectiveness of NIPPV, HFNC and conventional oxygen therapy (COT) for improving oxygenation and ventilation in ILD patients with ARF.

Methods

MEDLINE, EMBASE and the Cochrane Library searches were conducted from inception to August 2023. An additional search of relevant primary literature and review articles was also performed. A random effects model was used to estimate the PF ratio (ratio of arterial oxygen partial pressure to fractional inspired oxygen), PaCO2 (partial pressure of carbon dioxide), mortality, intubation rate and hospital length of stay.

Results

Ten studies were included in the systematic review and meta-analysis. Noninvasive respiratory supports demonstrated a significant improvement in PF ratio compared to conventional oxygen therapy (COT); the mean difference was 55.92 (95% CI [18.85-92.99]; p=0.003). Compared to HFNC, there was a significant increase in PF ratio in NIPPV (mean difference 0.45; 95% CI [0.12-0.79]; p=0.008). There were no mortality and intubation rate benefits when comparing NIPPV and HFNC; the mean difference was 1.1; 95% CI [0.83-1.44]; p=0.51 and 1.86; 95% CI [0.42-8.33]; p=0.42, respectively. In addition, there was a significant decrease in hospital length of stay in HFNC compared to NIPPV (mean difference 9.27; 95% Cl [1.45 - 17.1]; p=0.02).

Conclusions

Noninvasive respiratory supports might be an alternative modality in ILDs with ARF. NIPPV demonstrated a potential to improve the PF ratio compared to HFNC. There was no evidence to support the benefit of NIPPV or HFNC in terms of mortality and intubation rate.

Efficay of high-flow nasal cannula in the paediatric population: A systematic evidence map

PROBLEM

High-flow nasal cannula (HFNC) has been widely used in paediatric medicine as a non-invasive ventilation mode for respiratory support. However, the differences in its efficacy across different diseases and intervention types remain poorly understood.

ELIGIBILITY CRITERIA

An extensive literature search was performed across multiple academic databases to investigate the systematic reviews and meta-analyses of HFNC.

SAMPLE

This study included 35 systematic reviews and meta-analyses, which collectively examined 355 randomised controlled trials and assessed 51 outcome indicators.

RESULTS

The findings suggest that the existing clinical research evidence predominantly supports the therapeutic efficacy of HFNC. Notably, there is a significant focus on treating acute lower respiratory infection, hypoxaemia, bronchiolitis, and respiratory distress syndrome following extubation. However, concerning the respiratory status, the existing clinical research evidence mainly demonstrates the therapeutic benefits in post-extubation respiratory support and primary respiratory support.

CONCLUSIONS

The research on HFNC has witnessed significant expansion, primarily focusing on respiratory disorders, post-extubation respiratory support, conscious sedation, and related fields. The evidence mapping provides a systematic and comprehensive overview of the available evidence on HFNC therapy in paediatric patients.

IMPLICATIONS

This study systematically and comprehensively assessed the clinical subjects and populations involved in HFNC therapy. Notably, this study analyzed the trends, current status, and evidence gaps of research, and furnished decision-makers and relevant researchers with a more comprehensive reference basis.

Transnasal Humidified Rapid-Insufflation Ventilatory Exchange Versus Conventional Facemask Breathing for Preoxygenation During Rapid Sequence Induction

INTRODUCTION

Transnasal humidified rapid-insufflation ventilatory exchange (THRIVE), if used for pre-oxygenation and apnoeic oxygenation, has the propensity to extend the safe apnoea time and thereby decrease the incidence of desaturation during rapid sequence induction (RSI) for emergency surgeries. Hence, we proposed to evaluate the comparative efficacy of pre-oxygenation with the use of conventional facemask breathing versus THRIVE during RSI in patients undergoing general anaesthesia (GA) for emergency surgeries.

MATERIALS AND METHODS

Eighty patients undergoing RSI under GA for emergency abdominopelvic surgery were divided randomly into two groups. Patients were preoxygenated for three minutes with 100% oxygen via either a high-flow nasal cannula at a flow of 60 L/minute using THRIVE or a tightly-held, snuggly-fitting facemask at a flow of 12L/minute using a circle system. RSI was administered followed by laryngoscopy and endotracheal intubation. Arterial partial pressure of oxygen (PaO2) measured immediately after successful endotracheal intubation was our primary outcome. The lowest peripheral oxygen saturation (SpO2), apnoea time, number of attempts at laryngoscopy, use of any rescue manoeuvres, and any adverse event were also recorded. Data thus collected were statistically analysed.

RESULTS

No statistically significant difference in PaO2 value was observed after successful intubation, lowest SpO2, apnoea time, number of attempts at laryngoscopy, use of any rescue manoeuvres, and adverse event between both the groups (p>0.05).

CONCLUSION

We conclude that though not superior to conventional facemasks, THRIVE is a safe, practicable, and efficient pre-oxygenation tool during RSI of GA for patients undergoing emergency surgeries.

The use of High-Flow Nasal Oxygen Therapy in 4 dogs undergoing bronchoscopy

Introduction

High-Flow Nasal Oxygen Therapy is a method to deliver warmed, humidified air-oxygen blended at high flow rates to patients through a nasal cannula using a specialized, commercially available machine. This is a well-tolerated, safe and effective method for oxygen delivery to healthy and hypoxemic dogs. Patients undergoing bronchoscopic procedures frequently develop hypoxemia. Human trials have shown a reduction in incidents of hypoxemic events and higher pulse oximeter oxygen saturation during bronchoscopies in patients on High-Flow Nasal Oxygen.

Materials and methods

This is a single-centre, prospective case series. All dogs weighing between 5 and 15 kg and undergoing bronchoscopy during the study period (03/07/2022-01/10/2022) were eligible.

Results

Twelve patients were eligible for inclusion of which four were enrolled. No clinically significant complications related to the use of High-Flow Nasal Oxygen Therapy were recorded. Two of the patients were re-intubated post bronchoscopy due to clinician preference for recovery. One of the patients had a self-limiting period of severe hypoxemia with a pulse oximeter oxygen saturation of 84% for &lt; 1 min during bronchoalveolar lavage, and whilst undergoing High-Flow Nasal Oxygen administration. Another patient had a self-limiting episode of mild hypoxemia (SpO2 of 94% lasting &lt; 1 min) 5 min after completion of bronchoalveolar lavage.

Conclusion

No clinically relevant complications relating to High-Flow Nasal Oxygen Therapy were recorded in this case series, although further studies are required to confirm this conclusion. This initial data suggests that the use of High-Flow Nasal Oxygen therapy during bronchoscopy is feasible and potentially safe, although it may not prevent hypoxemia in these patients. The use of High-Flow Nasal Oxygen Therapy during bronchoscopy in small patients carries multiple potential benefits and further studies to compare its efficacy against other traditional oxygen delivery systems are warranted in this patient population.

High-flow nasal cannula oxygen therapy is superior to conventional oxygen therapy in intensive care unit patients after extubation

BACKGROUND

Optimal oxygen supply is the cornerstone of the management of critically ill patients after extubation. High flow oxygen system is an alternative to standard oxygen therapy. This research explored the efficacy of high-flow nasal cannula (HFNC) oxygen therapy in patients after extubation in the intensive care unit (ICU).

METHOD

We retrospectively analyzed critically ill patients admitted to the ICU and subjected to HFNC or conventional oxygen therapy from January 2018 to June 2022 at the Suzhou Hospital of Integrated Traditional Chinese and Western Medicine. Blood gas analysis, a cough and sputum assessment, and cardiovascular function examinations were performed to evaluate the effect of HFNC oxygen therapy on patients. Also, the 28-d mortality rate, reintubation rate and incidence of respiratory failure were analyzed to evaluate whether HFNC oxygen therapy could improve patients' outcome.

RESULTS

In patients who received HFNC oxygen therapy, the partial pressure of oxygen and oxygenation index increased, and the respiratory rate decreased. HFNC oxygen therapy improved the patients' ability to cough up sputum and promoted the expulsion of sputum. In terms of cardiovascular function, patients who received HFNC oxygen therapy had a significant improvement in heart rate, but there was no real effect on patients' arterial pressure. There was no significant difference in the rates of reintubation (P = 0.202), 28-d mortality (P = 0.558) or respiratory failure (P = 0.677) between patients who received different oxygen therapies including HFNC oxygen therapy.

CONCLUSION

HFNC oxygen therapy improves the respiratory function of patients after extubation in their ICU and improves their coughing ability.

Incidence of oxygen desaturation using a high-flow nasal cannula versus a facemask during flexible bronchoscopy in patients at risk of hypoxemia: a randomised controlled trial

BACKGROUND

Patients with obstructive sleep apnoea (OSA), male sex, obesity, older age or hypertension are prone to hypoxemia during flexible bronchoscopy. This study investigated whether using a high-flow nasal cannula (HFNC) could reduce the incidence of oxygen desaturation during bronchoscopy under deep sedation in patients at risk of hypoxemia.

METHODS

A total of 176 patients at risk of hypoxemia who underwent flexible bronchoscopy under deep sedation were randomly assigned to two groups: the HFNC group (humidified oxygen was supplied via a high-flow nasal cannula at a rate of 60 L/min and a concentration of 100%, n = 87) and the facemask group (oxygen was supplied via a tight-fitting facemask at a rate of 6 L/min and a concentration of 100%, n = 89).

RESULTS

Oxygen desaturation occurred in 4 (4.6%) patients in the HFNC group and 26 (29.2%) patients in the facemask group (P < 0.001). The facemask group required more jaw thrust manoeuvres than the HFNC group (43[48.3%] vs. 5[5.7%], P < 0.001). 8 patients (9.0%) in the facemask group and none in the HFNC group required bag-mask ventilation (P = 0.012).

CONCLUSION

The use of an HFNC can reduce the incidence of oxygen desaturation and the requirement for airway intervention in patients at risk of hypoxemia during flexible bronchoscopy under deep sedation.

TRIAL REGISTRATION

www.chiCTR.org.cn Identifier: ChiCTR2100044105. Registered 11/03/2021.

High flow nasal oxygen versus conventional oxygen therapy in gastrointestinal endoscopy with conscious sedation: Systematic review and meta-analysis with trial sequential analysis

OBJECTIVES

Although conventional oxygen therapy (COT) is widely used, hypoxemia frequently occurs in gastrointestinal endoscopy with conscious sedation and can lead to life-threatening consequences. High flow nasal oxygen (HFNO) has been applied to improve oxygenation in clinical entities. However, its efficacy to prevent hypoxemia in gastrointestinal endoscopy with conscious sedation has not been evaluated.

METHODS

We searched databases to identify randomized controlled trials that compared the efficacy of HFNO with COT in gastrointestinal endoscopy with conscious sedation. The primary outcome was hypoxemia. Meta-analyses with trial sequential analysis were performed using a random-effects model.

RESULTS

Eight trials with 3212 patients were included. Compared with COT, HFNO significantly reduced the risk of hypoxemia (eight trials; 3212 patients; risk ratio 0.30; 95% confidence interval [CI] 0.13-0.70). Trial sequential analysis showed that the cumulative Z curve did not cross the monitoring or futility boundaries, nor reach the required information size line, indicating that more trials are needed to reach a definitive conclusion. Subgroup analyses indicated the superiority of HFNO over COT with respect to hypoxemia in patients at low risk and high risk. HFNO further improved the lowest oxygen saturation (four trials; 459 patients; mean difference 2.30, 95% CI 0.84-3.77).

CONCLUSIONS

Compared with COT, HFNO can reduce the risk of hypoxemia and improve the lowest oxygen saturation in gastrointestinal endoscopy with conscious sedation. However, the results should be interpreted with caution due to substantial heterogeneity and limited evidence. Further studies are needed to verify the preliminary findings.

Effect of heated humidified high-flow nasal cannula (HFNC) oxygen therapy in dyspnea patients with advanced cancer, a randomized controlled clinical trial

PURPOSE

Heated humidified high-flow nasal cannula (HFNC) oxygen therapy is one of the most important oxygen therapy methods, which are commonly applied to relieve dyspnea in advanced cancer patients. Our study aims to observe the efficacy and safety of HFNC oxygen therapy on dyspnea patients with advanced cancer and explore the clinical application.

METHODS

Sixty subjects with advanced cancer requiring oxygen therapy from a grade 3, class A hospital in China were recruited and randomized (1:1) to traditional nasal catheter oxygen therapy or HFNC. Primary outcomes were dyspnea, oral dryness, and sleep condition, which were recorded after 72-h treatment. Secondary outcomes were heart rate (HR), respiration rate (RR), S_pO₂, P_aO₂, and P_aCO₂, which were recorded after 2, 6, 24, and 72 h treatment.

RESULTS

Seventy-two hours after treatment, there were significant improvements in all primary outcomes (P < 0.001). P_aO₂ and RR were statistically changed 2 h after HFNC treatment (P < 0.001). P_aCO₂ and HR were statistically changed 24 h after HFNC treatment (P < 0.001).

CONCLUSION

HFNC oxygen therapy has good effect, high safety, and is easy to be accepted by dyspnea patients with advanced cancer. It can be used as the first choice of oxygen therapy for these patients and has broad clinical prospects.

TRIAL REGISTRATION

This work was retrospectively registered in the Chinese Clinical Trials Registry (ChiCTR2100049582) on August 4, 2021.

IPF Respiratory Symptoms Management — Current Evidence

Idiopathic pulmonary fibrosis (IPF) is a progressive, chronic disease of the lungs which is characterized by heavy symptom burden, especially in the last year of life. Despite recently established anti-fibrotic treatment IPF prognosis is one of the worst among interstitial lung diseases. In this review available evidence regarding pharmacological and non-pharmacological management of the main IPF symptoms, dyspnea and cough, is presented.

Recomendaciones para el uso de oxígeno y sus dispositivos básicos y avanzados: racionalidad y seguridad en tiempos de pandemia por SARS-CoV-2 en Colombia

En medio de la pandemia de COVID-19, y ante la inminencia de desabastecimiento de oxígeno en Colombia, la red de Gestión y Transferencia de Conocimiento, integrada por 19 sociedades científicas, instituciones de salud y universidades, genera una actualización al documento liderado por la Asociación Colombiana de Medicina Crítica e incluye nuevos lineamientos informados en evidencia para el manejo racional de la oxigenoterapia, así como los dispositivos básicos y avanzados para la oxigenoterapia. Las recomendaciones se refieren a: uso racional de oxígeno orientado por metas, estandarización del seguimiento y ajuste de dosis, uso adecuado de los dispositivos de oxigenoterapia, uso racional de ventilación mecánica invasiva y uso racional de la terapia con membrana de oxigenación extracorpórea. Al ejercer su juicio, se espera que los profesionales y equipos de atención tengan en cuenta estos lineamientos, con el fin de hacer un uso racional y seguro de la oxigenoterapia y sus dispositivos básicos y avanzados, junto con las necesidades individuales y preferencias de las personas que están bajo su cuidado.

High-flow nasal cannula oxygen in patients with haematological malignancy: a retrospective observational study

Patients with haematological malignancies (HM) face high rates of intensive care unit (ICU) admission and mortality. High-flow nasal cannula oxygen (HFNCO) is increasingly used to support HM patients in ward settings, but there is limited evidence on the safety and efficacy of HFNCO in this group. We retrospectively reviewed all HM patients receiving ward-based HFNCO, supervised by a critical care outreach service (CCOS), from January 2014 to January 2019. We included 130 consecutive patients. Forty-three (33.1%) were weaned off HFNCO without ICU admission. Eighty-seven (66.9%) were admitted to ICU, 20 (23.3%) required non-invasive and 34 (39.5%) invasive mechanical ventilation. ICU and hospital mortality were 42% and 55% respectively. Initial FiO₂ < 0.4 (OR 0.27, 95% CI 0.09-0.81, p = 0.019) and HFNCO use on the ward > 1 day (OR 0.16, 95% CI 0.04, 0.59, p = 0.006) were associated with reduced likelihood for ICU admission. Invasive ventilation was associated with reduced survival (OR 0.27, 95%CI 0.1-0.7, p = 0.007). No significant adverse events were reported. HM patients receiving ward-based HFNCO have higher rates of ICU admission, but comparable hospital mortality to those requiring CCOS review without respiratory support. Results should be interpreted cautiously, as the model proposed depends on the existence of CCOS.

High-flow nasal cannula versus conventional oxygen therapy in acute COPD exacerbation with mild hypercapnia: a multicenter randomized controlled trial

Background

High-flow nasal cannula (HFNC) can improve ventilatory function in patients with acute COPD exacerbation. However, its effect on clinical outcomes remains uncertain.

Methods

This randomized controlled trial was conducted from July 2017 to December 2020 in 16 tertiary hospitals in China. Patients with acute COPD exacerbation with mild hypercapnia (pH ≥ 7.35 and arterial partial pressure of carbon dioxide > 45 mmHg) were randomly assigned to either HFNC or conventional oxygen therapy. The primary outcome was the proportion of patients who met the criteria for intubation during hospitalization. Secondary outcomes included treatment failure (intolerance and need for non-invasive or invasive ventilation), length of hospital stay, hospital cost, mortality, and readmission at day 90.

Results

Among 337 randomized patients (median age, 70.0 years; 280 men [83.1%]; median pH 7.399; arterial partial pressure of carbon dioxide 51 mmHg), 330 completed the trial. 4/158 patients on HFNC and 1/172 patient on conventional oxygen therapy met the criteria for intubation (P = 0.198). Patients progressed to NPPV in both groups were comparable (15 [9.5%] in the HFNC group vs. 22 [12.8%] in the conventional oxygen therapy group; P = 0.343). Compared with conventional oxygen therapy, HFNC yielded a significantly longer median length of hospital stay (9.0 [interquartile range, 7.0–13.0] vs. 8.0 [interquartile range, 7.0–11.0] days) and a higher median hospital cost (approximately $2298 [interquartile range, $1613–$3782] vs. $2005 [interquartile range, $1439–$2968]). There were no significant differences in other secondary outcomes between groups.

Conclusions

In this multi-center randomized controlled study, HFNC compared to conventional oxygen therapy did not reduce need for intubation among acute COPD exacerbation patients with mild hypercapnia. The future studies should focus on patients with acute COPD exacerbation with respiratory acidosis (pH < 7.35). However, because the primary outcome rate was well below expected, the study was underpowered to show a meaningful difference between the two treatment groups.

Trial registration: NCT03003559. Registered on December 28, 2016.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13054-022-03973-7.

High-Flow Nasal Cannula in Transport: Process, Results, and Considerations

Objective

The current coronavirus disease 2019 pandemic has increased interest in the use of high-flow nasal cannula (HFNC) in the transport setting. The purpose of this report was to outline the clinical workflow of using HFNC in transport and the results of a retrospective chart review of patients undergoing interhospital transfer on HFNC.

Methods

We conducted a retrospective chart review of all patient transfers using HFNC between January 2018 and June 2019. The primary data abstracted from patient charts included patient demographics, transport distance, HFNC settings including flow rate in liters per minute and fraction of inspired oxygen (Fio₂), and vital signs.

Results

There was a total of 220 patients, 148 pediatric and 72 adult patients. Both pediatric groups experienced statistically significant reductions in heart rate, systolic blood pressure, and diastolic blood pressure. The most common flow rate for both pediatric groups was 10 L/min and 50 L/min for adults. For pediatrics, the most common settings ranged between 30% and 50% Fio₂, with the most common setting being 30% Fio₂. The adult Fio₂ settings ranged from 30% to 100% Fio₂, with the 2 most common settings being 50% Fio₂ and 80% Fio₂. No patients were intubated during the transport encounter.

Conclusion

Our study provides evidence that HFNC is feasible and tolerated by patients and is an additional option for noninvasive ventilation in transport across the age continuum. Future studies are needed to compare HFNC with other noninvasive modalities that include assessing patient tolerance and comfort as contributing factors and to identify indications and contraindications for use in the transport setting.

Analysis of risk factors for the failure of respiratory support with high-flow nasal cannula oxygen therapy in children with acute respiratory dysfunction: A case-control study

BACKGROUND

Evidence-based clinical practice guidelines regarding high-flow nasal cannula (HFNC) use for respiratory support in critically ill children are lacking. Therefore, we aimed to determine the risk factors for early HFNC failure to reduce the failure rate and prevent adverse consequences of HFNC failure in children with acute respiratory dysfunction.

METHODS

Demographic and laboratory data were compared among patients, admitted to the pediatric intensive care unit between January 2017 and December 2018, who were included in a retrospective cohort study. Univariate and multivariate analyses were performed to determine risk factors for eventual entry into the predictive model for early HFNC failure and to perform an external validation study in a prospective observational cohort study from January to February 2019. Further, the association of clinical indices and trends pre- and post-treatment with HFNC treatment success or failure in these patients was dynamically observed.

RESULTS

In total, 348 pediatric patients were included, of these 282 (81.0%) were included in the retrospective cohort study; HFNC success was observed in 182 patients (64.5%), HFNC 0-24 h failure in 74 patients (26.2%), and HFNC 24-48 h failure in 26 patients (9.2%). HFNC 24 h failure was significantly associated with the pediatric risk of mortality (PRISM) III score [odds ratio, 1.391; 95% confidence interval (CI): 1.249-1.550], arterial partial pressure of carbon dioxide-to-arterial partial pressure of oxygen (PaCO₂/PaO₂) ratio (odds ratio, 38.397; 95% CI: 6.410-230.013), and respiratory rate-oxygenation (ROX) index (odds ratio, 0.751; 95% CI: 0.616-0.915). The discriminating cutoff point for the new scoring system based on the three risk factors for HFNC 24 h failure was ≥ 2.0 points, with an area under the receiver operating characteristic curve of 0.794 (95% CI, 0.729-0.859, P < 0.001), sensitivity of 68%, and specificity of 79%; similar values were noted on applying the model to the prospective observational cohort comprising 66 patients (AUC = 0.717, 95% CI, 0.675-0.758, sensitivity 83%, specificity 44%, P = 0.009). In this prospective cohort, 11 patients with HFNC failure had an upward trend in PaCO₂/PaO₂ ratio and downward trends in respiratory failure index (P/F ratio) and ROX index; however, opposite directions of change were observed in 55 patients with HFNC success. Furthermore, the fractional changes (FCs) in PaCO₂/PaO₂ ratio, P/F ratio, percutaneous oxygen saturation-to-fraction of inspired oxygen (S/F) ratio, and ROX index at 2 h post-HFNC therapy onset were statistically significant between the two groups (all, P < 0.05).

CONCLUSION

In the pediatric patients with acute respiratory insufficiency, pre-treatment PRISM III score, PaCO₂/PaO₂ ratio, and ROX index were risk factors for HFNC 24 h failure, and the direction and magnitude of changes in the PaCO₂/PaO₂ ratio, P/F ratio, and ROX index before and 2 h after HFNC treatment were warning indicators for HFNC 24 h failure. Further close monitoring should be considered for patients with these conditions.

[Weaning from invasive mechanical ventilation]

Weaning from invasive mechanical ventilation is challenging for the ICU team in terms of shortening time of ventilation via endotracheal tube in order to improve the patient's prognosis by early extubation. Thereby prolonged mechanical ventilation (> 14 days), which is associated with risk of tracheotomy and prolonged weaning, shall be avoided. This article will give an overview about weaning categories, causes for weaning failure and strategies to overcome this problem. In the last part we will cover concepts in the process of prolonged weaning including discharge management with invasive mechanical ventilation.

A Review of High Flow Nasal Cannula Oxygen Therapy in Human and Veterinary Medicine

Respiratory distress is a common ailment in small animal medicine. Oxygen supplementation is a mainstay of initial therapy. High Flow Nasal Cannula Oxygen Therapy (HFNCOT) has become increasingly popular as a treatment modality in human medicine, and more recently in canine patients. These devices deliver high flow rates of heated and humidified oxygen at an adjustable fraction of inspired oxygen (FiO₂). This article reviews current literature in human patients on HFNCOT as well as studies that have evaluated its use in veterinary patients. A discussion of the respiratory physiology that is associated with respiratory distress, in addition to an overview of currently available oxygen supplementation modalities is provided. The physiologic benefits of HFNCOT are explained, as are technical aspects associated with its use. Recommendations on initial settings, maintenance therapy, and weaning are also described.

High flow nasal oxygen, procedural sedation, and clinical governance

Procedural sedation for therapeutic and diagnostic procedures can now be achieved through deep sedation techniques that guarantee procedural success. Deep sedation techniques are delivered in a variety of non-theatre environments where the usual levels of anaesthetic equipment are not practical or economical. Hypoxic events are particularly frequent, and challenge sedation providers. Traditional low flow nasal or facial oxygen therapy techniques are often insufficient to maintain acceptable oxygen levels and prevent peri-procedural hypoxia. High flow nasal oxygen delivers warm humidified oxygen up to 70l/min, at oxygen concentrations between 21 - 100%, and reduces the incidence of hypoxic events. The provision of deep sedation is a complex process, fraught with risk, which can challenge even the skilled anaesthetist. Therefore, regulatory authorities previously stipulated that anaesthesia personnel be present during deep sedation. Changing attitudes by regulatory authorities and practical challenges providing anaesthesia specialists have led to the acknowledgement that appropriately trained non-anaesthetic staff can safely provide deep sedation. Deep sedation services are increasingly applied to subjects with complex comorbidities, sometimes excluded for safety reasons from surgery under general anaesthesia. The development of deep sedation services, delivered by non-anaesthesia personnel, to patients with complex co-morbidities requires that services implement appropriate clinical governance tools to prevent deep sedation being the wild west of anaesthesia services. Therefore, whilst high flow nasal oxygen may reduce the incidence of peri-procedural hypoxia, the introduction of clinical governance tools and the systematic introduction of initiatives to improve quality, will maintain the safety of deep sedation services.

The Role of Noninvasive Respiratory Management in Patients with Severe COVID-19 Pneumonia

Acute hypoxemic respiratory failure is the principal cause of hospitalization, invasive mechanical ventilation and death in severe COVID-19 infection. Nearly half of intubated patients with COVID-19 eventually die. High-Flow Nasal Oxygen (HFNO) and Noninvasive Ventilation (NIV) constitute valuable tools to avert endotracheal intubation in patients with severe COVID-19 pneumonia who do not respond to conventional oxygen treatment. Sparing Intensive Care Unit beds and reducing intubation-related complications may save lives in the pandemic era. The main drawback of HFNO and/or NIV is intubation delay. Cautious selection of patients with severe hypoxemia due to COVID-19 disease, close monitoring and appropriate employment and titration of HFNO and/or NIV can increase the rate of success and eliminate the risk of intubation delay. At the same time, all precautions to protect the healthcare personnel from viral transmission should be taken. In this review, we summarize the evidence supporting the application of HFNO and NIV in severe COVID-19 hypoxemic respiratory failure, analyse the risks associated with their use and provide a path for their proper implementation.

High-Flow Nasal Cannula Treatment in Patients with COVID-19 Acute Hypoxemic Respiratory Failure: A Prospective Cohort Study

BACKGROUND

Early use of high-flow nasal cannula (HFNC) decreases the need for endotracheal intubation (EI) in different respiratory failure causes. While HFNC is used in coronavirus disease 2019 (COVID-19)-related acute hypoxemic respiratory failure (AHRF) under weak recommendations, its efficacy remains to be investigated.

OBJECTIVES

The primary objective was to examine HFNC efficacy in preventing EI among COVID-19 patients with AHRF. Secondary objectives were to determine predictors of HFNC success/failure, mortality rate, and length of hospital and intensive care unit (ICU) stay.

PATIENTS AND METHODS

This is a prospective cohort study conducted at a single tertiary care centre in Saudi Arabia from April to August 2020. Adult patients admitted to the ICU with AHRF secondary to COVID-19 pneumonia and managed with HFNC were included. We excluded patients who were intubated or managed with non-invasive ventilation before HFNC.

RESULTS

Forty-four patients received HFNC for a median duration of 3 days (interquartile range, 1-5 days). The mean age was 57 ± 14 years, and 86% were men. HFNC failure and EI occurred in 29 (66%) patients. Patients in whom HNFC treatment failed had a higher risk of death (52% versus 0%; P = 0.001). After adjusting for confounding factors, a high SOFA score and a low ROX index were significantly associated with HFNC failure (hazard ratio [HR], 1.42; 95% confidence interval [CI], 1.04-1.93; P = 0.025; and HR, 0.61; 95% CI, 0.42-0.88; P = 0.008, respectively).

CONCLUSIONS

One-third of hypoxemic COVID-19 patients who received HFNC did not require intubation. High SOFA score and low ROX index were associated with HFNC failure.

The Japanese Clinical Practice Guidelines for Management of Sepsis and Septic Shock 2020 (J-SSCG 2020)

The Japanese Clinical Practice Guidelines for Management of Sepsis and Septic Shock 2020 (J-SSCG 2020), a Japanese-specific set of clinical practice guidelines for sepsis and septic shock created as revised from J-SSCG 2016 jointly by the Japanese Society of Intensive Care Medicine and the Japanese Association for Acute Medicine, was first released in September 2020 and published in February 2021. An English-language version of these guidelines was created based on the contents of the original Japanese-language version. The purpose of this guideline is to assist medical staff in making appropriate decisions to improve the prognosis of patients undergoing treatment for sepsis and septic shock. We aimed to provide high-quality guidelines that are easy to use and understand for specialists, general clinicians, and multidisciplinary medical professionals. J-SSCG 2016 took up new subjects that were not present in SSCG 2016 (e.g., ICU-acquired weakness [ICU-AW], post-intensive care syndrome [PICS], and body temperature management). The J-SSCG 2020 covered a total of 22 areas with four additional new areas (patient- and family-centered care, sepsis treatment system, neuro-intensive treatment, and stress ulcers). A total of 118 important clinical issues (clinical questions, CQs) were extracted regardless of the presence or absence of evidence. These CQs also include those that have been given particular focus within Japan. This is a large-scale guideline covering multiple fields; thus, in addition to the 25 committee members, we had the participation and support of a total of 226 members who are professionals (physicians, nurses, physiotherapists, clinical engineers, and pharmacists) and medical workers with a history of sepsis or critical illness. The GRADE method was adopted for making recommendations, and the modified Delphi method was used to determine recommendations by voting from all committee members.As a result, 79 GRADE-based recommendations, 5 Good Practice Statements (GPS), 18 expert consensuses, 27 answers to background questions (BQs), and summaries of definitions and diagnosis of sepsis were created as responses to 118 CQs. We also incorporated visual information for each CQ according to the time course of treatment, and we will also distribute this as an app. The J-SSCG 2020 is expected to be widely used as a useful bedside guideline in the field of sepsis treatment both in Japan and overseas involving multiple disciplines.

[High-flow nasal cannula oxygen therapy can reduce occurrence of hypoxia in elderly patients during anesthesia recovery]

OBJECTIVE

To explore the effect of high-flow nasal cannula (HFNC) oxygen therapy in elderly patients during anesthesia recovery.

METHOD

A total of 178 elderly patients undergoing elective non-cardiac surgeries were randomly assigned into HFNC oxygen therapy group (group H) or nasal cannula oxygen therapy group (group N), with 89 patients in each group.All the patients were admitted in postanesthesia care unit (PACU) after the surgery for recovery following the routine procedure.After trachea extubation, the patients in group H received HFNC oxygen therapy and those in group N had nasal cannula oxygen therapy.In both groups, arterial blood gas analysis was performed at 10 min after oxygen inhalation and the respiratory parameters were recorded.During oxygen inhalation, the occurrence and frequency of hypoxia (oxygen saturation < 90%), trachea reintubation and adverse events (unplanned admission to ICU, vomiting, aspiration, etc.) were recorded.

RESULTS

All the patients recovered safely from anesthesia in the PACU and subsequently received routine care, and only 1 patient in group N required trachea reintubation.Compared with those in group N, that patients in group H had a significantly lower incidence of hypoxia (3.4% vs 11.2%, P=0.044), a higher arterial partial pressure of oxygen (161.96±51.21 vs 114.35±43.60 mmHg, P < 0.001), and a higher oxygenation index(398.76±231.86 vs 324.10±194.16, P=0.021).The mean respiratory rate, arterial partial pressure of carbon dioxide and blood oxygen saturation were all comparable between the two groups.

CONCLUSION

HFNC oxygen therapy during anesthesia recovery is safe and effective in elderly patients and can reduce the occurrence of hypoxia after tracheal extubation and improve arterial partial pressure of oxygen and oxygenation.

Automatic versus manual oxygen titration using a novel nasal high-flow device in medical inpatients with an acute illness: a randomised controlled trial

Background

Guideline recommendations state oxygen should be administered to acutely unwell patients to achieve a target oxygen saturation (SpO₂) range. The current practice of manual oxygen titration frequently results in SpO₂ outside of a prescribed range. The aim of this study was to assess the efficacy of automatic oxygen titration using a closed-loop feedback system to achieve SpO₂ within a prescribed target range

Methods

An open-label randomised parallel group trial was undertaken comparing automatic oxygen titration using a novel nasal high-flow device to manual oxygen titration using nasal high flow. Medical inpatients requiring oxygen therapy in Wellington Regional Hospital, New Zealand with a prescribed target SpO₂ range of 88%–92% or 92%–96% were recruited and randomised equally between the interventions for a period of 24 hours. The primary outcome was the proportion of time spent with SpO₂ within the prescribed range.

Results

20 patients were included in the analysis. Automatic oxygen titration resulted in a median (IQR) 96.2% (95.2–97.8) of time within the target range compared with 71% (59.4–88.3) with manual titration; difference (95% CI) 24.2% (7.9% to 35%), p<0.001. There was a reduction in the time spent with SpO₂ ≥2% above and ≥2% below range in the automatic titration group, although the point estimate for the differences were small; −1% (−8.2% to −0.04%), p=0.017 and −2.4% (−11.5% to 0.3%), p=0.05 respectively.

Conclusions

Nasal high-flow with automatic oxygen titration resulted in a greater proportion of time spent with SpO₂ in target range compared with manual titration.

Trial registration

The trial was registered with the Australian and New Zealand Clinical Trials Registry (ACTRN12619000901101).

High Flow Oxygen Therapy at Two Initial Flow Settings versus Conventional Oxygen Therapy in Cardiac Surgery Patients with Postextubation Hypoxemia: A Single-Center, Unblinded, Randomized, Controlled Trial

In cardiac surgery patients with pre-extubation PaO₂/inspired oxygen fraction (FiO₂) < 200 mmHg, the possible benefits and optimal level of high-flow nasal cannula (HFNC) support are still unclear; therefore, we compared HFNC support with an initial gas flow of 60 or 40 L/min and conventional oxygen therapy. Ninety nine patients were randomly allocated (respective ratio: 1:1:1) to I = intervention group 1 (HFNC initial flow = 60 L/min, FiO₂ = 0.6), intervention group 2 (HFNC initial flow = 40 L/min, FiO₂ = 0.6), or control group (Venturi mask, FiO₂ = 0.6). The primary outcome was occurrence of treatment failure. The baseline characteristics were similar. The hazard for treatment failure was lower in intervention group 1 vs. control (hazard ratio (HR): 0.11, 95% CI: 0.03–0.34) and intervention group 2 vs. control (HR: 0.30, 95% CI: 0.12–0.77). During follow-up, the probability of peripheral oxygen saturation (SpO₂) > 92% and respiratory rate within 12–20 breaths/min was 2.4–3.9 times higher in intervention group 1 vs. the other 2 groups. There was no difference in PaO₂/FiO₂, patient comfort, intensive care unit or hospital stay, or clinical course complications or adverse events. In hypoxemic cardiac surgery patients, postextubation HFNC with an initial gas flow of 60 or 40 L/min resulted in less frequent treatment failure vs. conventional therapy. The results in terms of SpO₂/respiratory rate targets favored an initial HFNC flow of 60 L/min.

Prevent deterioration and long-term ventilation: intensive care following thoracic surgery

PURPOSE OF REVIEW

Patients with indication for lung surgery besides the pulmonary pathology often suffer from independent comorbidities affecting several other organ systems. Preventing patients from harmful complications due to decompensation of underlying organ insufficiencies perioperatively is pivotal. This review draws attention to the peri- and postoperative responsibility of the anaesthetist and intensivist to prevent patients undergoing lung surgery deterioration.

RECENT FINDINGS

During the last decades we had to accept that 'traditional' intensive care medicine implying deep sedation, controlled ventilation, liberal fluid therapy, and broad-spectrum antimicrobial therapy because of several side-effects resulted in prolongation of hospital length of stay and a decline in quality of life. Modern therapy therefore should focus on the convalescence of the patient and earliest possible reintegration in the 'life-before.' Avoidance of sedative and anticholinergic drugs, early extubation, prophylactic noninvasive ventilation and high-flow nasal oxygen therapy, early mobilization, well-adjusted fluid balance and reasonable use of antibiotics are the keystones of success.

SUMMARY

A perioperative interprofessional approach and a change in paradigms are the prerequisites to improve outcome and provide treatment for elder and comorbid patients with an indication for thoracic surgery.

The Japanese Clinical Practice Guidelines for Management of Sepsis and Septic Shock 2020 (J-SSCG 2020)

The Japanese Clinical Practice Guidelines for Management of Sepsis and Septic Shock 2020 (J-SSCG 2020), a Japanese-specific set of clinical practice guidelines for sepsis and septic shock created as revised from J-SSCG 2016 jointly by the Japanese Society of Intensive Care Medicine and the Japanese Association for Acute Medicine, was first released in September 2020 and published in February 2021. An English-language version of these guidelines was created based on the contents of the original Japanese-language version. The purpose of this guideline is to assist medical staff in making appropriate decisions to improve the prognosis of patients undergoing treatment for sepsis and septic shock. We aimed to provide high-quality guidelines that are easy to use and understand for specialists, general clinicians, and multidisciplinary medical professionals. J-SSCG 2016 took up new subjects that were not present in SSCG 2016 (e.g., ICU-acquired weakness [ICU-AW], post-intensive care syndrome [PICS], and body temperature management). The J-SSCG 2020 covered a total of 22 areas with four additional new areas (patient- and family-centered care, sepsis treatment system, neuro-intensive treatment, and stress ulcers). A total of 118 important clinical issues (clinical questions, CQs) were extracted regardless of the presence or absence of evidence. These CQs also include those that have been given particular focus within Japan. This is a large-scale guideline covering multiple fields; thus, in addition to the 25 committee members, we had the participation and support of a total of 226 members who are professionals (physicians, nurses, physiotherapists, clinical engineers, and pharmacists) and medical workers with a history of sepsis or critical illness. The GRADE method was adopted for making recommendations, and the modified Delphi method was used to determine recommendations by voting from all committee members. As a result, 79 GRADE-based recommendations, 5 Good Practice Statements (GPS), 18 expert consensuses, 27 answers to background questions (BQs), and summaries of definitions and diagnosis of sepsis were created as responses to 118 CQs. We also incorporated visual information for each CQ according to the time course of treatment, and we will also distribute this as an app. The J-SSCG 2020 is expected to be widely used as a useful bedside guideline in the field of sepsis treatment both in Japan and overseas involving multiple disciplines.

Prolonged Weaning: S2k Guideline Published by the German Respiratory Society

Mechanical ventilation (MV) is an essential part of modern intensive care medicine. MV is performed in patients with severe respiratory failure caused by respiratory muscle insufficiency and/or lung parenchymal disease; that is, when other treatments such as medication, oxygen administration, secretion management, continuous positive airway pressure (CPAP), or nasal high-flow therapy have failed. MV is required for maintaining gas exchange and allows more time to curatively treat the underlying cause of respiratory failure. In the majority of ventilated patients, liberation or "weaning" from MV is routine, without the occurrence of any major problems. However, approximately 20% of patients require ongoing MV, despite amelioration of the conditions that precipitated the need for it in the first place. Approximately 40-50% of the time spent on MV is required to liberate the patient from the ventilator, a process called "weaning". In addition to acute respiratory failure, numerous factors can influence the duration and success rate of the weaning process; these include age, comorbidities, and conditions and complications acquired during the ICU stay. According to international consensus, "prolonged weaning" is defined as the weaning process in patients who have failed at least 3 weaning attempts, or require more than 7 days of weaning after the first spontaneous breathing trial (SBT). Given that prolonged weaning is a complex process, an interdisciplinary approach is essential for it to be successful. In specialised weaning centres, approximately 50% of patients with initial weaning failure can be liberated from MV after prolonged weaning. However, the heterogeneity of patients undergoing prolonged weaning precludes the direct comparison of individual centres. Patients with persistent weaning failure either die during the weaning process, or are discharged back to their home or to a long-term care facility with ongoing MV. Urged by the growing importance of prolonged weaning, this Sk2 Guideline was first published in 2014 as an initiative of the German Respiratory Society (DGP), in conjunction with other scientific societies involved in prolonged weaning. The emergence of new research, clinical study findings and registry data, as well as the accumulation of experience in daily practice, have made the revision of this guideline necessary. The following topics are dealt with in the present guideline: Definitions, epidemiology, weaning categories, underlying pathophysiology, prevention of prolonged weaning, treatment strategies in prolonged weaning, the weaning unit, discharge from hospital on MV, and recommendations for end-of-life decisions. Special emphasis was placed on the following themes: (1) A new classification of patient sub-groups in prolonged weaning. (2) Important aspects of pulmonary rehabilitation and neurorehabilitation in prolonged weaning. (3) Infrastructure and process organisation in the care of patients in prolonged weaning based on a continuous treatment concept. (4) Changes in therapeutic goals and communication with relatives. Aspects of paediatric weaning are addressed separately within individual chapters. The main aim of the revised guideline was to summarize both current evidence and expert-based knowledge on the topic of "prolonged weaning", and to use this information as a foundation for formulating recommendations related to "prolonged weaning", not only in acute medicine but also in the field of chronic intensive care medicine. The following professionals served as important addressees for this guideline: intensivists, pulmonary medicine specialists, anaesthesiologists, internists, cardiologists, surgeons, neurologists, paediatricians, geriatricians, palliative care clinicians, rehabilitation physicians, intensive/chronic care nurses, physiotherapists, respiratory therapists, speech therapists, medical service of health insurance, and associated ventilator manufacturers.

High-flow nasal cannula oxygen therapy: Alternative respiratory therapy for severe post-transplant hypoxemia in children with hepatopulmonary syndrome

Severe post-transplant hypoxemia, which is defined as <50 mm Hg of the partial pressure of oxygen in arterial blood/fraction of inspired oxygen (P/F) ratio, is a major post-operative complication with high mortality rates in patients with hepatopulmonary syndrome (HPS). Non-invasive positive pressure ventilation therapy and mechanical ventilation are options for respiratory support of patients with severe post-transplant hypoxemia. However, these therapies are associated with several problems, such as compliance, ventilator-associated pneumonia, and lung injury. We here firstly described two children with HPS who developed severe post-transplant hypoxemia (lowest post-operative P/F ratio, 49.7 and 34.0 mm Hg, respectively) that was successfully managed with high-flow nasal cannula (HFNC) oxygen therapy and vasodilation drugs without adverse complications or necessity of reintubation. We consider that HFNC oxygen therapy could become a safe alternative respiratory therapy or be added to the other such as inhaled nitric oxide (iNO), methylene blue (MB), inhaled epoprostenol, embolization of abnormal pulmonary vessels, and combination of iNO and MB for severe post-transplant hypoxemia in children with HPS.

High-Flow Nasal Oxygen in Coronavirus Disease 2019 Patients With Acute Hypoxemic Respiratory Failure: A Multicenter, Retrospective Cohort Study

Supplemental Digital Content is available in the text.

Objectives:

An ongoing outbreak of coronavirus disease 2019 is spreading globally. Acute hypoxemic respiratory failure is the most common complication of coronavirus disease 2019. However, the clinical effectiveness of early high-flow nasal oxygen treatment in patients with coronavirus disease 2019 with acute hypoxemic respiratory failure has not been explored. This study aimed to analyze the effectiveness of high-flow nasal oxygen treatment and to identify the variables predicting high-flow nasal oxygen treatment failure in coronavirus disease 2019 patients with acute hypoxemic respiratory failure.

Design:

A multicenter, retrospective cohort study.

Setting:

Three tertiary hospitals in Wuhan, China.

Patients:

Forty-three confirmed coronavirus disease 2019 adult patients with acute hypoxemic respiratory failure treated with high-flow nasal oxygen.

Interventions:

None.

Measurements and Main Results:

Mean age of the enrolled patients was 63.0 ± 9.7 years; female patients accounted for 41.9%. High-flow nasal oxygen failure (defined as upgrading respiratory support to positive pressure ventilation or death) was observed in 20 patients (46.5%), of which 13 (30.2%) required endotracheal intubation. Patients with high-flow nasal oxygen success had a higher median oxygen saturation (96.0% vs 93.0%; p < 0.001) at admission than those with high-flow nasal oxygen failure. High-flow nasal oxygen failure was more likely in patients who were older (p = 0.030) and male (p = 0.037), had a significant increase in respiratory rate and a significant decrease in the ratio of oxygen saturation/Fio₂ to respiratory rate index within 3 days of high-flow nasal oxygen treatment. In a multivariate logistic regression analysis model, male and lower oxygen saturation at admission remained independent predictors of high-flow nasal oxygen failure. The hospital mortality rate of the cohort was 32.5%; however, the hospital mortality rate in patients with high-flow nasal oxygen failure was 65%.

Conclusions:

High-flow nasal oxygen may be effective for treating coronavirus disease 2019 patients with mild to moderate acute hypoxemic respiratory failure. However, high-flow nasal oxygen failure was associated with a poor prognosis. Male and lower oxygenation at admission were the two strong predictors of high-flow nasal oxygen failure.

Nasal high-flow oxygen versus noninvasive ventilation in acute exacerbation of COPD: protocol for a randomised noninferiority clinical trial

Background

Noninvasive ventilation (NIV) is considered as the first-line treatment for acute exacerbation of COPD (AECOPD) complicated by respiratory acidosis. Recent studies demonstrate a role of nasal high-flow oxygen (NHF) in AECOPD as an alternative treatment in patients intolerant to NIV or with contraindications to it.

Aim

The study aimed to evaluate whether NHF respiratory support is noninferior compared to NIV in respect to treatment failure, defined as need for intubation or change to alternative treatment group, in patients with AECOPD and mild-to-moderate acute or acute-on-chronic hypercapnic respiratory failure.

Methods

We designed a multicentre, prospective, randomised trial on patients with AECOPD, who have pH<7.35 but >7.25 and P_aCO2 >45 mmHg, in whom NIV is indicated as a first-line treatment. According to power analysis, 498 participants will be required for establishing noninferiority of NHF compared to NIV. Patients will be randomly assigned to receive NIV or NHF. Treatment will be adjusted to maintain S_pO2 between 88%–92% for both groups. Arterial blood gases, respiratory variables, comfort, dyspnoea score and any pulmonary or extrapulmonary complications will be assessed at baseline, before treatment initiation, and at 1, 2, 4, 6, 12, 24, 48 h, then once daily from day 3 to patient discharge, intubation or death.

Conclusion

Given the increasing number of studies demonstrating the physiological effects of NHF in COPD patients, we hypothesise that NHF respiratory support will be noninferior to NIV in patients with AECOPD and mild-to-moderate acute or acute on chronic hypercapnic respiratory failure.

Nasal high-flow oxygen could be an effective alternative to NIV respiratory support for patients with mild-to-moderate #AECOPD, especially for those who do not tolerate or have contraindications for NIVhttps://bit.ly/3bgxDYx

The combination of inspiratory muscle training and high-flow nasal cannula oxygen therapy for promoting weaning outcomes in difficult-to-wean patients: protocol for a randomised controlled trial

Background

According to the literature, 20-30% of intubated patients are difficult to wean off mechanical ventilation and have a prolonged intensive care unit (ICU) stay with detrimental effects on muscle strength, functional ability and quality of life. Inspiratory muscle training (IMT) via a threshold device has been proposed as an effective exercise for minimising the effects of mechanical ventilation on respiratory muscles of critically ill patients with prolonged weaning. In addition, high-flow nasal cannula (HFNC) oxygen has been proved to provide efficient support for both high- and low-risk patients after extubation, thus preventing re-intubation.

Material and methods

A randomised controlled trial was designed to assess the efficacy of combining IMT and HFNC as therapeutic strategies for patients with high risk for weaning failure. Once patients with prognostic factors of difficult weaning are awake, ventilated with support settings and cooperative, they will be randomised to one of the two following study groups: intervention group (IMT and HFNC) and control group (IMT and Venturi mask). IMT will start as soon as possible. Each allocated oxygen delivery device will be applied immediately after extubation. IMT intervention will continue until patients' discharge from ICU. The primary outcome is the rate of weaning failure. Secondary outcomes are maximal inspiratory and expiratory strength, endurance of respiratory muscles, global muscle strength, functional ability and quality of life along with duration of ventilation (days) and ICU and hospital length of stay.

Conclusion

The present study could significantly contribute to knowledge of how best to treat patients with difficult weaning and high risk of re-intubation.

Nasal High Flow Use in COPD Patients with Hypercapnic Respiratory Failure: Treatment Algorithm & Review of the Literature

Nasal high flow (NHF) therapy has recently gained attention as a new respiratory support system and is increasingly being utilized in every day clinical practice. Recent studies suggest that it may also be effective in patients with hypercapnia and suggest NHF as a possible alternative for patients who cannot tolerate standard noninvasive ventilation. The present review discusses the mechanisms of action that make NHF potentially suitable for chronic obstructive pulmonary disease (COPD) patients and evaluates the current evidence of NHF use for treatment of stable hypercapnic COPD patients as well as acute hypercapnic exacerbation of COPD. An algorithm is also proposed for the clinical application of NHF in patients with acute hypercapnic exacerbation of COPD, based on current literature.

Assessment of the potential for pathogen dispersal during high-flow nasal therapy

High-flow nasal therapy is increasingly used in hospitals because of its effectiveness and patient comfort. However, pathogens in the patient's nasal and oral cavities may be dispersed by forced air. This study aimed to investigate the risk of pathogen dispersal during high-flow nasal therapy. Liquid and bacterial dispersal were assessed via in-vitro experimental set-ups using a manikin. Thickened water or fresh yeast solution mimicked saliva and nasal mucus secretions. Dispersal was limited to the proximal area of the face and nasal cannula, suggesting that high-flow nasal therapy does not increase the risk of droplet and contact infection.

[High-risk factors for early failure of high-flow nasal cannula oxygen therapy in children]

OBJECTIVE

To determine the high-risk factors for early failure of high-flow nasal cannula (HFNC) oxygen therapy in children with acute respiratory insufficiency (ARI).

METHODS

The clinical data of 123 children with ARI were reviewed who received HFNC oxygen therapy in the pediatric intensive care unit from January to June, 2018. The children who did not require an upgrade of respiratory support during hospitalization and were successfully weaned from HFNC were classified as HFNC success group (69 cases). Of the remaining children (54 cases) who required an upgrade of their respiratory support during hospitalization, those that needed to upgrade their respiratory support within 48 hours of receiving HFNC were classified as early HFNC failure group (46 cases). Risk factors for early failure of HFNC were determined using multivariate logistic regression analysis.

RESULTS

The incidence rates of shock, sepsis, intracranial hypertension syndrome, and multiple organ dysfunction syndrome were significantly higher in the early HFNC failure group than in the HFNC success group (P<0.05). Before implementation of respiratory support, the early HFNC failure group had significantly lower Glasgow coma score, pH value, and oxygenation index and significantly higher Pediatric Risk of Mortality (PRISM) score and PaCO₂/PaO₂ ratio than the HFNC success group (P<0.05). Multivariate logistic regression analysis showed that PRISM score >4.5 and PaCO₂/PaO₂ ratio >0.64 were independent risk factors for early HFNC failure (OR=5.535 and 9.089 respectively; P<0.05).

CONCLUSIONS

Pediatric ARI patients with PRISM score >4.5 or PaCO₂/PaO₂ ratio >0.64 have relatively high risk of early HFNC failure.

High flow nasal cannula oxygen therapy versus non-invasive ventilation for chronic obstructive pulmonary disease with acute-moderate hypercapnic respiratory failure: an observational cohort study

Background

High-flow nasal cannula (HFNC) oxygen therapy in acute hypoxic respiratory failure is becoming increasingly popular. However, evidence to support the use of HFNC in acute respiratory failure (ARF) with hypercapnia is limited.

Methods

Chronic obstructive pulmonary disease (COPD) patients with moderate hypercapnic ARF (arterial blood gas pH 7.25–7.35, PaCO₂>50 mmHg) who received HFNC or non-invasive ventilation (NIV) in the intensive care uint from April 2016 to March 2018 were analyzed retrospectively. The endpoint was treatment failure, defined as either invasive ventilation, or a switch to the other study treatment (NIV for patients in the NFNC group, and vice-versa), and 28-day mortality.

Results

Eighty-two COPD patients (39 in the HFNC group and 43 in the NIV group) were enrolled in this study. The mean age was 71.8±8.2 and 54 patients (65.9%) were male. The treatment failed in 11 out of 39 patients with HFNC (28.2%) and in 17 of 43 patients with NIV (39.5%) (P=0.268). No significant differences were found for 28-day mortality (15.4% in the HFNC group and 14% in the NIV group, P=0.824). During the first 24 hrs of treatment, the number of nursing airway care interventions in the HFNC group was significantly less than in the NIV group, while the duration of device application was significantly longer in the HFNC group (all P<0.05). Skin breakdown was significantly more common in the NIV group (20.9% vs 5.1%, P<0.05).

Conclusion

Among COPD patients with moderate hypercarbic ARF, the use of HFNC compared with NIV did not result in increased rates of treatment failure, while there were fewer nursing interventions and skin breakdown episodes reported in the HFNC group.

Aerosol drug delivery to the lungs during nasal high flow therapy: an in vitro study

Background

Aerosol delivery through a nasal high flow (NHF) system is attractive for clinicians as it allows for simultaneous administration of oxygen and inhalable drugs. However, delivering a fine particle fraction (FPF, particle wt. fraction < 5.0 μm) of drugs into the lungs has been very challenging, with highest value of only 8%. Here, we aim to develop an efficient nose-to-lung delivery system capable of delivering improved quantities (FPF > 16%) of dry powder aerosols to the lungs via an NHF system.

Methods

We evaluated the FPF of spray-dried mannitol with leucine with a next generation impactor connected to a nasopharyngeal outlet of an adult nasal airway replica. In addition, we investigated the influence of different dispersion (20–30 L/min) and inspiratory (20–40 L/min) flow rates, on FPF.

Results

We found an FPF of 32% with dispersion flow rate at 25 L/min and inspiratory flow rate at 40 L/min. The lowest FPF (21%) obtained was at the dispersion flow rate at 30 L/min and inspiratory flow rate at 30 L/min. A higher inspiratory flow rate was generally associated with a higher FPF. The nasal cannula accounted for most loss of aerosols.

Conclusions

In conclusion, delivering a third of inhalable powder to the lungs is possible in vitro through an NHF system using a low dispersion airflow and a highly dispersible powder. Our results may lay the foundation for clinical evaluation of powder aerosol delivery to the lungs during NHF therapy in humans.

A physiological study to determine the mechanism of carbon dioxide clearance during apnoea when using transnasal humidified rapid insufflation ventilatory exchange (THRIVE)

Clinical observations suggest that compared with standard apnoeic oxygenation, transnasal humidified rapid‐insufflation ventilatory exchange using high‐flow nasal oxygenation reduces the rate of carbon dioxide accumulation in patients who are anaesthetised and apnoeic. This suggests that active gas exchange takes place, but the mechanisms by which it may occur have not been described. We used three laboratory airway models to investigate mechanisms of carbon dioxide clearance in apnoeic patients. We determined flow patterns using particle image velocimetry in a two‐dimensional model using particle‐seeded fluorescent solution; visualised gas clearance in a three‐dimensional printed trachea model in air; and measured intra‐tracheal turbulence levels and carbon dioxide clearance rates using a three‐dimensional printed model in air mounted on a lung simulator. Cardiogenic oscillations were simulated in all experiments. The visualisation experiments indicated that gaseous mixing was occurring in the trachea. With no cardiogenic oscillations applied, mean (SD) carbon dioxide clearance increased from 0.29 (0.04) ml.min⁻¹ to 1.34 (0.14) ml.min⁻¹ as the transnasal humidified rapid‐insufflation ventilatory exchange flow rate was increased from 20 l.min⁻¹ to 70 l.min⁻¹ (p = 0.0001). With a cardiogenic oscillation of 20 ml.beat⁻¹ applied, carbon dioxide clearance increased from 11.9 (0.50) ml.min⁻¹ to 17.4 (1.2) ml.min⁻¹ as the transnasal humidified rapid‐insufflation ventilatory exchange flow rate was increased from 20 l.min⁻¹ to 70 l.min⁻¹ (p = 0.0014). These findings suggest that enhanced carbon dioxide clearance observed under apnoeic conditions with transnasal humidified rapid‐insufflation ventilatory exchange, as compared with classical apnoeic oxygenation, may be explained by an interaction between entrained and highly turbulent supraglottic flow vortices created by high‐flow nasal oxygen and cardiogenic oscillations.