Humidified high-flow nasal oxygen utilization in patients with cancer at Memorial Sloan-Kettering Cancer Center

Oxygen therapy and noninvasive respiratory supports in acute hypoxemic respiratory failure: a narrative review

BACKGROUND

This narrative review was written by an expert panel to the members of the jury to help in the development of clinical practice guidelines on oxygen therapy.

RESULTS

According to the expert panel, acute hypoxemic respiratory failure was defined as PaO2 < 60 mm Hg or SpO2 < 90% on room air, or PaO2/FiO2 ≤ 300 mm Hg. Supplemental oxygen should be administered according to the monitoring of SpO2, with the aim at maintaining SpO2 above 92% and below 98%. Noninvasive respiratory supports are generally reserved for the most hypoxemic patients with the aim of relieving dyspnea. High-flow nasal cannula oxygen (HFNC) seems superior to conventional oxygen therapy (COT) as a means of avoiding intubation and may therefore be should probably be used as a first-line noninvasive respiratory support in patients requiring more than 6 L/min of oxygen or PaO2/FiO2 ≤ 200 mm Hg and a respiratory rate above 25 breaths/minute or clinical signs of respiratory distress, but with no benefits on mortality. Continuous positive airway pressure (CPAP) cannot currently be recommended as a first-line noninvasive respiratory support, since its beneficial effects on intubation remain uncertain. Despite older studies favoring noninvasive ventilation (NIV) over COT, recent clinical trials fail to show beneficial effects with NIV compared to HFNC. Therefore, there is no evidence to support the use of NIV or CPAP as first-line treatment if HFNC is available. Clinical trials do not support the hypothesis that noninvasive respiratory supports may lead to late intubation. The potential benefits of awake prone positioning on the risk of intubation in patients with COVID-19 cannot be extrapolated to patients with another etiology.

CONCLUSIONS

Whereas oxygen supplementation should be initiated for patients with acute hypoxemic respiratory failure defined as PaO2 below 60 mm Hg or SpO2 < 90% on room air, HFNC should be the first-line noninvasive respiratory support in patients with PaO2/FiO2 ≤ 200 mm Hg with increased respiratory rate. Further studies are needed to assess the potential benefits of CPAP, NIV through a helmet and awake prone position in patients with acute hypoxemic respiratory failure not related to COVID-19.

Oxygen therapy in acute hypoxemic respiratory failure: guidelines from the SRLF-SFMU consensus conference

INTRODUCTION

Although largely used, the place of oxygen therapy and its devices in patients with acute hypoxemic respiratory failure (ARF) deserves to be clarified. The French Intensive Care Society (Société de Réanimation de Langue Française, SRLF) and the French Emergency Medicine Society (Société Française de Médecine d'Urgence, SFMU) organized a consensus conference on oxygen therapy in ARF (excluding acute cardiogenic pulmonary oedema and hypercapnic exacerbation of chronic obstructive diseases) in December 2023.

METHODS

A committee without any conflict of interest (CoI) with the subject defined 7 generic questions and drew up a list of sub questions according to the population, intervention, comparison and outcomes (PICO) model. An independent work group reviewed the literature using predefined keywords. The quality of the data was assessed using the GRADE methodology. Fifteen experts in the field from both societies proposed their own answers in a public session and answered questions from the jury (a panel of 16 critical-care and emergency medicine physicians, nurses and physiotherapists without any CoI) and the public. The jury then met alone for 48 h to write its recommendations.

RESULTS

The jury provided 22 statements answering 11 questions: in patients with ARF (1) What are the criteria for initiating oxygen therapy? (2) What are the targets of oxygen saturation? (3) What is the role of blood gas analysis? (4) When should an arterial catheter be inserted? (5) Should standard oxygen therapy, high-flow nasal cannula oxygen therapy (HFNC) or continuous positive airway pressure (CPAP) be preferred? (6) What are the indications for non-invasive ventilation (NIV)? (7) What are the indications for invasive mechanical ventilation? (8) Should awake prone position be used? (9) What is the role of physiotherapy? (10) Which criteria necessarily lead to ICU admission? (11) Which oxygenation device should be preferred for patients for whom a do-not-intubate decision has been made?

CONCLUSION

These recommendations should optimize the use of oxygen during ARF.

Focus on the Role of Non-Invasive Respiratory Support (NRS) during Palliative Care in Patients with Life-Limiting Respiratory Disease

The management of patients with life-threatening respiratory disease in the ICU and at home has become increasingly of interest over the past decades. Growing knowledge supports the use of NRS, aimed at improving patient comfort and improving quality of life. However, its role during palliative care is not well defined, and evidence of support remains limited. The aim of this narrative review is to examine the recent evidence relating to the use of non-invasive respiratory support at the end of life, in order to clarify who benefits and when. The literature research was conducted on PubMed, using MeSH words. A review of the relevant literature showed that non-invasive respiratory support techniques for patients with life-limiting respiratory disease vary (from high-flow oxygen therapy to conventional oxygen therapy, from CPAP to NPPV) and each has precise indications. To date, from the hospital to the home setting, the monitoring and application of these respiratory support techniques have varied widely. In conclusion, the choice of respiratory support in this category of patients should be based on the technique that will optimize the comfort of the patient and improve the quality of their life. On the other hand, regarding monitoring, both telemedicine and ultrasound diagnostics help to satisfy the patient's wish to spend the last period of his life in the home environment, to avoid inappropriately aggressive diagnostic interventions, and to reduce the high costs of hospitalized procedures in this category of patients.

A Phase II Study of High-Flow Nasal Cannula for Relieving Dyspnea in Advanced Cancer Patients

CONTEXT

The efficacy and tolerability of high-flow nasal cannula (HFNC) for relieving dyspnea in advanced cancer patients with limited prognosis requires elucidation.

OBJECTIVES

The primary aim of this trial was to assess the efficacy and tolerability of HFNC regarding dyspnea including severe as well as moderate for longer durations in patients under palliative care.

METHODS

In this prospective study, hospitalized patients with advanced cancer who had dyspnea at rest (numeric rating scale, NRS≥3) and hypoxemia were enrolled. They were treated with HFNC for five days in the respiratory unit. Primary endpoint was mean change of modified Borg scale at 24 hours. Key secondary endpoints consisted of mean changes in modified Borg scale during the study period and feasibility (Trial Identifier, UMIN000035738).

RESULTS

Between February 2019 and February 2022, 25 patients were enrolled and 21 were analyzed. Twenty patients used inspired oxygen and the mean fraction of inspired oxygen (FiO2) was 0.34 (range, 0.21-1.0). At baseline, mean NRS (dyspnea) was 5.9 (range, 3-10). Median survival time was 19 days (range, 3-657). The mean change of modified Borg scale was 1.4 (80% confidence interval [CI]: 0.8-1.9) at 24 hours, 12 patients (57%) showed 1.0 points improvement of modified Borg scale. Within two hours, 15 patients showed 1.0 points improvement of modified Borg scale and such early responders were likely to maintain dyspnea improvement for 24 hours. Nineteen patients could continue HFNC for 24 hours and 11 patients completed five days of HFNC.

CONCLUSION

To our knowledge, this trial is the first prospective study to assess the five-day efficacy and tolerability of HFNC for dyspnea in patients under palliative care. Although this did not reach the prespecified endpoint, about half of the patients showed 1.0 point improvement, a minimally clinically important difference (MCID) in the chronic lung disease. HFNC can be a palliative treatment option in advanced cancer patients with dyspnea.

High-Flow Nasal Cannula Oxygen Therapy in the Management of Respiratory Failure: A Review

High-flow nasal cannula (HFNC) oxygen therapy is gaining traction globally as a treatment for respiratory failure. There are several physiological benefits, and there is a growing body of evidence showing improved quality of life and patient comfort with HFNC, both in acute and home settings. Due to the increased burden of long-term respiratory conditions such as chronic obstructive pulmonary disease (COPD) on healthcare systems worldwide, the role of ward-based and post-discharge interventions in the prevention of hospital readmissions is an area of increasing interest. In this narrative review, we outline the physiological effects of HFNC and assess its applications in both the hospital and home settings for acute and chronic respiratory failure. We also consider the evidence of non-invasive ventilation (NIV) versus HFNC in the hospital setting and the application of HFNC at home in stable hypercapnic respiratory failure to improve the quality of life and prevent readmissions. We also look at applications of HFNC in specific circumstances, such as the perioperative period, emergency department, and acute (mainly critical care) setting including in immunocompromised patients and palliative care.

In-hospital Mortality among Patients with High-flow Nasal Cannulas in the General Ward

High-flow nasal cannulas (HFNCs) have become common devices for patients with respiratory failure who are treated in general wards. Few reports have been published on in-hospital mortality associated with the ratio of oxygen saturation (ROX) index, measured by pulse oximetry/fraction of inspired oxygen to respiratory rate, in patients treated with HFNCs. We aimed to examine in-hospital mortality and associated factors in patients who initiated HFNC use in a general ward. Sixty patients who initiated HFNC use in general wards at Kobe University Hospital between December 2016 and October 2020 were retrospectively enrolled. We assessed in-hospital mortality, comorbidities, and ROX index. The in-hospital mortality was 48.3%, and ROX index values were significantly lower in patients who died than in those who did not (at HFNC oxygen therapy initiation; 6.93 [2.73-18.5] vs. 9.01 [4.62-18.1], p = 0.00861). Although the difference was not statistically significant, the change in ROX index values between HFNC initiation and 12 hours after initiation tended to be greater in the patients who died in the hospital (0.732 [-2.84-3.5] vs. -0.35[-4.3-2.6], p = 0.0536). Lower ROX index values may be associated with the in-hospital death of patients who are treated with HFNCs in general wards.

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.

Spanish COPD Guideline (GesEPOC) Update: Comorbidities, Self-Management and Palliative Care

The current health care models described in GesEPOC indicate the best way to make a correct diagnosis, the categorization of patients, the appropriate selection of the therapeutic strategy and the management and prevention of exacerbations. In addition, COPD involves several aspects that are crucial in an integrated approach to the health care of these patients. The evaluation of comorbidities in COPD patients represents a healthcare challenge. As part of a comprehensive assessment, the presence of comorbidities related to the clinical presentation, to some diagnostic technique or to some COPD-related treatments should be studied. Likewise, interventions on healthy lifestyle habits, adherence to complex treatments, developing skills to recognize the signs and symptoms of exacerbation, knowing what to do to prevent them and treat them within the framework of a self-management plan are also necessary. Finally, palliative care is one of the pillars in the comprehensive treatment of the COPD patient, seeking to prevent or treat the symptoms of a disease, the side effects of treatment, and the physical, psychological and social problems of patients and their caregivers. Therefore, the main objective of this palliative care is not to prolong life expectancy, but to improve its quality. This chapter of GesEPOC 2021 presents an update on the most important comorbidities, self-management strategies, and palliative care in COPD, and includes a recommendation on the use of opioids for the treatment of refractory dyspnea in COPD.

High-flow nasal cannula for respiratory failure in adult patients

The high-flow nasal cannula (HFNC) has been recently used in several clinical settings for oxygenation in adults. In particular, the advantages of HFNC compared with low-flow oxygen systems or non-invasive ventilation include enhanced comfort, increased humidification of secretions to facilitate expectoration, washout of nasopharyngeal dead space to improve the efficiency of ventilation, provision of a small positive end-inspiratory pressure effect, and fixed and rapid delivery of an accurate fraction of inspired oxygen (FiO₂) by minimizing the entrainment of room air. HFNC has been successfully used in critically ill patients with several conditions, such as hypoxemic respiratory failure, hypercapneic respiratory failure (exacerbation of chronic obstructive lung disease), post-extubation respiratory failure, pre-intubation oxygenation, and others. However, the indications are not absolute, and much of the proven benefit remains subjective and physiologic. This review discusses the practical application and clinical uses of HFNC in adults, including its unique respiratory physiologic effects, device settings, and clinical indications.

Treatment of acute respiratory failure: high-flow nasal cannula

Background: High-flow nasal cannulas (HFNCs) have recently been used for several conditions, such as hypoxemic respiratory failure, hypercapnic respiratory failure, post-extubation respiratory failure, and preintubation oxygenation, in critically ill patients.Current Concepts: The advantages of HFNC compared with those of low-flow oxygen systems or noninvasive ventilation include enhanced comfort, increased humidification of secretions to facilitate expectoration, washout of the nasopharyngeal dead space to improve ventilation efficiency, provisioning for low positive end-inspiratory pressure effect, and fixed and rapid delivery of accurate fraction of inspired oxygen by minimizing the entrainment of room air. However, the indications are not absolute, with much of the proven benefit being subjective and physiologic.Discussion and Conclusion: The goal of this review is to discuss the practical application and clinical uses of HFNCs in patients with acute respiratory failure, highlighting its unique respiratory and physiologic effects, device settings, and clinical indications.

Nasal high flow oxygen therapy during acute admissions or periods of worsening symptoms

PURPOSE OF REVIEW

Nasal high flow therapy (NHF) is increasingly used in acute care settings. In this review, we consider recent advances in the utilization of NHF in chronic obstructive pulmonary disease (COPD), terminal cancer and symptom management. Considerations around NHF use during the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic are also discussed.

RECENT FINDINGS

NHF enables humidification and high flows to be provided together with titrated, supplemental oxygen therapy. Compared to conventional oxygen therapy, NHF improves respiratory physiology by reducing workload, enhancing muco-ciliary clearance and improving dead space washout. Some studies suggest that early use of NHF in people being cared for in the emergency department leads to lower rates of invasive ventilation and noninvasive ventilation. There is also emerging evidence for NHF use in people with COPD and chronic respiratory failure, and in palliative care. NHF is comfortable, well-tolerated and safe for use in the management of breathlessness in people with cancer. NHF can be delivered by face mask to patients with SARS-CoV-2 infection, to ease the burden on critical care resources.

SUMMARY

The evidence base for NHF is rapidly growing and offers promise in relieving troublesome symptoms and for people receiving palliative care.

Oxygenation strategy during acute respiratory failure in immunocompromised patients

Acute respiratory failure (ARF) in immunocompromised patients remains challenging to treat. A large number of case require admission to intensive care unit (ICU) where mortality remains high. Oxygenation without intubation is important in this setting. This review summarizes recent studies assessing oxygenation devices for immunocompromised patients. Previous studies showed that non-invasive ventilation (NIV) has been associated with lower intubation and mortality rates. Indeed, in recent years, the outcomes of immunocompromised patients admitted to the ICU have improved. In the most recent randomized controlled trials, including immunocompromised patients admitted to the ICU with ARF, neither NIV nor high-flow nasal oxygen (HFNO) could reduce the mortality rate. In this setting, other strategies need to be tested to decrease the mortality rate. Early admission strategy and avoiding late failure of oxygenation strategy have been assessed in retrospective studies. However, objective criteria are still lacking to clearly discriminate time to admission or time to intubation. Also, diagnosis strategy may have an impact on intubation or mortality rates. On the other hand, lack of diagnosis has been associated with a higher mortality rate. In conclusion, improving outcomes in immunocompromised patients with ARF may include strategies other than the oxygenation strategy alone. This review discusses other unresolved questions to decrease mortality after ICU admission in such patients.

Failure of High-Flow Nasal Cannula Therapy in Pneumonia and Non-Pneumonia Sepsis Patients: A Prospective Cohort Study

Despite the increasing use of high-flow nasal cannulas (HFNCs) to treat critically ill patients, data on their effectiveness for sepsis patients remains very limited. We studied a prospective cohort of sepsis patients from the Korean Sepsis Registry (18 intensive care units (ICUs)). Patients started on HFNC therapy for hypoxemia within the first three ICU days were enrolled. HFNC failure was defined as intubation or ICU death, and the primary outcome was early HFNC failure occurring within 72 h of HFNC initiation. Of 901 patients with sepsis admitted to the ICU, 206 who received HFNC therapy were finally included (117 with pneumonia vs. 89 with non-pneumonia sepsis; median age, 71.0 (63.0–78.0) years; P_aO₂/F_iO₂ ratio, 160.2 (107.9–228.2) mm Hg; septic shock, n = 81 (39.3%)). During HFNC therapy, 72 (35.0%) patients were intubated and 51 (24.8%) died. HFNC failure developed in 95 (46.1%) patients, and among them, early failure rate was 85.3% (81/95). On multivariate analysis, an immunocompromised state (odds ratio (OR) = 2.730), use of a combination of antibiotics (OR = 0.219), and the P_aO₂/F_iO₂ ratio (OR = 0.308) were significantly associated with early HFNC failure in pneumonia sepsis patients. However, in non-pneumonia sepsis patients, lactate levels (OR = 1.532) were significantly associated with early HFNC failure. In conclusion, a high proportion of sepsis patients experience HFNC failure, usually within 72 h after therapy initiation, which emphasizes the importance of close monitoring. Furthermore, unlike in pneumonia sepsis, organ failure (i.e., lactate) might serve as a prognostic marker in non-pneumonia sepsis (i.e., type IV respiratory failure).

＜Editors' Choice＞ Effects of high-flow nasal cannula oxygen therapy on oral intake of do-not-intubate patients with respiratory diseases

High-flow nasal cannula (HFNC) oxygen therapy is used widely for hypoxemic respiratory failure. However, it is unknown whether the use of HFNC is compatible with retaining the ability to eat and drink of patients with end-stage respiratory diseases as a part of palliative care. A retrospective study was conducted on subjects with hypoxic respiratory failure due to end-stage respiratory diseases, including interstitial pneumonia and malignant respiratory diseases, who were treated with HFNC or reservoir mask oxygen therapy and died with do-not-resuscitate (DNR) and do-not-intubate (DNI) status. We compared the duration of eating solids and drinking liquids and clinical variables in the HFNC group with those in the reservoir mask group. The data from a total 43 subjects including 20 with HFNC and 23 with a reservoir mask were analyzed. Fitting HFNC to subjects temporarily improved oxygenation. Durations of survival, eating solids, and drinking liquids in the HFNC group were significantly longer than those in the reservoir mask group. No significant adverse effects were observed in either group. In conclusion, the use of HFNC led to prolonged survival while preserving the ability of oral intake in patients with DNR and DNI status.

High flow nasal cannula for adult acute hypoxemic respiratory failure in the ED setting: A narrative review

Introduction

High flow nasal cannula (HFNC) is a noninvasive ventilation (NIV) system that has demonstrated promise in the emergency department (ED) setting.

Objective

This narrative review evaluates the utility of HFNC in adult patients with acute hypoxemic respiratory failure in the ED setting.

Discussion

HFNC provides warm (37 °C), humidified (100% relative humidity) oxygen at high flows with a reliable fraction of inspired oxygen (FiO₂). HFNC can improve oxygenation, reduce airway resistance, provide humidified flow that can flush anatomical dead space, and provide a low amount of positive end expiratory pressure. Recent literature has demonstrated efficacy in acute hypoxemic respiratory failure, including pneumonia, acute respiratory distress syndrome (ARDS), coronavirus disease 2019 (COVID-19), interstitial lung disease, immunocompromised states, the peri-intubation state, and palliative care, with reduced need for intubation, length of stay, and mortality in some of these conditions. Individual patient factors play an important role in infection control risks with respect to the use of HFNC in patients with COVID-19. Appropriate personal protective equipment, adherence to hand hygiene, surgical mask placement over the HFNC device, and environmental controls promoting adequate room ventilation are the foundation for protecting healthcare personnel. Frequent reassessment of the patient placed on HFNC is necessary; those with severe end organ dysfunction, thoracoabdominal asynchrony, significantly increased respiratory rate, poor oxygenation despite HFNC, and tachycardia are at increased risk of HFNC failure and need for further intervention.

Conclusions

HFNC demonstrates promise in several conditions requiring respiratory support. Further randomized trials are needed in the ED setting.

Comparison of high-flow nasal oxygen therapy and non-invasive ventilation in ICU patients with acute respiratory failure and a do-not-intubate orders: a multicentre prospective study OXYPAL

INTRODUCTION

A palliative approach to intensive care unit (ICU) patients with acute respiratory failure and a do-not-intubate order corresponds to a poorly evaluated target for non-invasive oxygenation treatments. Survival alone should not be the only target; it also matters to avoid discomfort and to restore the patient's quality of life. We aim to conduct a prospective multicentre observational study to analyse clinical practices and their impact on outcomes of palliative high-flow nasal oxygen therapy (HFOT) and non-invasive ventilation (NIV) in ICU patients with do-not-intubate orders.

METHODS AND ANALYSIS

This is an investigator-initiated, multicentre prospective observational cohort study comparing the three following strategies of oxygenation: HFOT alone, NIV alternating with HFOT and NIV alternating with standard oxygen in patients admitted in the ICU for acute respiratory failure with a do-not-intubate order. The primary outcome is the hospital survival within 14 days after ICU admission in patients weaned from NIV and HFOT. The sample size was estimated at a minimum of 330 patients divided into three groups according to the oxygenation strategy applied. The analysis takes into account confounding factors by modelling a propensity score.

ETHICS AND DISSEMINATION

The study has been approved by the ethics committee and patients will be included after informed consent. The results will be submitted for publication in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

NCT03673631.

High-Flow Nasal Cannula Therapy for Exertional Dyspnea in Patients with Cancer: A Pilot Randomized Clinical Trial

BACKGROUND

Exertional dyspnea is common in patients with cancer and limits their function. The impact of high-flow nasal cannula on exertional dyspnea in nonhypoxemic patients is unclear. In this double-blind, parallel-group, randomized trial, we assessed the effect of flow rate (high vs. low) and gas (oxygen vs. air) on exertional dyspnea in nonhypoxemic patients with cancer.

PATIENTS AND METHODS

Patients with cancer with oxygen saturation >90% at rest and exertion completed incremental and constant work (80% maximal) cycle ergometry while breathing low-flow air at 2 L/minute. They were then randomized to receive high-flow oxygen, high-flow air, low-flow oxygen, or low-flow air while performing symptom-limited endurance cycle ergometry at 80% maximal. The primary outcome was modified 0-10 Borg dyspnea intensity scale at isotime. Secondary outcomes included dyspnea unpleasantness, exercise time, and adverse events.

RESULTS

Seventy-four patients were enrolled, and 44 completed the study (mean age 63; 41% female). Compared with low-flow air at baseline, dyspnea intensity was significantly lower at isotime with high-flow oxygen (mean change, -1.1; 95% confidence interval [CI], -2.1, -0.12) and low-flow oxygen (-1.83; 95% CI, -2.7, -0.9), but not high-flow air (-0.2; 95% CI, -0.97, 0.6) or low-flow air (-0.5; 95% CI, -1.3, 0.4). Compared with low-flow air, high-flow oxygen also resulted in significantly longer exercise time (difference + 2.5 minutes, p = .009), but not low-flow oxygen (+0.39 minutes, p = .65) or high-flow air (+0.63 minutes, p = .48). The interventions were well tolerated without significant adverse effects.

CONCLUSION

Our preliminary findings support that high-flow oxygen improved both exertional dyspnea and exercise duration in nonhypoxemic patients with cancer. (ClinicalTrials.gov ID: NCT02357134).

IMPLICATIONS FOR PRACTICE

In this four-arm, double-blind, randomized clinical trial examining the role of high-flow nasal cannula on exertional dyspnea in patients with cancer without hypoxemia, high-flow oxygen, but not high-flow air, resulted in significantly lower dyspnea scores and longer exercise time. High-flow oxygen delivered by high-flow nasal cannula devices may improve clinically relevant outcomes even in patients without hypoxemia.

Use of nasal high flow oxygen during acute respiratory failure

Nasal high flow (NHF) has gained popularity among intensivists to manage patients with acute respiratory failure. An important literature has accompanied this evolution. In this review, an international panel of experts assessed potential benefits of NHF in different areas of acute respiratory failure management. Analyses of the physiological effects of NHF indicate flow-dependent improvement in various respiratory function parameters. These beneficial effects allow some patients with severe acute hypoxemic respiratory failure to avoid intubation and improve their outcome. They require close monitoring to not delay intubation. Such a delay may worsen outcome. The ROX index may help clinicians decide when to intubate. In immunocompromised patients, NHF reduces the need for intubation but does not impact mortality. Beneficial physiological effects of NHF have also been reported in patients with chronic respiratory failure, suggesting a possible indication in acute hypercapnic respiratory failure. When intubation is required, NHF can be used to pre-oxygenate patients either alone or in combination with non-invasive ventilation (NIV). Similarly, NHF reduces reintubation alone in low-risk patients and in combination with NIV in high-risk patients. NHF may be used in the emergency department in patients who would not be offered intubation and can be better tolerated than NIV.

High-flow nasal cannula oxygen therapy as an emerging option for respiratory failure: the present and the future

Conventional oxygen therapy (COT) and noninvasive ventilation (NIV) have been considered for decades as frontline treatment for acute or chronic respiratory failure. However, COT can be insufficient in severe hypoxaemia whereas NIV, although highly effective, is poorly tolerated by patients and its use requires a specific expertise. High-flow nasal cannula (HFNC) is an emerging technique, designed to provide oxygen at high flows with an optimal degree of heat and humidification, which is well tolerated and easy to use in all clinical settings. Physiologically, HFNC reduces the anatomical dead space and improves carbon dioxide wash-out, reduces the work of breathing, and generates a positive end-expiratory pressure and a constant fraction of inspired oxygen. Clinically, HFNC effectively reduces dyspnoea and improves oxygenation in respiratory failure from a variety of aetiologies, thus avoiding escalation to more invasive supports. In recent years it has been adopted to treat de novo hypoxaemic respiratory failure, exacerbation of chronic obstructive pulmonary disease (COPD), postintubation hypoxaemia and used for palliative respiratory care. While the use of HFNC in acute respiratory failure is now routine as an alternative to COT and sometimes NIV, new potential applications in patients with chronic respiratory diseases (e.g. domiciliary treatment of patients with stable COPD), are currently under evaluation and will become a topic of great interest in the coming years.

High-Flow Nasal Cannula Oxygen in Patients with Acute Respiratory Failure and Do-Not-Intubate or Do-Not-Resuscitate Orders: A Systematic Review

BACKGROUND AND OBJECTIVES

High-flow nasal cannula (HFNC) oxygen may provide tailored benefits in patients with preset treatment limitations. The objective of this study was to assess the effectiveness of HFNC oxygen in patients with do-not-intubate (DNI) and/or do-not-resuscitate (DNR) orders.

METHODS

We conducted a systematic review of interventional and observational studies. A search was performed using MEDLINE, EMBASE, CINAHL, Scopus, and Web of Science, from inception to October 15, 2018.

RESULTS

We included six studies evaluating 293 patients. All studies had a high risk of bias. The hospital mortality rates of patients with DNI and/or DNR orders receiving HFNC oxygen were variable and ranged from 40% to 87%. In two before and after studies, the initiation of HFNC oxygen was associated with improved oxygenation and reduced respiratory rates. One comparative study found no difference in dyspnea reduction or morphine doses between patients using HFNC oxygen versus conventional oxygen. No studies evaluated quality of life in survivors or quality of death in nonsurvivors. HFNC was generally well tolerated with few adverse events identified.

CONCLUSIONS

While HFNC oxygen remains a viable treatment option for hospitalized patients who have acute respiratory failure and a DNI and/or DNR order, there is a paucity of high-quality, comparative, effectiveness data to guide the usage of HFNC oxygen compared with other treatments, such as noninvasive ventilation, conventional oxygen, and palliative opioids.

Acute and Chronic Respiratory Failure in Cancer Patients

In 2016, there was an estimated 1.8 million new cases of cancer diagnosed in the United States. Remarkable advances have been made in cancer therapy and the 5-year survival has increased for most patients affected by malignancy. There are growing numbers of patients admitted to intensive care units (ICU) and up to 20% of all patients admitted to an ICU carry a diagnosis of malignancy. Respiratory failure remains the most common reason for ICU admission and remains the leading causes of death in oncology patients. There are many causes of respiratory failure in this population. Pneumonia is the most common cause of respiratory failure, yet there are many causes of respiratory insufficiency unique to the cancer patient. These causes are often a result of immunosuppression, chemotherapy, radiation treatment, or hematopoietic stem cell transplant (HCT). Treatment is focused on supportive care and specific therapy for the underlying cause of respiratory failure. Noninvasive modalities of respiratory support are available; however, careful patient selection is paramount as indiscriminate use of noninvasive positive pressure ventilation is associated with a higher mortality if mechanical ventilation is later required. Historically, respiratory failure in the cancer patient had a grim prognosis. Outcomes have improved over the past 20 years. Survivors are often left with significant disability.

High-Flow Nasal Cannula Versus Conventional Oxygen Therapy in Relieving Dyspnea in Emergency Palliative Patients With Do-Not-Intubate Status: A Randomized Crossover Study

STUDY OBJECTIVE

Palliative patients often visit the emergency department (ED) with respiratory distress during their end-of-life period. The goal of management is alleviating dyspnea and providing comfort. High-flow nasal cannula may be an alternative oxygen-delivering method for palliative patients with do-not-intubate status. We therefore aim to compare the efficacy of high-flow nasal cannula with conventional oxygen therapy in improving dyspnea of palliative patients with do-not-intubate status who have hypoxemic respiratory failure in the ED.

METHODS

This randomized, nonblinded, crossover study was conducted with 48 palliative patients aged 18 years or older with do-not-intubate status who presented with hypoxemic respiratory failure to the ED of Siriraj Hospital, Bangkok, Thailand. The participants were randomly allocated to conventional oxygen therapy for 60 minutes, followed by high-flow nasal cannula for 60 minutes (n=24) or vice versa (n=24). The primary outcome was modified Borg scale score. The secondary outcomes were numeric rating scale score of dyspnea and vital signs.

RESULTS

Intention-to-treat analysis included 44 patients, 22 in each group. Baseline mean modified Borg scale score was 7.6 (SD 2.2) (conventional oxygen therapy first) and 8.2 (SD 1.8) (high-flow nasal cannula first). At 60 minutes, mean modified Borg scale score in patients receiving conventional oxygen therapy and high-flow nasal cannula was 4.9 (standard of mean 0.3) and 2.9 (standard of mean 0.3), respectively (mean difference 2.0; 95% confidence interval 1.4 to 2.6). Results for the numeric rating scale score of dyspnea were similar to those for the modified Borg scale score. Respiratory rates were lower with high-flow nasal cannula (mean difference 5.9; 95% confidence interval 3.5 to 8.3), and high-flow nasal cannula was associated with a significantly lower first-hour morphine dose.

CONCLUSION

High-flow nasal cannula was superior to conventional oxygen therapy in reducing the severity of dyspnea in the first hour of treatment in patients with do-not-intubate status and hypoxemic respiratory failure.

Do-not-intubate orders in patients with acute respiratory failure: a systematic review and meta-analysis

PURPOSE

To assess the rates and variability of do-not-intubate orders in patients with acute respiratory failure.

METHODS

We conducted a systematic review of observational studies that enrolled adult patients with acute respiratory failure requiring noninvasive ventilation or high-flow nasal cannula oxygen from inception to 2019.

RESULTS

Twenty-six studies evaluating 10,755 patients were included. The overall pooled rate of do-not-intubate orders was 27%. The pooled rate of do-not-intubate orders in studies from North America was 14% (range 9-22%), from Europe was 28% (range 13-58%), and from Asia was 38% (range 9-83%), p = 0.001. Do-not-intubate rates were higher in studies with higher patient age and in studies where do-not-intubate decisions were made without reported patient/family input. There were no significant differences in do-not-intubate orders according to illness severity, observed mortality, malignancy comorbidity, or methodological quality. Rates of do-not-intubate orders increased over time from 9% in 2000-2004 to 32% in 2015-2019. Only 12 studies (46%) reported information about do-not-intubate decision-making processes. Only 4 studies (15%) also reported rates of do-not-resuscitate.

CONCLUSIONS

One in four patients with acute respiratory failure (who receive noninvasive ventilation or high-flow nasal cannula oxygen) has a do-not-intubate order. The rate of do-not-intubate orders has increased over time. There is high inter-study variability in do-not-intubate rates-even when accounting for age and illness severity. There is high variability in patient/family involvement in do-not-intubate decision making processes. Few studies reported differences in rates of do-not-resuscitate and do-not-intubate-even though recovery is very different for acute respiratory failure and cardiac arrest.

High-flow nasal cannula oxygenation utilization in respiratory failure

High flow nasal cannula (HFNC) represents a new oxygenation system to be used in the treatment of respiratory emergencies. During HFNC therapy, the active humidification and air heating system allow the patient to tolerate higher flows by favouring physiologic mucociliary clearance and improving fluidity of respiratory secretions. Following this, FiO₂ values are more stable and reliable, by reducing losses and minimizing ambient air entrainment. Several clinical trials in acute respiratory failure patients have suggested lower rate of invasive mechanical ventilation, improved comfort and enhanced survival by early HFNC utilization in comparison with conventional oxygen therapy (COT) or non-invasive ventilation (NIV). This review aims to summarize the main evidences on the use of HFNC in the acute setting and its major indications.

Strategies to relieve dyspnoea in patients with advanced chronic respiratory diseases. A narrative review

BACKGROUND AND OBJECTIVE

The management of symptoms in patients with advanced chronic respiratory diseases needs more attention. This review summarizes the latest evidence on interventions to relieve dyspnoea in these patients.

METHODS

We searched randomised controlled trials, observational studies, systematic reviews, and meta-analyses published between 1990 and 2019 in English in PubMed data base using the keywords. Dyspnoea, Breathlessness AND: pharmacological and non pharmacological therapy, oxygen, non invasive ventilation, pulmonary rehabilitation, alternative medicine, intensive care, palliative care, integrated care, self-management. Studies on drugs (e.g. bronchodilators) or interventions (e.g. lung volume reduction surgery, lung transplantation) to manage underlying conditions and complications, or tools for relief of associated symptoms such as pain, are not addressed.

RESULTS

Relief of dyspnoea has received relatively little attention in clinical practice and literature. Many pharmacological and non pharmacological therapies are available to relieve dyspnoea, and improve patients' quality of life. There is a need for greater knowledge of the benefits and risks of these tools by doctors, patients and families to avoid unnecessary fears which might reduce or delay the delivery of appropriate care. We need services for multidisciplinary care in early and late phases of diseases. Early integration of palliative care with respiratory, primary care, and rehabilitation services can help patients and caregivers.

CONCLUSION

Relief of dyspnoea as well as of any distressing symptom is a human right and an ethical duty for doctors and caregivers who have many potential resources to achieve this.

Acute respiratory failure in immunocompromised adults

Acute respiratory failure occurs in up to half of patients with haematological malignancies and 15% of those with solid tumours or solid organ transplantation. Mortality remains high. Factors associated with mortality include a need for invasive mechanical ventilation, organ dysfunction, older age, frailty or poor performance status, delayed intensive care unit admission, and acute respiratory failure due to an invasive fungal infection or unknown cause. In addition to appropriate antibacterial therapy, initial clinical management aims to restore oxygenation and predict the most probable cause based on variables related to the underlying disease, acute respiratory failure characteristics, and radiographic findings. The cause of acute respiratory failure must then be confirmed using the most efficient, least invasive, and safest diagnostic tests. In patients with acute respiratory failure of undetermined cause, a standardised diagnostic investigation should be done immediately at admission before deciding whether to perform more invasive diagnostic procedures or to start empirical treatments. Collaborative and multidisciplinary clinical and research networks are crucial to improve our understanding of disease pathogenesis and causation and to develop less invasive diagnostic strategies and more targeted treatment options.

Significance of urinary 11-dehydro-thromboxane B2 in age-related diseases: Focus on atherothrombosis

Platelet activation plays a key role in atherogenesis and atherothrombosis. Biochemical evidence of increased platelet activation in vivo can be reliably obtained through non-invasive measurement of thromboxane metabolite (TXM) excretion. Persistent biosynthesis of TXA₂ has been associated with several ageing-related diseases, including acute and chronic cardio-cerebrovascular diseases and cardiovascular risk factors, such as cigarette smoking, type 1 and type 2 diabetes mellitus, obesity, hypercholesterolemia, hyperhomocysteinemia, hypertension, chronic kidney disease, chronic inflammatory diseases. Given the systemic nature of TX excretion, involving predominantly platelet but also extraplatelet sources, urinary TXM may reflect either platelet cyclooxygenase-1 (COX-1)-dependent TX generation or COX-2-dependent biosynthesis by inflammatory cells and/or platelets, or a combination of the two, especially in clinical settings characterized by low-grade inflammation or enhanced platelet turnover. Although urinary 11-dehydro-TXB₂ levels are largely suppressed with low-dose aspirin, incomplete TXM suppression by aspirin predicts the future risk of vascular events and death in high-risk patients and may identify individuals who might benefit from treatments that more effectively block in vivo TX production or activity. Several disease-modifying agents, including lifestyle intervention, antidiabetic drugs and antiplatelet agents besides aspirin have been shown to reduce TX biosynthesis. Taken together, these aspects may contribute to the development of promising mechanism-based therapeutic strategies to reduce the progression of atherothrombosis. We intended to critically review current knowledge on both the pathophysiological significance of urinary TXM excretion in clinical settings related to ageing and atherothrombosis, as well as its prognostic value as a biomarker of vascular events.

High-flow nasal therapy vs standard oxygen during breaks off noninvasive ventilation for acute respiratory failure: A pilot randomized controlled trial

PURPOSE

To assess the role of high-flow nasal therapy (HFNT) compared to standard oxygen (SO) as complementary therapy to non-invasive ventilation (NIV).

METHODS

Multicenter trial including patients (n = 54) anticipated to receive NIV for ≥24 h due to acute or acute-on-chronic respiratory failure. Subjects were randomized (1:1) to SO or HFNT during breaks off NIV. Primary outcome was total time on and off NIV. Secondary outcomes were comfort and dyspnea, respiratory rate (RR), oxygen saturation (S_pO₂), tolerance and side effects.

RESULTS

Total time per patient on NIV (1315 vs 1441 min) and breaks (1362 vs 1196 min), and mean duration of each break (520 vs 370 min) were similar in the HFNT and SO arms (p > .05). Comfort score was higher on HFNT than on SO (8.3 ± 2.7 vs 6.9 ± 2.3, p = .001). Dyspnea, RR and S_pO₂ were similar in the two arms, but the increase in RR and dyspnea seen with SO during breaks did not occur with HFNT.

CONCLUSION

Compared to SO, HFNT did not reduce time on NIV. However, it was more comfortable and the increase in RR and dyspnea seen with SO did not occur with HFNT. Therefore, HFNT could be a suitable alternative to SO during breaks off NIV.

A Systematic Review of the High-flow Nasal Cannula for Adult Patients

This article is one of ten reviews selected from the Annual Update in Intensive Care and Emergency Medicine 2018. Other selected articles can be found online at https://www.biomedcentral.com/collections/annualupdate2018. Further information about the Annual Update in Intensive Care and Emergency Medicine is available from http://www.springer.com/series/8901.

The clinical practice of high-flow nasal cannula oxygen therapy in adults: A Japanese cross-sectional multicenter survey

BACKGROUND

High-flow nasal cannula oxygen therapy (HFNC) is widely used mainly in the acute care setting, but limited data are available on real-world practice in adults. The objective of this study was to describe HFNC practices in Japanese adults.

METHODS

A retrospective cross-sectional multicenter survey of adult patients receiving HFNC from January through March 2015 was conducted in 33 participating hospitals in Japan.

RESULTS

We obtained information on 321 patients (median age, 76; 218 men, 103 women; median estimated PaO₂/F_IO_2, 178 mm Hg) from 22 hospitals. Do-not-intubate status was determined in 37.4% of patients. Prior to HFNC, 57.9% of patients received conventional oxygen therapy; 25.9%, noninvasive ventilation; and 15.0%, invasive mechanical ventilation. The common indications for HFNC were acute hypoxemic respiratory failure (ARF) (65.4%), postoperative respiratory support (15.9%), and post-extubation respiratory support (11.2%). The underlying etiology of ARF included interstitial lung disease, pneumonia, and cardiogenic pulmonary edema. HFNC was administered mostly in intensive care units or intermittent care units (60.7%) and general wards (36.1%). Median duration of HFNC was 4 days; median total flow rate, 40 L/min; and median F_IO₂, 50%. HFNC significantly improved PaO₂, PaCO₂, SpO₂ and respiratory rate from baseline. Two-thirds of patients finally survived to be discharged or transferred.

CONCLUSIONS

We documented patient demographics, clinical indications, and settings of HFNC use in the real world. We also demonstrated positive effects of HFNC on respiratory parameters. Further studies are urgently needed regarding the efficacy and safety of HFNC in populations outside of previous clinical trials.

High-flow nasal oxygen vs. standard oxygen therapy in immunocompromised patients with acute respiratory failure: study protocol for a randomized controlled trial

Background

Acute respiratory failure (ARF) is the leading reason for intensive care unit (ICU) admission in immunocompromised patients. High-flow nasal oxygen (HFNO) therapy is an alternative to standard oxygen. By providing warmed and humidified gas, HFNO allows the delivery of higher flow rates via nasal cannula devices, with FiO₂ values of nearly 100%. Benefits include alleviation of dyspnea and discomfort, decreased respiratory distress and decreased mortality in unselected patients with acute hypoxemic respiratory failure. However, in preliminary reports, HFNO benefits are controversial in immunocompromised patients in whom it has never been properly evaluated.

Methods/design

This is a multicenter, open-label, randomized controlled superiority trial in 30 intensive care units, part of the Groupe de Recherche Respiratoire en Réanimation Onco-Hématologique (GRRR-OH). Inclusion criteria will be: (1) adults, (2) known immunosuppression, (3) ARF, (4) oxygen therapy ≥ 6 L/min, (5) written informed consent from patient or proxy. Exclusion criteria will be: (1) imminent death (moribund patient), (2) no informed consent, (3) hypercapnia (PaCO₂ ≥ 50 mmHg), (4) isolated cardiogenic pulmonary edema, (5) pregnancy or breastfeeding, (6) anatomical factors precluding insertion of a nasal cannula, (7) no coverage by the French statutory healthcare insurance system, and (8) post-surgical setting from day 1 to day 6 (patients with ARF occurring after day 6 of surgery can be included).

The primary outcome measure is day-28 mortality. Secondary outcomes are intubation rate, comfort, dyspnea, respiratory rate, oxygenation, ICU length of stay, and ICU-acquired infections.

Based on an expected 30% mortality rate in the standard oxygen group, and 20% in the HFNO group, error rate set at 5%, and a statistical power at 90%, 389 patients are required in each treatment group (778 patients overall). Recruitment period is estimated at 30 months, with 28 days of additional follow-up for the last included patient.

Discussion

The HIGH study will be the largest multicenter, randomized controlled trial seeking to demonstrate that survival benefits from HFNO reported in unselected patients also apply to a large immunocompromised population.

Trial registration

ClinicalTrials.gov, ID: NCT02739451. Registered on 15 April 2016.

Electronic supplementary material

The online version of this article (10.1186/s13063-018-2492-z) contains supplementary material, which is available to authorized users.

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

Nasal high flow is a promising novel oxygen delivery device, whose mechanisms of action offer some beneficial effects over conventional oxygen systems. The administration of a high flow of heated and humidified gas mixture promotes higher and more stable inspiratory oxygen fraction values, decreases anatomical dead space and generates a positive airway pressure that can reduce the work of breathing and enhance patient comfort and tolerance. Nasal high flow has been used as a prophylactic tool or as a treatment device mostly in patients with acute hypoxaemic respiratory failure, with the majority of studies showing positive results. Recently, its clinical indications have been expanded to post-extubated patients in intensive care or following surgery, for pre- and peri-oxygenation during intubation, during bronchoscopy, in immunocompromised patients and in patients with “do not intubate” status. In the present review, we differentiate studies that suggest an advantage (benefit) from other studies that do not suggest an advantage (no benefit) compared to conventional oxygen devices or noninvasive ventilation, and propose an algorithm in cases of nasal high flow application in patients with acute hypoxaemic respiratory failure of almost any cause.

Critical care of patients with cancer

Answer questions and earn CME/CNE The increasing prevalence of patients living with cancer in conjunction with the rapid progress in cancer therapy will lead to a growing number of patients with cancer who will require intensive care treatment. Fortunately, the development of more effective oncologic therapies, advances in critical care, and improvements in patient selection have led to an increased survival of critically ill patients with cancer. As a consequence, critical care has become an important cornerstone in the continuum of modern cancer care. Although, in many aspects, critical care for patients with cancer does not differ from intensive care for other seriously ill patients, there are several challenging issues that are unique to this patient population and require special knowledge and skills. The optimal management of critically ill patients with cancer necessitates expertise in oncology, critical care, and palliative medicine. Cancer specialists therefore have to be familiar with key principles of intensive care for critically ill patients with cancer. This review provides an overview of the state-of-the-art in the individualized management of critically ill patients with cancer. CA Cancer J Clin 2016;66:496-517. © 2016 American Cancer Society.

High-flow nasal cannula therapy for adult patients

High-flow nasal cannula (HFNC) oxygen therapy has several physiological advantages over traditional oxygen therapy devices, including decreased nasopharyngeal resistance, washing out of the nasopharyngeal dead space, generation of positive pressure in the pharynx, increasing alveolar recruitment in the lungs, humidification of the airways, increased fraction of inspired oxygen and improved mucociliary clearance. Recently, the use of HFNC in treating adult critical illness patients has significantly increased, and it is now being used in many patients with a range of different disease conditions. However, there are no established guidelines to direct the safe and effective use of HFNC for these patients. This review article summarizes the available published literature on the positive physiological effects, mechanisms of action, and the clinical applications of HFNC, compared with traditional oxygen therapy devices. The available literature suggests that HFNC oxygen therapy is an effective modality for the early treatment of critically adult patients.

Treatment Recommendations for Respiratory Symptoms in Cancer Patients: Clinical Guidelines from the Japanese Society for Palliative Medicine

BACKGROUND

Respiratory symptoms, dyspnea, cough, and death rattle, are common and distressing in advanced cancer patients. Palliation of respiratory symptoms is important to improve quality of life in cancer patients and their families/caregivers. Currently published clinical guidelines for the management of these respiratory symptoms in cancer patients did not cover the topics comprehensively or were not based on formal process for the development of clinical guidelines.

METHODS

The Japanese Society for Palliative Medicine (JSPM) decided to develop comprehensive clinical guidelines for the management of respiratory symptoms in cancer patients following the formal guideline developing process.

RESULTS

This article provides a summary of the recommendations with the rationales, as well as a short summary of the developing process, of the JSPM respiratory symptom management guidelines. We established 26 recommendations and all recommendations are based on the best available evidences and expert consensus.

DISCUSSION

More future clinical researches and continuous guideline updates are required to improve the quality of respiratory symptom management in cancer patients.

Heated, humidified, high-flow nasal oxygen usage in the adult Emergency Department

OBJECTIVE

The aim of this study was to determine the role that heated, humidified high-flow nasal oxygen (HHHFNO) plays in the adult ED with particular focus on the indications and outcomes of use.

METHODS

An explorative study was undertaken using retrospective chart review to identify characteristics of adult patients who received HHHFNO in a tertiary adult ED between January and December 2014.

RESULTS

Thirty-nine patients were identified as having received HHHFNO during the study period with a range of indications for this use. No clear guidelines existed for initiation of this use. Two patients failed on HHHFNO therapy, requiring increased respiratory support; twenty-seven patients were admitted to hospital with HHHFNO still being delivered and seven patients were successfully treated with HHHFNO in the ED. The use of HHHFNO was associated with a 4.91bpm (95% CI 2.23-7.59; P=0.001) decrease in mean RR and an 11.26bpm (95% CI 4.62-17.90; P=0.002) decrease in mean HR from baseline at 120min of use. Hypercapnic patients showed a significant decrease in mean PaCO₂ levels after one hour of HHHFNO use (70.33mmHg (SD 19.63) vs. 55.00mmHg (SD 13.28), P=0.041) with no change in PaCO₂ levels in patients who were not hypercapnic prior to HHHFNO use (PaCO₂ 32.71mmHg (SD 5.28) vs. 32.38mmHg (SD 3.70), P=0.919).

CONCLUSIONS

HHHFNO is currently being used as a device for supplemental oxygen delivery within the adult Emergency Department; however, further research is needed in this area to quantify its use in many of the indications seen.

Current evidence for the effectiveness of heated and humidified high flow nasal cannula supportive therapy in adult patients with respiratory failure

High flow nasal cannula (HFNC) supportive therapy has emerged as a safe, useful therapy in patients with respiratory failure, improving oxygenation and comfort. Recently several clinical trials have analyzed the effectiveness of HFNC therapy in different clinical situations and have reported promising results. Here we review the current knowledge about HFNC therapy, from its mechanisms of action to its effects on outcomes in different clinical situations.