The role for high flow nasal cannula as a respiratory support strategy in adults: a clinical practice guideline

What barriers do paediatric nurses encounter when attempting to wean paediatric patients off humidified high flow nasal cannula oxygen therapy? A qualitative study

PURPOSE

This study aimed to explore nurse perceptions of barriers and facilitators to weaning humidified high flow nasal cannula (HHFNC) in Australian paediatric settings.

DESIGN AND METHODS

A qualitative descriptive two phased study was conducted across Australia. Purposeful sampling and snowballing technique were used to recruit nurses with the study advertised widely on social media nursing groups. Phase One data collection was via a survey with open and closed ended questions, and Phase Two via semi-structured interviews. Data were analysed using descriptive statistics (Phase One) and thematic analysis (Phase One and Two) to identify themes and patterns in the narrative.

RESULTS

Phase one: 36(56.25 %) participants identified their workplace had clear guidelines, 57(89.06 %) received education on HHFNC and 34(57.63 %) experienced barriers when weaning. Three themes and nine subthemes were identified i) variable clinical process for weaning HHFNC, ii) knowledge and skills and iii) clinical observation and assessment of the child. Phase two: four themes and nine subthemes were identified, i) 'There doesn't seem to be any pattern': no evidence to guide practice, ii) Nursing and medical led weaning, iii) Knowledge and skills and iv) Family centred approaches to weaning.

CONCLUSIONS

Current research on HHFNC does not consider best practice for weaning. This study identified barriers as inconsistency in weaning practice and availability of guidelines and facilitators were a robust education program and confidence in weaning. Multidisciplinary team need to collaborate to determine standardised weaning practice.

PRACTICE IMPLICATIONS

Further research is essential to determine best practice weaning methods and inform national/international guidelines.

Long-Term High-Flow Nasal Therapy in Patients with Bronchiectasis of Different Severity: A Retrospective Cohort Study

Background/Objectives: High-flow nasal therapy (HFNT) has been shown to reduce exacerbations of COPD and some evidence displays benefits in non-cystic fibrosis bronchiectasis (NCFB) patients. The present study aimed to compare the effectiveness of 12 months of home HFNT on the annual exacerbation rate between mild/moderate and severe NCFB patients, classified by the bronchiectasis severity index (BSI). Secondary outcomes were the evaluation of the dyspnea, pulmonary function, and sputum cultures in both groups. Methods: The study population included NCFB adult patients, with at least one severe exacerbation in the previous year on optimized therapy. NCFB exacerbations, dyspnea (mMRC score), pulmonary function test, and sputum cultures were assessed at baseline and after 12 months of HFNT. Results: A total of 86 NCFB patients were enrolled: 36 in the mild/moderate (BSI < 9) and 50 in the severe (BSI ≥ 9) group. A significant improvement in the annual exacerbation rate was found in both BSI ≥ 9 (p < 0.0001) and BSI < 9 cohorts (p < 0.0001), with a between-group difference of -1 (95% CI: -2 to 0) exacerbations per year (p = 0.0209). The change in the annual exacerbation rate was significantly correlated with BSI (ρ = -0.26, p = 0.0151) and with HFNT daily use (ρ = -0.22, p = 0.0460). The mMRC score significantly improved by -2 points (95% CI: -2 to -1) after treatment in both groups (p < 0.0001). The percentage of patients with P. aeruginosa colonization decreased from 34.9% to 27.9%. Conclusions: Long-term HFNT reduces the annual exacerbation rate in NCFB patients and its effectiveness increases alongside disease severity and daily use of HFNT.

Non-invasive respiratory support in elderly hospitalized patients

INTRODUCTION

The proportion of elderly people among hospitalized patients is rapidly growing. Between 7% to 25% of ICU patients are aged 85 and over and noninvasive respiratory support is often offered to avoid the risks of invasive mechanical ventilation or in patients with a 'do-not-intubate' order. However, while noninvasive respiratory support has been extensively studied in the general population, there is limited data available on its efficacy in elderly patients with ARF.

AREAS COVERED

PubMed/Medline, Web of Science, Scopus and Embase online databases were searched for studies that assessed clinical efficacy of high flow nasal cannula, continuous positive airway pressure and noninvasive ventilation in patients ≥ 65 years old with acute de novo ARF, showing that short to mid-term benefits provided by noninvasive respiratory support in elderly patients in terms of reduction of mechanical ventilation risk and mortality are similar to younger patients, if adjusted for the severity of comorbidities and respiratory failure.

EXPERT OPINION

Noninvasive support strategies can represent an effective opportunity in elderly patients with ARF, especially in patients too frail to undergo endotracheal intubation and in whom received or decided for a 'do not intubate' order. Indeed, noninvasive support has a different impact, depending on the setting.

High-flow nasal cannula and in-line aerosolised bronchodilator delivery during severe exacerbation of asthma in adults: a feasibility observational study

BACKGROUND

Asthma is a common chronic respiratory disease affecting 1-29% of the population in different countries. Exacerbations represent a change in symptoms and lung function from the patient's usual condition that requires emergency department (ED) admission. Recently, the use of a High-Flow Nasal Cannula (HFNC) plus an in-line vibrating mesh nebulizer (VMN) for aerosol drug delivery has been advocated in clinical practice. Thus, this pilot observational study aims to investigate the feasibility of HFNC treatment with VMN for in-line bronchodilator delivery in patients with severe asthma.

METHODS

This study was conducted from May 2022 to May 2023. Subjects ≥18 years old with a previous diagnosis of asthma who were admitted to the ED during severe exacerbation were included. The primary endpoint was the change in peak expiratory flow ratio (PEFR) after 2-h of treatment with bronchodilator delivered by HFNC with in-line VMN. Additional outcomes were changes in forced expiratory volume in 1 s (FEV1) and clinical variables before treatment.

RESULTS

30 patients, mean age of 43 (SD ± 16) years, mostly female (67%) were studied. A significant change in PEFR (147 ± 31 L/m vs. 220 ± 38 L/m; p < 0.001) was observed after treatment with HFNC and in-line VMN with significant improvement in clinical variables. And no subjects required invasive mechanical ventilation (IMV) during the study.

CONCLUSIONS

HFNC treatment with in-line VMN for bronchodilator delivery appears feasible and safe for patients with severe asthma exacerbation. These preliminary promising results should be confirmed with appropriately large-designed studies.

Physiological Effects of High-Flow Tracheal Oxygen in Tracheostomized Patients Weaning From Mechanical Ventilation

BACKGROUND

High-flow tracheal oxygen (HFTO) is being used as supportive therapy during weaning in tracheostomized patients difficult to wean from invasive mechanical ventilation. There is, however, no clinical evidence for such a strategy. Therefore, we conducted a systematic review to summarize studies evaluating the physiologic effects of HFTO during tracheostomy-facilitated weaning and to identify potential areas for future research in this field.

METHODS

Observational and interventional studies on critically ill subjects weaning from mechanical ventilation via tracheostomy published until December 22, 2022, were eligible. Studies on high-flow oxygen, only in children, non-human models or animals, on clinical outcome only, abstracts without full-text availability, case reports, and reviews were excluded. Main outcomes were end-expiratory lung volume (EELV) and tidal volume using electrical impedance tomography, respiratory effort assessed by esophageal manometry, work of breathing and neuroventilatory drive as assessed by electrical activity of the diaphragm (EAdi) signal, airway pressure (Paw), oxygenation (PaO2 /FIO2 or SpO2 /FIO2 ), breathing frequency, tidal volume, and PaCO2 .

RESULTS

In total, 1,327 references were identified, of which 5 were included. In all studies, HFTO was administered with flow 50 L/min and compared to conventional O2 therapy in a crossover design. The total average duration of invasive ventilation at time of measurements ranged from 11-27 d. In two studies, PaO2 /FIO2 and mean Paw were higher with HFTO. EELV, tidal volumes, esophageal pressure swings, and EAdi were similar during high-flow tracheal oxygen and conventional O2 therapy.

CONCLUSIONS

The main physiological effect of HFTO as compared to conventional O2 therapy in tracheostomized subjects weaning from mechanical ventilation was improved oxygenation that is probably flow-dependent. Respiratory effort, lung aeration, neuroventilatory drive, and ventilation were similar for HFTO and conventional O2 therapy. Future studies on HFTO should be performed early in the weaning process and should evaluate its effect on sputum clearance and patient-centered outcomes like dyspnea.

Construction of an extubation protocol for adult tracheal intubation patients in the intensive care unit: A Delphi study

OBJECTIVE

The objective of this study was to develop an extubation practice protocol for adult intensive care unit (ICU) patients who underwent endotracheal intubation, providing theoretical guidance for clinical extubation procedures in the ICU.

METHODS

A research team was established consisting of medical, nursing, anaesthesia, and respiratory therapy professionals; the multidisciplinary team systematically searched domestic and foreign literature, summarised the best evidence, and combined it with clinical practice experience to preliminarily develop an extubation protocol for adult ICU patients who underwent endotracheal intubation. Seventeen experts in critical care medicine, intensive care nursing, clinical anaesthesia, and respiratory therapy were invited to participate in a Delphi expert consultation to screen and modify the draft protocol.

RESULTS

The response rates of the two Delphi expert enquiries were 100% and 94.1%, with expert authority coefficients of 0.94 and 0.93, respectively, and Kendall's concordance coefficients were 0.152 and 0.198, respectively, indicating statistically significant differences (p < 0.001). The final protocol included three level I indicators, 14 level II indicators, and 34 level III indicators, covering extubation evaluation, implementation, and postextubation management.

CONCLUSION

The extubation protocol for adult tracheal intubation patients in the ICU constructed in this study is scientific, practical, and reliable. This study can provide theoretical guidance for extubation in ICU patients who have undergone endotracheal intubation.

Incidence, Risk Factors, and Long-Term Outcomes for Extubation Failure in ICU in Patients With Obesity: A Retrospective Analysis of a Multicenter Prospective Observational Study

BACKGROUND

To our knowledge, no large observational study has compared the incidence and risk factors for extubation failure within 48 h and during ICU stay in the same cohort of unselected critically ill patients with and without obesity.

RESEARCH QUESTION

Which are the incidence and risk factors of extubation failure in patients with and without obesity?

STUDY DESIGN AND METHODS

In this prospective multicenter observational FREE-REA study in 26 ICUs, the primary objective was to compare the incidence of extubation failure within 48 h in patients with and without obesity. Secondary objectives were to describe and to identify the independent specific risk factors for extubation failure, using first a logistic regression model and second a decision tree analysis.

RESULTS

Of 1,370 extubation procedures analyzed, 288 (21%) were performed in patients with obesity and 1,082 (79%) in patients without obesity. The incidence of extubation failure within 48 h among patients with or without obesity was 23 of 288 (8.0%) vs 118 of 1,082 (11%), respectively (unadjusted OR, 0.71; 95% CI, 0.45-1.13; P = .15); alongside patients with obesity receiving significantly more noninvasive ventilation [87 of 288 (30%) vs 233 of 1,082 (22%); P = .002] and physiotherapy [165 of 288 (57%) vs 527 of 1,082 (49%); P = .02] than patients without obesity. Risk factors for extubation failure also differed according to obesity status: female sex (adjusted OR, 4.88; 95% CI, 1.61-13.9; P = .002) and agitation before extubation (adjusted OR, 6.39; 95% CI, 1.91-19.8; P = .001) in patients with obesity, and absence of strong cough before extubation (adjusted OR, 2.38; 95% CI, 1.53-3.84; P = .0002) and duration of invasive mechanical ventilation before extubation (adjusted OR, 1.03/d; 95% CI, 1.01-1.06; P = .01) in patients without obesity. The decision tree analysis found similar risk factors.

INTERPRETATION

Our findings indicate that anticipation and application of preventive measures for patients with obesity before and after extubation led to similar rate of extubation failure among patients with and without obesity.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov; No.: NCT02450669; URL: www.

CLINICALTRIALS

gov.

Noninvasive vs invasive respiratory support for patients with acute hypoxemic respiratory failure

BACKGROUND

Noninvasive respiratory support modalities are common alternatives to mechanical ventilation in acute hypoxemic respiratory failure. However, studies historically compare noninvasive respiratory support to conventional oxygen rather than mechanical ventilation. In this study, we compared outcomes in patients with acute hypoxemic respiratory failure treated initially with noninvasive respiratory support to patients treated initially with invasive mechanical ventilation.

METHODS

This is a retrospective observational cohort study between January 1, 2018 and December 31, 2019 at a large healthcare network in the United States. We used a validated phenotyping algorithm to classify adult patients (≥18 years) with eligible International Classification of Diseases codes into two cohorts: those treated initially with noninvasive respiratory support or those treated invasive mechanical ventilation only. The primary outcome was time-to-in-hospital death analyzed using an inverse probability of treatment weighted Cox model adjusted for potential confounders. Secondary outcomes included time-to-hospital discharge alive. A secondary analysis was conducted to examine potential differences between noninvasive positive pressure ventilation and nasal high flow.

RESULTS

During the study period, 3177 patients met inclusion criteria (40% invasive mechanical ventilation, 60% noninvasive respiratory support). Initial noninvasive respiratory support was not associated with a decreased hazard of in-hospital death (HR: 0.65, 95% CI: 0.35-1.2), but was associated with an increased hazard of discharge alive (HR: 2.26, 95% CI: 1.92-2.67). In-hospital death varied between the nasal high flow (HR 3.27, 95% CI: 1.43-7.45) and noninvasive positive pressure ventilation (HR 0.52, 95% CI 0.25-1.07), but both were associated with increased likelihood of discharge alive (nasal high flow HR 2.12, 95 CI: 1.25-3.57; noninvasive positive pressure ventilation HR 2.29, 95% CI: 1.92-2.74).

CONCLUSIONS

These data show that noninvasive respiratory support is not associated with reduced hazards of in-hospital death but is associated with hospital discharge alive.

New Treatment Modality for Burn Injury-Related Acute Respiratory Distress Syndrome: High-Flow Nasal Oxygen Therapy in Major Burns

Pulmonary insufficiency is the primary cause of death in cases of major burns accompanied by inhalation damage. It is important to consider the impact on the face and neck in flame burns. Early implementation of bronchial hygiene measures and oxygenation treatment in inhalation injury can reduce mortality. This case series presents the effects of high-flow nasal oxygen (HFNO) application on patient outcomes in major burns and inhalation injury. This report discusses 3 different patients. One patient, a 29-year-old male with 35% TBSA burns, received HFNO treatment for inhalation injury on the sixth day after the trauma. After 72 hours of HFNO application, the patient's pulmonary symptoms improved. The second patient had 60% TBSA burns and developed respiratory distress symptoms on the fifth day after the trauma. After 7 days of HFNO application, all symptoms and findings of acute respiratory distress syndrome (ARDS) were resolved. HFNO has been used for the treatment of ARDS related to major burn (60% of burned TBSA) in a 28-year-old patient, and improvement was achieved. The use of HFNO in pulmonary insufficiency among burn patients has not been reported previously. This series of patient cases demonstrates the successful application of HFNO in treating inhalation injury and burn-related ARDS. However, further clinical studies are necessary to increase its clinical utilization.

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.

A Comprehensive Review on High-Flow Nasal Cannula Oxygen Therapy in Critical Care: Evidence-Based Insights and Future Directions

High-flow nasal cannula (HFNC) therapy has emerged as a significant advancement in respiratory support, offering a non-invasive alternative to traditional oxygen delivery methods in critical care settings. This review comprehensively evaluates HFNC therapy, focusing on its definition, historical evolution, and current clinical applications. HFNC therapy delivers humidified and heated oxygen at high flow rates through a nasal cannula, enhancing oxygenation and patient comfort. The review highlights the physiological mechanisms underlying HFNC and its efficacy in managing acute respiratory failure, chronic obstructive pulmonary disease exacerbations, and postoperative respiratory support. Key findings from clinical trials and meta-analyses are discussed, emphasizing HFNC's advantages over conventional methods, such as reduced intubation rates and shorter ICU stays. The review also addresses safety considerations, including potential risks and complications associated with HFNC therapy. Furthermore, it explores future directions for research and technological advancements aimed at optimizing HFNC use in diverse patient populations. This review aims to provide evidence-based insights to inform clinical practice and guide future investigations in respiratory therapy.

Outcome of Early Initiation of High-flow Nasal Oxygen Therapy among Pneumonia Patients Presenting with Acute Hypoxemic Respiratory Failure

Background

High-flow nasal oxygen (HFNO) therapy is an upcoming and beneficial modality for patients with acute hypoxemic respiratory failure (AHRF).

Objectives

To evaluate whether early use of HFNO in pneumonia patients with AHRF can reduce the need for invasive ventilation.

Patients and methods

In this prospective, randomized controlled trial, 160 patients who fulfilled the criteria were included. The patient's characteristics, sequential organ failure assessment score, and simplified acute physiology score were recorded. Respiratory rate (RR), and oxygenation parameters (PaO2/FiO2), and RR-oxygenation index at selected time intervals were collected and analyzed. The primary outcome was the number of patients who needed intubation. Secondary outcomes included length of intensive care unit (ICU) and hospital stay and mortality at day 28.

Results

The rate of intubation was not statistically significant between the two groups 15 vs 18.7%; difference 3.7% [(95% confidence interval (CI): 2.5-5.7%]. In 48-hour time periods, the mean PaO2/FiO2 ratio was significantly increased in the HFNO group compared with the non-invasive ventilation (NIV) group. The RRs and heart rate (HR) showed a significant decrease in the HFNO group.The length of ICU and hospital stays was not different between both groups. No significant differences were found in mortality rates between the HFNO and NIV groups 9 (11.2%) and 10 (12.5%), with 1.3% (95% CI: 0.7-3.8%) (p = 0.21). Multivariate analysis demonstrated that low baseline PaO2/FiO2, Respiratory rate-oxygenation index (ROX index) ≤ 5.4 measured at 12 hour and high severity scores were independent risk factors for intubation.

Conclusion

Treatment with HFNO did not reduce the need for intubation among patients with pneumonia-induced AHRF, despite the improved PaO2/FiO2 observed with HFNO compared with NIV.

Clinical trial no

NCT05809089.

How to cite this article

Magdy DM. Outcome of Early Initiation of High-flow Nasal Oxygen Therapy among Pneumonia Patients Presenting with Acute Hypoxemic Respiratory Failure. Indian J Crit Care Med 2024;28(8):753-759.

Noninvasive ventilation on reintubation in patients with obesity and hypoxemic respiratory failure following abdominal surgery: a post hoc analysis of a randomized clinical trial

PURPOSE

Although noninvasive ventilation (NIV) may reduce reintubation in patients with acute hypoxemic respiratory failure following abdominal surgery, this strategy has not been specifically assessed in patients with obesity.

METHODS

We conducted a post hoc analysis of a multicenter randomized controlled trial comparing NIV delivered via facial mask to standard oxygen therapy among patients with obesity and acute hypoxemic respiratory failure within 7 days after abdominal surgery. The primary outcome was reintubation within 7 days. Secondary outcomes were invasive ventilation-free days at day 30, intensive care unit (ICU)-acquired pneumonia and 30-day survival.

RESULTS

Among 293 patients with hypoxemic respiratory failure following abdominal surgery, 76 (26%) patients had obesity and were included in the intention-to-treat analysis. Reintubation rate was significantly lower with NIV (13/42, 31%) than with standard oxygen therapy (19/34, 56%) within 7 days (absolute difference: - 25%, 95% confidence interval (CI) - 49 to - 1%, p = 0.03). NIV was associated with significantly more invasive ventilation-free days compared with standard oxygen therapy (27.1 ± 8.6 vs 22.7 ± 11.1 days; p = 0.02), while fewer patients developed ICU-acquired pneumonia (1/42, 2% vs 6/34, 18%; p = 0.04). The 30-day survival was 98% in the NIV group (41/42) versus 85% in the standard oxygen therapy (p = 0.08). In patients with body mass index (BMI) < 30 kg/m2, no significant difference was observed between NIV (36/105, 34%) and standard oxygen therapy (47/109, 43%, p = 0.03). An interaction test showed no statistically significant difference between the two subsets (BMI ≥ 30 kg/m2 and BMI < 30 kg/m2).

CONCLUSIONS

Among patients with obesity and hypoxemic respiratory failure following abdominal surgery, use of NIV compared with standard oxygen therapy reduced the risk of reintubation within 7 days, contrary to patients without obesity. However, no interaction was found according to the presence of obesity or not, suggesting either a lack of power to conclude in the non-obese subgroup despite existing differences, or that the statistical difference found in the overall sample was driven by a large effect in the obese subsets.

Operator independent continuous ultrasound monitoring of diaphragm excursion predicts successful weaning from mechanical ventilation: a prospective observational study

BACKGROUND

In mechanically ventilated patients, diaphragm ultrasound can identify diaphragm weakness and predict weaning failure. We evaluated whether a novel operator-independent ultrasound-based medical device allowing continuous monitoring of the diaphragm (CUSdi) could reliably (1) measure diaphragm excursion (EXdi) and peak contraction velocity (PCVdi), (2) predict weaning outcome, and (3) approximate transdiaphragmatic pressure (Pdi).

METHODS

In 49 mechanically ventilated patients, CUSdi was recorded during a 30-min spontaneous breathing trial (SBT), and EXdi and PCVdi were measured. In subgroups of patients, standard ultrasound measurement of EXdi and PCVdi was performed (n = 36), and Pdi derived parameters (peak and pressure time product, n = 30) were measured simultaneously.

RESULTS

The agreement bias between standard ultrasound and CUSdi for EXdi was 0.1 cm (95% confidence interval -0.7-0.9 cm). The regression of Passing-Bablok indicated a lack of systematic difference between EXdi measured with standard ultrasound and CUSdi, which were positively correlated (Rho = 0.84, p < 0.001). Weaning failure was observed in 54% of patients. One, two and three minutes after the onset of the SBT, EXdi was higher in the weaning success group than in the failure group. Two minutes after the onset of the SBT, an EXdi < 1.1 cm predicted weaning failure with a sensitivity of 0.83, a specificity of 0.68, a positive predictive value of 0.76, and a negative predictive value of 0.24. There was a weak correlation between EXdi and both peak Pdi (r = 0.22, 95% confidence interval 0.15 - 0.28) and pressure time product (r = 0.13, 95% confidence interval 0.06 - 0.20). Similar results were observed with PCVdi.

CONCLUSIONS

Operator-independent continuous diaphragm monitoring quantifies EXdi reliably and can predict weaning failure with an identified cut-off value of 1.1 cm. Trial registration clinicaltrial.gov, NCT04008875 (submitted 12 April 2019, posted 5 July 2019) and NCT03896048 (submitted 27 March 2019, posted 29 March 2019).

Effect of noninvasive ventilation on mortality and clinical outcomes among patients with severe hypoxemic COVID-19 pneumonia after high-flow nasal oxygen failure: a multicenter retrospective French cohort with propensity score analysis

BACKGROUND

We assessed the effect of noninvasive ventilation (NIV) on mortality and length of stay after high flow nasal oxygenation (HFNO) failure among patients with severe hypoxemic COVID-19 pneumonia.

METHODS

In this multicenter, retrospective study, we enrolled COVID-19 patients admitted in intensive care unit (ICU) for severe COVID-19 pneumonia with a HFNO failure from December 2020 to January 2022. The primary outcome was to compare the 90-day mortality between patients who required a straight intubation after HFNO failure and patients who received NIV after HFNO failure. Secondary outcomes included ICU and hospital length of stay. A propensity score analysis was performed to control for confounding factors between groups. Exploratory outcomes included a subgroup analysis for 90-day mortality.

RESULTS

We included 461 patients with HFNO failure in the analysis, 233 patients in the straight intubation group and 228 in the NIV group. The 90-day mortality did not significantly differ between groups, 58/228 (25.4%) int the NIV group compared with 59/233 (25.3%) in the straight intubation group, with an adjusted hazard ratio (HR) after propensity score weighting of 0.82 [95%CI, 0.50-1.35] (p = 0.434). ICU length of stay was significantly shorter in the NIV group compared to the straight intubation group, 10.0 days [IQR, 7.0-19.8] versus 18.0 days [IQR,11.0-31.0] with a propensity score weighted HR of 1.77 [95%CI, 1.29-2.43] (p < 0.001). A subgroup analysis showed a significant increase in mortality rate for intubated patients in the NIV group with 56/122 (45.9%), compared to 59/233 (25.3%) for patients in the straight intubation group (p < 0.001).

CONCLUSIONS

In severely hypoxemic COVID-19 patients, no significant differences were observed on 90-day mortality between patients receiving straight intubation and those receiving NIV after HFNO failure. NIV strategy was associated with a significant reduction in ICU length of stay, despite an increase in mortality in the subgroup of patients finally intubated.

Effects of high-flow nasal therapy on swallowing function: a scoping review

Background

High-flow nasal therapy is widely used in patients with respiratory failure in different clinical settings, but the effect of high-flow nasal therapy on respiratory-swallow coordination is unknown. Understanding this relationship is crucial, considering the necessity for patients to maintain adequate nutrition during daytime high-flow nasal therapy. This scoping review aims to synthesise available data on the effects of high-flow nasal therapy flow rates on swallowing function and the possible risk of aspiration during treatment, focusing on knowledge and evidence gaps.

Methods

PubMed, Scopus, Web of Science and Google Scholar databases were searched from inception to 30 May 2023 for studies reporting data on swallowing assessment in healthy adults or patients with acute or chronic respiratory failure receiving high-flow nasal therapy. Data on study design, patients' characteristics and quality outcomes were extracted.

Results

Eight studies were included, four including cohorts of healthy volunteers (n=148) and four including patients with acute or chronic respiratory failure (n=151). Study designs, patient populations and quality outcome measures were heterogeneous. Two studies indicated improvement while four articles showed impairment in swallowing function during high-flow nasal therapy; two studies showed that patients' overall clinical picture and underlying medical conditions influenced swallowing-breathing coordination rather than high-flow nasal therapy per se.

Conclusion

This scoping review found limited and controversial evidence on the impact of high-flow nasal therapy on swallowing function. Remarkably, methods for swallowing function assessment were quite heterogeneous. Additional research is required to test the effect of high-flow nasal therapy on respiratory-swallowing coordination.

[High-flow nasal oxygen versus conventional oxygen therapy during cesarean section under neuraxial anesthesia in pregnant women with heart disease: a randomized controlled trial]

OBJECTIVE

To evaluate the beneficial effects of high-flow nasal cannula (HFNC) oxygen therapy during cesarean section in pregnant women with heart disease.

METHODS

We conducted a single-center, single-blinded randomized trial of HFNC oxygen therapy in pregnant women with heart disease undergoing cesarean section under neuraxial anesthesia.The participants were randomly assigned to receive either HFNC oxygen therapy with inspiratory flow of 30 L/min with 40% FIO2(n=27) or conventional oxygen therapy (COT) with oxygen flow rate of 5 L/min via a nasal cannula (n=31).The primary outcome was maternal desaturation (SpO2 < 94% lasting more than 3 min or PaO2/FIO2≤300 mmHg).

RESULTS

Maternal desaturation was observed in 7.4%(2/27) of the women in HFNC group and in 32.3%(10/31) in the COT group.None of the cases required tracheal intubation during the perioperative period.The HFNC group had a significantly higher incidence of postoperative leukocytosis (P < 0.05) but without pyrexia or other inflammation-related symptoms.There were no significant differences between the two groups in the secondary maternal outcomes (need for respiratory support, maternal ICU admission, postoperative respiratory complications, and cardiovascular complications) or neonatal outcomes (P>0.05).

CONCLUSION

In pregnant women with heart disease, HFNC therapy can significantly reduce the rate of maternal desaturation during the perioperative period of cesarean section without adverse effects on short-term maternal or fetal outcomes.

Assessment of Swallowing Function in Healthy Adults While Using High-Flow Nasal Cannula

OBJECTIVE

Despite widespread use of high flow nasal cannula (HFNC) for respiratory support, the effect of HFNC on swallowing physiology is poorly understood. Flow rates that permit safe swallowing have not been established. We aim to assess if healthy individuals have diminished swallowing function and safety at high flow rates.

STUDY DESIGN

Repeated measures with planned data collection.

SETTING

Outpatient dysphagia clinic.

METHODS

Swallowing function in a cohort of healthy individuals was assessed using Flexible Endoscopic Evaluation of Swallowing (FEES). Participants' safety of swallowing was assessed with different textures under randomized rates of HFNC (0, 30, 40, 50, and 60 LPM). Swallowing trials included quantities of thin liquids, mildly-thick liquids, and purees. Trials were scored using the Penetration-Aspiration Scale (PAS). Pearson chi-square tests were used to test for correlation between PAS result, flow rate, and consistency across each quantity of material.

RESULTS

Twenty-seven subjects were enrolled. Forty-one percent were male with mean age of 34 years (11 standard deviation). Ninety-nine percent (267/270), 97% (n = 263/270), and 99% (399/405) of 1 sip swallows, 3 sip swallows, and 5 mL swallows, respectively, were safe. There was no significant correlation between swallow safety and flow rate using Pearson Chi-Square test across all consistencies and across all quantities of materials (P > 0.05). Of note, out of all subtrials, the thin liquid, 3 sips trial at 60 LPM, had the largest percent of unsafe swallows (14%).

CONCLUSION

Our results suggest rate of aspiration is not significantly affected by high flow nasal cannula in healthy individuals.

Association between high-flow nasal cannula use and mortality in patients with sepsis-induced acute lung injury: a retrospective propensity score-matched cohort study

BACKGROUND

High-flow nasal cannula (HFNC) has emerged as a promising noninvasive method for delivering oxygen to critically ill patients, particularly those with sepsis and acute lung injury. However, uncertainties persist regarding its therapeutic benefits in this specific patient population.

METHODS

This retrospective study utilized a propensity score-matched cohort from the Medical Information Mart in Intensive Care-IV (MIMIC-IV) database to explore the correlation between HFNC utilization and mortality in patients with sepsis-induced acute lung injury. The primary outcome was 28-day all-cause mortality.

RESULTS

In the propensity score-matched cohort, the 28-day all-cause mortality rate was 18.63% (95 out of 510) in the HFNC use group, compared to 31.18% (159 out of 510) in the non-HFNC group. The use of HFNC was associated with a lower 28-day all-cause mortality rate (hazard ratio [HR] = 0.53; 95% confidence interval [CI] = 0.41-0.69; P < 0.001). HFNC use was also associated with lower ICU mortality (odds ratio [OR] = 0.52; 95% CI = 0.38-0.71; P < 0.001) and lower in-hospital mortality (OR = 0.51; 95% CI = 0.38-0.68; P < 0.001). Additionally, HFNC use was found to be associated with a statistically significant increase in both the ICU and overall hospitalization length.

CONCLUSIONS

These findings indicate that HFNC may be beneficial for reducing mortality rates among sepsis-induced acute lung injury patients; however, it is also associated with longer hospital stays.

Noninvasive respiratory support in the perioperative setting: a narrative review

The application of preoperative noninvasive respiratory support (NRS) has been expanding with increasing recognition of its potential role in this setting as a physiological optimization for patients with a high risk of developing atelectasis and postoperative pulmonary complications (PPC). The increased availability of high-performance anesthesia ventilator machines providing an easy way for NRS support in patients with reduced lung function should not be under-evaluated. This support can reduce hypoxia, restore lung volumes and theoretically reduce atelectasis formation after general anesthesia. Therapeutic purposes should also be considered in the perioperative setting, such as preoperative NRS to optimize treatment of patients' pre-existing diseases, e.g., sleep-disordered breathing. Finally, the recent guidelines for airway management suggest preoperative NRS application before anesthesia induction in difficult airway management to prolong the time needed to secure the airway with an orotracheal tube. This narrative review aims to revise all these aspects and to provide some practical notes to maximize the efficacy of perioperative noninvasive respiratory support.

Lower vs Higher Oxygenation Target and Days Alive Without Life Support in COVID-19: The HOT-COVID Randomized Clinical Trial

Importance

Supplemental oxygen is ubiquitously used in patients with COVID-19 and severe hypoxemia, but a lower dose may be beneficial.

Objective

To assess the effects of targeting a Pao2 of 60 mm Hg vs 90 mm Hg in patients with COVID-19 and severe hypoxemia in the intensive care unit (ICU).

Design, Setting, and Participants

Multicenter randomized clinical trial including 726 adults with COVID-19 receiving at least 10 L/min of oxygen or mechanical ventilation in 11 ICUs in Europe from August 2020 to March 2023. The trial was prematurely stopped prior to outcome assessment due to slow enrollment. End of 90-day follow-up was June 1, 2023.

Interventions

Patients were randomized 1:1 to a Pao2 of 60 mm Hg (lower oxygenation group; n = 365) or 90 mm Hg (higher oxygenation group; n = 361) for up to 90 days in the ICU.

Main Outcomes and Measures

The primary outcome was the number of days alive without life support (mechanical ventilation, circulatory support, or kidney replacement therapy) at 90 days. Secondary outcomes included mortality, proportion of patients with serious adverse events, and number of days alive and out of hospital, all at 90 days.

Results

Of 726 randomized patients, primary outcome data were available for 697 (351 in the lower oxygenation group and 346 in the higher oxygenation group). Median age was 66 years, and 495 patients (68%) were male. At 90 days, the median number of days alive without life support was 80.0 days (IQR, 9.0-89.0 days) in the lower oxygenation group and 72.0 days (IQR, 2.0-88.0 days) in the higher oxygenation group (P = .009 by van Elteren test; supplemental bootstrapped adjusted mean difference, 5.8 days [95% CI, 0.2-11.5 days]; P = .04). Mortality at 90 days was 30.2% in the lower oxygenation group and 34.7% in the higher oxygenation group (risk ratio, 0.86 [98.6% CI, 0.66-1.13]; P = .18). There were no statistically significant differences in proportion of patients with serious adverse events or in number of days alive and out of hospital.

Conclusion and Relevance

In adult ICU patients with COVID-19 and severe hypoxemia, targeting a Pao2 of 60 mm Hg resulted in more days alive without life support in 90 days than targeting a Pao2 of 90 mm Hg.

Trial Registration

ClinicalTrials.gov Identifier: NCT04425031.

High-Flow Nasal Cannula Oxygen Therapy versus Non-Invasive Ventilation in patients at very high risk for extubating failure: A systematic review of randomized controlled trials

BACKGROUND

Mechanical ventilation is commonly used for managing respiratory failure in chronic obstructive pulmonary disease (COPD) patients, but weaning patients off ventilator support can be challenging and associated with complications. While many patients respond well to Non-invasive ventilation (NIV), a significant proportion may not respond as favourably. We aimed to assess whether high-flow nasal cannula (HFNC) is equally effective as NIV in reducing extubation failure among previously intubated COPD patients.

METHODS

This systematic review was carried out in line with PRISMA guidelines We searched PubMed, Scopus, Web of Science, and Cochrane library from inception until February 15, 2023. Randomized Clinical Trials (RCTs) of adults at high risk for extubating failure were included. We examined the use of HFNC as the intervention and NIV as the comparator. Our outcome of interest included, reintubation rate, length of hospital or intensive care unit (ICU) stay, adverse events, and time to reintubation. The Cochrane risk-of-bias tool was used for randomized trials to assess risk of bias.

RESULTS

We identified 348 citations, 11 of which were included, representing 2,666 patients. The trials indicate that HFNC is comparable to NIV in preventing reintubation after extubating in COPD patients. In comparison to NIV, HFNC also produced improved tolerance, comfort, and less complications such as airway care interventions. NIV with active humification may be more effective that HFNC in avoiding reintubation in patients who are at extremely high risk for extubating failure.

CONCLUSION

The inconclusive nature of emerging evidence highlights the need for additional studies to establish the efficacy and suitability of HFNC as an alternative to NIV for previously intubated COPD patients. Clinicians should consider the available options and individualize their approach based on patient characteristics. Future research should focus on addressing these gaps in knowledge to guide clinical decision-making and optimize outcomes for this patient population.

Severe Community-Acquired Pneumonia: Noninvasive Mechanical Ventilation, Intubation, and HFNT

Severe acute respiratory failure (ARF) is a major issue in patients with severe community-acquired pneumonia (CAP). Standard oxygen therapy is the first-line therapy for ARF in the less severe cases. However, respiratory supports may be delivered in more severe clinical condition. In cases with life-threatening ARF, invasive mechanical ventilation (IMV) will be required. Noninvasive strategies such as high-flow nasal therapy (HFNT) or noninvasive ventilation (NIV) by either face mask or helmet might cover the gap between standard oxygen and IMV. The objective of all the supporting measures for ARF is to gain time for the antimicrobial treatment to cure the pneumonia. There is uncertainty regarding which patients with severe CAP are most likely to benefit from each noninvasive support strategy. HFNT may be the first-line approach in the majority of patients. While NIV may be relatively contraindicated in patients with excessive secretions, facial hair/structure resulting in air leaks or poor compliance, NIV may be preferable in those with increased work of breathing, respiratory muscle fatigue, and congestive heart failure, in which the positive pressure of NIV may positively impact hemodynamics. A trial of NIV might be considered for select patients with hypoxemic ARF if there are no contraindications, with close monitoring by an experienced clinical team who can intubate patients promptly if they deteriorate. In such cases, individual clinician judgement is key to choose NIV, interface, and settings. Due to the paucity of studies addressing IMV in this population, the protective mechanical ventilation strategies recommended by guidelines for acute respiratory distress syndrome can be reasonably applied in patients with severe CAP.

Noninvasive respiratory support in the emergency department: Controversies and state-of-the-art recommendations

Acute respiratory failure is a common reason for emergency department visits and hospital admissions. Diverse underlying physiologic abnormalities lead to unique aspects about the most common causes of acute respiratory failure: acute decompensated heart failure, acute exacerbation of chronic obstructive pulmonary disease, and acute de novo hypoxemic respiratory failure. Noninvasive respiratory support strategies are increasingly used methods to support work of breathing and improve gas exchange abnormalities to improve outcomes relative to conventional oxygen therapy or invasive mechanical ventilation. Noninvasive respiratory support includes noninvasive positive pressure ventilation and nasal high flow, each with unique physiologic mechanisms. This paper will review the physiology of respiratory failure and noninvasive respiratory support modalities and offer data and guideline-driven recommendations in the context of key clinical controversies.

ACE2 Receptor-Targeted Inhaled Nanoemulsions Inhibit SARS-CoV-2 and Attenuate Inflammatory Responses

Three kinds of coronaviruses are highly pathogenic to humans, and two of them mainly infect humans through Angiotensin-converting enzyme 2 （ACE2）receptors. Therefore, specifically blocking ACE2 binding at the interface with the receptor-binding domain is promising to achieve both preventive and therapeutic effects of coronaviruses. Alternatively, drug-targeted delivery based on ACE2 receptors can further improve the efficacy and safety of inhalation drugs. Here, these two approaches are innovatively combined by designing a nanoemulsion (NE) drug delivery system (termed NE-AYQ) for inhalation that targets binding to ACE2 receptors. This inhalation-delivered remdesivir nanoemulsion (termed RDSV-NE-AYQ) effectively inhibits the infection of target cells by both wild-type and mutant viruses. The RDSV-NE-AYQ strongly inhibits Severe acute respiratory syndrome coronavirus 2 at two dimensions: they not only block the binding of the virus to host cells at the cell surface but also restrict virus replication intracellularly. Furthermore, in the mouse model of acute lung injury, the inhaled drug delivery system loaded with anti-inflammatory drugs (TPCA-1-NE-AYQ) can significantly alleviate the lung tissue injury of mice. This smart combination provides a new choice for dealing with possible emergencies in the future and for the rapid development of inhaled drugs for the treatment of respiratory diseases.

The effect of high-flow oxygen via tracheostomy on respiratory pattern and diaphragmatic function in patients with prolonged mechanical ventilation: A randomized, physiological, crossover study

Background

Compared to conventional oxygen devices, high-flow oxygen treatment (HFOT) through the nasal cannulae has demonstrated clinical benefits. Limited data exist on whether such effects are also present in HFOT through tracheostomy. Hence, we aimed to examine the short-term effects of HFOT through tracheostomy on diaphragmatic function and respiratory parameters in tracheostomized patients on prolonged mechanical ventilation.

Methods

A randomized, crossover, physiological study was conducted in our ICU between December 2020 and April 2021, in patients with tracheostomy and prolonged mechanical ventilation. The patients underwent a 30-min spontaneous breathing trial (SBT) and received oxygen either via T-piece or by HFOT through tracheostomy, followed by a washout period of 15-min breathing through the T-piece and receipt of 30-min oxygen with the other modality in a randomized crossover manner. At the start and end of each session, blood gasses, breathing frequency (f), and tidal volume (VT) via a Wright's spirometer were measured, along with diaphragm ultrasonography including diaphragm excursion and diaphragmatic thickening fraction, which expressed the inspiratory muscle effort.

Results

Eleven patients were enrolled in whom 19 sessions were uneventfully completed; eight patients were studied twice on two different days with alternate sessions; and three patients were studied once. Patients were randomly assigned to start the SBT with a T-piece (n=10 sessions) or with HFOT (n=9 sessions). With HFOT, VT and minute ventilation (VE) significantly increased during SBT (from [465±119] mL to [549±134] mL, P <0.001 and from [12.4±4.3] L/min to [13.1±4.2] L/min, P <0.05, respectively), but they did not change significantly during SBT with T-piece (from [495±132] mL to [461±123] mL and from [12.8±4.4] mL to [12.0±4.4] mL, respectively); f/VT decreased during HFOT (from [64±31] breaths/(min∙L) to [49±24] breaths/(min∙L), P <0.001), but it did not change significantly during SBT with T-piece (from [59±28] breaths/(min∙L) to [64±33] breaths/(min∙L)); partial pressure of arterial oxygen increased during HFOT (from [99±39] mmHg to [132±48] mmHg, P <0.001), but it decreased during SBT with T-piece (from [124±50] mmHg to [83±22] mmHg, P <0.01). In addition, with HFOT, diaphragmatic excursion increased (from [12.9±3.3] mm to [15.7±4.4] mm, P <0.001), but it did not change significantly during SBT with T-piece (from [13.4±3.3] mm to [13.6±3.3] mm). The diaphragmatic thickening fraction did not change during SBT either with T-piece or with HFOT.

Conclusion

In patients with prolonged mechanical ventilation, HFOT through tracheostomy compared with T-piece improves ventilation, pattern of breathing, and oxygenation without increasing the inspiratory muscle effort.

Trial Registration

Clinicaltrials.gov ldentifer: NCT04758910.

The chest X-ray score baseline in predicting continuous oxygen therapy failure in low-risk aged patients after thoracic surgery

Background

Radiographic severity assessment can be instrumental in diagnosing postoperative pulmonary complications (PPCs) and guiding oxygen therapy. The radiographic assessment of lung edema (RALE) and Brixia scores correlate with disease severity, but research on low-risk elderly patients is lacking. This study aimed to assess the efficacy of two chest X-ray scores in predicting continuous oxygen therapy (COT) treatment failure in patients over 70 years of age after thoracic surgery.

Methods

From January 2019 to December 2021, we searched for patients aged 70 years and above who underwent thoracic surgery and received COT treatment, with a focus on those at low risk of respiratory complications. Bedside chest X-rays, RALE, Brixia scores, and patient data were collected. Univariate, multivariate analyses, and 1:2 matching identified risk factors. Receiver operating characteristic (ROC) curves determined score sensitivity, specificity, and predictive values.

Results

Among the 242 patients surviving to discharge, 19 (7.9%) patients experienced COT failure. COT failure correlated with esophageal cancer surgeries, thoracotomies (36.8% vs. 9%, P=0.003; 26.3% vs. 9.4%, P=0.004), and longer operation time (3.4 vs. 2.8 h, P=0.003). Surgical approach and RALE score were independent risk factors. The prediction model had an area under the curve (AUC) of 0.839 [95% confidence interval (CI), 0.740-0.938]. Brixia and RALE scores predicted COT failure with AUCs of 0.764 (95% CI, 0.650-0.878) with a cut-off value of 6.027 and 0.710 (95% CI, 0.588-0.832) with a cut-off value of 17.134, respectively, after 1:2 matching.

Conclusions

The RALE score predict the risk of COT failure in elderly, low-risk thoracic patients better than the Brixia score. This simple, cheap, and noninvasive method helps evaluate postoperative lung damage, monitor treatment response, and provide early warning for oxygen therapy escalation. Further studies are required to confirm the validity and applicability of this model in different settings and populations.

Effect of high flow nasal oxygen on inspiratory effort of patients with acute hypoxic respiratory failure and do not intubate orders

High flow nasal oxygen (HFNO) is recommended as a first-line respiratory support during acute hypoxic respiratory failure (AHRF) and represents a proportionate treatment option for patients with do not intubate (DNI) orders. The aim of the study is to assess the effect of HFNO on inspiratory effort as assessed by esophageal manometry in a population of DNI patients suffering from AHRF. Patients with AHRF and DNI orders admitted to Respiratory intermediate Care Unit between January 1st, 2018 and May 31st, 2023 to receive HFNO and subjected to esophageal manometry were enrolled. Esophageal pressure swing (ΔPes), clinical variables before and after 2 h of HFNO and clinical outcome (including HFNO failure) were collected and compared as appropriate. The change in physiological and clinical parameters according to the intensity of baseline breathing effort was assessed and the correlation between baseline ΔPes values and the relative change in breathing effort and clinical variables after 2 h of HFNO was explored. Eighty-two consecutive patients were enrolled according to sample size calculation. Two hours after HFNO start, patients presented significant improvement in ΔPes (12 VS 16 cmH2O, p < 0.0001), respiratory rate (RR) (22 VS 28 bpm, p < 0.0001), PaO2/FiO2 (133 VS 126 mmHg, p < 0.0001), Heart rate, Acidosis, Consciousness, Oxygenation and respiratory rate (HACOR) score, (4 VS 6, p < 0.0001), Respiratory rate Oxygenation (ROX) index (8.5 VS 6.1, p < 0.0001) and BORG (1 VS 4, p < 000.1). Patients with baseline ΔPes below 20 cmH2O where those who improved all the explored variables, while patients with baseline ΔPes above 30 cmH2O did not report significant changes in physiological or clinical features. A significant correlation was found between baseline ΔPes values and after 2 h of HFNO (R2 = 0.9, p < 0.0001). ΔPes change 2 h after HFNO significantly correlated with change in BORG (p < 0.0001), ROX index (p < 0.0001), HACOR score (p < 0.001) and RR (p < 0.001). In DNI patients with AHRF, HFNO was effective in reducing breathing effort and improving respiratory and clinical variables only for those patients with not excessive inspiratory effort.

High flow nasal oxygen vs. conventional oxygen therapy over respiratory oxygenation index after esophagectomy: an observational study

Background

Postoperative pulmonary complications after esophagectomy still represent a matter of concern. High flow nasal cannula (HFNC) early after major abdominal and thoracic surgery has demonstrated some advantages over conventional oxygen therapy. Data about respiratory effect of HFNC after esophagectomy is scarce. The primary aim of this study is to investigate if the early use of HFNC after esophagectomy could enhance patients' postoperative respiratory oxygenation (ROX) index and, ultimately, reduce postoperative pneumonia.

Methods

In this single center retrospective study all patients undergoing to esophagectomy for cancer from May 2020 to November 2022 were evaluated. Historical cohort (HC) received postoperative oxygen supplementation with Venturi mask or nasal goggles, and a cohort was put under HFNC (HFNC cohort). ROX index, blood gas analysis, radiological atelectasis score (RAS), post-operative complications' data and information on hospital stay have been collected and analyzed.

Results

Seventy-one patients were included for the final statistical analysis, 31 in the HFNC and 40 in the HC cohort. Mean age was 64±10 years and body mass index (BMI) was 26 [24-29] kg/m2. ROX index was higher in the HFNC patients than in the HC, 20.8 [16.7-25.9] vs. 14.9 [10.8-18.2] (P<0.0001). In the HFNC cohort patients, pH was higher, 7.42 [7.40-7.44] vs. 7.39 [7.37-7.43] than HC, while PaCO2 was lower in HFNC cohort compared with HC, 39 [36-41] vs. 42 [39-45] mmHg, respectively (P=0.01). RAS was similar between the two cohorts of patients, 1.5±0.98 vs. 1.4±1.04 in the HFNC and the HC cohort, respectively (P=0.611). Lower acute respiratory failure (ARF) rate was recorded among HFNC than HC cohort, 0% vs. 13% respectively, P=0.06. No difference in pneumonia frequency between two cohorts was shown.

Conclusions

HFNC improved the ROX index after esophagectomy through significant respiratory rate reduction. This tool should be considered for early respiratory support after extubation in this category of patients, not only as a rescue therapy for ARF, but also to optimize early postoperative respiratory function. Whether this will improve patients' outcomes requires further large randomized controlled trials.

Administering Nitric Oxide (NO) with High Flow Nasal Cannulas: A Simple Method

Inhaled nitric oxide (iNO) is a pulmonary vasodilator that plays an important clinical ICU role. The administration of iNO is usually performed through an endotracheal tube, but spontaneously breathing patients might also benefit from iNO administration. The use of the non-invasive administration of iNO through high-flow nasal cannula (HFNC) allows for NO delivery in spontaneously breathing patients who still need supplemental oxygen and positive airway pressure. A simple method to administer NO through HFNC is described here using standard commercially available NO administration and HFNC.

Bronchodilator Efficacy of High-Flow Nasal Cannula in COPD: Vibrating Mesh Nebulizer Versus Jet Nebulizer

BACKGROUND

Jet nebulizers are commonly used for bronchodilator therapy in COPD. High-flow nasal cannula with vibrating mesh nebulizer (HFNC-VMN) is a recently developed system; however, few studies have compared the efficacy of bronchodilator administration via HFNC-VMN to jet nebulizer in stable COPD. This study aimed to compare the effect of salbutamol administered via HFNC-VMN versus jet nebulizer on airway and lung function in subjects with stable COPD.

METHODS

This randomized non-inferiority crossover physiologic study enrolled subjects with stable COPD. Salbutamol was nebulized via HFNC-VMN or jet nebulizer in random order with a 4-h washout period between crossover sequences. Spirometry, lung volume, and impulse oscillometry were performed at baseline and after each intervention. The primary outcome was change in FEV1 from baseline. Secondary outcomes included changes in other respiratory-related parameters and nebulization time compared between the 2 devices.

RESULTS

Seventeen subjects were enrolled. HFNC-VMN and jet nebulizer both significantly improved FEV1 from baseline (P = .005 and P = .002, respectively). The difference between respiratory resistance at 5 Hz and 20 Hz significantly decreased after HFNC-VMN compared to baseline (P = .02), while no significant change was observed after jet nebulizer (P = .056). Area of reactance and resonant frequency of reactance were both significantly decreased (P = .035 and P = .03, respectively), and respiratory reactance at 5 Hz significantly increased (P = .02) in the HFNC-VMN group compared to baseline indicating improved lung mechanics, with no significant changes with the jet nebulizer. HFNC-VMN had a shorter nebulization time (6 [5-9] min vs 20 [16-22] min, respectively, P < .001).

CONCLUSIONS

Bronchodilator therapy via HFNC-VMN was not inferior to jet nebulizer for subjects with stable COPD and can significantly improve airway oscillometry mechanics and decrease nebulization time compared to jet nebulizer.

Effect of maternal oxygen supplementation for parturient undergoing elective cesarean section by high-flow nasal oxygen compared with room air on fetal acidemia: study protocol for a randomized controlled trial

BACKGROUND

Maternal oxygen supplementation is usually used as an intrauterine resuscitation technique to prevent fetal hypoxia and acidemia during delivery. However, there has been a great deal of controversy regarding the effects of prophylactic maternal oxygen during cesarean section, during which the incidence of fetal acidemia seems to be higher compared with that during labor. High-flow nasal oxygen (HFNO) can improve oxygenation better in patients with high-flow oxygen airflow. The purpose of this study is to determine whether maternal oxygen supplementation with HFNO has a positive effect on fetal acidemia during cesarean section through umbilical arterial blood gas analysis.

METHOD

This prospective, single-center, randomized, double-blinded trial will enroll 120 patients undergoing cesarean section. Participants will be randomly assigned to the HFNO group or air group at a 1:1 ratio. For parturients in the HFNO group, the flow rate is 40L/min, and the oxygen is heated to 37℃ with humidity 100% oxygen concentration through the Optiflow high-flow nasal oxygen system. And for the air group, the flow rate is 2 L/min with an air pattern through the same device. The primary outcome was umbilical artery (UA) lactate. Secondary outcomes include UA pH, PO2, PCO2, BE, the incidence of pH < 7.20 and pH < 7.10, Apgar scores at 1 and 5 min, and neonatal adverse outcomes.

DISCUSSION

Our study is the first trial investigating whether maternal oxygen supplementation with HFNO can reduce the umbilical artery lactate levels and the incidence of fetal acidemia in cesarean section under combined spinal-epidural anesthesia.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05921955. Registered on 27 June 2023.

Machine learning prediction of the failure of high-flow nasal oxygen therapy in patients with acute respiratory failure

Acute respiratory failure (ARF) is a prevalent and serious condition in intensive care unit (ICU), often associated with high mortality rates. High-flow nasal oxygen (HFNO) therapy has gained popularity for treating ARF in recent years. However, there is a limited understanding of the factors that predict HFNO failure in ARF patients. This study aimed to explore early indicators of HFNO failure in ARF patients, utilizing machine learning (ML) algorithms to more accurately pinpoint individuals at elevated risk of HFNO failure. Utilizing ML algorithms, we developed seven predictive models. Their performance was evaluated using various metrics, including the area under the receiver operating characteristic curve, calibration curve, and precision recall curve. The study enrolled 700 patients, with 490 in the training group and 210 in the validation group. The overall HFNO failure rate was 14.1% among the 700 patients. The ML algorithms demonstrated robust performance in our study. This research underscores the potential of ML techniques in creating clinically relevant models for predicting HFNO outcomes in ARF patients. These models could play a pivotal role in enhancing the risk management of HFNO, leading to more patient-centered and personalized care approaches.

Safety and Outcome of High-Flow Nasal Oxygen Therapy Outside ICU Setting in Hypoxemic Patients With COVID-19

OBJECTIVE

High-flow nasal oxygen (HFNO) therapy is frequently applied outside ICU setting in hypoxemic patients with COVID-19. However, safety concerns limit more widespread use. We aimed to assess the safety and clinical outcomes of initiation of HFNO therapy in COVID-19 on non-ICU wards.

DESIGN

Prospective observational multicenter pragmatic study.

SETTING

Respiratory wards and ICUs of 10 hospitals in The Netherlands.

PATIENTS

Adult patients treated with HFNO for COVID-19-associated hypoxemia between December 2020 and July 2021 were included. Patients with treatment limitations were excluded from this analysis.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Outcomes included intubation and mortality rate, duration of hospital and ICU stay, severity of respiratory failure, and complications. Using propensity-matched analysis, we compared patients who initiated HFNO on the wards versus those in ICU. Six hundred eight patients were included, of whom 379 started HFNO on the ward and 229 in the ICU. The intubation rate in the matched cohort ( n = 214 patients) was 53% and 60% in ward and ICU starters, respectively ( p = 0.41). Mortality rates were comparable between groups (28-d [8% vs 13%], p = 0.28). ICU-free days were significantly higher in ward starters (21 vs 17 d, p < 0.001). No patient died before endotracheal intubation, and the severity of respiratory failure surrounding invasive ventilation and clinical outcomes did not differ between intubated ward and ICU starters (respiratory rate-oxygenation index 3.20 vs 3.38; Pa o2 :F io2 ratio 65 vs 64 mm Hg; prone positioning after intubation 81 vs 78%; mortality rate 17 vs 25% and ventilator-free days at 28 d 15 vs 13 d, all p values > 0.05).

CONCLUSIONS

In this large cohort of hypoxemic patients with COVID-19, initiation of HFNO outside the ICU was safe, and clinical outcomes were similar to initiation in the ICU. Furthermore, the initiation of HFNO on wards saved time in ICU without excess mortality or complicated course. Our results indicate that HFNO initiation outside ICU should be further explored in other hypoxemic diseases and clinical settings aiming to preserve ICU capacity and healthcare costs.

High-Flow Nasal Cannula in COVID-19 Patients With Moderate to Severe Respiratory Distress: A Retrospective Analysis

BACKGROUND

A high-flow nasal cannula (HFNC) is a device for non-invasive ventilation (NIV). It was utilized during the COVID-19 pandemic in patients with moderate to severe respiratory distress due to its benefit profile in delaying intubation, ease of use, and comfort of patients in comparison to NIV.

OBJECTIVES

Our main objective is to calculate the intubation rate of patients with suspected or lab-confirmed COVID-19 in moderate to severe respiratory distress who failed graded oxygen therapy (GOT). Before incorporating HFNC as a treatment option, the intubation rate was 100% after GOT failure. We calculated the rate of intubation at two, six, and 12 hours of starting HFNC, where each patient is in their own control with an assumed intubation rate of 100%. Other objectives include measuring the rate of improvement of the ROX index, respiratory rate (RR), and oxygen saturation (SPO2) levels at two, six, and 12 hours.

METHODS

We retrospectively screened patients with suspected or lab-confirmed COVID-19 infection in moderate to severe respiratory distress at Rashid Hospital Trauma Center, Emergency Department in Dubai, United Arab Emirates, from April 10, 2020, until December 31, 2020. The list of patients was pooled from the SALAMA electronic system.

RESULTS

A total of 121 patients were included in the analysis. Assuming an intubation rate of 100% at 0 hours (end of GOT), after starting HFNC, the intubation rate (primary outcome) at two hours was 7.43% (9/121), at six hours was 7.14% (8/112), and at 12 hours was 5.77% (6/104). The total intubation rate at 12 hours was 19% (23/121). The use of HFNC was also shown to improve the ROX index, RR, and SPO2 at two, six, and 12 hours.

CONCLUSION

In patients with suspected or lab-confirmed COVID-19 in moderate to severe respiratory distress who failed GOT and were started on HFNC, it was noted that the intubation rate decreased from an assumed rate of 100% to 19% at 12 hours from starting the treatment. There was also a statistically significant improvement in the ROX index, SPO2, and RR at two, six, and 12 hours from the initiation at 0 hours.

Heart Transplantation-Postoperative Considerations

Heart transplantation (HT) remains the best treatment of patients with severe heart failure who are deemed to be transplant candidates. The authors discuss postoperative management of the HT recipient by system, emphasizing areas where care might differ from other cardiac surgery patients. Working together, critical care physicians, heart transplant surgeons and cardiologists, advanced practice providers, pharmacists, transplant coordinators, nursing staff, physical therapists, occupational therapists, rehabilitation specialists, nutritionists, health psychologists, social workers, and the patient and their loved ones partner to increase the likelihood of a successful outcome.

Personalized Noninvasive Respiratory Support in the Perioperative Setting: State of the Art and Future Perspectives

Background: Noninvasive respiratory support (NRS), including high-flow nasal oxygen therapy (HFNOT), noninvasive ventilation (NIV) and continuous positive airway pressure (CPAP), are routinely used in the perioperative period. Objectives: This narrative review provides an overview on the perioperative use of NRS. Preoperative, intraoperative, and postoperative respiratory support is discussed, along with potential future areas of research. Results: During induction of anesthesia, in selected patients at high risk of difficult intubation, NIV is associated with improved gas exchange and reduced risk of postoperative respiratory complications. HFNOT demonstrated an improvement in oxygenation. Evidence on the intraoperative use of NRS is limited. Compared with conventional oxygenation, HFNOT is associated with a reduced risk of hypoxemia during procedural sedation, and recent data indicate a possible role for HFNOT for intraoperative apneic oxygenation in specific surgical contexts. After extubation, "preemptive" NIV and HFNOT in unselected cohorts do not affect clinical outcome. Postoperative "curative" NIV in high-risk patients and among those exhibiting signs of respiratory failure can reduce reintubation rate, especially after abdominal surgery. Data on postoperative "curative" HFNOT are limited. Conclusions: There is increasing evidence on the perioperative use of NRS. Use of NRS should be tailored based on the patient's specific characteristics and type of surgery, aimed at a personalized cost-effective approach.

Noninvasive vs Invasive Respiratory Support for Patients with Acute Hypoxemic Respiratory Failure

Rationale

Noninvasive respiratory support modalities are common alternatives to mechanical ventilation for patients with early acute hypoxemic respiratory failure. These modalities include noninvasive positive pressure ventilation, using either continuous or bilevel positive airway pressure, and nasal high flow using a high flow nasal cannula system. However, outcomes data historically compare noninvasive respiratory support to conventional oxygen rather than to mechanical ventilation.

Objectives

The goal of this study was to compare the outcomes of in-hospital death and alive discharge in patients with acute hypoxemic respiratory failure when treated initially with noninvasive respiratory support compared to patients treated initially with invasive mechanical ventilation.

Methods

We used a validated phenotyping algorithm to classify all patients with eligible International Classification of Diseases codes at a large healthcare network between January 1, 2018 and December 31, 2019 into noninvasive respiratory support and invasive mechanical ventilation cohorts. The primary outcome was time-to-in-hospital death analyzed using an inverse probability of treatment weighted Cox model adjusted for potential confounders, with estimated cumulative incidence curves. Secondary outcomes included time-to-hospital discharge alive. A secondary analysis was conducted to examine potential differences between noninvasive positive pressure ventilation and nasal high flow.

Results

During the study period, 3177 patients met inclusion criteria (40% invasive mechanical ventilation, 60% noninvasive respiratory support). Initial noninvasive respiratory support was not associated with a decreased hazard of in-hospital death (HR: 0.65, 95% CI: 0.35 - 1.2), but was associated with an increased hazard of discharge alive (HR: 2.26, 95% CI: 1.92 - 2.67). In-hospital death varied between the nasal high flow (HR 3.27, 95% CI: 1.43 - 7.45) and noninvasive positive pressure ventilation (HR 0.52, 95% CI 0.25 - 1.07), but both were associated with increased likelihood of discharge alive (nasal high flow HR 2.12, 95 CI: 1.25 - 3.57; noninvasive positive pressure ventilation HR 2.29, 95% CI: 1.92 - 2.74).

Conclusion

These observational data from a large healthcare network show that noninvasive respiratory support is not associated with reduced hazards of in-hospital death but is associated with hospital discharge alive. There are also potential differences between the noninvasive respiratory support modalities.

Effect of noninvasive respiratory support after extubation on postoperative pulmonary complications in obese patients: A systematic review and network meta-analysis

STUDY OBJECTIVE

Obesity is associated with an increased risk of sleep-disordered breathing (SDB) and postoperative pulmonary complications (PPCs). Postoperative noninvasive respiratory support (NRS) has been recommended to obese patients despite the controversy about its benefit. The network meta-analysis (NMA) was used in this study to compare the effect of different methods of NRS on preventing PPCs in obese patients.

DESIGN

This study is a network meta-analysis.

SETTING

Post-anesthesia care unit and inpatient ward.

PATIENTS

20 randomized controlled trials involving 1184 obese patients were included in the final analysis.

INTERVENTIONS

One of the four NRS techniques, which include continuous positive airway pressure (CPAP), bi-level positive airway pressure (BiPAP), high-flow nasal cannula (HFNC), or conventional oxygen therapy (COT), was performed after general anesthesia.

MEASUREMENTS

The primary outcome was the incidence of PPCs, e.g., atelectasis, pneumonia, hypoxemia, and respiratory failure. The secondary outcomes included the incidence of oxygen treatment failure and anastomotic leakage, oxygenation index, and length of hospital stay (LOS). RevMan 5.3 and STATA 16.0 were used to analyze the results and any potential bias.

MAIN RESULTS

Compared with COT, BiPAP and HFNC were both effective in reducing the occurrence of postoperative atelectasis. There were no significant differences in the occurrence of other PPCs including pneumonia, hypoxemia and respiratory failure between the four NRS techniques. CPAP and HFNC were superior to other techniques in improving oxygenation and shortening LOS respectively. No differences were found in oxygen treatment failure and anastomotic leakage between the patients with different NRS. HFNC ranked the first in five of the eight outcomes (hypoxemia, respiratory failure, treatment failure, anastomotic leakage, LOS) in this review by the surface under the cumulative ranking curve (SUCRA).

CONCLUSION

Among the four postoperative NRS techniques, HFNC seems to be the optimal choice for obese patients which shows certain advantages in reducing the risk of PPCs and shortening LOS.

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.

Subphenotypes in patients with acute respiratory distress syndrome treated with high-flow oxygen

BACKGROUND

Acute respiratory distress syndrome (ARDS) subphenotypes differ in outcomes and treatment responses. Subphenotypes in high-flow nasal oxygen (HFNO)-treated ARDS patients have not been investigated.

OBJECTIVES

To identify biological subphenotypes in HFNO-treated ARDS patients.

METHODS

Secondary analysis of a prospective multicenter observational study including ARDS patients supported with HFNO. Plasma inflammation markers (interleukin [IL]-6, IL-8, and IL-33 and soluble suppression of tumorigenicity-2 [sST2]) and lung epithelial (receptor for advanced glycation end products [RAGE] and surfactant protein D [SP-D]) and endothelial (angiopoietin-2 [Ang-2]) injury were measured. These biomarkers and bicarbonate were used in K-means cluster analysis to identify subphenotypes. Logistic regression was performed on biomarker combinations to predict clustering. We chose the model with the best AUROC and the lowest number of variables. This model was used to describe the HAIS (High-flow ARDS Inflammatory Subphenotype) score.

RESULTS

Among 41 HFNO patients, two subphenotypes were identified. Hyperinflammatory subphenotype (n = 17) showed higher biomarker levels than hypoinflammatory (n = 24). Despite similar baseline characteristics, the hyperinflammatory subphenotype had higher 60-day mortality (47 vs 8.3% p = 0.014) and longer ICU length of stay (22.0 days [18.0-30.0] vs 39.5 [25.5-60.0], p = 0.034). The HAIS score, based on IL-8 and sST2, accurately distinguished subphenotypes (AUROC 0.96 [95%CI: 0.90-1.00]). A HAIS score ≥ 7.45 was predictor of hyperinflammatory subphenotype.

CONCLUSION

ARDS patients treated with HFNO exhibit two biological subphenotypes that have similar clinical characteristics, but hyperinflammatory patients have worse outcomes. The HAIS score may identify patients with hyperinflammatory subphenotype and might be used for enrichment strategies in future clinical trials.

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.

High flow nasal cannula versus noninvasive ventilation in the treatment of acute hypercapnic respiratory failure: A systematic review and meta-analysis

Chronic obstructive pulmonary disease can lead to acute hypercapnic respiratory failure (AHRF), often treated using noninvasive ventilation (NIV). Emerging research suggests the potential utility of high flow nasal cannula (HFNC) for AHRF. This systematic review and meta-analysis aimed to determine the effect of HFNC versus NIV on AHRF management. A search of electronic databases (CINAHL, MEDLINE, and Academic Search Complete), web sources, and trial registries was last conducted on 9 February 2023. Quality and risk of bias assessments were conducted. Meta-analyses were used to synthesise data. Seven randomised controlled trials were included. No statistically significant differences between HFNC and NIV were found within the following outcomes of interest: (i) correction of pCO2: standardised mean difference (SMD) = -0.16, 95% confidence interval (CI) (-0.34 to 0.02), p = 0.08; (ii) correction of pH: SMD = -0.05, 95% CI (-0.25 to 0.14), p = 0.59; (iii) correction of pO2: SMD = -0.15, 95% CI (-0.40 to 0.09), p = 0.22; (iv) intubation rates: risk ratio (RR) = 0.87, 95% CI (0.41 to 1.82), p = 0.71; (v) mortality rates: RR = 0.85, 95% CI (0.47 to 1.56), p = 0.61; and (vi) treatment switch: RR = 1.30, 95% CI (0.43 to 3.94), p = 0.64. More controlled trials with large sample sizes are required to investigate the management of AHRF of various aetiologies. HFNC may be used as a final exhaustive measure for COPD-related AHRF where NIV is not tolerated, and when it is not clinically indicated to extend to endotracheal intubation.

Failure of Non-Invasive Respiratory Support in Patients with SARS-CoV-2

INTRODUCTION

The objective of this study is to assess the failure of therapies with HFNO (high-flow nasal oxygen), CPAP, Bilevel, or combined therapy in patients with hypoxemic acute respiratory failure due to SARS-CoV-2 during their hospitalization.

METHODS

This was a retrospective and observational study of SARS-CoV-2-positive patients who required non-invasive respiratory support (NIRS) at the Reina Sofía General University Hospital of Murcia between March 2020 and May 2021.

RESULTS

Of 7355 patients, 197 (11.8%) were included; 95 of them failed this therapy (48.3%). We found that during hospitalization in the ward, the combined therapy of HFNO and CPAP had an overall lower failure rate and the highest treatment with Bilevel (p = 0.005). In the comparison of failure in therapy without two levels of airway pressure, HFNO, CPAP, and combined therapy of HFNO with CPAP, (35.6% of patients) presented with 24.2% failure, compared to those who had two levels of pressure with Bilevel and combined therapy of HFNO with Bilevel (64.4% of patients), with 75.8% associated failure (OR: 0, 374; CI 95%: 0.203-0.688. p = 0.001).

CONCLUSIONS

The use of NIRS during conventional hospitalization is safe and effective in patients with respiratory failure secondary to SARS-CoV-2 infection. The therapeutic strategy of Bilevel increases the probability of failure, with the combined therapy strategy of CPAP and HFNO being the most promising option.

High-Flow Nasal Cannula oxygen therapy in COVID-19: retrospective analysis of clinical outcomes - single center experience

Background

High-Flow Nasal Cannula (HFNC) oxygen therapy emerged as the therapy of choice in COVID-19-related pneumonia and moderate to severe acute hypoxemic respiratory failure (AHRF). HFNC oxygen therapy in COVID-19 has been recommended based its use to treat AHRF of other etiologies, and studies on assessing outcomes in COVID-19 patients are highly needed. This study aimed to examine outcomes in COVID-19 patients with pneumonia and severe AHRF treated with HFNC.

Materials and methods

The study included 235 COVID-19 patients with pneumonia treated with HFNC. Data extracted from medical records included demographic characteristics, comorbidities, laboratory parameters, clinical and oxygenation status, clinical complications, as well as the length of hospital stay. Patients were segregated into two groups based on their oxygen therapy needs: HDU group, those who exclusively required HFNC and ICU group, those whose oxygen therapy needed to be escalated at some point of hospital stay. The primary outcome was the need for respiratory support escalation (noninvasive or invasive mechanical ventilation) and the secondary outcome was the in-hospital all-cause mortality.

Results

The primary outcome was met in 113 (48%) of patients. The overall mortality was 70%, significantly higher in the ICU group [102 (90.2%) vs. 62 (50.1%), p < 0.001]. The rate of intrahospital infections was significantly higher in the ICU group while there were no significant differences in the length of hospital stay between the groups. The ICU group exhibited significant increases in D-dimer, NLR, and NEWS values, accompanied by a significant decrease in the SaO2/FiO2 ratio. The multivariable COX proportional regression analysis identified malignancy, higher levels of 4C Mortality Score and NEWS2 as significant predictors of mortality.

Conclusion

High-Flow Nasal Cannula oxygen therapy is a safe type of respiratory support in patients with COVID-19 pneumonia and acute hypoxemic respiratory failure with significantly less possibility for emergence of intrahospital infections. In 52% of patients, HFNC was successful in treating AHRF in COVID-19 patients. Overall, mortality in COVID-19 pneumonia with AHRF is still very high, especially in patients treated with noninvasive/invasive mechanical ventilation.

Application of 24-h respiratory rate and oxygenation index variation to predict the outcome of high-flow nasal cannula therapy in patients with acute hypoxemic respiratory failure in a respiratory intensive care unit

Background: An evaluation system is urgently needed to describe early predictors of the outcome of high-flow nasal cannula (HFNC) oxygen therapy in acute hypoxemic respiratory failure (AHRF) patients. Methods: All consecutive AHRF patients in a Respiratory Intensive Care Unit (RICU) receiving HFNC therapy between January 2019 and December 2021 were enrolled. Results: Of the 106 enrolled AHRF subjects, 57 (53.8%) succeeded in HFNC therapy and 49 (46.2%) failed. Being male (p = 0.006), initial respiratory rate oxygenation (ROX) index (p = 0.011), Acute Physiology and Chronic Health Evaluation II score (p = 0.007) and 24-h ROX index variation rate (p = 0.004) were independent factors of HFNC outcome; among these, 24-h ROX index variation rate (area under the curve = 0.825) was the best evaluation indicator. Conclusion: 24-h ROX index variation rate, introduced by our study, has shown the best potential to predict HFNC outcome in AHRF patients.