High-flow nasal cannula reduces intubation rate in patients with COVID-19 with acute respiratory failure: a meta-analysis and systematic review

Incidence of nosocomial pneumonia in two intensive care units of a French University Hospital from 2016 to 2022 in the era of COVID-19 pandemic

Background

Hospital-Acquired Pneumonia (HAP) are common in intensive care units (ICUs). The COVID-19 pandemic led to a global increase in healthcare-associated infections (HAI) among ICU patients. The aim of this study was to evaluate the trends in HAP incidence over a seven-year period of surveillance in two ICUs at a French University Hospital, and to assess the impact of COVID-19 (as well as the associated bacterial ecology).

Methods

A prospective surveillance of HAI in ICUs was conducted during the 1st quarter of each year between 2016 and 2022 (2020: reference year). Socio-demographic, clinical and bacteriological data were collected and the incidence of HAP was calculated. Poisson regressions were done and crude and adjusted incidence rate ratio were calculated.

Results

1,797 patients were included, with 61.3% of male and a median age of 67 years. The median duration of intubation was 4 days (7 days in 2021 and 5 days in 2022). The proportion of COVID-19 patients was 45.7% in 2021 and 24.1% in 2022. Compared to 2020, the incidence of HAP increased in both 2021 [cIRR: 2.34 (95%CI: 1.30-4.23) and aIRR: 2.26 (95%CI: 1.25-4.08)] and 2022 [cIRR: 1.79 (95%CI: 0.97-3.32) and aIRR: 1.66 (95%CI: 0.90-3.07)]. The most commonly identified microorganisms were Enterobacteriaceae (42.4%), with a significantly higher incidence of HAP due to Enterobacteriaceae in COVID-19 patients.

Conclusions

These results indicate an increase of HAP incidence in 2021 and 2022, mainly caused by Enterobacteriaceae in COVID-19 patients. This trend needs to be confirmed or refuted in the post-pandemic era.

From pandemic onset to present: five years of insights into ARDS caused by COVID-19

INTRODUCTION

COVID-19-associated acute respiratory distress syndrome (ARDS) has challenged healthcare systems, initially resembling classical ARDS but later recognized as distinct. Unique features such as endothelial injury, microthrombosis, and dysregulated inflammation influenced treatment efficacy. Understanding its evolution is key to optimizing therapy and improving outcomes.

AREAS COVERED

This review synthesizes current evidence on COVID-19-associated ARDS, covering epidemiology, pathophysiology, clinical phenotypes, and treatments. It explores the shift from L and H phenotypes to a refined disease model and highlights key therapies, including corticosteroids, immunomodulators, prone positioning, ECMO, and vaccination's impact on severity and ARDS incidence.

EXPERT OPINION

At the onset of the COVID-19 pandemic in December 2019, uncertainty was overwhelming. Early clinical guidelines relied on case reports and small case series, offering only preliminary insights into disease progression and management. Despite the initial chaos, the scientific community launched an unprecedented research effort, with over 11,000 clinical trials registered on ClinicalTrials.gov investigating COVID-19 treatments. Several evidence-based strategies emerged as gold standards for managing COVID-19-associated acute respiratory distress syndrome, surpassing prior approaches. The pandemic exposed vulnerabilities in global healthcare, reshaped modern medicine, accelerated innovation, and reinforced the essential role of evidence-based practice in critical care and public health policy.

The role of high flow nasal oxygen therapy in acute hypoxemic respiratory failure due to COVID-19 pneumonia

BACKGROUND

The use of high flow nasal oxygen therapy (HFNO) may improve clinical outcomes in acute hypoxemic respiratory failure (AHRF) compared to conventional oxygen. However, whether the use of HFNO improves clinical outcomes in COVID-19 pneumonia remains unclear. In this study, we describe the use of HFNO, as compared to conventional oxygen therapy (COT), in moderate to severe COVID-19 pneumonia.

METHODS

This is a retrospective cohort study conducted at one academic medical center and one community hospital between March 1, 2020 and July 14, 2020. The primary purpose of the study was to determine the success of HFNO in preventing the composite outcome of invasive mechanical ventilation (IMV) or in-hospital death compared to COT. Secondary objectives included determining the predictors of this composite outcome, rate of endotracheal intubation, hospital mortality and outcomes of early versus late HFNO failure. Logistic and quantile regression were used to test for associations.

RESULTS

A total of 197 patients were included, 166 in the HFNO and 31 in the COT group. There was no significant difference between the groups in the composite outcome of IMV or death, odds ratio (OR) = 0.36, p = 0.08. Use of HFNO as opposed to COT was associated with a significant reduction in the rate of IMV (64 % versus 87 %, p = 0.03). Older age and coronary artery disease were associated with HFNO failure. There was no significant mortality difference between early and late IMV.

CONCLUSION

In our study, HFNO did not reduce our primary composite outcome of IMV or death in moderate to severe AHRF, although we found that HFNO was associated with lower rate of intubation compared to COT. We detected no benefit of early vs late IMV. Utilizing HFNO in COVID-19 patients with AHRF may be a reasonable initial respiratory support strategy with close monitoring. Additional studies are needed to determine subset(s) of such patients that would benefit the most from HFNO use.

High-flow nasal oxygen vs. conventional oxygen therapy in patients with COVID-19 related acute hypoxemic respiratory failure and a do not intubate order: a multicentre cohort study

BACKGROUND

High-flow nasal oxygen (HFNO) is frequently used to treat patients with acute hypoxemic respiratory failure (AHRF) due to viral pneumonia, including COVID-19. However, its clinical effect compared to conventional oxygen therapy (COT) remains largely unexplored in patients with a do not intubate (DNI) order. We aimed to assess whether HFNO compared to COT is associated with improved clinical outcomes in hospitalized patients with AHRF due to COVID-19 and a DNI order.

METHODS

This analysis included patients with a DNI order and SARS-CoV-2 infection, selected from three observational studies, who were treated with COT only or HFNO. The primary endpoint was in-hospital mortality, the secondary endpoint was hospital length of stay (LOS). The effect of HFNO vs. COT was assessed using multivariable regression, accounting for pre-selected confounders.

RESULTS

Between March 2020 and September 2021, 116 patients received HFNO and 110 patients received COT. Median age was 78 [72-83], and 78% of the patients had a Clinical Frailty Scale score of 4 to 9. In-hospital mortality was 64% for HFNO and 71% for COT (p = 0.29), with an adjusted odds ratio of 0.72 (95% confidence interval [0.34-1.54], p = 0.40). Hospital LOS was 11 [6-18] days for HFNO, and 7 [4-12] days for COT (p < 0.001), with a remaining difference after adjusting for confounders (p < 0.01).

CONCLUSION

The lack of survival benefit and increased hospital LOS should be taken into account when considering HFNO for patients with a DNI order, suffering from AHRF due to viral pneumonia, like COVID-19.

CLINICAL TRIAL REGISTRATION

HFNO-COVID-19 study: DTR, NL9067 (Dutch Trial Registry), registration date: 27-11-2020.

Factors associated with the survival of adults with COVID-19 using a high-flow nasal cannula in a tertiary hospital in northern Peru during the second wave of the pandemic

OBJECTIVES

To identify factors associated with survival in patients admitted to the intensive care unit (ICU) for COVID-19 who used high-flow nasal cannula (HFNC) in a tertiary hospital in northern Peru during March to May 2021.

METHODOLOGY

A retrospective observational cohort study was carried out, including medical records selected according to established inclusion criteria. The dependent variable was survival, measured in days from admission to hospital discharge or death. Factors associated with survival related to demographic, clinical, laboratory, and imaging characteristics were investigated, as well as treatment-related parameters and variables associated with the use of HFNC. Hazard ratios (HR) were estimated to identify independent risk factors associated with survival.

RESULTS

Of 154 patients, the mean age was 58.29 years. The most frequent comorbidities were arterial hypertension (29.2%), diabetes mellitus (20.6%), and obesity (17.4%). The median time of HFNC use was 5 days (interquartile range: 3-9 days). It was found that 32.2% of the patients required mechanical ventilation, and 51.6% died. The mean time of mechanical ventilation use was 15.1 ± 13.3 days. Survival was 97.5% at 48 hours, 85% at 7 days, 62% at 14 days, and 16.3% at the end of the study. Variables decreasing survival in patients with COVID-19 who were users of NFVC were age ≥ 60 years (HR = 2.23; 95% CI: 1.21-4.08), presence of arterial hypertension (HR = 1.87; 95% CI: 1.01-3.45), increased work of breathing on hospital admission (HR = 2.38; 95% CI: 1.31-4.35), and a ROX index (iROX) < 3.85 (HR = 1.71; 95% CI: 1.01-2.93).

CONCLUSIONS

Factors associated with survival were arterial hypertension and iROX < 3.85 with a mortality hazard of 1.5 times, age older than 60 years, and respiratory effort scale at admission WOB ≥ 4 points with more than twice the mortality hazard. The results of this study highlight the importance of early and accurate assessment of risk factors in patients with COVID-19 who use HFNC. Identifying these factors can help clinicians make more informed decisions and prioritize interventions that could potentially improve survival in this group of patients.

Short-acting β2 Agonist Inhalation Therapy for Asthma or Chronic Obstructive Pulmonary Disease with a High-flow Nasal Cannula in Japan -An Online Questionnaire Survey by the Japanese Respiratory Society, Japanese Society of Intensive Care Medicine, and Japanese Society of Respiratory Care Medicine

Objective Short-acting β2 agonists (SABAs) are key drugs for the treatment of asthma and chronic obstructive pulmonary disease (COPD). A high-flow nasal cannula (HFNC) is widely used for respiratory failure. Recently, a consensus statement on inhalation therapy with HFNC has been published. However, information regarding the real-world state of inhalation therapy practices in Japan is lacking. Methods An anonymous online questionnaire survey endorsed by three Japanese associations (the Japanese Respiratory Society, Japanese Society of Intensive Care Medicine, and Japanese Society of Respiratory Care Medicine) was administered from October to November 2023. Responses were stratified into three questions: Question A, "Do you routinely treat patients with asthma and COPD?" Question B "Do you routinely perform high-flow therapy?"; and Question C "How do you provide inhaled SABAs during high-flow therapy in patients with asthma or COPD?" Participants This questionnaire was distributed to all members of the three societies. Results Of the 567 participants who completed the questionnaire, 387 responded to all 3 questions. When a nebulizer was included in high-flow devices, the frequencies of using an ultrasonic nebulizer, jet, vibrating mesh, other, or not performing nebulization were 49.1%, 30.8%, 5.4%, 0.5%, and 14.2%, respectively; when a nebulizer was included in high-flow devices, these frequencies were 24.0%, 11.1%, 16.0%, 0%, and 48.9%, respectively. Conclusion Various techniques for inhalation therapy are being employed, revealing a discrepancy between current practices in Japan and the recommendations outlined in the consensus statement.

Efficacy of High Flow Nasal Cannula in the Treatment of Patients with COVID-19 with Acute Respiratory Distress Syndrome: Results of Single Centre Study in Vietnam

INTRODUCTION

Most hospitalized patients required invasive or non-invasive ventilation and High Flow Nasal Cannula (HFNC). Therefore, this study was conducted to describe the characteristics of patients with severe Coronavirus Disease-2019 (COVID-19) treated by HFNC and its effectiveness for reducing the rate of intubated-mechanical ventilation in the Intensive Care Unit (ICU) of Phu Chanh COVID-19 Department-Binh Duong General Hospital.

METHODS

It was a cross-sectional and descriptive study. All severe patients with COVID-19 with acute respiratory failure eligible for the study were included. Patient characteristics, clinical symptoms, laboratory results, and treatment methods were collected for analysis; parameters and data related to HFNC treatment and follow-up were analysed.

RESULTS

80 patients, aged of 49.7 ± 16.6 years, were treated with HFNC at admission in ICU. 14 patients had type 2 diabetes (17.5%), 3 patients had chronic respiratory disease (3.8%), 19 patients had high blood pressure (23.8%), and 5 patients with other comorbidities (7.4%). The majority of patients with severe COVID-19 had typical symptoms of COVID-19 such as shortness of breath (97.5%), intensive tired (81.3%), cough (73.7%), anosmia (48.3%), ageusia (41.3%), and fever (26.3%). The results of arterial blood gases demonstrated severe hypoxia under optimal conventional oxygen therapy (PaO2 = 52.5 ± 17.4 mmHg). Respiratory rate, SpO2, PaO2 were significantly improved after using HFNC at 1st day, 3rd day and 7th day (P < 0.05; P < 0.05; P < 0.01; respectively). Receiver operating characteristics (ROC) index was significantly increased after treating with HFNC vs before HFNC treatment (4.79 ± 1.86, 5.53 ± 2.39, and 7.41 ± 4.24 vs 2.97 ± 0.39; P < 0.05, P < 0.05 and P < 0.01, respectively). 54 (67.5%) patients were success with HFNC treatment and 26 (32.5%) patients with HFNC failure needed to treat with Continuous Positive Airway Pressure (CPAP) (13 patients; 50%) or intubated ventilation (13 patients; 50%).

CONCLUSION

HFNC therapy could be considered as a useful and effective alternative treatment for patients with acute respiratory failure. HFNC might help to delay the intubated ventilation for patients with respiratory failure and to minimise the risk of invasive ventilation complications and mortality. However, it is crucial to closely monitor the evolution of patient's respiratory status and responsiveness of HFNC treatment to avoid unintended delay of intubation-mechanical ventilation.

TRIAL REGISTRATION

An independent ethics committee approved the study (The Ethics Committee of Binh Duong General Hospital; No. HDDD-BVDK BINH DUONG 9.2021), which was performed in accordance with the Declaration of Helsinki, Guidelines for Good Clinical Practice.

2023 Year in Review: High-Flow Nasal Cannula for COVID-19

COVID-19, caused by SARS-CoV-2 infection, led to a pandemic of acute respiratory illness that is ongoing. High-flow nasal cannula (HFNC) is a commonly used form of respiratory support during acute respiratory distress and is used to treat patients with COVID-19 in many centers. Due to the novel nature of COVID-19 at the onset of the pandemic, evidence to support the use and best practices of HFNC for treating patients with COVID-19 was lacking. This is a review of key peer-reviewed manuscripts from 2022-2023 discussing the efficacy and best practices for using HFNC for patients with COVID-19. Efficacy of HFNC for COVID-19, the use of the respiratory oxygenation index to guide HFNC for COVID-19, and concerns of generated/fugitive aerosols when using HFNC for COVID-19 are emphasized.

CPAP vs HFNC in treatment of patients with COVID-19 ARDS: A retrospective propensity-matched study

Background

Previous studies exploring the application of noninvasive ventilation or high-flow nasal cannula in patients with COVID-19-related acute respiratory distress syndrome (ARDS) have yielded conflicting results on whether any method of respiratory support is superior. Our aim is to compare the efficacy and safety of respiratory therapy with high-flow nasal cannula and noninvasive ventilation with continuous positive airway pressure in treatment of COVID-19-related ARDS.

Methods

This is a retrospective cohort study based on data from patients who received respiratory support as part of their treatment in the COVID intensive care unit at the University Hospital Centre Zagreb between February 2021 and February 2023. Using propensity score analysis, 42 patients treated with high-flow nasal cannula (HFNC group) were compared to 42 patients treated with noninvasive ventilation with continuous positive airway pressure (CPAP group). Primary outcome was intubation rate.

Results

Intubation rate was 71.4% (30/42) in the HFNC group and 40.5% (17/42) in the CPAP group (p = 0.004). Hazard ratio for intubation was 3.676 (95% confidence interval [CI] 1.480 to 9.232) with the HFNC versus CPAP group. Marginally significant difference in survival between the two groups was observed at 30 days (p = 0.050) but was statistically significant at 60 days (p = 0.043).

Conclusions

Respiratory support with high-flow nasal cannula and noninvasive ventilation with continuous positive airway pressure yielded significantly different intubation rates in favour of continuous positive airway pressure. The same patients also had better 30-day and 60-day survival post-admission.

Specific and Non-specific Aspects and Future Challenges of ICU Care Among COVID-19 Patients with Obesity: A Narrative Review

PURPOSE OF REVIEW

Since the end of 2019, the coronavirus disease 2019 (COVID-19) pandemic has infected nearly 800 million people and caused almost seven million deaths. Obesity was quickly identified as a risk factor for severe COVID-19, ICU admission, acute respiratory distress syndrome, organ support including mechanical ventilation and prolonged length of stay. The relationship among obesity; COVID-19; and respiratory, thrombotic, and renal complications upon admission to the ICU is unclear.

RECENT FINDINGS

The predominant effect of a hyperinflammatory status or a cytokine storm has been suggested in patients with obesity, but more recent studies have challenged this hypothesis. Numerous studies have also shown increased mortality among critically ill patients with obesity and COVID-19, casting doubt on the obesity paradox, with survival advantages with overweight and mild obesity being reported in other ICU syndromes. Finally, it is now clear that the increase in the global prevalence of overweight and obesity is a major public health issue that must be accompanied by a transformation of our ICUs, both in terms of equipment and human resources. Research must also focus more on these patients to improve their care. In this review, we focused on the central role of obesity in critically ill patients during this pandemic, highlighting its specificities during their stay in the ICU, identifying the lessons we have learned, and identifying areas for future research as well as the future challenges for ICU activity.

Predictors of high-flow nasal cannula failure in COVID-19 patients in a northern Peruvian hospital

OBJECTIVES

To determine predictors of high-flow nasal cannula (HFNC) failure in COVID-19 patients in a hospital in northern Peru.

METHODOLOGY

A retrospective cohort study was conducted during the months of March and May 2021. Data collection was based on a follow-up of 156 hospitalized patients with a diagnosis of COVID-19 who were users of HFNC. Epidemiological factors and clinical outcomes of treatment were analyzed from medical records. Epidemiological, analytical, and HFNC use-related characteristics were described using measures of absolute and relative frequencies, measures of central tendency, and dispersion. A multivariate Poisson regression analysis with robust variance and a 95% confidence interval was performed.

RESULTS

We found that age, SpO2/FiO2, work of breathing (WOB scale) at admission, degree of involvement, type of infiltrate on CT scan, lymphocytes, c-reactive protein, and D-dimer were significantly associated with failure of HFNC (p < 0.05). In addition, the WOB scale, PaO2/FiO2, SaO2/FiO2, and ROX index were variables that presented statistical significance (p < 0.0001). In the multivariate analysis model, a risk of failure of HFNC was determined with age > = 60 years [RRa 1.39 (1.05-1.85)] and PaO2/FiO2 score less than 100 [Rra 1.65 (0.99-2.76)].

CONCLUSIONS

Predictors to failure of HFNC are age older than 60 years and minimally significantly lower PaO2/FiO2 than 100.

Effectiveness, Adherence and Safety of Home High Flow Nasal Cannula in Chronic Respiratory Disease and Respiratory Insufficiency: A Systematic Review

INTRODUCTION

The effectiveness of home high flow nasal cannula (HFNC) for the treatment of chronic respiratory failure in patients with chronic respiratory diseases (CRDs) has not been summarized. We aimed to conduct a systematic review of the effectiveness, adherence, and safety of HFNC in the long-term treatment of patients with chronic respiratory diseases and respiratory failure.

METHODS

A systematic review was conducted. PubMed, Web of science, and SCOPUS were search up to August 2023. Long-term HFNC studies (≥4 weeks) reporting dyspnea; exacerbations, hospitalizations; peripheral oxygen saturation (SpO2), comfort; patient experience, health-related quality of life or partial pressure of carbon dioxide (paCO2) were included.

RESULTS

Thirteen articles (701 patients) based on 10 studies were selected: randomized control trials (n=3), randomized crossover trials (n=2), crossover (n=3) and retrospective (n=2) studies. COPD (n=6), bronchiectasis (n=2), COPD/bronchiectasis (n=1) and ILD (n=1) were the underlined CRDs. HFNC reduced exacerbations when compared to usual care/home respiratory therapies (n=6). Quality of life outcomes were also in favor of HFNC in patients with COPD and bronchiectasis (n=6). HFNC had significant effects on hospitalizations, paCO2, and lung function. Adherence ranged from 5.2 to 8.6h/day (n=5). Three studies reported no events, 3 non-serious events and 2 no differences compared with other home respiratory therapies.

CONCLUSIONS

HFNC seems more effective than usual care or other home respiratory therapies in reducing exacerbations and improving quality of life in patients with COPD and bronchiectasis, while presenting good adherence and being safe. Its apparently superior effectiveness needs to be better studied in future real-world pragmatic trials.

A comparison study of temporal trends of SARS-CoV2 RNAemia and biomarkers to predict success and failure of high flow oxygen therapy among patients with moderate to severe COVID-19

Optimal timing for intubating patients with coronavirus disease 2019 (COVID-19) has been debated throughout the pandemic. Early use of high-flow nasal cannula (HFNC) can help reduce the need for intubation, but delay can result in poorer outcomes. This study examines trends in laboratory parameters and serum severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA levels of patients with COVID-19 in relation to HFNC failure. Patients requiring HFNC within three days of hospitalization between July 1 and September 30, 2021 were enrolled. The primary outcome was HFNC failure (early failure ≤Day 3; late failure ≥Day 4), defined as transfer to intensive care just before/after intubation or in-hospital death. We examined changes in laboratory markers and SARS-CoV2-RNAemia on Days 1, 4, and 7, together with demographic data, oxygenation status, and therapeutic agents. We conducted a univariate logistic regression with the explanatory variables defined as 10% change rate in each laboratory marker from Day 1 to 4. We utilized the log-rank test to assess the differences in HFNC failure rates, stratified based on the presence of SARS-CoV2 RNAemia. Among 122 patients, 17 (13.9%) experienced HFNC failure (early: n = 6, late: n = 11). Seventy-five patients (61.5%) showed an initial SpO2/FiO2 ratio ≤243, equivalent to PaO2/FiO2 ratio ≤200, and the initial SpO2/FiO2 ratio was significantly lower in the failure group (184 vs. 218, p = 0.018). Among the laboratory markers, a 10% increase from Day 1 to 4 of lactate dehydrogenase (LDH) and interleukin (IL)-6 was associated with late failure (Odds ratio [OR]: 1.42, 95% confidence interval [CI]: 1.09-1.89 and OR: 1.04, 95%CI: 1.00-1.19, respectively). Furthermore, in patients with persistent RNAemia on Day 4 or 7, the risk of late HFNC failure was significantly higher (Log-rank test, p<0.01). In conclusion, upward trends in LDH and IL-6 levels and the persistent RNAemia even after treatment were associated with HFNC failure.

Respiratory Rate Oxygenation (ROX) index as predictor of high flow nasal cannula in pediatric patients in pediatric intensive care unit

BACKGROUND

High-flow nasal cannula (HFNC) is often used in pediatric populations with respiratory distress. In adults, the respiratory-rate oxygenation (ROX) index is used as a predictor of HFNC therapy; however, children have age-associated differences in respiratory rate, thus may not be applicable to children. This study aims to find the reliability of ROX index and modified P-ROX index as predictors of HFNC therapy failure in pediatric patients.

METHODS

Subjects in this analytical cross-sectional study were taken from January 2023 until November 2023 in Cipto Mangunkusumo Hospital. Inclusion criteria are children aged 1 month to 18 years with respiratory distress and got HFNC therapy. Receiver operating characteristics (ROC) analysis was used to find mP-ROX index cutoff value as a predictor of HFNC failure. The area under curve (AUC) score of mP-ROX index was assessed at different time point.

RESULTS

A total of 102 patients, with 70% of the population with pneumonia, were included in this study. There are significant differences in the ROX index between the successful and failed HFNC group therapy (p < 0.05). This study suggests that mP-ROX index is not useful as predictor of HFNC therapy in pediatrics. While ROX index < 5.52 at 60 min and < 5.68 at 90 min after HFNC initiation have a sensitivity of 90% and specificity of 71%, sensitivity of 78% and specificity of 76%, respectively.

CONCLUSION

mP-ROX index is not useful as a predictor of HFNC therapy in pediatrics. Meanwhile, ROX index at 60 min and 90 min after initiation of HFNC is useful as a predictor of HFNC failure.

Risk factors for intubation and mortality in patients treated with high flow nasal cannula due to COVID-19 infection. Survival Analysis Study in a Northern Mexican Population

BACKGROUND

COVID-19-related acute hypoxic respiratory failure patients often use high-flow nasal cannula (HFNO) oxygen therapy. COVID-19 HFNO intubation and mortality risk factors are understudied in the Mexican population, so the aim was to study them.

METHODS

This retrospective study searched electronic medical records from March 2020 to June 2022 for patients with COVID-19 who required hospitalization and HFNO. Descriptive statistics, a survival curve analysis, and Cox proportional hazard models were used to determine predictor factors for intubation and mortality in patients with HFNO and COVID-19, respectively.

RESULTS

A total of 134 patients received HFNO treatment. Ninety-one (67.9%) were men with a mean (SD) age of 54.5 (17.9) years. Common medical history included obesity (n = 89, 66.4%) with a Body Mass Index (BMI) mean (SD) of 31.8 (5.9), hypertension (n = 67, 50.0%), type 2 diabetes (n = 55, 41.0%), and dyslipidemias (n = 43, 32.1%). The variables associated with a greater risk of requiring intubation after high-flow therapy were age (HR = 1.018, 95% CI 1.003-1.034, p = 0.022) and BMI (HR = 1.071, 95% CI 1.024-1.120, p = 0.003). No variables were associated with lower risk. Increased mortality was associated with increasing age (HR = 1.151, 95% CI 1.102-1.201, p = <0.001), hypertension (HR = 4.092, 95% CI 1.369-12.236, p = 0.012), and dyslipidemia (HR = 3.954, 95% CI 1.395-11.209, p = 0.010). Patients with type 2 diabetes had a lower risk of mortality (HR = 0.235, 95% CI 0.080-0.688, p = 0.008).

CONCLUSIONS

A higher age and BMI were associated with an increased risk of intubation in patients with HFNO and COVID-19. Hypertension and dyslipidemias were associated with a higher risk of mortality.

dCROX and ROX Indices Predict Clinical Outcomes in Patients with COVID-19 Pneumonia Treated with High-Flow Nasal Cannula Oxygen Therapy

Background

High-flow nasal cannula (HFNC) therapy is a common respiratory support in patients with COVID-19 pneumonia. Predictive tools for the evaluation of successful weaning from HFNC therapy for COVID-19 pneumonia have been limited. This study aimed to develop a new predictor for weaning success from HFNC treatment in patients with COVID-19 pneumonia.

Methods

We conducted a retrospective cohort study at Thammasat University Hospital, Thailand. Patients with COVID-19 pneumonia requiring HFNC therapy from April 2020 to September 2021 were included. The ROX index was defined as the ratio of oxygen saturation (SpO2)/fraction of inspired oxygen (FiO2) to respiratory rate. The CROX index was defined as the ratio of C-reactive protein (CRP) to the ROX index. dCROX was defined as the difference in CROX index between 24 hours and 72 hours. Weaning success was defined as the ability to sustain spontaneous breathing after separation from HFNC without any invasive or noninvasive ventilatory support for ≥48 hours or death.

Results

A total of 106 patients (49.1% male) were included. The mean age was 62.1 ± 16.2 years. Baseline SpO2/FiO2 was 276.1 ± 124.8. The rate of HFNC weaning success within 14 days was 61.3%. The best cutoff value of the dCROX index to predict HFNC weaning success was 3.15 with 66.2% sensitivity, 70.7% specificity, and an area under the ROC curve (AUC) of 0.71 (95% CI: 0.59-0.81, p < 0.001). The best cutoff value of the ROX index was 9.13, with 75.4% sensitivity, 78.0% specificity, and an AUC of 0.79 (95% CI: 0.69-0.88, p < 0.001).

Conclusions

ROX index has the highest accuracy for predicting successful weaning from HFNC in patients with COVID-19 pneumonia. dCROX index is the alternative tool for this setting. However, a larger prospective cohort study is needed to verify these indices for determining separation from HFNC therapy. This trial is registered with TCTR20221107004.

Ursodeoxycholic acid does not affect the clinical outcome of SARS-CoV-2 infection: A retrospective study of propensity score-matched cohorts

BACKGROUND

Ursodeoxycholic acid (UDCA) has been recently proposed as a modulator of angiotensin-converting enzyme 2 (ACE2) receptor expression, with potential effects on COVID-19.

AIM AND STUDY DESIGN

We retrospectively evaluated the clinical course and outcome of subjects taking UDCA admitted to the hospital for COVID-19 compared with matched infected subjects. Differences regarding the severity and outcome of the disease between treated and non-treated subjects were assessed. The Kaplan-Meier survival analysis and log-rank test were used to evaluate the effect of UDCA on all-cause intra-hospital mortality.

RESULTS

Among 6444 subjects with confirmed COVID-19 admitted to the emergency department (ED) from 1 March 2020 to 31 December 2022, 109 subjects were taking UDCA. After matching 629 subjects were included in the study: 521 in the no UDCA group and 108 in the UDCA group. In our matched cohort, 144 subjects (22.9%) died, 118 (22.6%) in the no-UDCA group and 26 (24.1%) in the UDCA group. The Kaplan-Meier analysis showed no significant difference in survival between groups. In univariate regression analysis, the presence of pneumonia, National Early Warning Score (NEWS) score, and Charlson Comorbidity Index (CCI) were significant independent predictors of death. At multivariate Cox regression analysis, age, NEWS, pneumonia and CCI index were confirmed significant independent predictors of death. UDCA treatment was not a predictor of survival both in univariate and multivariate regressions.

CONCLUSIONS

UDCA treatment does not appear to have significant effects on the outcome of COVID-19. Specially designed prospective studies are needed to evaluate efficacy in preventing infection and severe disease.

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.

High-flow nasal cannula oxygen versus conventional oxygen therapy for acute respiratory failure due to COVID-19: a systematic review and meta-analysis

BACKGROUND

The effectiveness of high-flow nasal cannula oxygen therapy (HFNC) in patients with acute respiratory failure due to COVID-19 remains uncertain. We aimed at assessing whether HFNC is associated with reduced risk of intubation or mortality in patients with acute respiratory failure due to COVID-19 compared with conventional oxygen therapy (COT).

METHODS

In this systematic review and meta-analysis, we searched MEDLINE, Embase, Web of Science, and CENTRAL databases for randomized controlled trials (RCTs) and observational studies comparing HFNC vs. COT in patients with acute respiratory failure due to COVID-19, published in English from inception to December 2022. Pediatric studies, studies that compared HFNC with a noninvasive respiratory support other than COT and those in which intubation or mortality were not reported were excluded. Two authors independently screened and selected articles for inclusion, extracted data, and assessed the risk of bias. Fixed-effects or random-effects meta-analysis were performed according to statistical heterogeneity. Primary outcomes were risk of intubation and mortality across RCTs. Effect estimates were calculated as risk ratios and 95% confidence interval (RR; 95% CI). Observational studies were used for sensitivity analyses.

RESULTS

Twenty studies were analyzed, accounting for 8383 patients, including 6 RCTs (2509 patients) and 14 observational studies (5874 patients). By pooling the 6 RCTs, HFNC compared with COT significantly reduced the risk of intubation (RR 0.89, 95% CI 0.80 to 0.98; p = 0.02) and reduced length of stay in hospital. HFNC did not significantly reduce the risk of mortality (RR 0.93, 95% CI 0.77 to 1.11; p = 0.40).

CONCLUSIONS

In patients with acute respiratory failure due to COVID-19, HFNC reduced the need for intubation and shortened length of stay in hospital without significant decreased risk of mortality. Trial registration The study was registered on the International prospective register of systematic reviews (PROSPERO) at https://www.crd.york.ac.uk/prospero/ with the trial registration number CRD42022340035 (06/20/2022).

International Survey of High-Flow Nasal Therapy Use for Respiratory Failure in Adult Patients

(1) Background: High-flow nasal therapy (HFNT) has shown several benefits in addressing respiratory failure. However, the quality of evidence and the guidance for safe practice are lacking. This survey aimed to understand HFNT practice and the needs of the clinical community to support safe practice. (2) Method: A survey questionnaire was developed and distributed to relevant healthcare professionals through national networks in the UK, USA and Canada; responses were collected between October 2020 and April 2021. (3) Results: In the UK and Canada, HFNT was used in 95% of hospitals, with the highest use being in the emergency department. HNFT was widely used outside of a critical care setting. HFNT was mostly used to treat acute type 1 respiratory failure (98%), followed by acute type 2 respiratory failure and chronic respiratory failure. Guideline development was felt to be important (96%) and urgent (81%). Auditing of practice was lacking in 71% of hospitals. In the USA, HFNT was broadly similar to UK and Canadian practice. (4) Conclusions: The survey results reveal several key points: (a) HFNT is used in clinical conditions with limited evidence; (b) there is a lack of auditing; (c) it is used in wards that may not have the appropriate skill mix; and (d) there is a lack of guidance for HFNT use.