Association of Noninvasive Oxygenation Strategies With All-Cause Mortality in Adults With Acute Hypoxemic Respiratory Failure: A Systematic Review and Meta-analysis

Stepwise implementation of prevention strategies and their impact on ventilator-associated pneumonia incidence: A 13-Year observational surveillance study

OBJECTIVE

To describe the practice of ventilator-associated pneumonia (VAP) prevention and control through the incremental introduction of prevention strategies and assess the effect on VAP incidence.

DESIGN

Historical observational surveillance study conducted over 13 years.

SETTING

A 12-bed adult intensive care unit (ICU) in a general hospital in Belgium.

PARTICIPANTS

Patients admitted between 2007 and 2019, with ICU stays of ≥48 h.

INTERVENTIONS

Incremental introduction of VAP preventive measures from 2008, including head-of-bed elevation, cuff pressure control, endotracheal tubes with tapered cuffs, subglottic secretion drainage, chlorhexidine oral care, and daily sedation assessment.

MEASUREMENTS AND MAIN RESULTS

A significant decline in VAP incidence density rates was observed, from 18.3 to 2.6 cases per 1000 ventilator days from the baseline to the final period.

CONCLUSIONS

Systematic implementation of VAP preventive measures significantly reduced VAP incidence. However, this reduction did not translate into decreased overall ICU mortality.

IMPLICATIONS FOR PRACTICE

The study underscores the importance of continuous VAP surveillance and preventive measures in reducing VAP incidence.

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.

High-flow nasal oxygen therapy compared with conventional oxygen therapy in hospitalised patients with respiratory illness: a systematic review and meta-analysis

BACKGROUND

High-flow nasal oxygen therapy (HFNO) is used in diverse hospital settings to treat patients with acute respiratory failure (ARF). This systematic review aims to summarise the evidence regarding any benefits HFNO therapy has compared with conventional oxygen therapy (COT) for patients with ARF.

METHODS

Three databases (Embase, Medline and CENTRAL) were searched on 22 March 2023 for studies evaluating HFNO compared with COT for the treatment of ARF, with the primary outcome being hospital mortality and secondary outcomes including (but not limited to) escalation to invasive mechanical ventilation (IMV) or non-invasive ventilation (NIV). Risk of bias was assessed using the Cochrane risk-of-bias tool (randomised controlled trials (RCTs)), ROBINS-I (non-randomised trials) or Newcastle-Ottawa Scale (observational studies). RCTs and observational studies were pooled together for primary analyses, and secondary analyses used RCT data only. Treatment effects were pooled using the random effects model.

RESULTS

63 studies (26 RCTs, 13 cross-over and 24 observational studies) were included, with 10 230 participants. There was no significant difference in the primary outcome of hospital mortality (risk ratio, RR 1.08, 95% CI 0.93 to 1.26; p=0.29; 17 studies, n=5887) between HFNO and COT for all causes ARF. However, compared with COT, HFNO significantly reduced the overall need for escalation to IMV (RR 0.85, 95% CI 0.76 to 0.95 p=0.003; 39 studies, n=8932); and overall need for escalation to NIV (RR 0.70, 95% CI 0.50 to 0.98; p=0.04; 16 studies, n=3076). In subgroup analyses, when considering patients by illness types, those with acute-on-chronic respiratory failure who received HFNO compared with COT had a significant reduction in-hospital mortality (RR 0.58, 95% CI 0.37 to 0.91; p=0.02).

DISCUSSION

HFNO was superior to COT in reducing the need for escalation to both IMV and NIV but had no impact on the primary outcome of hospital mortality. These findings support recommendations that HFNO may be considered as first-line therapy for ARF.

PROSPERO REGISTRATION NUMBER

CRD42021264837.

[Non-invasive Mechanical Ventilation in Acute Respiratory Failure. Clinical Practice Guidelines - on behalf of the German Society of Pneumology and Ventilatory Medicine]

The guideline update outlines the advantages as well as the limitations of NIV in the treatment of acute respiratory failure in daily clinical practice and in different indications.Non-invasive ventilation (NIV) has a high value in therapy of hypercapnic acute respiratory failure, as it significantly reduces the length of ICU stay and hospitalization as well as mortality.Patients with cardiopulmonary edema and acute respiratory failure should be treated with continuous positive airway pressure (CPAP) and oxygen in addition to necessary cardiological interventions. This should be done already prehospital and in the emergency department.In case of other forms of acute hypoxaemic respiratory failure with only mild or moderately disturbed gas exchange (PaO2/FiO2 > 150 mmHg) there is no significant advantage or disadvantage compared to high flow nasal oxygen (HFNO). In severe forms of ARDS NIV is associated with high rates of treatment failure and mortality, especially in cases with NIV-failure and delayed intubation.NIV should be used for preoxygenation before intubation. In patients at risk, NIV is recommended to reduce extubation failure. In the weaning process from invasive ventilation NIV essentially reduces the risk of reintubation in hypercapnic patients. NIV is regarded useful within palliative care for reduction of dyspnea and improving quality of life, but here in concurrence to HFNO, which is regarded as more comfortable. Meanwhile NIV is also recommended in prehospital setting, especially in hypercapnic respiratory failure and pulmonary edema.With appropriate monitoring in an intensive care unit NIV can also be successfully applied in pediatric patients with acute respiratory insufficiency.

The respiratory oxygenation index for identifying the risk of orotracheal intubation in COVID-19 patients receiving high-flow nasal cannula oxygen

OBJECTIVE

To assess whether the respiratory oxygenation index (ROX index) measured after the start of high-flow nasal cannula oxygen therapy can help identify the need for intubation in patients with acute respiratory failure due to coronavirus disease 2019.

METHODS

This retrospective, observational, multicenter study was conducted at the intensive care units of six Brazilian hospitals from March to December 2020. The primary outcome was the need for intubation up to 7 days after starting the high-flow nasal cannula.

RESULTS

A total of 444 patients were included in the study, and 261 (58.7%) were subjected to intubation. An analysis of the area under the receiver operating characteristic curve (AUROC) showed that the ability to discriminate between successful and failed high-flow nasal cannula oxygen therapy within 7 days was greater for the ROX index measured at 24 hours (AUROC 0.80; 95%CI 0.76 - 0.84). The median interval between high-flow nasal cannula initiation and intubation was 24 hours (24 - 72), and the most accurate predictor of intubation obtained before 24 hours was the ROX index measured at 12 hours (AUROC 0.75; 95%CI 0.70 - 0.79). Kaplan-Meier curves revealed a greater probability of intubation within 7 days in patients with a ROX index ≤ 5.54 at 12 hours (hazard ratio 3.07; 95%CI 2.24 - 4.20) and ≤ 5.96 at 24 hours (hazard ratio 5.15; 95%CI 3.65 - 7.27).

CONCLUSION

The ROX index can aid in the early identification of patients with acute respiratory failure due to COVID-19 who will progress to the failure of high-flow nasal cannula supportive therapy and the need for intubation.

Noninvasive Ventilation for Moderate to Severe Acute Respiratory Distress Syndrome Due to COVID-19

BACKGROUND

Use of noninvasive ventilation in patients with acute respiratory distress syndrome (ARDS) is debated. The COVID-19 pandemic posed challenges due to high patient volumes and worldwide resource strain.

OBJECTIVES

To determine associations between use of noninvasive ventilation in adult patients with moderate to severe ARDS due to SARS-CoV-2 pneumonia, progression to intubation, and hospital mortality.

METHODS

This retrospective cohort study included patients in an institutional COVID-19 registry. Adult patients were included if they were admitted for COVID-19 between March 1, 2020, and March 31, 2022, and developed moderate to severe ARDS. Primary outcomes were progression to intubation and hospital mortality in patients who received noninvasive ventilation or mechanical ventilation. A secondary outcome was successful treatment with noninvasive ventilation without intubation.

RESULTS

Of 823 patients who met inclusion criteria, 454 (55.2%) did not receive noninvasive ventilation and 369 (44.8%) received noninvasive ventilation. Patients receiving noninvasive ventilation were more likely to require mechanical ventilation than were patients not receiving noninvasive ventilation. Among patients requiring endotracheal intubation, those receiving noninvasive ventilation had a higher likelihood of mortality. Patients receiving noninvasive ventilation had lower severity-adjusted odds of survival to discharge without intubation than did patients not receiving noninvasive ventilation.

CONCLUSION

Patients with moderate to severe ARDS due to SARS-CoV-2 pneumonia treated with noninvasive ventilation had increased likelihood of progression to endotracheal intubation and hospital mortality.

Nonlinear relationship between platelet count and 30-day in-hospital mortality in ICU acute respiratory failure patients: a multicenter retrospective cohort study

BACKGROUND

Limited evidence exists regarding the link between platelet count and 30-day in-hospital mortality in acute respiratory failure (ARF) patients. Thus, this study aims to investigate this association among ICU patients experiencing acute respiratory failure.

METHODS

We conducted a retrospective cohort study across multiple centers, utilizing data from the US eICU-CRD v2.0 database covering 22,262 patients with ARF in the ICU from 2014 to 2015. Our aim was to investigate the correlation between platelet count and 30-day in-hospital mortality using binary logistic regression, subgroup analyses, and smooth curve fitting.

RESULTS

The 30-day in-hospital mortality rate was 19.73% (4393 out of 22,262), with a median platelet count of 213 × 109/L. After adjusting for covariates, our analysis revealed an inverse association between platelet count and 30-day in-hospital mortality (OR = 0.99, 95% CI 0.99, 0.99). Subgroup analyses supported the robustness of these findings. Furthermore, a nonlinear relationship was identified between platelet count and 30-day in-hospital mortality, with the inflection point at 120 × 109/L. Below the inflection point, the effect size (OR) was 0.89 (0.87, 0.91), indicating a significant association. However, beyond this point, the relationship was not statistically significant.

CONCLUSION

This study establishes a clear negative association between platelet count and 30-day in-hospital mortality among ICU patients with ARF. Furthermore, we have identified a nonlinear relationship with saturation effects, indicating that among ICU patients with acute respiratory failure, the lowest 30-day in-hospital mortality rate occurs when the baseline platelet count is approximately 120 × 109/L.

Preoxygenation and apneic oxygenation in emergency airway management

Preoxygenation during the peri-intubation period is now considered a critical aspect of rapid sequence intubation and an important skill for emergency medicine and critical care providers. Peri-intubation hypoxemia carries significant risk, including cardiac arrest, and care must be taken for appropriate management including through apnea and initiation of laryngoscopy. Appropriate selection of preoxygenation devices should depend on underlying physiology to optimize oxygenation prior to intubation attempts. A PubMed MEDLINE search was completed with selection of articles from March 2008 to March 2023 describing various techniques for preoxygenation for intubation in the critical care and operating room setting with pregnant and obese patient populations included. Prehospital and pediatric populations were excluded in this review. This review provides an overview of methods of preoxygenation with their clinical indications as well as methods for determining end points to preoxygenation and apneic oxygenation. An overview of approaches to preoxygenation was included for patients considered to have a physiologically difficult airway and obese and pregnant patient populations.

Efficacy and Safety of High PEEP NIV in COVID-19 Patients

OBJECTIVE

To investigate the efficacy and safety of non-invasive ventilation (NIV) with high PEEP levels application in patients with COVID-19-related acute respiratory distress syndrome (ARDS).

METHODS

This is a retrospective cohort study with data collected from 95 patients who were administered NIV as part of their treatment in the COVID-19 intensive care unit (ICU) at University Hospital Centre Zagreb between October 2021 and February 2022. The definite outcome was NIV failure.

RESULTS

High PEEP NIV was applied in all 95 patients; 54 (56.84%) patients could be kept solely on NIV, while 41 (43.16%) patients required intubation. ICU mortality of patients solely on NIV was 3.70%, while total ICU mortality was 35.79%. The most significant difference in the dynamic of respiratory parameters between 2 patient groups was visible on Day 3 of ICU stay: By that day, patients kept solely on NIV required significantly lower PEEP levels and had better improvement in PaO2, P/F ratio, and HACOR score.

CONCLUSION

High PEEP applied by NIV was a safe option for the initial respiratory treatment of all patients, despite the severity of ARDS. For some patients, it was also shown to be the only necessary form of oxygen supplementation.

High-flow nasal oxygen versus conventional oxygen therapy and noninvasive ventilation in COVID-19 respiratory failure: a systematic review and network meta-analysis of randomised controlled trials

BACKGROUND

Noninvasive methods of respiratory support, including noninvasive ventilation (NIV), continuous positive airway pressure (CPAP), and high-flow nasal oxygen (HFNO), are potential strategies to prevent progression to requirement for invasive mechanical ventilation in acute hypoxaemic respiratory failure. The COVID-19 pandemic provided an opportunity to understand the utility of noninvasive respiratory support among a homogeneous cohort of patients with contemporary management of acute respiratory distress syndrome. We performed a network meta-analysis of studies evaluating the efficacy of NIV (including CPAP) and HFNO, compared with conventional oxygen therapy (COT), in patients with COVID-19.

METHODS

PubMed, Embase, and the Cochrane library were searched in May 2023. Standard random-effects meta-analysis was used first to estimate all direct pairwise associations and the results from all studies were combined using frequentist network meta-analysis. Primary outcome was treatment failure, defined as discontinuation of HFNO, NIV, or COT despite progressive disease. Secondary outcome was mortality.

RESULTS

We included data from eight RCTs with 2302 patients, (756 [33%] assigned to COT, 371 [16%] to NIV, and 1175 [51%] to HFNO). The odds of treatment failure were similar for NIV (P=0.33) and HFNO (P=0.25), and both were similar to that for COT (reference category). The odds of mortality were similar for all three treatments (odds ratio for NIV vs COT: 1.06 [0.46-2.44] and HFNO vs COT: 0.97 [0.57-1.65]).

CONCLUSIONS

Noninvasive ventilation, high-flow nasal oxygen, and conventional oxygen therapy are comparable with regards to treatment failure and mortality in COVID-19-associated acute respiratory failure.

PROSPERO REGISTRATION

CRD42023426495.

Multidisciplinary Consensus on the Management of Non-Invasive Respiratory Support in the COVID-19 Patient

Acute respiratory failure due to COVID-19 pneumonia often requires a comprehensive approach that includes non-pharmacological strategies such as non-invasive support (including positive pressure modes, high flow therapy or awake proning) in addition to oxygen therapy, with the primary goal of avoiding endotracheal intubation. Clinical issues such as determining the optimal time to initiate non-invasive support, choosing the most appropriate modality (based not only on the acute clinical picture but also on comorbidities), establishing criteria for recognition of treatment failure and strategies to follow in this setting (including palliative care), or implementing de-escalation procedures when improvement occurs are of paramount importance in the ongoing management of severe COVID-19 cases. Organizational issues, such as the most appropriate setting for management and monitoring of the severe COVID-19 patient or protective measures to prevent virus spread to healthcare workers in the presence of aerosol-generating procedures, should also be considered. While many early clinical guidelines during the pandemic were based on previous experience with acute respiratory distress syndrome, the landscape has evolved since then. Today, we have a wealth of high-quality studies that support evidence-based recommendations to address these complex issues. This document, the result of a collaborative effort between four leading scientific societies (SEDAR, SEMES, SEMICYUC, SEPAR), draws on the experience of 25 experts in the field to synthesize knowledge to address pertinent clinical questions and refine the approach to patient care in the face of the challenges posed by severe COVID-19 infection.

Comparison between high-flow nasal oxygen (HFNO) alternated with non-invasive ventilation (NIV) and HFNO and NIV alone in patients with COVID-19: a retrospective cohort study

BACKGROUND

Non-invasive respiratory support (conventional oxygen therapy [COT], non-invasive ventilation [NIV], high-flow nasal oxygen [HFNO], and NIV alternated with HFNO [NIV + HFNO] may reduce the need for invasive mechanical ventilation (IMV) in patients with COVID-19. The outcome of patients treated non-invasively depends on clinical severity at admission. We assessed the need for IMV according to NIV, HFNO, and NIV + HFNO in patients with COVID-19 according to disease severity and evaluated in-hospital survival rates and hospital and intensive care unit (ICU) lengths of stay.

METHODS

This cohort study was conducted using data collected between March 2020 and July 2021. Patients ≥ 18 years admitted to the ICU with a diagnosis of COVID-19 were included. Patients hospitalized for < 3 days, receiving therapy (COT, NIV, HFNO, or NIV + HFNO) for < 48 h, pregnant, and with no primary outcome data were excluded. The COT group was used as reference for multivariate Cox regression model adjustment.

RESULTS

Of 1371 patients screened, 958 were eligible: 692 (72.2%) on COT, 92 (9.6%) on NIV, 31 (3.2%) on HFNO, and 143 (14.9%) on NIV + HFNO. The results for the patients in each group were as follows: median age (interquartile range): NIV (64 [49-79] years), HFNO (62 [55-70] years), NIV + HFNO (62 [48-72] years) (p = 0.615); heart failure: NIV (54.5%), HFNO (36.3%), NIV + HFNO (9%) (p = 0.003); diabetes mellitus: HFNO (17.6%), NIV + HFNO (44.7%) (p = 0.048). > 50% lung damage on chest computed tomography (CT): NIV (13.3%), HFNO (15%), NIV + HFNO (71.6%) (p = 0.038); SpO2/FiO2: NIV (271 [118-365] mmHg), HFNO (317 [254-420] mmHg), NIV + HFNO (229 [102-317] mmHg) (p = 0.001); rate of IMV: NIV (26.1%, p = 0.002), HFNO (22.6%, p = 0.023), NIV + HFNO (46.8%); survival rate: HFNO (83.9%), NIV + HFNO (63.6%) (p = 0.027); ICU length of stay: NIV (8.5 [5-14] days), NIV + HFNO (15 [10-25] days (p < 0.001); hospital length of stay: NIV (13 [10-21] days), NIV + HFNO (20 [15-30] days) (p < 0.001). After adjusting for comorbidities, chest CT score and SpO2/FiO2, the risk of IMV in patients on NIV + HFNO remained high (hazard ratio, 1.88; 95% confidence interval, 1.17-3.04).

CONCLUSIONS

In patients with COVID-19, NIV alternating with HFNO was associated with a higher rate of IMV independent of the presence of comorbidities, chest CT score and SpO2/FiO2. Trial registration ClinicalTrials.gov identifier: NCT05579080.

Comparative Analysis of Clinical Outcomes Using Propensity Score Matching: Coronavirus Disease 2019 vs. Seasonal Influenza in Korea

BACKGROUND

The advent of the omicron variant and the formulation of diverse therapeutic strategies marked a new epoch in the realm of coronavirus disease 2019 (COVID-19). Studies have compared the clinical outcomes between COVID-19 and seasonal influenza, but such studies were conducted during the early stages of the pandemic when effective treatment strategies had not yet been developed, which limits the generalizability of the findings. Therefore, an updated evaluation of the comparative analysis of clinical outcomes between COVID-19 and seasonal influenza is requisite.

METHODS

This study used data from the severe acute respiratory infection surveillance system of South Korea. We extracted data for influenza patients who were infected between 2018 and 2019 and COVID-19 patients who were infected in 2021 (pre-omicron period) and 2022 (omicron period). Comparisons of outcomes were conducted among the pre-omicron, omicron, and influenza cohorts utilizing propensity score matching. The adjusted covariates in the propensity score matching included age, sex, smoking, and comorbidities.

RESULTS

The study incorporated 1,227 patients in the pre-omicron cohort, 1,948 patients in the omicron cohort, and 920 patients in the influenza cohort. Following propensity score matching, 491 patients were included in each respective group. Clinical presentations exhibited similarities between the pre-omicron and omicron cohorts; however, COVID-19 patients demonstrated a higher prevalence of dyspnea and pulmonary infiltrates compared to their influenza counterparts. Both COVID-19 groups exhibited higher in-hospital mortality and longer hospital length of stay than the influenza group. The omicron group showed no significant improvement in clinical outcomes compared to the pre-omicron group.

CONCLUSION

The omicron group did not demonstrate better clinical outcomes than the pre-omicron group, and exhibited significant disease severity compared to the influenza group. Considering the likely persistence of COVID-19 infections, it is imperative to sustain comprehensive studies and ongoing policy support for the virus to enhance the prognosis for individuals affected by COVID-19.

Severe Community-Acquired Pneumonia in Immunocompromised Patients

Due to higher survival rates with good quality of life, related to new treatments in the fields of oncology, hematology, and transplantation, the number of immunocompromised patients is increasing. But these patients are at high risk of intensive care unit admission because of numerous complications. Acute respiratory failure due to severe community-acquired pneumonia is one of the leading causes of admission. In this setting, the need for invasive mechanical ventilation is up to 60%, associated with a high hospital mortality rate of around 40 to 50%. A wide range of pathogens according to the reason of immunosuppression is associated with severe pneumonia in those patients: documented bacterial pneumonia represents a third of cases, viral and fungal pneumonia both account for up to 15% of cases. For patients with an undetermined etiology despite comprehensive diagnostic workup, the hospital mortality rate is very high. Thus, a standardized diagnosis strategy should be defined to increase the diagnosis rate and prescribe the appropriate treatment. This review focuses on the benefit-to-risk ratio of invasive or noninvasive strategies, in the era of omics, for the management of critically ill immunocompromised patients with severe pneumonia in terms of diagnosis and oxygenation.

A non-invasive continuous and real-time volumetric monitoring in spontaneous breathing subjects based on bioimpedance-ExSpiron®Xi: a validation study in healthy volunteers

Tidal volume (TV) monitoring breath-by-breath is not available at bedside in non-intubated patients. However, TV monitoring may be useful to evaluate the work of breathing. A non-invasive device based on bioimpedance provides continuous and real-time volumetric tidal estimation during spontaneous breathing. We performed a prospective study in healthy volunteers aimed at evaluating the accuracy, the precision and the trending ability of measurements of ExSpiron®Xi as compared with the gold standard (i.e. spirometry). Further, we explored whether the differences between the 2 devices would be improved by the calibration of ExSpiron®Xi with a pre-determined tidal volume. Analysis accounted for the repeated nature of measurements within each subject. We enrolled 13 healthy volunteers, including 5 men and 8 women. Tidal volume, TV/ideal body weight (IBW) and respiratory rate (RR) measured with spirometer (TVSpirometer) and with ExSpiron®Xi (TVExSpiron) showed a robust correlation, while minute ventilation (MV) showed a weak correlation, in both non/calibrated and calibrated steps. The analysis of the agreement showed that non-calibrated TVExSpiron underestimated TVspirometer, while in the calibrated steps, TVExSpiron overestimated TVspirometer. The calibration procedure did not reduce the average absolute difference (error) between TVSpirometer and TVExSpiron. This happened similarly for TV/IBW and MV, while RR showed high accuracy and precision. The trending ability was excellent for TV, TV/IBW and RR. The concordance rate (CR) was >95% in both calibrated and non-calibrated measurements. The trending ability of minute ventilation was limited. Absolute error for both calibrated and not calibrated values of TV, TV/IBW and MV accounting for repeated measurements was variably associated with BMI, height and smoking status. Conclusions: Non-invasive TV, TV/IBW and RR estimation by ExSpiron®Xi was strongly correlated with tidal ventilation according to the gold standard spirometer technique. This data was not confirmed for MV. The calibration of the device did not improve its performance. Although the accuracy of ExSpiron®Xi was mild and the precision was limited for TV, TV/IBW and MV, the trending ability of the device was strong specifically for TV, TV/IBW and RR. This makes ExSpiron®Xi a non-invasive monitoring system that may detect real-time tidal volume ventilation changes and then suggest the need to better optimize the patient ventilatory support.

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.

Switches in non-invasive respiratory support strategies during acute hypoxemic respiratory failure: Need to monitoring from a retrospective observational study

OBJECTIVE

To explore combined non-invasive-respiratory-support (NIRS) patterns, reasons for NIRS switching, and their potential impact on clinical outcomes in acute-hypoxemic-respiratory-failure (AHRF) patients.

DESIGN

Retrospective, single-center observational study.

SETTING

Intensive Care Medicine.

PATIENTS

AHRF patients (cardiac origin and respiratory acidosis excluded) underwent combined NIRS therapies such as non-invasive-ventilation (NIV) and High-Flow-Nasal-Cannula (HFNC).

INTERVENTIONS

Patients were classified based on the first NIRS switch performed (HFNC-to-NIV or NIV-to-HFNC), and further specific NIRS switching strategies (NIV trial-like vs. Non-NIV trial-like and single vs. multiples switches) were independently evaluated.

MAIN VARIABLES OF INTEREST

Reasons for switching, NIRS failure and mortality rates.

RESULTS

A total of 63 patients with AHRF were included, receiving combined NIRS, 58.7% classified in the HFNC-to-NIV group and 41.3% in the NIV-to-HFNC group. Reason for switching from HFNC to NIV was AHRF worsening (100%), while from NIV to HFNC was respiratory improvement (76.9%). NIRS failure rates were higher in the HFNC-to-NIV than in NIV-to-HFNC group (81% vs. 35%, p < 0.001). Among HFNC-to-NIV patients, there was no difference in the failure rate between the NIV trial-like and non-NIV trial-like groups (86% vs. 78%, p = 0.575) but the mortality rate was significantly lower in NIV trial-like group (14% vs. 52%, p = 0.02). Among NIV to HFNC patients, NIV failure was lower in the single switch group compared to the multiple switches group (15% vs. 53%, p = 0.039), with a shorter length of stay (5 [2-8] vs. 12 [8-30] days, p = 0.001).

CONCLUSIONS

NIRS combination is used in real life and both switches' strategies, HFNC to NIV and NIV to HFNC, are common in AHRF management. Transitioning from HFNC to NIV is suggested as a therapeutic escalation and in this context performance of a NIV-trial could be beneficial. Conversely, switching from NIV to HFNC is suggested as a de-escalation strategy that is deemed safe if there is no NIRS failure.

Use of CPAP Ventilation in Non-ICU Wards May Influence Outcomes in Patients with Severe Respiratory COVID-19

Background and Objectives: The COVID-19 disease has significantly burdened the healthcare system, including all units of severe patient treatment. Non-intensive care units were established to rationalize the capacity within the Intensive Care Unit (ICU) and to create a unit where patients with Acute Respiratory Distress Syndrome (ARDS) could be treated with non-invasive Continuous Positive Air Pressure (CPAP) outside the ICU. This unicentric retrospective study aimed to assess the efficacy of NIV Treatment in Patients of the fourth pandemic wave and how its application affects the frequency and mortality of ICU-treated patients at University Hospital Rijeka compared to earlier waves of the COVID-19 pandemic. Furthermore, the study showcases the effect of the Patient/Nurse ratio (P/N ratio) on overall mortality in the ICU. Materials and Methods: The study was conducted on two groups of patients with respiratory insufficiency in the second and third pandemic waves, treated in the COVID Respiratory Centre (CRC) (153 patients). We also reviewed a cohort of patients from the fourth pandemic wave who were initially hospitalized in a COVID-6 non-intensive unit from 1 October 2021 to 1 November 2022 (102 patients), and some of them escalated to CRC. Results: The introduction of the CPAP non-invasive ventilation method as a means of hypoxic respiratory failure treatment in non-intensive care units has decreased the strain, overall number of admissions, and CRC patient mortality. The overall fourth wave mortality was 29.4%, compared to the 58.2% overall mortality of the second and third waves. Conclusions: As a result, this has decreased CRC patient admissions and, by itself, overall mortality.

Prognosis of mechanically ventilated patients with COVID-19 after failure of high-flow nasal cannula: a retrospective cohort study

BACKGROUND

There is an argument whether the delayed intubation aggravate the respiratory failure in Acute respiratory distress syndrome (ARDS) patients with coronavirus disease 2019 (COVID-19). We aimed to investigate the effect of high-flow nasal cannula (HFNC) failure before mechanical ventilation on clinical outcomes in mechanically ventilated patients with COVID-19.

METHODS

This retrospective cohort study included mechanically ventilated patients who were diagnosed with COVID-19 and admitted to the intensive care unit (ICU) between February 2020 and December 2021 at Asan Medical Center. The patients were divided into HFNC failure (HFNC-F) and mechanical ventilation (MV) groups according to the use of HFNC before MV. The primary outcome of this study was to compare the worst values of ventilator parameters from day 1 to day 3 after mechanical ventilation between the two groups.

RESULTS

Overall, 158 mechanically ventilated patients with COVID-19 were included in this study: 107 patients (67.7%) in the HFNC-F group and 51 (32.3%) in the MV group. The two groups had similar profiles of ventilator parameter from day 1 to day 3 after mechanical ventilation, except of dynamic compliance on day 3 (28.38 mL/cmH2O in MV vs. 30.67 mL/H2O in HFNC-F, p = 0.032). In addition, the HFNC-F group (5.6%) had a lower rate of ECMO at 28 days than the MV group (17.6%), even after adjustment (adjusted hazard ratio, 0.30; 95% confidence interval, 0.11-0.83; p = 0.045).

CONCLUSIONS

Among mechanically ventilated COVID-19 patients, HFNC failure before mechanical ventilation was not associated with deterioration of respiratory failure.

Prognostic analysis of high-flow nasal cannula therapy and non-invasive ventilation in mild to moderate hypoxemia patients and construction of a machine learning model for 48-h intubation prediction-a retrospective analysis of the MIMIC database

Background

This study aims to investigate the clinical outcome between high-flow nasal cannula (HFNC) and non-invasive ventilation (NIV) therapy in mild to moderate hypoxemic patients on the first ICU day and to develop a predictive model of 48-h intubation.

Methods

The study included adult patients from the MIMIC III and IV databases who first initiated HFNC or NIV therapy due to mild to moderate hypoxemia (100 < PaO2/FiO2 ≤ 300). The 48-h and 30-day intubation rates were compared using cross-sectional and survival analysis. Nine machine learning and six ensemble algorithms were deployed to construct the 48-h intubation predictive models, of which the optimal model was determined by its prediction accuracy. The top 10 risk and protective factors were identified using the Shapley interpretation algorithm.

Result

A total of 123,042 patients were screened, of which, 673 were from the MIMIC IV database for ventilation therapy comparison (HFNC n = 363, NIV n = 310) and 48-h intubation predictive model construction (training dataset n = 471, internal validation set n = 202) and 408 were from the MIMIC III database for external validation. The NIV group had a lower intubation rate (23.1% vs. 16.1%, p = 0.001), ICU 28-day mortality (18.5% vs. 11.6%, p = 0.014), and in-hospital mortality (19.6% vs. 11.9%, p = 0.007) compared to the HFNC group. Survival analysis showed that the total and 48-h intubation rates were not significantly different. The ensemble AdaBoost decision tree model (internal and external validation set AUROC 0.878, 0.726) had the best predictive accuracy performance. The model Shapley algorithm showed Sequential Organ Failure Assessment (SOFA), acute physiology scores (APSIII), the minimum and maximum lactate value as risk factors for early failure and age, the maximum PaCO2 and PH value, Glasgow Coma Scale (GCS), the minimum PaO2/FiO2 ratio, and PaO2 value as protective factors.

Conclusion

NIV was associated with lower intubation rate and ICU 28-day and in-hospital mortality. Further survival analysis reinforced that the effect of NIV on the intubation rate might partly be attributed to the other impact factors. The ensemble AdaBoost decision tree model may assist clinicians in making clinical decisions, and early organ function support to improve patients' SOFA, APSIII, GCS, PaCO2, PaO2, PH, PaO2/FiO2 ratio, and lactate values can reduce the early failure rate and improve patient prognosis.

Impact of different oxygen therapy strategies on the risk of endotracheal reintubation in mechanically ventilated patients: A systematic review and meta-analysis

BACKGROUND

Mechanical ventilation (MV) is a crucial intervention for the support of patients with acute and severe respiratory failure in modern intensive care medicine. However, the mechanical forces resulting from the interplay between the ventilator and the respiratory system may cause pulmonary injury.

OBJECTIVE

To compare the effects of high-flow nasal cannula (HFNC) therapy and other oxygen therapy modalities on the risk of endotracheal reintubation in mechanically ventilated patients after extubation in the intensive care unit (ICU).

METHODS

An electronic search was carried out across various databases including PubMed, Embase, Ovid, Medline, Cochrane Library, Embase, VIP, and Wanfang. The objective of this search was to locate prospective randomized controlled trials that examined the effects of multiple oxygen therapy approaches on the incidence of reintubation in patients in the ICU after undergoing mechanical ventilation. The meta package in R language was used to analyze parameters adopted by the included studies such as reintubation rate, mortality rate, and length of hospital stay.

RESULTS

This study enrolled 22 articles, involving 4,160 participants, with 2,061 in the study group and 2,099 in the control group. Among these, 20 articles presented data on the reintubation rate of the patients included with an odds ratio (OR) of 0.90 (95% CI: 0.74, 1.09) for HFNC and an OR of 1.77 (95% CI: 0.93, 3.38) for HFNC in the chronic obstructive pulmonary disease (COPD) subgroup. Moreover, 10 articles assessed the incidence of respiratory failure after extubation, revealing an OR for HFNC was 0.68 (95% CI: 0.55, 0.84) using a fixed-effects model. Nine articles addressed ICU mortality, while 13 pieces of literature examined hospital mortality. HFNC showed no significant impact on either ICU mortality or hospital mortality.

CONCLUSION

HFNC therapy markedly reduces the incidence of respiratory failure in mechanically ventilated patients following extubation in the ICU. Furthermore, it specifically reduces the risk of reintubation in patients diagnosed with COPD.

Continuous positive airway pressure versus high-flow nasal cannula oxygen therapy for acute hypoxemic respiratory failure: A randomized controlled trial

BACKGROUND AND OBJECTIVE

The relative effectiveness of initial non-invasive respiratory strategies for acute respiratory failure using continuous positive airway pressure (CPAP) or high-flow nasal cannula (HFNC) is unclear.

METHODS

We conducted a multicenter, open-label, parallel-group randomized controlled trial to compare the efficacy of CPAP and HFNC on reducing the risk of meeting the prespecified criteria for intubation and improving clinical outcomes of acute hypoxemic respiratory failure. The primary endpoint was the time taken to meet the prespecified criteria for intubation within 28 days.

RESULTS

Eighty-five patients were randomly assigned to the CPAP or HFNC group. Eleven (28.9%) in the CPAP group and twenty (42.6%) in the HFNC group met the criteria for intubation within 28 days. Compared with HFNC, CPAP reduced the risk of meeting the intubation criteria (hazard ratio [HR], 0.327; 95% CI, 0.148-0.724; p = 0.006). There were no significant between-group differences in the intubation rates, in-hospital and 28-day mortality rates, ventilator-free days, duration of the need for respiratory support, or duration of hospitalization for respiratory illness. Pulmonary oxygenation was significantly better in the CPAP group, with significantly lower pH and higher partial pressure of carbon dioxide, but there were no differences in the respiratory rate between groups. CPAP and HFNC were associated with few possibly causal adverse events.

CONCLUSION

CPAP is more effective than HFNC at reducing the risk of meeting the intubation criteria in patients with acute hypoxemic respiratory failure.

Patients' recollections of helmet-CPAP treatment during COVID-19 pandemic: A qualitative study

BACKGROUND

During the pandemic outbreak, helmet continuous positive airway pressure (CPAP) was widely used as respiratory support for COVID-19 patients, inside and outside of intensive care units. The available literature suggests specific interventions to improve the comfort of patients treated with helmet-CPAP. Few reports are available on the experiences of patients undergoing this treatment.

AIM

This qualitative study aimed to explore the views and recollections of COVID-19 patients undergoing helmet-CPAP.

STUDY DESIGN

We conducted semi-structured interviews with thematic analysis. Participants were recruited from the follow-up programme for COVID-19 patients discharged from an Italian general intensive care unit. Participants were interviewed by telephone. Data analysis followed the principles of thematic synthesis approach.

FINDINGS

We conducted 29 phone calls in patients eligible for the study. Five participants declared that they did not remember the time spent in hospital on helmet-CPAP. Twenty-four patients were then included. Two themes and six subthemes were generated from their interview data: (1) The helmet-CPAP as a life-saving treatment (subthemes: recognition of the usefulness of treatment and resilience); (2) the negative feelings related to helmet-CPAP application (subthemes: communication problems, entrapment, mental confusion, fear of dying). Each patient's experience was unique, but some discomfort elements such as noise, gas flow turbulence, choking sensation and thirst were found to be very common.

CONCLUSIONS

The application of helmet-CPAP treatment generated positive and negative memories and feelings in COVID-19 patients during the pandemic. The patients' experience has provided an overview of the main factors of discomfort. This can be a starting point for taking corrective measures to promote greater helmet tolerance and subsequent treatment success.

RELEVANCE TO CLINICAL PRACTICE

This study has provided an insight into the patient's recollections about helmet-CPAP treatment during a worldwide pandemic. The findings suggested strict applications of interventions aimed to reduce some issues that participants reported, to improve their compliance to treatment. Results from this study could help nurses in understanding the needs of patients treated with helmet-CPAP and may foster a care focused on patient-centred outcomes.

Efficiency of continuous positive airway pressure and high-flow nasal oxygen therapy in critically ill patients with COVID-19

OBJECTIVE

Critically ill patients with COVID-19 develop acute respiratory distress syndrome characterized by relatively well-preserved pulmonary compliance but severe hypoxemia. The challenge in managing such patients lies in optimizing oxygenation, which can be achieved through either high oxygen flow or noninvasive mechanical ventilation. This study was performed to compare the efficiency of two methods of noninvasive oxygen therapy: continuous positive airway pressure (CPAP) and high-flow nasal oxygen therapy (HFNO).

METHODS

This retrospective cohort study involved 668 patients hospitalized in the intensive care unit (ICU) of the "Sf. Apostol Andrei" Emergency Clinical Hospital, Galati, Romania from 1 April 2020 to 31 March 2021 (CPAP, n = 108; HFNO, n = 108).

RESULTS

Mortality was significantly lower in the CPAP and HFNO groups than in the group of patients who underwent intubation and mechanical ventilation after ICU admission. Mortality in the ICU was not significantly different between the CPAP and HFNO groups.

CONCLUSIONS

HFNO and CPAP represent efficient alternative therapies for patients with severe COVID-19 whose respiratory treatment has failed. Studies involving larger groups of patients are necessary to establish a personalized, more complex management modality for critically ill patients with COVID-19.

Stratification of COVID-19 Patients with Moderate-to-Severe Hypoxemic Respiratory Failure for Response to High-Flow Nasal Cannula: A Retrospective Observational Study

Background and Objectives: In patients with COVID-19, high-flow nasal cannula (HFNC) and continuous positive airway pressure (CPAP) are widely applied as initial treatments for moderate-to-severe acute hypoxemic respiratory failure. The aim of the study was to assess which respiratory supports improve 28-day mortality and to identify a predictive index of treatment response. Materials and Methods: This is a single-center retrospective observational study including 159 consecutive adult patients with COVID-19 and moderate-to-severe hypoxemic acute respiratory failure. Results: A total of 159 patients (82 in the CPAP group and 77 in the HFNC group) were included in the study. Mortality within 28 days was significantly lower with HFNC compared to CPAP (16.8% vs. 50%), while ICU admission and tracheal intubation within 28 days were significantly higher with CPAP compared to HFNC treatment (32% vs. 13%). We identified an index for survival in HFNC by including three variables easily available at admission (LDH, age, and respiratory rate) and the PaO2/FiO2 ratio at 48 h. The index showed high discrimination for survival with an AUC of 0.88, a negative predictive value of 86%, and a positive predictive value of 95%. Conclusions: Treatment with HFNC appears to be associated with greater survival and fewer ICU admission than CPAP. LDH, respiratory rate, age, and PaO2/FiO2 at 48 h were independently associated with survival and an index based on these variables allows for the prediction of treatment success and the assessment of patient allocation to the appropriate intensity of care after 48 h. Further research is warranted to determine effects on other outcomes and to assess the performance of the index in larger cohorts.

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.

Qualitative study of COVID-19 patient experiences with non-invasive ventilation and pronation: strategies to enhance treatment adherence

INTRODUCTION

Non-invasive ventilation (NIV) treatment combined with pronation in patients with COVID-19 respiratory failure has been shown to be effective in improving respiratory function and better patient outcomes. These patients may experience discomfort or anxiety that may reduce adherence to treatment.

OBJECTIVE

The aim of this study was to explore and describe the subjective experiences of patients undergoing helmet NIV and pronation during hospitalisation for COVID-19 respiratory failure, with a focus on the elements of care and strategies adopted by patients that enabled good adaptation to treatments.

METHOD

A qualitative descriptive study, using face-to-face interviews, was carried out with a purposeful sample of 20 participants discharged from a pulmonary intensive care unit who underwent helmet continuous positive airway pressure and pronation during hospitalisation for COVID-19.

RESULTS

Content analysis of the transcripts revealed feelings and experiences related to illness and treatments, strategies for managing one's own negative thoughts, and practical strategies of one's own and healthcare workers to facilitate adaptation to pronation and helmet. Experience was reflected in five major topics related to specific time points and settings: feelings and experiences, helmet and pronation: heavy but beneficial, positive thinking strategies, patients' practical strategies, support of healthcare professionals (HCPs).

CONCLUSIONS

This study may be useful to HCPs to improve the quality and appropriateness of care they provide.

A technique to measure tidal volume during noninvasive respiratory support by continuous-flow helmet CPAP

PURPOSE

The coronavirus disease 2019 (COVID-19) pandemic has promoted the use of helmet continuous positive airway pressure (CPAP) for noninvasive respiratory support in hypoxic respiratory failure patients, despite the lack of tidal volume monitoring. We evaluated a novel technique designed to measure tidal volume during noninvasive continuous-flow helmet CPAP.

METHODS

A bench model of spontaneously breathing patients undergoing helmet CPAP therapy (three positive end-expiratory pressure [PEEP] levels) at different levels of respiratory distress was used to compare measured and reference tidal volumes. Tidal volume measurement by the novel technique was based on helmet outflow-trace analysis. Helmet inflow was increased from 60 to 75 and 90 L/min to match the patient's peak inspiratory flow; an additional subset of tests was conducted under the condition of purposely insufficient inflow (i.e., high respiratory distress and 60 L/min inflow).

RESULTS

The tidal volumes examined herein ranged from 250 to 910 mL. The Bland‒Altman analysis showed a bias of -3.2 ± 29.3 mL for measured tidal volumes compared to the reference, corresponding to an average relative error of -1 ± 4.4%. Tidal volume underestimation correlated with respiratory rate (rho = .411, p = .004) but not with peak inspiratory flow, distress, or PEEP. When the helmet inflow was maintained purposely low, tidal volume underestimation occurred (bias - 93.3 ± 83.9 mL), corresponding to an error of -14.8 ± 6.3%.

CONCLUSION

Tidal volume measurement is feasible and accurate during bench continuous-flow helmet CPAP therapy by the analysis of the outflow signal, provided that helmet inflow is adequate to match the patient's inspiratory efforts. Insufficient inflow resulted in tidal volume underestimation. In vivo data are needed to confirm these findings.

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.

Comparison of Noninvasive Mechanical Ventilation With High-Flow Nasal Cannula, Face-Mask, and Helmet in Hypoxemic Respiratory Failure in Patients With COVID-19: A Randomized Controlled Trial

OBJECTIVES

For COVID-19-related respiratory failure, noninvasive respiratory assistance via a high-flow nasal cannula (HFNC), helmet, and face-mask noninvasive ventilation is used. However, which of these options is most effective is yet to be determined. This study aimed to compare the three techniques of noninvasive respiratory support and to determine the superior technique.

DESIGN

A randomized control trial with permuted block randomization of nine cases per block for each parallel, open-labeled arm.

SETTING AND PATIENTS

Adult patients with COVID-19 with a Pa o2 /F io2 ratio of less than 300, admitted between February 4, 2021, and August 9, 2021, to three tertiary centers in Oman, were studied.

INTERVENTIONS

This study included three interventions: HFNC ( n = 47), helmet continuous positive airway pressure (CPAP; n = 52), and face-mask CPAP ( n = 52).

MEASUREMENTS AND MAIN RESULTS

The endotracheal intubation rate and mortality at 28 and 90 days were measured as the primary and secondary outcomes, respectively. Of the 159 randomized patients, 151 were analyzed. The median age was 52 years, and 74% were men. The endotracheal intubation rates were 44%, 45%, and 46% ( p = 0.99), and the median intubation times were 7.0, 5.5, and 4.5 days ( p = 0.11) in the HFNC, face-mask CPAP, and helmet CPAP, respectively. In comparison to face-mask CPAP, the relative risk of intubation was 0.97 (95% CI, 0.63-1.49) for HFNC and 1.0 (95% CI 0.66-1.51) for helmet CPAP. The mortality rates were 23%, 32%, and 38% at 28 days ( p = 0.24) and 43%, 38%, and 40% ( p = 0.89) at 90 days for HFNC, face-mask CPAP, and helmet CPAP, respectively. The trial was stopped prematurely because of a decline in cases.

CONCLUSIONS

This exploratory trial found no difference in intubation rate and mortality among the three intervention groups for the COVID-19 patients with hypoxemic respiratory failure; however, more evidence is needed to confirm these findings as the trial was aborted prematurely.

The Association between Non-Invasive Ventilation and the Rate of Ventilator-Associated Pneumonia

Ventilator-associated pneumonia (VAP) has significant effects on patient outcomes, including prolonging the duration of both mechanical ventilation and stay in the intensive care unit (ICU). The aim of this study was to assess the association between non-invasive ventilation/oxygenation (NIVO) prior to intubation and the rate of subsequent VAP. This was a multicenter retrospective cohort study of adult patients who were admitted to the medical ICU from three tertiary care academic centers in three distinct regions. NIVO was defined as continuous positive airway pressure (CPAP), bilevel positive airway pressure (BiPAP), or high-flow nasal cannula (HFNC) for any duration during the hospitalization prior to intubation. The primary outcome variable was VAP association with NIVO. A total of 17,302 patients were included. VAP developed in 2.6% of the patients (444/17,302), 2.3% (285/12,518) of patients among those who did not have NIVO, 1.6% (30/1879) of patients who had CPAP, 2.5% (17/690) of patients who had HFNC, 8.1% (16/197) of patients who had BiPAP, and 4.8% (96/2018) of patients who had a combination of NIVO types. Compared to those who did not have NIVO, VAP was more likely to develop among those who had BiPAP (adj OR 3.11, 95% CI 1.80-5.37, p < 0.001) or a combination of NIVO types (adj OR 1.91, 95% CI 1.49-2.44, p < 0.001) after adjusting for patient demographics and comorbidities. The use of BiPAP or a combination of NIVO types significantly increases the odds of developing VAP once receiving IMV.

Personalized Nasal Protective Devices: Importance and Perspectives

Nowadays, in addition to diseases caused by environmental pollution, the importance of personalized protection against various infectious agents has become of paramount importance. Besides medicine, several technical and technological studies have been carried out to develop suitable devices. One such revolutionary solution is the use of personalized nasal filters, which allow our body to defend itself more effectively against external environmental damage and pathogens. These filters are small devices that are placed in the nose and specifically filter the inhaled environmental contaminants, allergens, and microorganisms according to individual needs. These devices not only play a key role in maintaining our health but also contribute to environmental protection, reducing the inhalation of pollutants and their harmful impact on the natural environment. Another advantage of personalized filters is that they also provide an opportunity to strengthen our individual immune systems. The use of personalized filters allows medicine to provide optimized protection for everyone, focusing on individual genetic and immunological conditions. The momentum behind the development and research of personalized nasal filters has reached astonishing proportions today. Nowadays, many research groups and medical institutions are working to create new materials, nanotechnologies, and bioinformatics solutions in order to create even more effective personalized nasal filters that can also be shaped easily and safely. Considering the needs of the users is at least as important during development as the efficiency of the device. These two properties together determine the success of the product. Industry research focuses not only on improving the efficiency of devices, but also on making them more responsive to user needs, comfort, and portability. Based on all this, it can be concluded that personalized nasal filters can be a promising and innovative solution for protection against environmental pollutants and pathogens. Through a commitment to the research and development of technology, the long-term impact of such devices on our health and the environment can be significant, contributing to improving people's quality of life and creating a sustainable future. With unique solutions and continuous research, we give hope that in the future, despite the environmental challenges, we can enjoy the protection of our health with even more efficient and sophisticated devices.

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.

Noninvasive Oxygenation Strategies in Adult Patients With Acute Hypoxemic Respiratory Failure: A Systematic Review and Network Meta-Analysis

BACKGROUND

Several recently published randomized controlled trials have evaluated various noninvasive oxygenation strategies for the treatment of acute hypoxemic respiratory failure.

RESEARCH QUESTION

Which available noninvasive oxygen strategies are effective for acute hypoxic respiratory failure?

STUDY DESIGN AND METHODS

A systematic review of Medline, Embase, Cochrane CENTRAL, CINAHL, Web of Science, MedRxiv, and Research Square was conducted from inception to October 1, 2022. A random effects frequentist network meta-analysis was performed, and the results are presented using absolute risk difference per 1,000 patients. The Grading of Recommendations, Assessment, Development and Evaluation framework was used to rate the certainty of the evidence. Mortality, invasive mechanical ventilation, duration of hospitalization and ICU stay, ventilator-free days, and level of comfort are reported.

RESULTS

Thirty-six trials (7,046 patients) were included. It was found that helmet CPAP probably reduces mortality compared with standard oxygen therapy (SOT) (231 fewer deaths per 1,000; 95% CI, 126-273 fewer) (moderate certainty). A high-flow nasal cannula (HFNC) probably reduces the need for invasive mechanical ventilation (103.5 fewer events per 1,000; 95% CI, 40.5-157.5 fewer) (moderate certainty). All noninvasive oxygenation strategies may reduce the duration of hospitalization as compared with SOT (low certainty). Helmet bilevel ventilation (4.84 days fewer; 95% CI, 2.33-7.36 days fewer) and helmet CPAP (1.74 days fewer; 95% CI, 4.49 fewer-1.01 more) may reduce the duration of ICU stay as compared with SOT (both low certainty). SOT may be more comfortable than face mask noninvasive ventilation and no different in comfort compared with an HFNC (both low certainty).

INTERPRETATION

A helmet interface for noninvasive ventilation probably reduces mortality and the risk of mechanical ventilation, as well as the duration of hospital and ICU stay. An HFNC probably reduces the risk of invasive mechanical ventilation and may be as comfortable as SOT. Further research is necessary to understand the role of these interfaces in acute hypoxemic respiratory failure.

COVID-19 Acute Respiratory Distress Syndrome: Treatment with Helmet CPAP in Respiratory Intermediate Care Unit by Pulmonologists in the Three Italian Pandemic Waves

COVID-19 Acute Respiratory Distress Syndrome (CARDS) is the most serious complication of COVID-19. The SARS-CoV-2 outbreaks rapidly saturated intensive care unit (ICU), forcing the application of non-invasive respiratory support (NIRS) in respiratory intermediate care unit (RICU). The primary aim of this study is to compare the patients' clinical characteristics and outcomes (Helmet-Continuous Positive Airway Pressure (H-CPAP) success/failure and survival/death). The secondary aim is to evaluate and detect the main predictors of H-CPAP success and survival/death. A total of 515 patients were enrolled in our observational prospective study based on CARDS developed in RICU during the three Italian pandemic waves. All selected patients were treated with H-CPAP. The worst ratio of arterial partial pressure of oxygen (PaO2) and fraction of inspired oxygen (FiO2) PaO2/FiO2 during H-CPAP stratified the subjects into mild, moderate and severe CARDS. H-CPAP success has increased during the three waves (62%, 69% and 77%, respectively) and the mortality rate has decreased (28%, 21% and 13%). H-CPAP success/failure and survival/death were related to the PaO2/FiO2 (worst score) ratio in H-CPAP and to steroids' administration. D-dimer at admission, FiO2 and positive end expiratory pressure (PEEP) were also associated with H-CPAP success. Our study suggests good outcomes with H-CPAP in CARDS in RICU. A widespread use of steroids could play a role.

Ultrasonographic evaluation of the diaphragm in critically ill patients to predict invasive mechanical ventilation

BACKGROUND

Diaphragm dysfunction is common in critically ill patients and associated with poorer outcomes. The function of the diaphragm can be evaluated at the bedside by measuring diaphragmatic excursion using ultrasonography. In this study, we investigated the ability of right-sided diaphragmatic excursion (RDE) to predict the need for invasive mechanical ventilation (IMV).

METHODS

Critically ill patients aged 18 years and older who presented to our emergency department between May 20, 2021 and May 19, 2022 and underwent measurement of RDE within 10 min of arrival were enrolled in this prospective study. The ability of RDE to predict the need for IMV was assessed by multivariable logistic regression and analysis of the area under the receiver-operating characteristic curve (AUROC).

RESULTS

A total of 314 patients were enrolled in the study; 113 (35.9%) of these patients required IMV. An increase of RDE value per each 0.1 cm was identified to be an independent predictor of IMV (adjusted odds ratio 0.08, 95% confidence interval [CI] 0.04-0.17, p < 0.001; AUROC 0.850, 95% CI 0.807-0.894). The RDE cutoff value was 1.2 cm (sensitivity 82.3%, 95% CI 74.0-88.8; specificity 78.1%, 95% CI 71.7-83.6). Time on a ventilator was significantly longer when the RDE was ≤ 1.2 cm (13 days [interquartile range 5, 27] versus 5 days [interquartile range 3, 8], p = 0.006).

CONCLUSIONS

In this study, RDE had a good ability to predict the need for IMV in critically ill patients. The optimal RDE cutoff value was 1.2 cm. Its benefit in patient management requires further investigation.

Analysis of an Individualised Stepwise Approach to Non-Pharmacological Therapy in COVID-19

BACKGROUND

Early intubation versus use of conventional or high-flow nasal cannula oxygen therapy (COT/HFNC), continuous positive airway pressure (CPAP), and non-invasive ventilation (NIV) has been debated throughout the COVID-19 pandemic. Our centre followed a stepwise approach, in concordance with German national guidelines, escalating non-invasive modalities prior to invasive mechanical ventilation (IMV) or extracorporeal membrane oxygenation (ECMO), rather than early or late intubation.

OBJECTIVES

The aims of the study were to investigate the real-life usage of these modalities and analyse patient characteristics and survival.

METHOD

A retrospective monocentric observation was conducted of all consecutive COVID-19 hospital admissions between March 2020 and December 2021 at a university-affiliated pulmonary centre in Germany. Anthropometric data, therapy, and survival status were descriptively analysed.

RESULTS

From 1,052 COVID-19-related admissions, 835 patients were included (54% male, median 58 years). Maximum therapy was as follows: 34% (n = 284) no therapy, 40% (n = 337) COT, 3% (n = 22) HFNC, 9% (n = 73) CPAP, 7% (n = 56) NIV, 4% (n = 34) IMV, and 3% (n = 29) ECMO. Of 551 patients treated with at least COT, 12.3% required intubation. Overall, 183 patients required intensive unit care, and 106 (13%) died. Of the 68 patients who received IMV/ECMO, 48 died (74%). The strategy for non-pharmacological therapy was individual but remained consistent throughout the studied period.

CONCLUSIONS

This study provides valuable insight into COVID-19 care in Germany and shows how the majority of patients could be treated with the maximum treatment required according to disease severity following the national algorithm. Escalation of therapy modality is interlinked with disease severity and thus associated with mortality.

Effect of awake prone positioning on tracheal intubation rates in patients with COVID-19: A meta-analysis

Purpose

We investigated the effect of awake prone positioning on endotracheal intubation rates in spontaneously breathing patients with COVID-19 not undergoing endotracheal intubation.

Methods

We searched the CINAHL, Cochrane Library, PUBMED, MEDLINE, and Web of Science databases until December 31, 2022. Prospective randomized controlled, cohort, and case-control studies were included. A meta-analysis was performed on the primary outcome measure, tracheal intubation rates, following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines.

Results

Ten studies with a total of 2641 patients were included. The tracheal intubation rate in the awake prone position was 34% (95%CI: 0.59-1.10; P = 0.18; I2 = 55%), showing a non-significant benefit. Mortality was lower in prone-positioned than in supine-positioned patients (odds ratio: 0.75; 95% CI: 0.61-0.93; P = 0.007; I2 = 46%), prone positioning significantly improved the PaO2/FiO2 ratio (mean difference -29.17; 95%CI: -50.91 to -7.43; P = 0.009; I2 = 44%).

Conclusions

Prone positioning can improve the PaO2/FIO2 ratio in patients with COVID-19 but we found no significant effect on tracheal intubation rates. Awake prone positioning seems to be associated with lower mortality, however, and may thus be a beneficial and effective intervention for patients with COVID-19. The optimal timing, duration, and target population need to be determined in future studies.

Acute dyspnea in the emergency department: a clinical review

Acute dyspnea represents one of the most frequent symptoms leading to emergency room evaluation. Its significant prognostic value warrants a careful evaluation. The differential diagnosis of dyspnea is complex due to the lack of specificity and the loose association between its intensity and the severity of the underlying pathological condition. The initial assessment of dyspnea calls for prompt diagnostic evaluation and identification of optimal monitoring strategy and provides information useful to allocate the patient to the most appropriate setting of care. In recent years, accumulating evidence indicated that lung ultrasound, along with echocardiography, represents the first rapid and non-invasive line of assessment that accurately differentiates heart, lung or extra-pulmonary involvement in patients with dyspnea. Moreover, non-invasive respiratory support modalities such as high-flow nasal oxygen and continuous positive airway pressure have aroused major clinical interest, in light of their efficacy and practicality to treat patients with dyspnea requiring ventilatory support, without using invasive mechanical ventilation. This clinical review is focused on the pathophysiology of acute dyspnea, on its clinical presentation and evaluation, including ultrasound-based diagnostic workup, and on available non-invasive modalities of respiratory support that may be required in patients with acute dyspnea secondary or associated with respiratory failure.

Mechanical Ventilation: Negative to Positive and Back Again

Critical care and mechanical ventilation have a relatively brief history in medicine. Premises existed through the seventeenth to nineteenth centuries but modern mechanical ventilation started in the twentieth century. Noninvasive ventilation techniques had started both in the intensive care unit and for home ventilation at the end of the 1980s and the 1990s. The need for mechanical ventilation is increasingly influenced worldwide by the spread of respiratory viruses, and the last coronavirus disease 2019 pandemic has seen a massive successful use of noninvasive ventilation.

Lower Versus Higher Oxygenation Targets for Critically Ill Patients: A Systematic Review

Supplemental oxygen is a standard therapeutic intervention for critically ill patients such as patients suffering from cardiac arrest, myocardial ischemia, traumatic brain injury, and stroke. However, the optimal oxygenation targets remain elusive owing to the paucity and inconsistencies in the relevant literature. A comprehensive analysis of the available scientific evidence was performed to establish the relative efficacy of the lower and higher oxygenation targets. A systematic literature search was conducted in PubMed, MEDLINE, and Scopus databases from 2010 to 2023. Further, Google Scholar was also searched. Studies evaluating the efficacy of oxygenation targets and the associated clinical outcomes were included. Studies that included participants with hyperbaric oxygen therapy, chronic respiratory diseases, or extracorporeal life support were excluded. The literature search was performed by two blinded reviewers. A total of 19 studies were included in this systemic review, including 72,176 participants. A total of 14 randomized control trials were included. A total of 12 studies investigated the efficacy of lower and higher oxygenation targets in ICU-admitted patients, and seven were assessed in patients with acute myocardial infarction and stroke. For ICU patients, the evidence was conflicting, with some studies showing the efficacy of conservative oxygen therapy while others reported no difference. Overall, nine studies concluded that lower oxygen targets are favorable. However, most studies (n=4) in stroke and myocardial infarction patients showed no difference in lower or higher oxygenation targets whereas only two supported lower oxygenation targets. Available evidence suggests that lower oxygenation targets result in either improved or equivalent clinical outcomes compared with higher oxygenation targets.

Oxygen Therapy Part 2 - Indications and Toxicity

Oxygen Therapy Part 2: Indications and ToxicityWemple et al. continue their review of oxygen therapy, discussing the acute and chronic indications for oxygen and the delivery of supplemental oxygen (and its potential adverse effects and toxicity).

Personalized Respiratory Support in ARDS: A Physiology-to-Bedside Review

Acute respiratory distress syndrome (ARDS) is a leading cause of disability and mortality worldwide, and while no specific etiologic interventions have been shown to improve outcomes, noninvasive and invasive respiratory support strategies are life-saving interventions that allow time for lung recovery. However, the inappropriate management of these strategies, which neglects the unique features of respiratory, lung, and chest wall mechanics may result in disease progression, such as patient self-inflicted lung injury during spontaneous breathing or by ventilator-induced lung injury during invasive mechanical ventilation. ARDS characteristics are highly heterogeneous; therefore, a physiology-based approach is strongly advocated to titrate the delivery and management of respiratory support strategies to match patient characteristics and needs to limit ARDS progression. Several tools have been implemented in clinical practice to aid the clinician in identifying the ARDS sub-phenotypes based on physiological peculiarities (inspiratory effort, respiratory mechanics, and recruitability), thus allowing for the appropriate application of personalized supportive care. In this narrative review, we provide an overview of noninvasive and invasive respiratory support strategies, as well as discuss how identifying ARDS sub-phenotypes in daily practice can help clinicians to deliver personalized respiratory support and potentially improve patient outcomes.

Does the use of a diving mask adapted for non-invasive ventilation in hypoxemic acute respiratory failure in individuals with and without COVID-19 increase the ratio of arterial oxygen partial pressure to fractional inspired oxygen? A randomized clinical trial

Non-invasive ventilation (NIV) can be used in acute hypoxemic respiratory failure (AHRF); however, verifying the best interface for its use needs to be evaluated in the COVID-19 pandemic scenario. The objective of this study was to evaluate the behavior of the ratio of arterial oxygen partial pressure to fractional inspired oxygen (PaO2/FiO2 ratio) in patients with AHRF with and without COVID-19 undergoing NIV with the conventional orofacial mask and the adapted diving mask. This is a randomized clinical trial in which patients were allocated into four groups: i) group 1: COVID-19 + adapted mask (n=12); ii) group 2: COVID-19 + conventional orofacial mask (n=12); iii) group 3: non-COVID-19 + adapted mask (n=2); iv) group 4: non-COVID-19 + conventional orofacial mask (n=12). The PaO2/FiO2 ratio was obtained 1, 24, and 48 hours after starting NIV, and the success of NIV was evaluated. This study followed the norms of the Consolidated Standards of Reporting Trials statement and was registered in the Brazilian Registry of Clinical Trials under registration RBR-7xmbgsz. Both the adapted diving mask and the conventional orofacial mask increased the PaO2/FiO2 ratio. The interfaces differed in terms of the PaO2/FiO2 ratio in the first hour [309.66 (11.48) and 275.71 (11.48), respectively] (p=0.042) and 48 hours [365.81 (16.85) and 308.79 (18.86), respectively] (p=0.021). NIV success was 91.7% in groups 1, 2, and 3, and 83.3% in group 4. No adverse effects related to interfaces or NIV were observed. NIV through the conventional orofacial mask interfaces and the adapted diving mask was effective in improving the PaO2/FiO2 ratio; however, the adapted mask presented a better PaO2/FiO2 ratio during use. There was no significant difference between interfaces regarding NIV failure.