Home-based respiratory support.

This review provides an overview of home-based respiratory support modalities for patients with chronic lung diseases. It discusses the increasing use of long-term high-flow nasal cannula (LT-HFNC) and long-term non-invasive ventilation (LT-NIV) and their potential to enhance patient quality of life. This review addresses various types of respiratory failure and their respective treatments, emphasising the significance of monitoring and telemedicine in home care. This comprehensive review underscores the clinical relevance of these interventions in the management of chronic lung diseases.

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

BACKGROUND: Mechanical ventilation is commonly used for managing respiratory failure in chronic obstructive pulmonary disease (COPD) patients, but weaning patients off ventilator support can be challenging and associated with complications. While many patients respond well to Non-invasive ventilation (NIV), a significant proportion may not respond as favourably. We aimed to assess whether high-flow nasal cannula (HFNC) is equally effective as NIV in reducing extubation failure among previously intubated COPD patients. METHODS: This systematic review was carried out in line with PRISMA guidelines We searched PubMed, Scopus, Web of Science, and Cochrane library from inception until February 15, 2023. Randomized Clinical Trials (RCTs) of adults at high risk for extubating failure were included. We examined the use of HFNC as the intervention and NIV as the comparator. Our outcome of interest included, reintubation rate, length of hospital or intensive care unit (ICU) stay, adverse events, and time to reintubation. The Cochrane risk-of-bias tool was used for randomized trials to assess risk of bias. RESULTS: We identified 348 citations, 11 of which were included, representing 2,666 patients. The trials indicate that HFNC is comparable to NIV in preventing reintubation after extubating in COPD patients. In comparison to NIV, HFNC also produced improved tolerance, comfort, and less complications such as airway care interventions. NIV with active humification may be more effective that HFNC in avoiding reintubation in patients who are at extremely high risk for extubating failure. CONCLUSION: The inconclusive nature of emerging evidence highlights the need for additional studies to establish the efficacy and suitability of HFNC as an alternative to NIV for previously intubated COPD patients. Clinicians should consider the available options and individualize their approach based on patient characteristics. Future research should focus on addressing these gaps in knowledge to guide clinical decision-making and optimize outcomes for this patient population.

Clinical characteristics and prognosis of patients with COVID-19 on mechanical ventilation undergoing continuous renal replacement therapy.

BACKGROUND: The coronavirus disease (COVID-19) pandemic has significantly strained global healthcare, particularly in the management of patients requiring mechanical ventilation (MV) and continuous renal replacement therapy (CRRT). This study investigated the characteristics and prognoses of these patients. METHODS: This multicenter retrospective cohort study gathered data from patients with COVID-19 across 26 medical centers. Logistic analysis was used to identify the factors associated with CRRT implementation. RESULTS: Of the 640 patients with COVID-19 who required MV, 123 (19.2%) underwent CRRT. Compared to the non-CRRT group, the CRRT group was older and exhibited higher sequential organ failure assessment scores. The incidence of hypertension, diabetes, cardiovascular disease, chronic neurological disease, and chronic kidney disease was also higher in the CRRT group. Moreover, the CRRT group had higher intensive care unit (ICU) (75.6% vs. 26.9%, p < 0.001) and in-hospital (79.7% vs. 29.6%, p < 0.001) mortality rates. CRRT implementation was identified as an independent risk factor for both ICU mortality (hazard ratio [HR]:1.833, 95% confidence interval [CI]:1.342-2.505, p < 0.001) and in-hospital mortality (HR: 2.228, 95% CI: 1.648-3.014, p < 0.001). Refractory respiratory failure (n = 99, 19.1%) was the most common cause of death in the non-CRRT death group, and shock with multi-organ failure (n = 50, 40.7%) was the most common cause of death in the CRRT death group. Shock with multi-organ failure and cardiac death were significantly more common in the CRRT death group, compared to non-CRRT death group. CONCLUSION: This study indicates that CRRT is associated with higher ICU and in-hospital mortality rates in patients with COVID-19 who require MV. Notably, the primary cause of death in the CRRT group was shock with multi-organ failure, emphasizing the severe clinical course for these patients, while refractory respiratory failure was most common in non-CRRT patients.

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. ... (AU)

Objetivo Explorar los patrones combinados de soporte-respiratorio-no-invasivo (SRNI), las razones para cambiar de SRNI y su potencial impacto en los resultados clínicos en pacientes con insuficiencia-respiratoria-aguda-hipoxémica (IRAH). Diseño Estudio observacional retrospectivo unicéntrico. Ámbito Cuidados Intensivos. Pacientes Pacientes con IRAH (excluyendo causa cardíaca y acidosis respiratoria) que recibieron tanto ventilación-no-invasiva (VNI) como cánula-nasal-de-alto-flujo (CNAF). Intervenciones Se categorizó a los pacientes según el primer cambio de SRNI realizado (CNAF-to-VNI o VNI-to-CNAF) y se evaluaron estrategias específicas de SRNI (VNI trial-like vs. Non-VNI trial-like y cambio único vs. múltiples cambios de NIRS) de manera independiente. Variables de interés principales Razones para el cambio, así como las tasas de fracaso de SRNI y la mortalidad. Resultados Un total de 63 pacientes recibieron SRNI combinado, 58,7% clasificados en el grupo CNAF-to-VNI y 41,3% en el grupo VNI-to-CNAF. Los cambios de CNAF a VNI ocurrieron por empeoramiento de la IRHA (100%) y de VNI a CNAF por mejora respiratoria (76.9%). Las tasas de fracaso de SRNI fueron mayores de CNAF a VNI que de VNI a CNAF (81% vs. 35%, p < 0.001). Dentro de los pacientes de CNAF a VNI, no hubo diferencia en las tasas de fracaso entre los grupos VNI trial-like y no-VNI trial-like (86% vs. 78%, p = 0.575), pero la mortalidad fue menor en el grupo VNI trial-like (14% vs. 52%, p = 0.02). Dentro de los pacientes de VNI a CNAF, el fracaso de VNI fue menor en grupo de cambio único vs. múltiple (15% vs. 53%, p = 0.039). Conclusiones Los cambios de estrategia de SRNI son comunes en el manejo clínico diario de la IRHA. El cambio de CNAF a VNI impresiona de ser una escalada terapéutica y en este contexto la realización de un VNI-trial puede ser beneficioso. Al contrario, cambiar de VNI a CNAF impresiona de ser una desescalada terapéutica y parece segura si no hay fracaso ... (AU)

Eficacia del protocolo Start to move en funcionalidad, DA-UCI y delirio: ensayo clínico aleatorizado / Efficacy of the «Start to move» protocol on functionality, ICU-acquired weakness and delirium: Randomized clinical trial

Objetivo Evaluar la eficacia del protocolo Start to move comparado con el tratamiento convencional en sujetos mayores de 15 años hospitalizados en la UCI sobre una mejoría en funcionalidad, disminución de debilidad adquirida en la UCI (DA-UCI), incidencia de delirio, días de ventilación mecánica (VM), estadía en la UCI y mortalidad a los 28 días. Diseño Ensayo clínico controlado aleatorizado. Ámbito Unidad de paciente crítico. Participantes Incluye adultos mayores a 15 años con VMI mayor a 48h, asignación aleatoria. Intervenciones Protocolo «Start to move» y tratamiento convencional. Variables de interés principales Se analizó funcionalidad, incidencia DA-UCI, incidencia delirio, días VM, estadía UCI y mortalidad-28 días, ClinicalTrials.gov número, NCT05053724. Resultados Sesenta y nueve sujetos fueron ingresados al estudio, 33 al grupo Start to move y 36 a tratamiento convencional, comparables clínico y sociodemograficamente. En el grupo Start to move la incidencia DAUCI al egreso de la UCI fue de 35,7 vs. 80,7% grupo tratamiento convencional (p=0,001). La funcionalidad (FSS-ICU) al egreso de la UCI corresponde a 26 vs. 17 puntos a favor del grupo Start to move (p=0,001). La diferencia en Barthel al egreso de la UCI fue del 20% a favor del grupo Start to move (p=0,006). No hubo diferencias significativas en incidencia de delirio, días de VM, estadía UCI y mortalidad-28 días. El estudio no reportó eventos adversos, ni suspensión de protocolo. Conclusiones La aplicación del protocolo Start to move en la UCI se asoció reducción en la incidencia DA-UCI, aumento en funcionalidad y menor caída en puntaje Barthel al egreso. (AU)

Objective To evaluate the efficacy of the Start to move protocol compared to conventional treatment in subjects over 15 years of age hospitalized in the ICU on an improvement in functionality, decrease in ICU-acquired weakness (IUCD), incidence of delirium, days of mechanical ventilation (MV), length of stay in ICU and mortality at 28 days. Design Randomized controlled clinical trial. Setting Intensive care unit. Participants Includes adults older than 15 years with invasive mechanical ventilation more than 48h, randomized allocation. Interventions Start to move protocol and conventional treatment. Main variables of interest Functionality, incidence of ICU-acquired weakness, incidence of delirium, days on mechanical ventilation, ICU stay and mortality-28 days, ClinicalTrials.gov number, NCT05053724. Results Sixty-nine subjects were admitted to the study, 33 to the Start to move group and 36 to conventional treatment, clinically and sociodemographic comparable. In the “Start to move” group, the incidence of IUCD at ICU discharge was 35.7% vs. 80.7% in the “conventional treatment” group (P=.001). Functionality (FSS-ICU) at ICU discharge corresponds to 26 vs. 17 points in favor of the “Start to move” group (P=.001). The difference in Barthel at ICU discharge was 20% in favor of the “Start to move” group (P=.006). There were no significant differences in the incidence of delirium, days of mechanical ventilation, ICU stay and 28-day mortality. The study did not report adverse events or protocol suspension. Conclusions The application of the “Start to move” protocol in ICU showed a reduction in the incidence of IUCD, an increase in functionality and a smaller decrease in Barthel score at discharge. (AU)

Manejo de la vía aérea ante un caso de paro respiratorio en un escenario clínico simulado. Experiencia en una residencia de pediatría / Airway management during a respiratory arrest in a clinical simulation scenario. Experience at a pediatric residency program

Introducción. La insuficiencia respiratoria es la causa más común de paro cardíaco en pediatría; su reconocimiento y el manejo adecuado son cruciales. La simulación se utiliza para mejorar las habilidades médicas. El objetivo del trabajo fue determinar la proporción de residentes de pediatría que reconocieron un paro respiratorio (PR) pediátrico en un centro de simulación. Métodos. Se realizó un estudio observacional con 77 médicos residentes. Se utilizó un caso simulado de un paciente con dificultad respiratoria que progresa a PR. Resultados. De los 77 participantes, 48 reconocieron el paro respiratorio (62,3 %). El tiempo medio para reconocer el PR fue de 34,43 segundos. Conclusión. El 62,3 % de los participantes logró reconocer el paro respiratorio. Entre aquellos que lo identificaron, el tiempo promedio fue de 34,43 segundos. Se observaron graves deficiencias en algunas de las intervenciones esperadas.

Introduction. Respiratory failure is the most common cause of cardiac arrest in pediatrics. Recognizing and managing it adequately is critical. Simulation is used to improve medical skills. The objective of this study was to establish the proportion of pediatric residents who recognized a respiratory arrest in a child at a simulation center. Methods. This was an observational study in 77 residents. A simulation of a patient with respiratory distress that progressed to respiratory arrest was used. Results. Among the 77 participants, 48 recognized respiratory arrest (62.3%). The mean time to recognize respiratory arrest was 34.43 seconds. Conclusion. Respiratory arrest was recognized by 62.3% of participants. Among those who did so, the average time was 34.43 seconds. Severe failures were noted in some of the expected interventions.

[Value of transnasal high-flow oxygen therapy and noninvasive ventilation in the management of acute respiratory distress syndrome].

Acute respiratory distress syndrome (ARDS) is one of the most common syndromes in the intensive care unit, with a high mortality and morbidity. Refractory hypoxia is the typical feature of ARDS, and improving hypoxia is the key to the treatment of ARDS. Due to the rapid progression of ARDS, invasive ventilation is usually used to improve hypoxia. But in recent years, with the extending of the understanding of ARDS and the development of non-invasive oxygen therapy, high flow nasal oxygen (HFNO) and non-invasive ventilation (NIV) are gradually used in ARDS. Therefore, we reviewed the role of HFNO and NIV in ARDS in this paper.

Oxygenation saturation index in neonatal hypoxemic respiratory failure.

BACKGROUND: This study aimed to assess the validity of the oxygenation saturation index (OSI) and the ratio of oxygen saturation to the fraction of inspired oxygen (FIO2) (S/F ratio) with percutaneous oxygen saturation (OSISpO2 and the Sp/F ratio) and to evaluate the correlation between these values and the oxygen index (OI). It also determined their cut-off values for predicting OI in accordance with neonatal hypoxic respiratory failure severity. METHODS: We reviewed the data of 77 neonates (gestational age 31.7 ± 6.1 weeks; birthweight, 1768 ± 983 g) requiring invasive mechanical ventilation between 2013 and 2020, 1233 arterial blood gas samples in total. We calculated the OI, OSISpO2, OSI with arterial oxygen saturation (SaO2) (OSISaO2), Sp/F ratio, and the ratio of SaO2 to FIO2 (Sa/F ratio). RESULTS: The regression and Bland-Altman analysis showed good agreement between OSISpO2 or the Sp/F ratio and OSISaO2 or the Sa/F ratio. Although a significant positive correlation was found between OSISpO2 and OI, OSISpO2 was overestimated in SpO2 > 98% with a higher slope of the fitted regression line than that below 98% of SpO2. Furthermore, receiver-operating characteristic curve analysis using only SpO2 ≤ 98% samples showed that the optimal cut-off points of OSISpO2 and the Sp/F ratio for predicting OI were: OI 5, 3.0 and 332; OI 10, 5.3 and 231; OI 15, 7.7 and 108; OI 20, 11.0 and 149; and OI 25, 17.1 and 103, respectively. CONCLUSION: The cut-off OSISpO2 and Sp/F ratio values could allow continuous monitoring for oxygenation changes in neonates with the potential for wider clinical applications.

Successful Recovery of a Catatonic Patient with Severe Pneumonia and Respiratory Failure: Modified Electroconvulsive Therapy Following Tracheotomy.

BACKGROUD: Catatonia encompasses a group of severe psychomotor syndromes affecting patients' motor, speech, and complex behaviors. Common features include rigidity, reduced mobility, speech, sputum production, defecation, and eating. Risks associated with catatonia, such as increased muscle tension and reduced swallowing and coughing reflexes, along with risks from therapeutic approaches like prolonged bed rest and sedative drugs, can elevate the risk of aspiration pneumonia, severe pneumonia, and acute respiratory failure. These complications significantly impede catatonia treatment, leading to poor prognosis and jeopardizing patient safety. CASE DESCRIPTION: In this report, we present a case of catatonia complicated by severe pneumonia and respiratory failure, successfully managed with modified electroconvulsive therapy alongside tracheotomy. We hope this case provides valuable insights for psychiatrists encountering similar scenarios, facilitating the development of rational therapeutic strategies for prompt improvement of patient condition.

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.

Remote pulmonary function testing allows for early identification of need for non-invasive ventilation in a subset of persons with ALS.

The traditional ALS multidisciplinary clinical practice of quarterly respiratory assessment may leave some individuals in danger of developing untreated respiratory insufficiency between visits or beginning non-invasive ventilation (NIV) later than would be optimal. Remote, or home-based, pulmonary function testing (rPFT) allows patients with ALS to perform regular respiratory testing at more frequent intervals in the home. The aim of this study was to determine the clinical benefit of weekly rPFT compared to standard, quarterly in-clinic respiratory assessments: the number of individuals with earlier identification of NIV need, the magnitude of this advance notice, and the individual factors predicting benefit. Participants with ALS (n = 39) completed rPFT training via telemedicine and then completed one year of weekly self-guided assessments in the home. Over this period, 17 individuals exhibited remotely-measured FVC dropping below 50% of predicted, the value often used for recommendation of NIV initiation. In 13 individuals with clinical detection of this event, the median and range of advance notice of need for NIV was 53 (-61-294) days. Prescription of NIV occurred for 21 individuals on the study, six of whom began NIV as a result of remote testing, prior to indication of need as determined by in-person assessments. Weekly home assessments appeared to be of greatest clinical value in a subset of patients with low baseline respiratory test values and rapid respiratory decline. This has potential implications for clinical management of ALS as well as the conduct of clinical trials that rely on respiratory endpoints.

Association between the ROX index and mortality in patients with acute hypoxemic respiratory failure: a retrospective cohort study.

BACKGROUND: Although ROX index is frequently used to assess the efficacy of high-flow nasal cannula treatment in acute hypoxemic respiratory failure (AHRF) patients, the relationship between the ROX index and the mortality remains unclear. Therefore, a retrospective cohort study was conducted to evaluate the ability of the ROX index to predict mortality risk in patients with AHRF. METHOD: Patients diagnosed with AHRF were extracted from the MIMIC-IV database and divided into four groups based on the ROX index quartiles. The primary outcome was 28-day mortality, while in-hospital mortality and follow-up mortality were secondary outcomes. To investigate the association between ROX index and mortality in AHRF patients, restricted cubic spline curve and COX proportional risk regression were utilized. RESULT: A non-linear association (L-shaped) has been observed between the ROX index and mortality rate. When the ROX index is below 8.28, there is a notable decline in the 28-day mortality risk of patients as the ROX index increases (HR per SD, 0.858 [95%CI 0.794-0.928] P < 0.001). When the ROX index is above 8.28, no significant association was found between the ROX index and 28-day mortality. In contrast to the Q1 group, the mortality rates in the Q2, Q3, and Q4 groups had a substantial reduction (Q1 vs. Q2: HR, 0.749 [0.590-0.950] P = 0.017; Q3: HR, 0.711 [0.558-0.906] P = 0.006; Q4: HR, 0.641 [0.495-0.830] P < 0.001). CONCLUSION: The ROX index serves as a valuable predictor of mortality risk in adult patients with AHRF, and that a lower ROX index is substantially associated with an increase in mortality.

Fluid Management in Acute Respiratory Failure.

Fluid management in acute respiratory failure is an area of uncertainty requiring a delicate balance of resuscitation and fluid removal to manage hypoperfusion and avoidance of hypoxemia. Overall, a restrictive fluid strategy (minimizing fluid administration) and careful attention to overall fluid balance may be beneficial after initial resuscitation and does not have major side effects. Further studies are needed to improve our understanding of patients who will benefit from a restrictive or liberal fluid management strategy.

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.

Inhalation Injury, Respiratory Failure, and Ventilator Support in Acute Burn Care.

Sustaining an inhalation injury increases the risk of severe complications and mortality. Current evidential support to guide treatment of the injury or subsequent complications is lacking, as studies either exclude inhalation injury or design limit inferences that can be made. Conventional ventilator modes are most commonly used, but there is no consensus on optimal strategies. Settings should be customized to patient tolerance and response. Data for pharmacotherapy adjunctive treatments are limited.

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.