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.

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

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

[Value of modified ROX index in predicting the outcome of patients with acute respiratory distress syndrome due to SARS-CoV-2 infection treated with high-flow nasal cannula oxygen therapy].

OBJECTIVE: To investigate the value of the modified ROX (mROX) index in predicting the outcome of patients with acute respiratory distress syndrome (ARDS) due to SARS-CoV-2 infection treated with high-flow nasal cannula oxygen therapy (HFNC). METHODS: A retrospective observational study was conducted, including 57 patients with ARDS caused by SARS-CoV-2 infection who required HFNC treatment in the intensive care unit (ICU) of the Lanzhou University Second Hospital from December 2022 to June 2023. The patients were divided into HFNC failure group and HFNC success group according to whether they were successfully weaned from HFNC. Laboratory tests, acute physiology and chronic health evaluation II (APACHE II), and sequential organ failure assessment (SOFA) in the first 24 hours of ICU admission were recorded in both groups, vital signs and arterial blood gas analysis immediately and after 6 hours of HFNC treatment, treatment regimen, length of ICU stay, and total length of hospital stay were recorded in both groups, and patients' outcomes at 28 days and 90 days were followed up by telephone. Univariate analysis was used to analyze the above indexes, and the significant indexes were included in the binary multivariate Logistic regression analysis to analyze the influencing factors of HFNC failure in patients. Kaplan-Meier survival curves were plotted to analyze the 28-day and 90-day outcomes of patients in both groups. Receiver operator characteristic curve (ROC curve) was plotted to analyze the value of treatment 6-hour mROX index and 6-hour ROX index in predicting the success of HFNC. RESULTS: A total of 57 patients with ARDS due to SARS-CoV-2 infection were enrolled, including 34 patients in the HFNC success group and 23 patients in the HFNC failure group. Procalcitonin (PCT), C-reactive protein (CRP), interleukin-6 (IL-6), lactic acid (Lac) and the proportion of vasopressors, the proportion of continuous renal replacement therapy (CRRT), the APACHE II score and the SOFA score, the respiratory rate (RR) immediately and 6 hours after treatment were significantly higher in the HFNC failure group compared with the HFNC success group. The length of ICU stay was significantly longer, and oxygenation index (PaO2/FiO2) at the time of treatment, and pulse oxygen saturation (SpO2), arterial partial pressure of oxygen (PaO2), ROX index, and mROX index at the time of treatment and at 6 hours after treatment were significantly lower in the HFNC failure group compared with the HFNC success group (all P < 0.05). Kaplan-Meier survival curves showed that the 28-day cumulative survival rates (100% vs. 26.1%) and 90-day cumulative survival rates (85.3% vs. 21.7%) of patients in the HFNC success group were significantly higher than those in the HFNC failure group (both P < 0.001). On binary multivariate Logistic regression analysis, Lac [odds ratio (OR) = 0.129, 95% confidence interval (95%CI) was 0.020-0.824], SOFA score (OR = 0.382, 95%CI was 0.158-0.925), 6-hour ROX index (OR = 0.099, 95%CI was 0.011-0.920), and 6-hour mROX index (OR = 23.703, 95%CI was 1.415-396.947) were associated with HFNC treatment outcome (all P < 0.05). ROC curve analysis showed that the area under the ROC curve (AUC) of the 6-hour mROX index and the 6-hour ROX index for predicting the success of HFNC were both higher (0.809 and 0.714, respectively), and the AUC of 6-hour mROX index was significantly higher than that of 6-hour ROX index (P < 0.01), and the sensitivity was 88.2% and the specificity was 52.2% when the cut-off value of 6-hour mROX index was 4.5. CONCLUSIONS: The predictive value of the 6-hour mROX index in the treatment of patients with ARDS caused by SARS-CoV-2 infection is higher than that of the 6-hour ROX index, and the 6-hour mROX index is greater than 4.5, which is more likely to predict the success of HFNC treatment.

Racial Differences in Accuracy of Predictive Models for High-Flow Nasal Cannula Failure in COVID-19.

OBJECTIVES: To develop and validate machine learning (ML) models to predict high-flow nasal cannula (HFNC) failure in COVID-19, compare their performance to the respiratory rate-oxygenation (ROX) index, and evaluate model accuracy by self-reported race. DESIGN: Retrospective cohort study. SETTING: Four Emory University Hospitals in Atlanta, GA. PATIENTS: Adult patients hospitalized with COVID-19 between March 2020 and April 2022 who received HFNC therapy within 24 hours of ICU admission were included. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Four types of supervised ML models were developed for predicting HFNC failure (defined as intubation or death within 7 d of HFNC initiation), using routine clinical variables from the first 24 hours of ICU admission. Models were trained on the first 60% (n = 594) of admissions and validated on the latter 40% (n = 390) of admissions to simulate prospective implementation. Among 984 patients included, 317 patients (32.2%) developed HFNC failure. eXtreme Gradient Boosting (XGB) model had the highest area under the receiver-operator characteristic curve (AUROC) for predicting HFNC failure (0.707), and was the only model with significantly better performance than the ROX index (AUROC 0.616). XGB model had significantly worse performance in Black patients compared with White patients (AUROC 0.663 vs. 0.808, p = 0.02). Racial differences in the XGB model were reduced and no longer statistically significant when restricted to patients with nonmissing arterial blood gas data, and when XGB model was developed to predict mortality (rather than the composite outcome of failure, which could be influenced by biased clinical decisions for intubation). CONCLUSIONS: Our XGB model had better discrimination for predicting HFNC failure in COVID-19 than the ROX index, but had racial differences in accuracy of predictions. Further studies are needed to understand and mitigate potential sources of biases in clinical ML models and to improve their equitability.

Efficacy of corticosteroid therapy for oxygen-free coronavirus disease 2019-derived pneumonia.

Corticosteroid therapy for oxygen-free coronavirus disease 2019 (COVID-19) is not recommended due to its negative prognostic impact, but the efficacy of corticosteroids when limited to COVID-19 pneumonia is unclear. We aimed to evaluate the efficacy of corticosteroid monotherapy for patients with COVID-19 pneumonia without supplemental oxygen. We retrospectively reviewed patients with oxygen-free COVID-19 pneumonia at our institute between September 2020 and August 2021 and assessed the use of corticosteroids and the timing of initiation. We classified the patients into the following 2 groups: those who were initiated corticosteroids without developing respiratory failure (early steroid group) and those who were not (standard of care [SOC] group). We used inverse probability of treatment weighting (IPW) to balance between the groups. The primary outcome was the incidence of respiratory failure. A total of 144 patient records were reviewed; 63 patients were in the early steroid group and 81 patients were in the SOC group. Of all patients, 14 (22.2%) and 27 (33.3%) patients in the early steroid and SOC group, respectively, required supplemental oxygen (P = .192). After adjusted by the IPW method, 10 (16.0%) and 32 (40.1%) patients in the early steroid and SOC groups, respectively, required supplemental oxygen (P = .004). The logistic regression analysis indicated that early corticosteroid use was significantly associated with a decreased incidence of respiratory failure (odds ratio; 0.17, 95% confidence intervals; 0.06-0.46, P < .001). Corticosteroid monotherapy may suppress the development of exacerbation requiring oxygen supply in patients with oxygen-free COVID-19 pneumonia.

In adults with COVID-19 and severe hypoxemia, lower vs. higher oxygenation targets increased days alive without life support.

SOURCE CITATION: Nielsen FM, Klitgaard TL, Siegemund M, et al; HOT-COVID Trial Group. Lower vs higher oxygenation target and days alive without life support in COVID-19: the HOT-COVID randomized clinical trial. JAMA. 2024;331:1185-1194. 38501214.

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

OBJECTIVE: To evaluate the beneficial effects of high-flow nasal cannula (HFNC) oxygen therapy during cesarean section in pregnant women with heart disease. METHODS: We conducted a single-center, single-blinded randomized trial of HFNC oxygen therapy in pregnant women with heart disease undergoing cesarean section under neuraxial anesthesia.The participants were randomly assigned to receive either HFNC oxygen therapy with inspiratory flow of 30 L/min with 40% FIO2(n=27) or conventional oxygen therapy (COT) with oxygen flow rate of 5 L/min via a nasal cannula (n=31).The primary outcome was maternal desaturation (SpO2 < 94% lasting more than 3 min or PaO2/FIO2≤300 mmHg). RESULTS: Maternal desaturation was observed in 7.4%(2/27) of the women in HFNC group and in 32.3%(10/31) in the COT group.None of the cases required tracheal intubation during the perioperative period.The HFNC group had a significantly higher incidence of postoperative leukocytosis (P < 0.05) but without pyrexia or other inflammation-related symptoms.There were no significant differences between the two groups in the secondary maternal outcomes (need for respiratory support, maternal ICU admission, postoperative respiratory complications, and cardiovascular complications) or neonatal outcomes (P>0.05). CONCLUSION: In pregnant women with heart disease, HFNC therapy can significantly reduce the rate of maternal desaturation during the perioperative period of cesarean section without adverse effects on short-term maternal or fetal outcomes.

[Long terme oxygen therapy in chronic respiratory diseases]. / Oxygénothérapie à long terme dans les pathologies respiratoires chroniques.

LONG TERM OXYGEN THERAPY IN CHRONIC RESPIRATORY DISEASES. Survival of severe chronic respiratory failure with chronic obstructive pulmonary disease (COPD) is improved by long-term oxygen therapy. Other benefits exist for COPD and other causes of chronic respiratory failure. The indications for this restrictive (more 15 hours per day) treatment require measurements of arterial blood gases in adults. Several actors are involved: the specialist for the prescription, the service provider for supplying and maintaining the equipment, the patient and his entourage, the referring doctor to ensure that oxygen therapy is well tolerated and used. The referring doctor can prescribe short-term oxygen therapy for transient respiratory failure. The choice of oxygen source depends on the patient's ability to ambulate and the required flow rate. Concentrators are increasingly used, despite limited flow rate with mobile devices. Liquid oxygen makes it possible to deliver high flow rates but is expensive. The main complications of oxygen therapy are the worsening of chronic hypercapnia, burns (especially in active smokers)...

OXYGÉNOTHÉRAPIE À LONG TERME DANS LES PATHOLOGIES RESPIRATOIRES CHRONIQUES. La survie des patients souffrant de bronchopneumopathie chronique obstructive (BPCO) insuffisants respiratoires chroniques (IRC) sévères est améliorée par l'oxygénothérapie à long terme (OLT). D'autres bénéfices existent pour les patients IRC. Les indications de ce traitement contraignant (plus de 15 heures par jour) imposent des mesures des gaz du sang artériel chez l'adulte. Plusieurs acteurs sont impliqués : le spécialiste pour la prescription, le prestataire de service pour la fourniture et l'entretien du matériel, le patient et son entourage, le médecin traitant pour s'assurer que l'oxygénothérapie est bien tolérée et utilisée. Le médecin traitant peut prescrire une oxygénothérapie de court terme. Le choix de la source d'oxygène dépend des possibilités de déambulation du patient et du débit requis. Les concentrateurs électriques sont de plus en plus utilisés malgré des débits limités avec les appareils mobiles. L'oxygène liquide permet de délivrer des débits importants mais reste coûteux. Les principales complications de l'oxygénothérapie sont l'aggravation d'une hypercapnie chronique, des brûlures (surtout chez le fumeur actif)...

Respiratory support with standard low-flow oxygen therapy, high-flow oxygen therapy or continuous positive airway pressure in adults with acute hypoxaemic respiratory failure in a resource-limited setting: protocol for a randomised, open-label, clinical trial - the Acute Respiratory Intervention StudiEs in Africa (ARISE-AFRICA) study.

RATIONALE: Acute hypoxaemic respiratory failure (AHRF) is associated with high mortality in sub-Saharan Africa. This is at least in part due to critical care-related resource constraints including limited access to invasive mechanical ventilation and/or highly skilled acute care workers. Continuous positive airway pressure (CPAP) and high-flow oxygen by nasal cannula (HFNC) may prove useful to reduce intubation, and therefore, improve survival outcomes among critically ill patients, particularly in resource-limited settings, but data in such settings are lacking. The aim of this study is to determine whether CPAP or HFNC as compared with standard oxygen therapy, could reduce mortality among adults presenting with AHRF in a resource-limited setting. METHODS: This is a prospective, multicentre, randomised, controlled, stepped wedge trial, in which patients presenting with AHRF in Uganda will be randomly assigned to standard oxygen therapy delivered through a face mask, HFNC oxygen or CPAP. The primary outcome is all-cause mortality at 28 days. Secondary outcomes include the number of patients with criteria for intubation at day 7, the number of patients intubated at day 28, ventilator-free days at day 28 and tolerance of each respiratory support. ETHICS AND DISSEMINATION: The study has obtained ethical approval from the Research and Ethics Committee, School of Biomedical Sciences, College of Health Sciences, Makerere University as well as the Uganda National Council for Science and Technology. Patients will be included after informed consent. The results will be submitted for publication in peer-reviewed journals. TRIAL REGISTRATION NUMBER: NCT04693403. PROTOCOL VERSION: 8 September 2023; version 5.

A randomized, embedded, pragmatic, Bayesian clinical trial examining clinical decision support for high flow nasal cannula management in children with bronchiolitis: design and statistical analysis plan.

BACKGROUND: High flow nasal cannula (HFNC) has been increasingly adopted in the past 2 decades as a mode of respiratory support for children hospitalized with bronchiolitis. The growing use of HFNC despite a paucity of high-quality data regarding the therapy's efficacy has led to concerns about overutilization. We developed an electronic health record (EHR) embedded, quality improvement (QI) oriented clinical trial to determine whether standardized management of HFNC weaning guided by clinical decision support (CDS) results in a reduction in the duration of HFNC compared to usual care for children with bronchiolitis. METHODS: The design and summary of the statistical analysis plan for the REspiratory SupporT for Efficient and cost-Effective Care (REST EEC; "rest easy") trial are presented. The investigators hypothesize that CDS-coupled, standardized HFNC weaning will reduce the duration of HFNC, the trial's primary endpoint, for children with bronchiolitis compared to usual care. Data supporting trial design and eventual analyses are collected from the EHR and other real world data sources using existing informatics infrastructure and QI data sources. The trial workflow, including randomization and deployment of the intervention, is embedded within the EHR of a large children's hospital using existing vendor features. Trial simulations indicate that by assuming a true hazard ratio effect size of 1.27, equivalent to a 6-h reduction in the median duration of HFNC, and enrolling a maximum of 350 children, there will be a > 0.75 probability of declaring superiority (interim analysis posterior probability of intervention effect > 0.99 or final analysis posterior probability of intervention effect > 0.9) and a > 0.85 probability of declaring superiority or the CDS intervention showing promise (final analysis posterior probability of intervention effect > 0.8). Iterative plan-do-study-act cycles are used to monitor the trial and provide targeted education to the workforce. DISCUSSION: Through incorporation of the trial into usual care workflows, relying on QI tools and resources to support trial conduct, and relying on Bayesian inference to determine whether the intervention is superior to usual care, REST EEC is a learning health system intervention that blends health system operations with active evidence generation to optimize the use of HFNC and associated patient outcomes. TRIAL REGISTRATION: ClinicalTrials.gov NCT05909566. Registered on June 18, 2023.

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.

The neuroprotective effects of normobaric oxygen therapy after stroke.

BACKGROUND: Stroke, including ischemic and hemorrhagic stroke, is a severe and prevalent acute cerebrovascular disease. The development of hypoxia following stroke can trigger a cascade of pathological events, including mitochondrial dysfunction, energy deficiency, oxidative stress, neuroinflammation, and excitotoxicity, all of which are often associated with unfavorable prognosis. Nonetheless, a noninvasive intervention, referred to as normobaric hyperoxia (NBO), is known to have neuroprotective effects against stroke. RESULTS: NBO can exert neuroprotective effects through various mechanisms, such as the rescue of hypoxic tissues, preservation of the blood-brain barrier, reduction of brain edema, alleviation of neuroinflammation, improvement of mitochondrial function, mitigation of oxidative stress, reduction of excitotoxicity, and inhibition of apoptosis. These mechanisms may help improve the prognosis of stroke patients. CONCLUSIONS: This review summarizes the mechanism by which hypoxia causes brain injury and how NBO can act as a neuroprotective therapy to treat stroke. We conclude that NBO has significant potential for treating stroke and may represent a novel therapeutic strategy.

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.

Mortalidad en pacientes hospitalizados por COVID-19 durante la primera ola en una institución de tercer nivel de Neuquén / Mortality in Patients Hospitalized for COVID-19 during the First Wave in a Tertiary Care Institution in Neuquén

Introducción: En diciembre de 2019, se detectó un brote de enfermedad por un nuevo coronavirus que evolucionó en pandemia con severa morbilidad respiratoria y mortali- dad. Los sistemas sanitarios debieron enfrentar una cantidad inesperada de pacientes con insuficiencia respiratoria. En Argentina, las medidas de cuarentena y control sani - tario retrasaron el primer pico de la pandemia y ofrecieron tiempo para preparar el sis- tema de salud con infraestructura, personal y protocolos basados en la mejor evidencia disponible en el momento. En una institución de tercer nivel de Neuquén, Argentina, se desarrolló un protocolo de atención para enfrentar la pandemia adaptado con la evo- lución de la mejor evidencia y evaluaciones periódicas de la mortalidad hospitalaria. Métodos: Estudio de cohorte observacional para evaluar la evolución de pacientes con COVID-19 con los protocolos asistenciales por la mortalidad hospitalaria global y al día 28 en la Clínica Pasteur de Neuquén en 2020. Resultados: Este informe describe los 501 pacientes diagnosticados hasta el 31 de di- ciembre de 2020. La mortalidad general fue del 16,6% (83/501) y del 12,2% (61/501) al día 28 de admisión. En los 139 (27,7%) pacientes con ventilación mecánica, la mortali- dad general y a los 28 días fue de 37,4% (52/139) y 28,1% (38/139) fallecieron, respec- tivamente. Los factores de riesgo identificados fueron edad, comorbilidades y altos re- querimientos de oxígeno al ingreso. Conclusión: La mortalidad observada en los pacientes hospitalizados en nuestra insti- tución en la primera ola de la pandemia COVID-19 fue similar a los informes internacio- nales y menor que la publicada en Argentina para el mismo período.

Introduction: In December 2019, an outbreak of disease due to a new coronavirus was detected that evolved into a pandemic with severe respiratory morbidity and mortality. Health systems had to face an unexpected number of patients with respiratory failure. In Argentina, quarantine and health control measures delayed the first peak of the pan - demic and offered time to prepare the health system with infrastructure, personnel and protocols based on the best evidence available at the time. In a third level institution of Neuquén, Argentina, a care protocol was developed to confront the pandemic adapted by evolving best evidence and periodic evaluations of hospital mortality. Methods: Observational cohort study to evaluate the evolution of patients hospitalized for COVID-19 with care protocols in terms of overall hospital mortality and at day 28 at the Pasteur Clinic in Neuquén in 2020. Results: This report describes the 501 patients diagnosed until December 31, 2020. Mortality was 16.6% (83/501) and 12.2% (61/501) on day 28 of admission. Among the 139 (27.7%) patients with mechanical ventilation, overall mortality and at 28 days it was 37.4% (52/139) and 28.1% (38/139), respectively. The risk factors identified were age, comorbidities and high oxygen requirements on admission. Conclusion: The mortality observed in patients hospitalized in our institution during the first wave of COVID-19 pandemic was similar to international reports and lower than other publications in Argentina for the same period.

Factores pronósticos de mortalidad a 30 días en neumonía por SARS-CoV-2 / Prognostic Factors for 30-day Mortality in SARS-CoV-2 Pneumonia

Introducción: SARS-CoV-2 ha causado millones de muertes a nivel global desde su primer caso reportado en China. En Guatemala existen pocos estudios que describan los factores pronósticos. Nuestro objetivo fue determinar los factores asociados de mortalidad a 30 días en pacientes con neumonía (Nm) por SARS-CoV-2 y construir un modelo predictor. Material y Métodos: Estudio retrospectivo en 144 sujetos en el Hospital Roosevelt de marzo a diciembre 2020 con criterios de Nm por SARS-CoV-2. Se revisó el expediente médico para datos clínicos y de laboratorio desde ingreso hasta alta hospitalaria o muerte. Resultados: Se evaluaron 105 hombres y 39 mujeres con media de edad 53 años. El 47% tenía comorbilidades como diabetes mellitus 2 e hipertensión arterial sistémica. Promedio de días de hospitalización: 13. Cuadros leves a moderados de Síndrome de Distrés Respiratorio Agudo (SDRA): 92%. Se indicó ventilación mecánica invasiva (VMI) a 46 pacientes. La mortalidad general fue 35%. Factores asociados a mortalidad a 30 días: edad ≥50 años, inicio de síntomas ≥7 días, SDRA severo, radio NL >4,4, recibir VMI, alteración en LDH y procalcitonina. Nuestro modelo mostró que los mejores predictores de mortalidad eran alteración en procalcitonina (OR: 4,45), recibir VMI (OR: 112) y días de estancia hospitalaria (OR: 1,12) con precisión de 91,5% y área bajo la curva de 94,4%. Conclusiones: Los factores pronósticos de mortalidad en pacientes guatemaltecos con Nm por SARS-CoV-2 son múltiples e incluyen rasgos demográficos, clínicos y serológicos; identificarlos y contar con un modelo pronóstico ayudará a brindar atención médica de precisión.

Introduction: SARS-CoV-2 has caused millions of deaths globally since its first case was reported in China. In Guatemala, few studies describe prognostic factors. Our objective was to determine the factors associated with 30 day mortality in patients with Pneumonia (Nm) due to SARS-CoV-2 and to build a predictor model. Material and Methods: Retrospective study in 144 subjects at Roosevelt Hospital from March to December 2020 with Nm criteria for SARS-CoV-2. The medical record was rviewed, obtaining clinical and laboratory data from admission to hospital discharge or death. Results: 105 men and 39 women with an average age of 53 years were evaluated. 47% had comorbidities, with type 2 diabetes mellitus and systemic arterial hypertension being common. The average number of days of hospitalization was 13. 92% had mild to moderate acute respiratory distress syndrome (ARDS). Invasive mechanical ventila-tion (IMV) was indicated for 46 patients. Overall mortality was 35%. The factors asso-ciated with 30-day mortality were age ≥50 years, the onset of symptoms ≥7 days, severe ARDS, N/L ratio >4.4, receiving IMV, alterations in LDH, and procalcitonin. Our model showed that the best predictors of mortality were altered procalcitonin (OR: 4.45), receiving IMV (OR: 112), and days of hospital stay (OR: 1.12) with precision of 91.5% and area under the curve of 94.4%. Conclusions: The prognostic factors of mortality in Guatemalan patients with Nm due to SARS-CoV-2 are multiple and include demographic, clinical and serological features; identifying them and having a prognostic model will help provide precision medical care.

Estrategias de destete y desmonte de cánula nasal de alto flujo en adultos / Adult High-Flow Nasal Cannula Weaning and Disassembly Strategies

Introducción: La cánula nasal de alto flujo es un sistema que utiliza una mezcla de aire-oxígeno humidificado y calentado con un caudal de hasta 70 litros por minuto. Es utilizada mayoritariamente en la insuficiencia respiratoria aguda de origen hipoxémico, donde ha demostrado brindar mayor comodidad y poder resolutivo de la hipoxemia, en comparación con la oxigenoterapia convencional. Aunque se conocen sus indicaciones y estrategia de seguimiento, en la práctica clínica no es claro su proceso de destete/desmonte. Objetivo: Identificar en la bibliografía la literatura existente acerca de estrategias de destete/desmonte de la cánula nasal de alto flujo en adultos. Métodos: Se realizó una revisión bibliográfica en las bases de datos del portal regional de la BVS, PubMed, Web Of Science, Scopus y Google scholar, sin límite de tiempo y es- tructurando una ecuación PIO con palabras clave y operadores booleanos. Se asumieron artículos publicados en inglés y español, texto completo. Resultados: En la bibliografía, aún se reporta discrepancia en el proceso de destete y desmonte de la cánula nasal de alto flujo, pero en la mayoría de los estudios encontrados en esta revisión se propone disminuir la FiO2 primero de forma gradual (5-10%) hasta valores de 30-50% y, posteriormente, el flujo. Para desmontarla, se podría considerar tener una FiO2 entre 30-50%, flujo entre 20-30 litros por minuto, SaO2 >92%, con adecuada mecánica respiratoria y estado de conciencia. Conclusión: Aún no existe unanimidad en el proceso de destete/desmonte en la cánula nasal de alto flujo en el paciente adulto.

Introduction: The high-flow nasal cannula is a system that uses a humidified and heated air-oxygen mixture with a flow rate of up to 70 liters per minute. It is mostly used in acute respiratory failure of hypoxemic origin, where it has been shown to provide greater comfort and resolving power of hypoxemia, compared to conventional oxygen therapy. Although its indications and follow-up strategy are known, in clinical practice the weaning/weaning process is not clear. Objective: To identify in the bibliography the existing literature on weaning/ weaning strategies of high-flow nasal cannula in adults. Methods: A bibliographic review was carried out in the databases of the regional portal of the BVS, PubMed, Web Of Science, Scopus and Google scholar, without time limit and structuring a PIO equation with keywords and boléan connectors. Articles published in English and Spanish, full text, were assumed. Results: The literature still reports discrepancy in the process of weaning and disassembling the high-flow nasal cannula, but most of the studies found in this review propose to decrease the FiO2 first gradually (5-10%) to values of 30-50% and then the flow. To dismantle it, one could consider having a FiO2 between 30-50%, flow between 20-30 liters per minute, SaO2 >92%, with adequate respiratory mechanics and state of consciousness. Conclusion: There is still no unanimity on the weaning/weaning process in the high- flow nasal cannula in the adult patient.

Normalization of eosinophil count is predictive of oxygen weaning over the course of COVID-19 infection among hospitalized adults during the first wave of 2020 pandemic.

Background: Understanding COVID-19 outcomes remains a challenge. While numerous biomarkers have been proposed for severity at admission, limited exploration exists for markers during the infection course, especially for the requirement of oxygen therapy. This study investigates the potential of eosinophil count normalization as a predictor for oxygen weaning during the initial wave of the pandemic. Methods: A retrospective study was conducted between March and April 2020 (first wave) among adults admitted directly to a medicine ward. Biological abnormalities, including lymphocyte count, eosinophil count, and C-reactive protein (CRP), were gathered daily during the first week of admission according to oxygen level. In case of worsening, oxygen level was censored at 15 L/min. The primary aim was to assess whether eosinophil count normalization predicts a subsequent decrease in oxygen requirements. Results: Overall, 132 patients were admitted, with a mean age of 59.0 ± 16.3 years. Of the patients, 72% required oxygen, and 20.5% were admitted to the intensive care unit after a median delay of 48 hours. The median CRP at admission was 79 (26-130) mg/L, whereas the eosinophil count was 10 (0-60)/mm3. Eosinophil count normalization (≥100/mm3) by day 2 correlated significantly with decreased oxygen needs (<2 L) with hazard ratio (HR) = 3.7 [1.1-12.9] (p = 0.04). Likewise, CRP < 80 mg/L was associated with reduced oxygen requirements (p < 0.001). Predictors, including underlying chronic respiratory disease, exhibited a trend toward a negative association (p = 0.06). Conclusion: The study highlights the relationship between eosinophil count and CRP, with implications for predicting oxygen weaning during COVID-19. Further research is warranted to explore the relevance of these biomarkers in other respiratory infections.

Implementing High-Flow Nasal Oxygen Therapy in Medical Wards: A Scoping Review to Understand Hospital Protocols and Procedures.

Acute hypoxemic respiratory failure (ARF) is a common cause for hospital admission. High-flow nasal oxygen (HFNO) is increasingly used as a first-line treatment for patients with ARF, including in medical wards. Clinical guidance is crucial when providing HFNO, and health services use local health guidance documents (LHGDs) to achieve this. It is unknown what hospital LHGDs recommend regarding ward administration of HFNO. This study examined Australian hospitals' LHGDs regarding ward-based HFNO administration to determine content that may affect safe delivery. A scoping review was undertaken on 2 May 2022 and updated on 29 January 2024 to identify public hospitals' LHGDs regarding delivery of HFNO to adults with ARF in medical wards in two Australian states. Data were extracted and analysed regarding HFNO initiation, monitoring, maintenance and weaning, and management of clinical deterioration. Of the twenty-six included LHGDs, five documents referenced Australian Oxygen Guidelines. Twenty LHGDs did not define a threshold level of hypoxaemia where HFNO use was recommended over conventional oxygen therapy. Thirteen did not provide target oxygen saturation ranges whilst utilising HFNO. Recommendations varied regarding maximal levels of inspired oxygen and flow rates in the medical ward. Eight LHGDs did not specify any system to identify and manage deteriorating patients. Five LHGDs did not provide guidance for weaning patients from HFNO. There was substantial variation in the LHGDs regarding HFNO care for adult patients with ARF in Australian hospitals. These findings have implications for the delivery of high-quality, safe clinical care in hospitals.

Exploring Heterogeneity in Cost-Effectiveness Using Machine Learning Methods: A Case Study Using the FIRST-ABC Trial.

OBJECTIVE: The aim of this study was to explore heterogeneity in the cost-effectiveness of high-flow nasal cannula (HFNC) therapy compared with continuous positive airway pressure (CPAP) in children following extubation. DESIGN: Using data from the FIRST-line support for Assistance in Breathing in Children (FIRST-ABC) trial, we explore heterogeneity at the individual and subgroup levels using a causal forest approach, alongside a seemingly unrelated regression (SUR) approach for comparison. SETTINGS: FIRST-ABC is a noninferiority randomized controlled trial (ISRCTN60048867) including children in UK paediatric intensive care units, which compared HFNC with CPAP as the first-line mode of noninvasive respiratory support. PATIENTS: In the step-down FIRST-ABC, 600 children clinically assessed to require noninvasive respiratory support were randomly assigned to HFNC and CPAP groups with 1:1 treatment allocation ratio. In this analysis, 118 patients were excluded because they did not consent to accessing their medical records, did not consent to follow-up questionnaire or did not receive respiratory support. MEASUREMENTS AND MAIN RESULTS: The primary outcome of this study is the incremental net monetary benefit (INB) of HFNC compared with CPAP using a willingness-to-pay threshold of £20,000 per QALY gain. INB is calculated based on total costs and quality adjusted life years (QALYs) at 6 months. The findings suggest modest heterogeneity in cost-effectiveness of HFNC compared with CPAP at the subgroup level, while greater heterogeneity is detected at the individual level. CONCLUSIONS: The estimated overall INB of HFNC is smaller than the INB for patients with better baseline status suggesting that HFNC can be more cost-effective among less severely ill patients.