Stratifying risk outcomes among adult COVID-19 inpatients with high flow oxygen: The R4 score

Prognostic models in COVID-19 infection that predict severity: a systematic review

Current evidence on COVID-19 prognostic models is inconsistent and clinical applicability remains controversial. We performed a systematic review to summarize and critically appraise the available studies that have developed, assessed and/or validated prognostic models of COVID-19 predicting health outcomes. We searched six bibliographic databases to identify published articles that investigated univariable and multivariable prognostic models predicting adverse outcomes in adult COVID-19 patients, including intensive care unit (ICU) admission, intubation, high-flow nasal therapy (HFNT), extracorporeal membrane oxygenation (ECMO) and mortality. We identified and assessed 314 eligible articles from more than 40 countries, with 152 of these studies presenting mortality, 66 progression to severe or critical illness, 35 mortality and ICU admission combined, 17 ICU admission only, while the remaining 44 studies reported prediction models for mechanical ventilation (MV) or a combination of multiple outcomes. The sample size of included studies varied from 11 to 7,704,171 participants, with a mean age ranging from 18 to 93 years. There were 353 prognostic models investigated, with area under the curve (AUC) ranging from 0.44 to 0.99. A great proportion of studies (61.5%, 193 out of 314) performed internal or external validation or replication. In 312 (99.4%) studies, prognostic models were reported to be at high risk of bias due to uncertainties and challenges surrounding methodological rigor, sampling, handling of missing data, failure to deal with overfitting and heterogeneous definitions of COVID-19 and severity outcomes. While several clinical prognostic models for COVID-19 have been described in the literature, they are limited in generalizability and/or applicability due to deficiencies in addressing fundamental statistical and methodological concerns. Future large, multi-centric and well-designed prognostic prospective studies are needed to clarify remaining uncertainties.

Efficacy and safety of high-flow nasal cannula therapy in elderly patients with acute respiratory failure

INTRODUCTION

To assess the efficacy and safety of high-flow nasal cannula (HFNC) in elderly patients with acute respiratory failure (ARF) not due to COVID-19, refractory to treatment with conventional oxygen therapy and/or intolerant to noninvasive ventilation (NIV) or continuous positive airway pressure (CPAP) and without criteria for admission to intensive care units (ICU).

METHODS

Prospective observational study of patients with ARF treated with HFNC who presented clinical and arterial blood gas deterioration after 24 h of medical treatment and oxygenation by conventional systems. The degree of dyspnoea, gas exchange parameters (arterial O2 pressure/inspired O2 fraction ratio (PaO2/FiO2); oxygen saturation measured by oximetry/ inspired fraction of oxygen (Sp02/Fi02), ROX index), degree of patient tolerance and mortality were evaluated. These were measured at discharge from the emergency department (ED), 24 h after treatment with conventional oxygenation and 60, 120 min and 24 h after initiation of HFNC. The results were analyzed for all patients as a whole and for patients with hypercapnia (arterial carbon dioxide tension (PaCO2) < 45 mmHg) separately.

RESULTS

200 patients were included in the study between November 2019 and November 2020, with a mean age of 83 years, predominantly women (61.9%), obese (Body Mass Index (BMI) 31.1), with high comorbidity (Charlson index 4) and mild-moderate degree of dependence (Barthel 60). A number of 128 patients (64%) were hypercapnic. None had respiratory acidosis (pH 7.39). Evaluation at 60 min, 120 min and 24 h showed significant improvement in all patients and in the subgroup of hypercapnic patients with respect to baseline parameters in respiratory rate (RR), dyspnoea, ROX index, PaO2/FiO2, SpO2/FiO2 and patient comfort. No changes in PaCO2 or level of consciousness were observed. HFNC was well tolerated. Ten patients (5%) died due to progression of the disease causing ARF.

CONCLUSIONS

HFNC is an effective and safe alternative in elderly patients with ARF not due to COVID-19, refractory to treatment with conventional oxygen therapy and/or intolerant to NIV or CPAP and without criteria for admission to ICU.

Effectiveness of high-flow nasal cannula therapy on clinical outcomes in adults with COVID-19: A systematic review

Introduction/Background

Coronavirus disease 2019 (COVID-19) has high transmissibility and mortality rates. High-flow nasal cannula therapy (HFNC) might reduce the need for orotracheal intubation, easing the burden on the health system caused by COVID-19. The objective of the present study was to examine the effectiveness of HFNC in adult patients hospitalized with COVID-19. Specifically, the present study explores the effects of HFNC on rates of mortality, intubation and intensive care units (ICU) length of stay. The present study also seeks to define predictors of success and failure of HFNC.

Methods

A systematic literature search was conducted in the PubMed, EMBASE and SCOPUS databases, and the study was prepared according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Study quality was assessed using the National Heart, Lung, and Blood Institute's Study Quality Assessment Tools.

Results

The search identified 1,476 unique titles; 95 articles received full-text reviews and 40 studies were included in this review. HFNC was associated with a reduction in the rate of orotracheal intubation, notably when compared to conventional oxygen therapy. Studies reported inconsistency in whether HFNC reduced ICU length of stay or mortality rates. Among the predictors of HFNC failure/success, a ratio of oxygen saturation index of approximately 5 or more was associated with HFNC success.

Conclusion

In adult patients hospitalized with COVID-19, HFNC may prove effective in reducing the rate of orotracheal intubation. The ratio of the oxygen saturation index was the parameter most examined as a predictor of HFNC success. Low-level research designs, inherent study weaknesses and inconsistent findings made it impossible to conclude whether HFNC reduces ICU length of stay or mortality. Future studies should employ higher level research designs.

Novel biomarker-based score (SAD-60) for predicting mortality in patients with COVID-19 pneumonia: a multicenter retrospective cohort of 1013 patients

Background: The aim was to explore a novel risk score to predict mortality in hospitalized patients with COVID-19 pneumonia. Methods: This was a retrospective, multicenter study. Results: A total of 1013 patients with COVID-19 were included. The mean age was 60.5 ± 14.4 years, and 581 (57.4%) patients were male. In-hospital death occurred in 124 (12.2%) patients. Multivariate analysis revealed peripheral capillary oxygen saturation (SpO2), albumin, D-dimer and age as independent predictors. The mortality score model was given the acronym SAD-60, representing SpO2, Albumin, D-dimer, age ≥60 years. The SAD-60 score (0.776) had the highest area under the curve compared with CURB-65 (0.753), NEWS2 (0.686) and qSOFA (0.628) scores. Conclusion: The SAD-60 score has a promising predictive capacity for mortality in hospitalized patients with COVID-19.