Utility of the ROX Index in Predicting Intubation for Patients With COVID-19-Related Hypoxemic Respiratory Failure Receiving High-Flow Nasal Therapy: Retrospective Cohort Study.

BACKGROUND: The use of high-flow nasal therapy (HFNT) to treat COVID-19 pneumonia has been greatly debated around the world due to concerns about increased health care worker transmission and delays in invasive mechanical ventilation (IMV). Herein, we analyzed the utility of the noninvasive ROX (ratio of oxygen saturation) index to predict the need for and timing of IMV. OBJECTIVE: This study aimed to assess whether the ROX index can be a useful score to predict intubation and IMV in patients receiving HFNT as treatment for COVID-19-related hypoxemic respiratory failure. METHODS: This is a retrospective cohort analysis of 129 consecutive patients with COVID-19 admitted to Temple University Hospital in Philadelphia, PA, from March 10, 2020, to May 17, 2020. This is a single-center study conducted in designated COVID-19 units (intensive care unit and other wards) at Temple University Hospital. Patients with moderate and severe hypoxemic respiratory failure treated with HFNT were included in the study. HFNT patients were divided into two groups: HFNT only and intubation (ie, patients who progressed from HFNT to IMV). The primary outcome was the value of the ROX index in predicting the need for IMV. Secondary outcomes were mortality, rate of intubation, length of stay, and rate of nosocomial infections in a cohort treated initially with HFNT. RESULTS: Of the 837 patients with COVID-19, 129 met the inclusion criteria. The mean age was 60.8 (SD 13.6) years, mean BMI was 32.6 (SD 8) kg/m², 58 (45%) were female, 72 (55.8%) were African American, 40 (31%) were Hispanic, and 48 (37.2%) were nonsmokers. The mean time to intubation was 2.5 (SD 3.3) days. An ROX index value of less than 5 at HFNT initiation was suggestive of progression to IMV (odds ratio [OR] 2.137, P=.052). Any further decrease in ROX index value after HFNT initiation was predictive of intubation (OR 14.67, P<.001). Mortality was 11.2% (n=10) in the HFNT-only group versus 47.5% (n=19) in the intubation group (P<.001). Mortality and need for pulmonary vasodilators were higher in the intubation group. CONCLUSIONS: The ROX index helps decide which patients need IMV and may limit eventual morbidity and mortality associated with the progression to IMV.

Impact of Chronic Obstructive Pulmonary Disease and Emphysema on Outcomes of Hospitalized Patients with Coronavirus Disease 2019 Pneumonia.

BACKGROUND: Comorbid disease is a risk factor for severe coronavirus disease 2019 (COVID-19) infection. However, initial rates of chronic obstructive pulmonary disease (COPD) in case series were low and severity of COVID-19 in COPD patients was variable. METHODS: We performed a retrospective study of patients admitted with COVID-19 and evaluated outcomes in those with and without COPD and/or emphysema. Patients were identified as having COPD if they had a diagnosis in the medical record and a history of airflow-obstruction on spirometry, or a history of tobacco use and prescribed long-acting bronchodilator(s). Computed tomography scans were evaluated by radiologists. Propensity matching was performed for age, body mass index (BMI), and serologic data correlated with severity of COVID-19 disease (D-dimer, C-reactive protein, ferritin, fibrinogen, absolute lymphocyte count, lymphocyte percentage, and lactate dehydrogenase). RESULTS: Of 577 patients admitted with COVID-19, 103 had a diagnosis of COPD and/or emphysema. The COPD/emphysema cohort was older (67 versus 58, p<0.0001) than the other cohort and had a lower BMI. Among unmatched cohorts those with COPD/emphysema had higher rates of intensive care unit (ICU) admission (35% versus 24.9%, p=0.036) and maximal respiratory support requirements, with more frequent invasive mechanical ventilation (21.4% versus 11.8%), but no significant difference in mortality. After propensity-matching there was no difference in ICU admission, maximal respiratory support requirements, or mortality. Univariate and multivariate regression analyses yielded similar results. DISCUSSION: Our propensity-matched retrospective cohort study suggests that patients hospitalized with COVID-19 who have COPD and/or emphysema may not have worse outcomes than those without these comorbid conditions.

Retrospective analysis of high flow nasal therapy in COVID-19-related moderate-to-severe hypoxaemic respiratory failure.

Invasive mechanical has been associated with high mortality in COVID-19. Alternative therapy of high flow nasal therapy (HFNT) has been greatly debated around the world for use in COVID-19 pandemic due to concern for increased healthcare worker transmission.This was a retrospective analysis of consecutive patients admitted to Temple University Hospital in Philadelphia, Pennsylvania, from 10 March 2020 to 24 April 2020 with moderate-to-severe respiratory failure treated with HFNT. Primary outcome was prevention of intubation. Of the 445 patients with COVID-19, 104 met our inclusion criteria. The average age was 60.66 (+13.50) years, 49 (47.12 %) were female, 53 (50.96%) were African-American, 23 (22.12%) Hispanic. Forty-three patients (43.43%) were smokers. Saturation to fraction ratio and chest X-ray scores had a statistically significant improvement from day 1 to day 7. 67 of 104 (64.42%) were able to avoid invasive mechanical ventilation in our cohort. Incidence of hospital-associated/ventilator-associated pneumonia was 2.9%. Overall, mortality was 14.44% (n=15) in our cohort with 13 (34.4%) in the progressed to intubation group and 2 (2.9%) in the non-intubation group. Mortality and incidence of pneumonia was statistically higher in the progressed to intubation group. CONCLUSION: HFNT use is associated with a reduction in the rate of invasive mechanical ventilation and overall mortality in patients with COVID-19 infection.