Outcomes Among Mechanically Ventilated Patients With Severe Pneumonia and Acute Hypoxemic Respiratory Failure From SARS-CoV-2 and Other Etiologies.

Importance: Early observations suggested that COVID-19 pneumonia had a higher mortality rate than other causes of pneumonia. Objective: To compare outcomes between mechanically ventilated patients with pneumonia due to COVID-19 (March 2020 to June 2021) and other etiologies (July 2016 to December 2019). Design, Setting, and Participants: This retrospective cohort study was conducted at the Johns Hopkins Healthcare System among adult patients (aged ≥18 years) with pneumonia who required mechanical ventilation in the first 2 weeks of hospitalization. Clinical, laboratory, and mechanical ventilation data were extracted from admission to hospital discharge or death. Exposures: Pneumonia due to COVID-19. Main Outcomes and Measures: The primary outcome was 90-day in-hospital mortality. Secondary outcomes were time to liberation from mechanical ventilation, hospital length of stay, static respiratory system compliance, and ventilatory ratio. Unadjusted and multivariable-adjusted logistic regression, proportional hazards regression, and doubly robust regression were used in propensity score-matched sets to compare clinical outcomes. Results: Overall, 719 patients (mean [SD] age, 61.8 [15.3] years; 442 [61.5%] were male; 460 [64.0%] belonged to a minoritized racial group and 253 [35.2%] were White) with severe COVID-19 pneumonia and 1127 patients (mean [SD] age, 60.9 [15.8] years; 586 [52.0%] were male; 459 [40.7%] belonged to a minoritized racial group and 655 [58.1%] were White) with severe non-COVID-19 pneumonia. In unadjusted analyses, patients with COVID-19 pneumonia had higher 90-day mortality (odds ratio, 1.21, 95% CI 1.04-1.41), longer time on mechanical ventilation (subdistribution hazard ratio 0.72, 95% CI 0.63-0.81), and lower compliance (32.0 vs 28.4 mL/kg PBW/cm H2O; P < .001) when compared with those with non-COVID-19 pneumonia. In propensity score-matched analyses, patients with COVID-19 pneumonia were equally likely to die within 90 days as those with non-COVID-19 pneumonia (odds ratio, 1.04; 95% CI, 0.81 to 1.35; P = .85), had similar respiratory system compliance (mean difference, 1.82 mL/cm H2O; 95% CI, -1.53 to 5.17 mL/cm H2O; P = .28) and ventilatory ratio (mean difference, -0.05; 95% CI, -0.22 to 0.11; P = .52), but had lower rates of liberation from mechanical ventilation (subdistribution hazard ratio, 0.81; 95% CI, 0.65 to 1.00) when compared with those with non-COVID-19 pneumonia. Patients with COVID-19 pneumonia had somewhat lower rates of being discharged from the hospital alive at 90 days (subdistribution hazard ratio, 0.83; 95% CI, 0.68 to 1.01) than those with non-COVID-19 pneumonia; however, this was not statistically significant. Conclusions and Relevance: In this study, mechanically ventilated patients with severe COVID-19 pneumonia had similar mortality rates as patients with other causes of severe pneumonia but longer times to liberation from mechanical ventilation. Mechanical ventilation use in COVID-19 pneumonia should follow the same evidence-based guidelines as for any pneumonia.

Comparing Prone Positioning Use in COVID-19 Versus Historic Acute Respiratory Distress Syndrome

IMPORTANCE: Use of prone positioning in patients with acute respiratory distress syndrome (ARDS) from COVID-19 may be greater than in patients treated for ARDS before the pandemic. However, the magnitude of this increase, sources of practice variation, and the extent to which use adheres to guidelines is unknown. OBJECTIVES: To compare prone positioning practices in patients with COVID-19 ARDS versus ARDS treated before the pandemic. DESIGN, SETTING, AND PARTICIPANTS: We conducted a multicenter retrospective cohort study of mechanically ventilated patients with early moderate-to-severe ARDS from COVID-19 (2020–2021) or ARDS from non-COVID-19 pneumonia (2018–2019) across 19 ICUs at five hospitals in Maryland. MAIN OUTCOMES AND MEASURES: The primary outcome was initiation of prolonged prone positioning (≥ 16 hr) within 48 hours of meeting oxygenation criteria. Comparisons were made between cohorts and within subgroups including academic versus community hospitals, and medical versus nonmedical ICUs. Other outcomes of interest included time to proning initiation, duration of prone sessions and temporal trends in proning frequency. RESULTS: Proning was initiated within 48 hours in 227 of 389 patients (58.4%) with COVID-19 and 11 of 123 patients (8.9%) with historic ARDS (49.4% absolute increase [95% CI for % increase, 41.7–57.1%]). Comparing COVID-19 to historic ARDS, increases in proning were similar in academic and community settings but were larger in medical versus nonmedical ICUs. Proning was initiated earlier in COVID-19 versus historic ARDS (median hours (hr) from oxygenation criteria, 12.9 vs 30.6;p = 0.002) and proning sessions were longer (median hr, 43.0 vs 28.0;p = 0.01). Proning frequency increased rapidly at the beginning of the pandemic and was sustained. CONCLUSIONS AND RELEVANCE: We observed greater overall use of prone positioning, along with shorter time to initiation and longer proning sessions in ARDS from COVID-19 versus historic ARDS. This rapid practice change can serve as a model for implementing evidence-based practices in critical care.

The Effectiveness of High-Flow Nasal Cannula in Coronavirus Disease 2019 Pneumonia: A Retrospective Cohort Study.

OBJECTIVES: High-flow nasal cannula is widely used in acute hypoxemic respiratory failure due to coronavirus disease 2019, yet data regarding its effectiveness is lacking. More evidence is needed to guide patient selection, timing of high-flow nasal cannula initiation, and resource allocation. We aimed to assess time to discharge and time to death in severe coronavirus disease 2019 in patients treated with high-flow nasal cannula compared with matched controls. We also evaluated the ability of the respiratory rate-oxygenation ratio to predict progression to invasive mechanical ventilation. DESIGN: Time-dependent propensity score matching was used to create pairs of individuals who were then analyzed in a Cox proportional-hazards regression model to estimate high-flow nasal cannula's effect on time to discharge and time to death. A secondary analysis excluded high-flow nasal cannula patients intubated within 6 hours of admission. A Cox proportional-hazards regression model was used to assess risk of invasive mechanical ventilation among high-flow nasal cannula patients stratified by respiratory rate-oxygenation. SETTING: The five hospitals of the Johns Hopkins Health System. PATIENTS: All patients who were admitted with a laboratory-confirmed diagnosis of coronavirus disease 2019 were eligible for inclusion. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: High-flow nasal cannula was associated with longer median time to discharge: 10.6 days (interquartile range, 7.1-15.8 d) versus 7.8 days (interquartile range, 4.9-12.1 d). Respiratory rate-oxygenation index performed poorly in predicting ventilation or death. In the primary analysis, there was no significant association between high-flow nasal cannula and hazard of death (adjusted hazard ratio, 0.79; 95% CI, 0.57-1.09). Excluding patients intubated within 6 hours of admission, high-flow nasal cannula was associated with reduced hazard of death (adjusted hazard ratio, 0.67; 95% CI, 0.45-0.99). CONCLUSIONS: Among unselected patients with severe coronavirus disease 2019 pneumonia, high-flow nasal cannula was not associated with a statistically significant reduction in hazard of death. However, in patients not mechanically ventilated within 6 hours of admission, high-flow nasal cannula was associated with a significantly reduced hazard of death.

Myocardial Injury in Severe COVID-19 Compared With Non-COVID-19 Acute Respiratory Distress Syndrome.

BACKGROUND: Knowledge gaps remain in the epidemiology and clinical implications of myocardial injury in coronavirus disease 2019 (COVID-19). We aimed to determine the prevalence and outcomes of myocardial injury in severe COVID-19 compared with acute respiratory distress syndrome (ARDS) unrelated to COVID-19. METHODS: We included intubated patients with COVID-19 from 5 hospitals between March 15 and June 11, 2020, with troponin levels assessed. We compared them with patients from a cohort study of myocardial injury in ARDS and performed survival analysis with primary outcome of in-hospital death associated with myocardial injury. In addition, we performed linear regression to identify clinical factors associated with myocardial injury in COVID-19. RESULTS: Of 243 intubated patients with COVID-19, 51% had troponin levels above the upper limit of normal. Chronic kidney disease, lactate, ferritin, and fibrinogen were associated with myocardial injury. Mortality was 22.7% among patients with COVID-19 with troponin under the upper limit of normal and 61.5% for those with troponin levels >10 times the upper limit of normal (P<0.001). The association of myocardial injury with mortality was not statistically significant after adjusting for age, sex, and multisystem organ dysfunction. Compared with patients with ARDS without COVID-19, patients with COVID-19 were older and had higher creatinine levels and less favorable vital signs. After adjustment, COVID-19-related ARDS was associated with lower odds of myocardial injury compared with non-COVID-19-related ARDS (odds ratio, 0.55 [95% CI, 0.36-0.84]; P=0.005). CONCLUSIONS: Myocardial injury in severe COVID-19 is a function of baseline comorbidities, advanced age, and multisystem organ dysfunction, similar to traditional ARDS. The adverse prognosis of myocardial injury in COVID-19 relates largely to multisystem organ involvement and critical illness.