Characterisation and outcomes of ARDS secondary to pneumonia in patients with and without SARS-CoV-2: a single-centre experience.

INTRODUCTION: Acute respiratory distress syndrome (ARDS) is the major cause of mortality in patients with SARS-CoV-2 pneumonia. It appears that development of 'cytokine storm' in patients with SARS-CoV-2 pneumonia precipitates progression to ARDS. However, severity scores on admission do not predict severity or mortality in patients with SARS-CoV-2 pneumonia. Our objective was to determine whether patients with SARS-CoV-2 ARDS are clinically distinct, therefore requiring alternative management strategies, compared with other patients with ARDS. We report a single-centre retrospective study comparing the characteristics and outcomes of patients with ARDS with and without SARS-CoV-2. METHODS: Two intensive care unit (ICU) cohorts of patients at the Queen Elizabeth Hospital Birmingham were analysed: SARS-CoV-2 patients admitted between 11 March and 21 April 2020 and all patients with community-acquired pneumonia (CAP) from bacterial or viral infection who developed ARDS between 1 January 2017 and 1 November 2019. All data were routinely collected on the hospital's electronic patient records. RESULTS: A greater proportion of SARS-CoV-2 patients were from an Asian ethnic group (p=0.002). SARS-CoV-2 patients had lower circulating leucocytes, neutrophils and monocytes (p<0.0001), but higher CRP (p=0.016) on ICU admission. SARS-CoV-2 patients required a longer duration of mechanical ventilation (p=0.01), but had lower vasopressor requirements (p=0.016). DISCUSSION: The clinical syndromes and respiratory mechanics of SARS-CoV-2 and CAP-ARDS are broadly similar. However, SARS-CoV-2 patients initially have a lower requirement for vasopressor support, fewer circulating leukocytes and require prolonged ventilation support. Further studies are required to determine whether the dysregulated inflammation observed in SARS-CoV-2 ARDS may contribute to the increased duration of respiratory failure.

Right Ventricular Dysfunction and Its Association With Mortality in Coronavirus Disease 2019 Acute Respiratory Distress Syndrome.

OBJECTIVES: To assess whether right ventricular dilation or systolic impairment is associated with mortality and/or disease severity in invasively ventilated patients with coronavirus disease 2019 acute respiratory distress syndrome. DESIGN: Retrospective cohort study. SETTING: Single-center U.K. ICU. PATIENTS: Patients with coronavirus disease 2019 acute respiratory distress syndrome undergoing invasive mechanical ventilation that received a transthoracic echocardiogram between March and December 2020. INTERVENTION: None. MEASUREMENTS AND MAIN RESULTS: Right ventricular dilation was defined as right ventricular:left ventricular end-diastolic area greater than 0.6, right ventricular systolic impairment as fractional area change less than 35%, or tricuspid annular plane systolic excursion less than 17 mm. One hundred seventy-two patients were included, 59 years old (interquartile range, 49-67), with mostly moderate acute respiratory distress syndrome (n = 101; 59%). Ninety-day mortality was 41% (n = 70): 49% in patients with right ventricular dilation, 53% in right ventricular systolic impairment, and 72% in right ventricular dilation with systolic impairment. The right ventricular dilation with systolic impairment phenotype was independently associated with mortality (odds ratio, 3.11 [95% CI, 1.15-7.60]), but either disease state alone was not. Right ventricular fractional area change correlated with Pao2:Fio2 ratio, Paco2, chest radiograph opacification, and dynamic compliance, whereas right ventricular:left ventricle end-diastolic area correlated negatively with urine output. CONCLUSIONS: Right ventricular systolic impairment correlated with pulmonary pathophysiology, whereas right ventricular dilation correlated with renal dysfunction. Right ventricular dilation with systolic impairment was the only right ventricular phenotype that was independently associated with mortality.