Neutrophils and secondary infections in COVID-19 induced acute respiratory distress syndrome.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus is the cause of the current global pandemic and has affected more than 188 countries worldwide. Infection by the virus can have diverse clinical manifestations, with one of the most severe clinical manifestation being respiratory failure and the development of acute respiratory distress syndrome. Clinical manifestations of acute respiratory distress syndrome secondary to SARS-CoV-2 are also diverse with a lack of diagnostic tools to distinguish between primary viral infection and secondary bacterial infections. This was a single-centre, retrospective case-control study of bronchoalveolar lavage fluid cell counts, flow cytometry and culture results from mechanically ventilated patients with SARS-CoV-2 (COVID-19) pneumonia and acute respiratory distress syndrome. Neutrophils were the predominant cell type in bronchoalveolar fluid samples up to 2 weeks into mechanical ventilation. There also was a strong correlation between positive respiratory cultures and significant elevation in bronchoalveolar fluid neutrophil counts/percentages and serum C-reactive protein levels. Absolute levels of T cell subtypes correlated with reduced lung compliance measurements. Patients with SARS-CoV-2 and severe respiratory disease are at risk for secondary infections. In some COVID-19 patients, serum C-reactive protein and bronchoalveolar fluid neutrophils may be correlated with a secondary infection.

“is it steroids?”- COVID-19 associated invasive pulmonary aspergillosis

INTRODUCTION: COVID-19 associated invasive pulmonary aspergillosis (CAPA) has been described in more than 33 case reports. The incidence is closely related to the increased of use of dexamethasone after publication of the RECOVERY trial. Diagnosis of CAPA remains challenging in critically ill patients due to absence of typical radiological features such as halo sign. Schauwvlieghe et al. developed modified AspICU criteria for influenza associated pulmonary aspergillosis (IAPA) which can be used for CAPA. CASE DESCRIPTION: A 63-year-old male with hypertension and diabetes was admitted to ICU with hypoxia requiring 100% oxygen on BiPAP. Upon presentation, he was tachycardic and hypertensive with respiratory distress. Laboratory findings were significant for leukocytosis and acute kidney injury with hyperkalemia necessitating renal replacement therapy. A chest radiograph demonstrated bilateral opacities (Image 1). SARS-CoV-2 PCR was positive. He received dexamethasone and broad-spectrum antibiotics. He was intubated on day four of hospitalization due to worsening of hypoxia and was proned multiple times for severe ARDS. After initial improvement in hypoxia, the patient developed fevers and new leukocytosis with worsening infiltrates on chest imaging (Image 2). Multiple cultures from tracheal aspirate grew Aspergillus Spp. The serum beta-D glucan was elevated at 197 pg/mL and aspergillus galactomannan index was 3.39. Intravenous voriconazole was promptly initiated for presumptive diagnosis of CAPA based on AspICU criteria. Unfortunately, the patient developed worsening of hypoxia and increasing vasopressor requirement, ultimately leading to withdrawal of care. DISCUSSION: Dexamethasone use in COVID-19 ARDS may be associated with increased incidence of CAPA. Diagnosis of CAPA can be made using AspICU criteria which are based on clinical, radiological, and laboratory findings;one of each criteria necessary for diagnosis. Clinical criteria include: Fever refractory to at least 3 days of appropriate antibiotic therapy;recrudescent fever after a period of defervescence of at least 48 hours while on antibiotics;pleuritic chest pain;pleuritic rub;dyspnea;hemoptysis;or worsening respiratory insufficiency in spite of appropriate antibiotic therapy and ventilatory support. Radiological criteria include: Abnormal opacification on portable chest radiography or CT scan of the lungs. Mycological criteria include: Histopathology or direct microscopic evidence of dichotomous septate hyphae with positive culture for Aspergillus from tissue;a positive Aspergillus culture from a bronchoalveolar lavage (BAL);a galactomannan optical index on BAL of ≥1;or a galactomannan optical index on serum of ≥0.5. Initiation of prompt antifungal therapy is essential in these cases considering high mortality associated with invasive pulmonary aspergillosis.