COVID-19: Acute respiratory distress syndrome (ARDS) secondary to SARS-CoV-2-related pneumonia

date : 03.07.2020

**Tsvetomir Karagechev
*Alexandra Boyapati
**Galina Kirova-Nedyalkova
*Kameliya Genova

*Department of Radiology, UMHATEM “N. I. Pirogov”, Sofia, Bulgaria **Department of Radiology, Acibadem City Clinic Tokuda Hospital, Sofia, Bulgaria

dr.karagechev@outlook.com

Keywords: COVID-19, ARDS, Viral pneumonia, Radiography, Computed Tomography

Clinical history: 65-year-old male patient presented to the Emergency Department in impaired general state with a 7-day history of dyspnea, non-productive cough and fever up to 39°C. Medical history – hypertension. Oxygen saturation on admission – 79,1%. IgG/IgM immunoassay was negative for both anti-SARS-CoV-2 IgM and IgG. Given the high clinical suspicion and the imaging findings nasopharyngeal and oropharyngeal swab specimens for real-time RT-PCR were collected and a positive test result was reported 24h later.

Imaging findings:

Figure 1: Baseline PA CXR demonstrates bilateral ill-defined patchy opacities with predominantly peripheral distribution in the middle and lower lung zones. Figures 2-5: Chest CT; Diffuse bilateral ground-glass opacities, crazy-paving pattern (interlobular septal thickening superimposed on a background of ground-glass opacity) and areas of consolidation with air bronchograms. The findings show peripheral subpleural distribution. There is no evidence of a pleural effusion or mediastinal lymphadenopathy. Figure 6 (24h after initial presentation and after the RT-PCR test for COVID-19 was reported positive): AP CXR demonstrates radiographic progression with bilateral perihilar airspace opacities. Arterial blood gasses analysis revealed O2Sat 93,4%, PаO2 57,87mmHg and PаCO2 25,73mmHg. The patient was intubated and transferred to ICU. Figure 7 (48h after initial presentation): AP CXR; Increased density of the bilateral infiltrates in keeping with progression of the disease. On the third day after admission the patient passed away.

Final diagnosis: The imaging pattern of parenchymal lung disease is in keeping with atypical pneumonia – viral pneumonia, caused by Coronavirus (SARS –CoV2) – COVID-19.

Discussion:

Acute respiratory distress syndrome (ARDS) is an acute diffuse, inflammatory lung injury, linked to structural impairment on cellular level - increased permeability of the alveolar–capillary membrane leading to oedema. The loss of aerated lung tissue results in respiratory failure, secondary to the ventilation perfusion mismatch and the abnormal gas exchange. The most common causes of ARDS are pulmonary and extrapulmonary infections, leading to sepsis. The diagnosis COVID-19-related ARDS is made when a case of confirmed COVID-19 infection (to date, real time RT-PCR is considered to be the only method for definite diagnosis) meets the Berlin definition of ARDS from 2012: acute onset of hypoxemic respiratory failure within one week of a known risk factor. These new criteria also include the imaging findings – bilateral, diffuse lung opacities that cannot be fully explained by pleural effusion, atelectasis or nodules. Respiratory failure is not fully explained by cardiac failure of fluid overload. Most of patients with COVID-19 who develop ARDS in the course of the disease are older, have concomitant diseases – most often hypertension and diabetes and the most common clinical symptoms on initial presentation are marked dyspnea and fever ≥ 39°C. Imaging studies have an important role not only in the initial evaluation of the pattern and extent of the lung involvement, but also in the follow-up of hospitalized patients. According to the available scientific data, patients with COVID-19 pneumonia develop ARDS with median time of 8.5 days after symptom onset. Portable bedside chest X-ray is used for the assessment of disease progression and monitoring the placement and position of supportive devices – endotracheal tubes, central venous catheters and others.

Differential diagnosis:

A viral pneumonia with different etiology. Multifocal bacterial pneumonia. Cardiogenic pulmonary oedema. Factors that can lead to indirect lung injury – severe trauma, pancreatitis, alcohol and drug overdose – aspirin, cocaine, tricyclic antidepressants and others, should be included in the differential diagnosis when additional clinical symptoms and data from the anamnesis are present, despite the current epidemiological situation in the country.

Take home messages:

1. The presented case from our daily clinical practice demonstrates that the SARS-CoV-2 infection can lead to rapidly progressive acute respiratory distress syndrome (ARDS). 2. In the setting of COVID-19 pandemic, the timely assessment of the typical lung injury pattern could be of paramount importance for the differential diagnosis. 3. ARDS is a dynamic process and patient follow-ups, most common with serial bedside chest X-rays have predictive value regarding the course and progression of the disease. 4. Despite the advances in diagnostics and treatment methods the mortality rate for ARDS remains very high.

Bibliography:

1. Maurizio Zompatori, Federica Ciccarese, Luca Fasano. Overview of current lung imaging in acute respiratory distress syndrome. European Respiratory Review Dec 2014, 23 (134) 519-530; DOI: 10.1183/09059180.00001314 2. N. D. Ferguson et al. The Berlin definition of ARDS: an expanded rationale, justification, and supplementary material. Intensive Care Med (2012) 38:1573–1582 DOI 10.1007/s00134-012-2682-1 3. Peter G Gibson, Ling Qin and Ser Hon Puah. COVID‐19 acute respiratory distress syndrome (ARDS): clinical features and differences from typical pre‐COVID‐19 ARDS The Medical Journal of Australia (2020) DOI: 10.5694/mja2.50674 4. Chaomin Wu, Xiaoyan Chen, Yanping Cai еt al. Risk Factors Associated With Acute Respiratory Distress Syndrome and Death in Patients With Coronavirus Disease 2019 Pneumonia in Wuhan, China. JAMA Intern Med. Published online March 13, 2020. doi:10.1001/jamainternmed.2020.0994

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