Current Advances in Lung Ultrasound in COVID-19 Critically Ill Patients: A Narrative Review

Abstract

Lung ultrasound (LUS) has a relatively recent democratization due to the better availability and training of physicians, especially in intensive care units. LUS is a relatively cheap and easy-to-learn and -use bedside technique that evaluates pulmonary morphology when using simple algorithms. During the global COVID-19 pandemic, LUS was found to be an accurate tool to quickly diagnose, triage and monitor patients with COVID-19 pneumonia. This paper aims to provide a comprehensive review of LUS use during the COVID-19 pandemic. The first section of our work defines the technique, the practical approach and the semeiotic signs of LUS examination. The second section exposed the COVID-19 pattern in LUS examination and the difference between the differential diagnosis patterns and the well-correlation found with computer tomography scan findings. In the third section, we described the utility of LUS in the management of COVID-19 patients, allowing an early diagnosis and triage in the emergency department, as the monitoring of pneumonia course (pneumonia progression, alveolar recruitment, mechanical ventilation weaning) and detection of secondary complications (pneumothorax, superinfection). Moreover, we describe the usefulness of LUS as a marker of the prognosis of COVID-19 pneumonia in the fourth section. Finally, the 5th part is focused on describing the interest of the LUS, as a non-ionized technique, in the management of pregnant COVID-19 women.

Lung Ultrasound in Critical Care and Emergency Medicine: Clinical Review

“…Physicians brought the LUS from the medical service to outpatient settings using portable devices [ 78 , 79 ]. The LUS was found to be an accurate tool to quickly diagnose, triage, and monitor patients with COVID-19 pneumonia [ 80 ]. In an Italian survey proposed to anesthesiologists and intensive care physicians after the first wave of the COVID-19 pandemic, the results showed that the LUS was extensively used during the first phase of the pandemic, and then, its adoption increased further [ 81 ].…”

“…Despite the good association described, in patients with other comorbidities (e.g., acute cardiogenic pulmonary edema, chronic interstitial lung disease, etc.) presenting with acute respiratory failure, the interstitial syndrome identified by LUS could be difficult to be attributed to COVID-19 pneumonia rather than to a decompensated previous illness [ 80 ]. A recently published systematic review including 66 articles with a pool of 4687 patients observed that the most frequent ultrasound findings in COVID-19 patients were B-lines and pleural abnormalities and confirmed the association between a high LUS score at admission and unfavourable outcomes [ 84 , 85 , 86 ].…”

COVID-19-Related Pleural Diseases

“…For unstable patients, thoracic ultrasound has been considered as a useful adjunct especially in the critical care setting, but the diagnosis cannot always be made with certainty due to artifacts arising from underlying lung parenchymal changes. 32 Computed tomography (CT-chest) is often performed in these patients with PTX and COVID-19 as it not only provides invaluable information about extent of PTX and associated PTM or SCE, but also helps to decide management. 10,31 With increasing evidence of coexistence of PTX or thromboembolic disease in COVID-19 patients, the majority of patients with moderate to severe disease undergo CT-chest examination early in their treatment course, especially if high risk to require ventilatory support, due to technical challenges in transporting these patients for scanning purposes.…”

“…For unstable patients, thoracic ultrasound has been considered as a useful adjunct especially in the critical care setting, but the diagnosis cannot always be made with certainty due to artifacts arising from underlying lung parenchymal changes. 32…”

Comparison of lung ultrasound scoring systems for the prognosis of COVID‐19 in the emergency department: An international prospective cohort study

“…If proven to accurately predict clinical deterioration, LUS findings could be integrated with clinical findings at the time of ED presentation, to triage patients to either outpatient management (low-risk features), ward admission (moderate-risk features) or intensive care unit (ICU) admission (high-risk features). 17 This could potentially impact patient outcomes, resource allocation and departmental flow, particularly in times of crisis and overcrowding.…”