Lung ultrasound to predict invasive ventilation of patients with COVID-19 lung disease

Abstract

Lung ultrasound (LUS) is known to be more sensitive for detection of lung pathology compared to plain radiography and comparable to computerised tomography (CT), particularly for peripheral or pleurally based lesions. For example, it can be used in diagnosing interstitial patterns including pulmonary edema, as well as consolidation and effusions. Point-of-care (POCUS) is readily available in most emergency departments (ED), where it can immediately supply clinical information at the bedside.

SARS-CoV-2 viral pneumonia (COVID-19) has led some practitioners to assess if LUS has utility in its diagnosis or prognosis. There are specific findings which represent viral pneumonias, such as increasing density of B-lines, subpleural consolidations, and absence of pleural effusions. Unfortunately LUS is currently unable to distinguish COVID-19 from other viral pneumonias but may be possible with further description of findings in a large cohort of patients. Although the current de facto “gold standard” for COVID-19 diagnosis, reverse-transcriptase polymerase chain reaction (RT-PCR) has a delayed turnaround of results and lacks sensitivity, particularly early in the course of the illness.

Although LUS is unlikely to replace nucleic acid testing for definitive diagnosis, it may have utility in predicting clinical deterioration indicating need for ventilatory support. If proven to be accurately predictive of 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). This could impact patient outcomes, resource allocation, and departmental flow, particularly in times of crisis. Furthermore, the findings from this study may inform the use of LUS in future respiratory virus pandemics.