Neumonía por COVID-19 en urgencias: ecografía pulmonar. Implicaciones pronósticas

Introduction and objectives

In COVID-19 patients, the clinical picture allows estimating a certain pre-test probability of lung involvement; prediction that increases when associating lung ultrasound. This provides greater sensitivity than chest radiography in the detection of infiltrates, and makes it possible to predict the result of pathological pulmonary CT. The characteristic findings of SARS-CoV-2 pneumonia have been described, and the location of the lesions has been related to the prognosis. Few experiences have been published on the prognostic capacity of lung ultrasound, which do not include hospital-obtained laboratory parameters.

Material and methods

Through a prospective, multicenter, observational study with consecutive sampling, carried out between April and July 2020, 263 adult patients who attended the emergency department of Spanish hospitals due to symptoms compatible with respiratory infection were recruited. Six fields per lung were explored, and the presence or absence of focal B lines, global B lines, parenchymal consolidation, subpleural consolidation, and pleural effusion were described. The patients underwent a postero-anterior chest X-ray on the same day.

Results

Males predominated in the study population. The main comorbidity was neoplasms, followed by chronic kidney disease and ischemic heart disease. Patients with a positive result for SARS-CoV-2 RT-PCR and who required admission were more frequent, and 8% died. The pathological chest x-ray was positive in 75% of the patients, compared to 94.59% of the ultrasound scans. The most frequent findings were focal B lines in zones R6, R3, and L3. The specificity of bilateral consolidation or unilateral patchy infiltrate stands out, and in ultrasound the specificity of global B lines, consolidations, both pulmonary and subpleural, and left pleural effusion.

Conclusions

A regression model has been developed that incorporates the findings of the lung ultrasound and predicts the probability of admission in patients presenting to the emergency department, without using other hospital laboratory tests. A tool can be developed that allows the family physician to identify patients with a high probability of being hospitalized from those who will have an outpatient follow-up, to prioritize an early therapeutic approach or referral to the emergency room.