Lung ultrasound helps predict clinical progression in patients with severe COVID-19

Lung ultrasound, seen as a simple method to diagnose lung disease, can also help predict clinical progression in patients with severe COVID-19, according to a study conducted at the University of São Paulo School of Medicine ( FM-USP) in São Paulo, Brazil. .

The principal investigator of the study was Heraldo Possolo de Souza, professor at FM-USP and attending physician at his university and general hospital, Hospital das Clínicas (HC).

The researchers applied an ultrasound examination protocol covering 12 lung regions in 180 COVID-19 patients treated with HC. The results showed that the higher the pulmonary ultrasound score, the higher the risk of intensive care unit (ICU) admission, intubation and death.

The study was supported by the São Paulo Research Foundation – FAPESP and reported in an article published in Annals of Intensive Care.

We have found that lung ultrasound is a good predictor of the need for intensive care with endotracheal intubation and the risk of death for COVID-19 patients admitted to the emergency room. This can be a simple and inexpensive way to estimate the prognosis of patients infected with the virus. “

Heraldo Possolo de Souza, professor, FM-USP

At the start of the pandemic, Souza and other emergency departments in HC and other hospitals around the world had to treat overwhelming numbers of patients with insufficient resources. As they learned to meet this challenge, which has now returned due to the rebound in patient numbers, healthcare teams have found that they need to use tools to assess the severity of each case so that resources such as ICU beds and ventilators are properly allocated and care priorities can be established.

Given the importance of diagnostic imaging of the lungs for the treatment of patients with severe COVID-19, the FM-USP group speculated that it might also be useful to screen patients admitted with the infection based on of the expected result. They chose pulmonary ultrasound to test the hypothesis because the method is widely used in emergency rooms, in addition to being quick, easy to perform with portable equipment, and inexpensive.

“Point-of-care lung ultrasound is extremely important in the pandemic. It can be performed at the bedside by emergency personnel who do not need to be as well trained to interpret images as they do in the case of ‘a chest CT scan, for example,’ said Julio Cesar Garcia of Alencar, an emergency department attending HC and first author of the article on the study.

Methodology

Study subjects were patients diagnosed by RT-PCR and admitted to HC between March and May 2020, in the early stages of the pandemic. The researchers performed lung ultrasound examinations on the volunteers and calculated their scores on the day they were admitted to the emergency room. The median age of the subjects was 60 years, and well over half (58%) were men.

The scoring methodology, known as the LUS protocol, involved examining 12 lung regions in the anterior, lateral, and posterior sides of the chest wall on both sides. Each region was evaluated by aeration model, with scores ranging from zero to 3 points according to the worst model observed. The final score was the sum of the points in the 12 regions, ranging from zero to 36.

The results showed that patients with a score of 14 to 16 were the most likely to require intensive care unit care, and a fatal outcome was more likely for those with scores above 20.

The mean LUS was 18.7, with a standard deviation of 6.8. Of the 180 patients enrolled, 109 (60%) were discharged alive, 74 (56%) were treated in the intensive care unit, 52 (39%) were intubated and 61 (33%) died.

“We have confirmed the hypothesis that LUS helps predict ICU admission, intubation, and death in patients with severe COVID-19,” Alencar said.

Higher risk of death

In another study conducted as part of the project and published in the journal PLOS ONE, the same group of researchers found that out of 506 patients with COVID-19 confirmed pneumonia admitted to the emergency room, 333 (65.9%) left their homes, 153 (30.2%) died and 20 ( 3.9%) remained in hospital. A total of 300 patients (59.3%) required intensive care and 227 (44.9%) required intubation. The overall mortality was 30.2% and 55.9% for the intubated patients.

“We have created a group of emergency doctors in HC not only to provide patient care, but also to work as researchers who collect data that can be used as markers to predict the outcome of severe cases of COVID-19” , said Souza.