Lung ultrasound-guided PEEP titration in COVID-19 patients treated with CPAP.

OBJECTIVES: An increasing number of COVID-19 patients were treated with continuous positive airways pressure (CPAP). To evaluate the clinical effects of personalized positive end-expiratory pressure (PEEP) compared to standard fixed PEEP in COVID-19 patients requiring CPAP. METHODS: This is a single center, prospective, randomized clinical study. Sixty-three COVID-19 patients with hypoxemic respiratory failure and bilateral pneumonia were randomized in two Groups: Group A received CPAP with fixed PEEP of 10 cm H2O, Group B performed the "PEEP trial", that consists in the evaluation of best PEEP defined as the PEEP value that precedes the echographic appearance of "lung pulse" determining a PaO2/FiO2 increase. Primary outcome was composite in-hospital mortality + intubation, secondary outcome was the percentage increase of PaO2/FiO2. As safety indicator, the incidence of pneumothorax was collected. RESULTS: Thirty-two patients were enrolled in Group A and 31 in Group B. The two groups were comparable for clinical characteristics and laboratory parameters. The primary outcome occurred in 36 (57.1 %) patients: 23 (71.8 %) in Group A and 13 (41.9 %) in Group B (p<0.01). Mortality was higher in Group A (53.1 vs. 19.3 %, p<0.01), while intubation rate was comparable between groups. Group B showed a higher PaO2/FiO2 increase than Group A (34.9 vs. 13.1 %, p<0.01). Five cases of pneumothorax were reported in Group A, none in Group B. CONCLUSIONS: Lung ultrasound-guided PEEP trial is associated with lower mortality in COVID-19 patients treated with CPAP. Identifying the best PEEP is useful to increase oxygenation and reduce the incidence of complications.

Lung ultrasound as diagnostic tool for SARS-CoV-2 infection.

The aim of this study was to explore the role of lung ultrasound (LUS) in the diagnosis of SARS-CoV-2 infection and to verify its utility in the prediction of lung disease's severity and outcome. Fifty-three consecutive patients presenting to the Emergency Department of Santa Maria delle Grazie Hospital with high suspicion of SARS-CoV-2 infection underwent diagnostic test for SARS-CoV-2 on samples obtained from nasopharyngeal swab as well as complete proper diagnostic work-up that included clinical evaluation, laboratory tests, blood gas analyses, chest CT and LUS. A semiquantitative analysis of B-lines distribution was performed to calculate the LUS score. Patients were divided into two groups according to the results of both SARS-CoV-2 diagnostic test and other exams (Group A = pneumonia due to SARS-CoV2 infection vs Group B = no SARS-CoV2 infection and another definite diagnosis). LUS showed an excellent accuracy in predicting the diagnosis of SARS-CoV-2 infection (area under the ROC curve of 0.92 with a sensibility of 73% and a specificity of 89% a the cut-off of 12.5). LUS score was more impaired in SARS-CoV-2 patients (18.1 ± 6.0 vs 7.6 ± 5.9, p < 0.00001) and it is significantly negatively correlated with PF ratio values (r = - 0.719, p < 0.0001). An intrahospital mortality rate of 46% was found; patients with adverse outcome had significant higher value of LUS, PF, LDH, and APACHE II score. None of these parameters was predictive of mortality. LUS is a useful tool for the early detection of SARS-CoV-2 infection and for the evaluation of the disease severity, but does not predict mortality. Further studies with repeated evaluations of LUS score are needed to further explore the role of LUS in the assessment of severity in SARS-CoV-2 disease and in the monitoring of the response to treatments.