Lung Ultrasound B-Lines Correlate With Static Compliance In Mechanically Ventilated Patients

SESSION TITLE: Insights into the Care of Patients with Respiratory Failure SESSION TYPE: Original Investigations PRESENTED ON: October 18-21, 2020 PURPOSE: Lung ultrasound is a quick, non-invasive, and widely available tool used to assess for a multitude of disease processes Recently, a quick point assessment of B-lines (B-line score) has been shown to be an accurate marker of extra-vascular lung water In mechanically ventilated patients, static lung compliance is calculated as Cstat = VT/(Pplat-PEEP), with VT meaning tidal volume, Pplat plateau pressure, and PEEP positive end expiratory pressure A limitation of this technique is that patients need to be passive on the ventilator to accurately measure PPlat, something which is difficult given efforts to reduce sedation Other techniques, such as esophageal manometry, have been used to estimate transpulmonary pressures, but is limited by being invasive and subject to error Our study sought to determine if the B-line score correlates with lung compliance in mechanically ventilated patients We hypothesized that the B-line score would inversely correlate with static lung compliance METHODS: This was a prospective observational study performed in the medical intensive care units of NYU Langone Health and Bellevue Hospital Center Inclusion criteria included all adult patients requiring mechanical ventilation Exclusion criteria included reasons to have reduced respiratory system compliance from an extrapulmonary etiology: BMI \u003e 35, abdominal hypertension, significant pleural effusions, or pneumothorax Lung ultrasound was performed at 4 points over the anterior chest Each image was independently scored by two intensivists The number of B-lines seen in each window were counted and added together to create the B-line score Static lung compliance was determined using the formula above;inspiratory hold maneuvers were used to obtain plateau pressures RESULTS: A total of 99 observations were performed The mean B-line score was 4 73 +/- 0 60 with a range score from 0 to 25 5 Ultrasound B-line score inversely correlated with static lung compliance (Spearman\u0027s r = -0 60, p\u003c0 001), net fluid balance in the 24 hours prior to the scan (Spearman\u0027s r = -0 26, p=0 02), and P/F ratio (Spearman\u0027s r = -0 37, p\u003c0 001) CONCLUSIONS: Ultrasound B-line score correlates with for static lung compliance in mechanically ventilated patients CLINICAL IMPLICATIONS: Our study demonstrates that an assessment of B-lines on lung ultrasound is an effective marker of important clinical characteristics in mechanically ventilated patients In patients where assessments of these factors are limited, use of this quick and simple B-line score may be clinically useful This is especially true in the recent COVID-19 pandemic, where imaging tests and monitoring may be limited given isolation precautions Whether serial B-line scores in the same patient correlate with clinical improvement in the above-mentioned markers is yet to be determined DISCLOSURES: No relevant relationships by Andrew Lehr, source=Web Response No relevant relationships by Vikramjit Mukherjee, source=Web Response, value=Consulting fee Removed 04/27/2020 by Vikramjit Mukherjee, source=Web Response No relevant relationships by Deepak Pradhan, source=Web Response No relevant relationships by Bishoy Zakhary, source=Web Response