LUS for COVID19 - Summary of latest evidence

Author: Dr. Cian McDermott

Key Points

• LUS is an established tool in the diagnosis of acute respiratory failure [1–5]

• LUS shows characteristic changes in COVID19 infection, similar to other patterns of viral pneumonitis. B-line patterns, sub-pleural consolidation, pleural line irregularity with thickening and larger consolidations develops as the disease progresses [1]

• CXR is a poor screening test for COVID19 while CT is best used for complications arising from COVID infection [1,2]

• LUS may be used as a decision support and risk stratification tool in COVID19. It is quick to perform, may be done at the bedside and adds much to the clinical evaluation of patients [2,3]

Key papers

Huang [1]

• N = 20, 12 zones

• CT findings compare with LUS findings

• Posterobasal zones involved

• Virus particles are small and lodge in terminal alveoli close to the pleural interface. These areas are well visualised on CT and LUS, but are more difficult to see on plain imaging 

Peng [2]

• N = 20, 12 zones

• CT findings compare with LUS findings, CXR is poor

• Lung abnormalities appear before PCR is positive

• Neat table comparing CT findings w LUS findings

Xie & Fang [6,7]

• Chest CT is 1* screening tool - more sensitive than PCR

• Reasonable to extrapolate this for LUS also

Vetrugno (Lichtenstein review group)

• CXR has Sn of 60%, also supported by Guan [8]

• LUS to reduce CXR and CT use

Italian EM physicians using LUS [9–11]

Risk stratification [1,12]

• Focal B-lines --- confluent B-lines --- subpleural consolidation & pleural irregularity

• Consolidation = poor prognostic factor (prone positioning)

• A-line pattern = disease regression

Disinfection & decontamination protocols

• ACEP Emergency Ultrasound Committee [13]

• BMUS [14]

• CPOCUS [15]

Best of FOAMed

• Twitter using #POCUSforCOVID

• https://www.pocus101.com/registry-of-evidence-for-point-of-care-ultrasound-in-covid-19-coronavirus/

• St Emlyn’s blogpost | https://www.stemlynsblog.org/combatting-covid19-is-lung-ultrasound-an-option/

References

1. Huang Y, Wang S, Liu Y, Zhang Y, Zheng C, Zheng Y, et al. A preliminary study on the ultrasonic manifestations of peripulmonary lesions of non-critical novel coronavirus pneumonia (COVID-19).

2. Peng Q-Y, Wang X-T, Zhang L-N, Chinese Critical Care Ultrasound Study Group (CCUSG). Findings of lung ultrasonography of novel corona virus pneumonia during the 2019-2020 epidemic. Intensive Care Med. 2020. doi:10.1007/s00134-020-05996-6

3. Miller A. Practical approach to lung ultrasound. BJA Educ. 2016;16: 39–45.

4. Tierney DM, Huelster JS, Overgaard JD, Plunkett MB, Boland LL, St Hill CA, et al. Comparative Performance of Pulmonary Ultrasound, Chest Radiograph, and CT Among Patients With Acute Respiratory Failure. Crit Care Med. 2020;48: 151–157.

5. Lee FCY. Lung ultrasound-a primary survey of the acutely dyspneic patient. J Intensive Care Med. 2016;4: 57.

6. Fang Y, Zhang H, Xie J, Lin M, Ying L, Pang P, et al. Sensitivity of Chest CT for COVID-19: Comparison to RT-PCR. Radiology. 2020; 200432.

7. Xie X, Zhong Z, Zhao W, Zheng C, Wang F, Liu J. Chest CT for Typical 2019-nCoV Pneumonia: Relationship to Negative RT-PCR Testing. Radiology. 2020; 200343.

8. Guan W-J, Ni Z-Y, Hu Y, Liang W-H, Ou C-Q, He J-X, et al. Clinical Characteristics of Coronavirus Disease 2019 in China. N Engl J Med. 2020. doi:10.1056/NEJMoa2002032

9. Soldati G, Smargiassi A, Inchingolo R, Buonsenso D, Perrone T, Briganti DF, et al. Is there a role for lung ultrasound during the COVID-19 pandemic? J Ultrasound Med. 2020. doi:10.1002/jum.15284

10. Buonsenso D, Piano A, Raffaelli F, Bonadia N, de Gaetano Donati K, Franceschi F. Point-of-Care Lung Ultrasound findings in novel coronavirus disease-19 pnemoniae: a case report and potential applications during COVID-19 outbreak. Eur Rev Med Pharmacol Sci. 2020;24: 2776–2780.

11. Poggiali E, Dacrema A, Bastoni D, Tinelli V, Demichele E, Mateo Ramos P, et al. Can Lung US Help Critical Care Clinicians in the Early Diagnosis of Novel Coronavirus (COVID-19) Pneumonia? Radiology. 2020; 200847.

12. COVID-19 – GiViTI. [cited 29 Mar 2020]. Available: http://giviti.marionegri.it/covid-19-en/

13. Guideline for Ultrasound Transducer Cleaning and Disinfection. [cited 29 Mar 2020]. Available: https://www.acep.org/patient-care/policy-statements/guideline-for-ultrasound-transducer-cleaning-and-disinfection/

14. Ultrasound Transducer Decontamination | News | BMUS. [cited 29 Mar 2020]. Available: https://www.bmus.org/mediacentre/news/ultrasound-transducer-decontamination/