11. POCUS for COVID

Today we’re focused on POCUS! Here’s what you need to know about point-of-care ultrasound in COVID-19.  

 

Potential advantages to POCUS in COVID

Lack of ionizing radiation Superiority to CXR for common diagnoses1 PPE conservation: performed by treating physician2 Potential to reduce transmission by minimizing transport and healthcare worker contacts3 Replace the use of the stethoscope?2

 

Safety and Infection Control

Development of infection-control procedures (IPC) before using POCUS is imperative for these patients. This will vary by centre/machine, but considerations include:4 Equipment Dedicated COVID-19 machine Minimizing equipment brought into the room Using sterile probe covers and single-use gel packets Handheld devices may be ideal if available due to ease of cleaning3 Cleaning and disinfecting Disinfect all machine surfaces with an appropriate product – see ipac-canada.org for choice of products PRACTICE your IPC including incorporation donning and doffing of PPE before performing on patients! Scanning personnel Minimize scanners at the bedside

 

Scanning protocols

Standard LUS: curvilinear or phased probe1 Linear to focus on the pleura How many zones to scan? More zones will be more sensitive Some groups recommend 8 per side5 Contrast-enhanced lung ultrasound?? See below

 

POCUS findings in COVID

There are NO pathognomonic findings Findings may include6 “Inflammatory” B-lines: Patchy/asymmetrical B-lines with irregular pleura and subpleural consolidations This pattern can be seen in ANY inflammatory/infectious cause of B-lines: Atypical pneumonia, other viral pneumonias, pulmonary hemorrhage, interstitial lung disease, etc. Subpleural consolidations: could these actually be representative of peripheral pulmonary infarcts due to PE? One group found PE in 3 of 3 ICU patients who had evidence of subpleural consolidations on POCUS7 Contrast-enhanced ultrasound (CEUS): a couple fascinating case reports demonstrating that subpleural consolidations were avascular and actually represented microinfarcts8,9 Bilateral dense consolidations With development to acute respiratory distress syndrome (ARDS) Cardiac findings10 May include pre-existing cardiac disease, LV involvement from COVID myocarditis, RV failure (due to PE, ARDS, mechanical ventilation)

 

Potential pitfalls11

Cannot distinguish between other causes of “infectious/inflammatory” B-lines Cannot distinguish acute vs chronic changes (eg ILD) Will miss pathology that doesn’t reach the pleura Limited scanning protocols (ie 3 zones per hemithorax) may miss early/localized disease

 

When to use POCUS

Employ POCUS in confirmed or suspected COVID-19 patients if it will change management4 No educational scans; and no novice scans. Have an experienced operator scanning. No scans in patients who are already have a confirmed diagnosis, in whom POCUS results won’t change management Times to consider POCUS use To look for other diagnoses To look for compatible signs of COVID is suspected patients in whom PCR testing is imperfect* To minimize use of other radiologic studies, especially CT scans To monitor critically ill patients, especially those in shock or profound respiratory failure

 

From SoMe

An EM physician diagnosed with COVID-19 who shared the progression of his self-scanned POCUS clips throughout his disease course: https://twitter.com/yaletung

 

 

Sources

Volpicelli G, Elbarbary M, Blaivas M et al. International recommendations for evidence-based point of care lung ultrasound. Intensive Care Med, (2012) 38:577–591. doi:10.1007/s00134-012-2513-4 Buonseno D, Pata D, Chiaretti A. COVID-19 outbreak: less stethoscope, more ultrasound. Lancet Resp Med, Apr 2020. doi:10.1016/ S2213-2600(20)30120-X Kiamanesh O, Harper L, Wiskar K et al. Lung Ultrasound for Cardiologists in the Time of COVID-19. Can J Cardiol, May 2020. doi: 10.1016/j.cjca.2020.05.008 Ma I, Somayaji R, Rennert-May E et al. Canadian Internal Medicine Ultrasound (CIMUS) Recommendations Regarding Internal Medicine Point-of-Care Ultrasound (POCUS) use during Coronavirus (COVID-19) Pandemic. Can J Gen Internal Med, Apr 2020. doi:10.22374/cjgim.v15i2.438 Soldati G, Smargiassi A, Inchingolo R et al. Is There a Role for Lung Ultrasound During the COVID‐19 Pandemic? J Ultrasound Med, Mar 2020. doi:10.1002/jum.15284 Peng QY, Wang XT, Zhang LN et al. Findings of lung ultrasonography of novel corona virus pneumonia during the 2019 – 2020 epidemic. Intensive Care Med, Mar 2020. doi:10.1007/s00134-020-05996-6 Zotzmann V, Lang C, Bamberg F et al. Are subpleural consolidations indicators for segmental pulmonary embolism in COVID-19? Intensive Care Med, Apr 2020. doi:10.1007/s00134-020-06044-z Tee A, Wong A, Yusuff T et al. Contrast-enhanced ultrasound (CEUS) of the lung reveals multiple areas of microthrombi in a COVID-19 patient. Intensive Care Med, May 2020. doi:10.1007/s00134-020-06085-4 Soldati G, Giannasi G, Smarigiassi A et al. Contrast‐Enhanced Ultrasound in Patients With COVID‐19. J Ultrasound Med, May 2020. doi:10.1002/jum.15338 Johri A, Galen B, Kirpatrick J et al. ASE Statement on Point-of-Care Ultrasound (POCUS) During the 2019 Novel Coronavirus Pandemic. Apr 2020. https://www.asecho.org/wp-content/uploads/2020/04/POCUS-COVID_FINAL2_web.pdf. Cheung JC, Lam KN. POCUS in COVID-19: pearls and pitfalls. Lancet Resp Med, Apr 2020. doi:10.1016/S2213-2600(20)30166-1