The role of mobile handheld lung ultrasound in the diagnosis and monitoring of C0VID-19 atypical pneumonia

Background: Our aim is to present the importance of mobile Handheld Lung Ultrasound (HLUS) in COVID-19 patients at the bedside, which is a pre-screening tool with high diagnostic value that can provide triage of symptomatic patients at home (pre-hospital), emergency services, Intensive Care Units (ICU). In this context, the current role and importance of HLUS at the bedside in COVID-19 pneumonia has been summarized.

methods naturally take their share from the refl ections of the problem. US, which has been used rapidly all over the world since the 1970s, has a special place among all imaging modalities in terms of being relatively harmless, inexpensive, reproducible, easily accessible and fast results. Its general disadvantages are that ultrasonic waves cannot physically pass through air or bone, and relatively user-dependent, laborintensive. Recently, the disadvantage of user dependency has been eliminated since video recordings can be taken and stored during the examination and remote consultation with Telemedicine [1]. As a clinical advantage, unlike other imaging methods, it requires close contact between the practitioner and the patient. https://www.peertechz.com/journals/global-journal-of-medical-and-clinical-case-reports Citation: Omeroglu  LUS is rarely done in routine radiology practice except for some emergency pathologies. This situation prevented radiologists from having suffi cient experience in US fi ndings of peripheral lung infections. It is a natural process that the physicians who undertake the treatment of the patient, using US as a diagnosis and treatment monitoring method. Nowadays, with the widespread use of US, experience and knowledge of clinicians, lung examination with handheld US devices has now replaced the stethoscope as an evidence-based imaging method [2]. These mobile US devices are pocket-sized, light and affordable. Convex probe 5-7 MHz is preferred mainly.
Linear probes are only preferrable to study the detail of the pleural and subpleural alterations [3,4].
Handheld US has been used very effectively at the bedside in home care services, outpatient clinics, emergency units, and intensive care units by Radiologists, Emergency physicians, Family physicians, Pediatricians, Cardiologists, Pulmonologists and Intensive Care physicians in all over the world [5]. Thus, the same and one clinician will be required to conduct an objective medical examination and imaging directly bedside [2,5]. Since it is diffi cult to predict how much the pandemic will force the imaging units, it has become of great importance to make a radiological algorithmic approach that includes bedside HLUS in the diagnosis and follow-up of COVID-19 patients.

Results
LUS at the bedside has been widely used in COVID-19 pneumonia in Italy, one of the countries most affected by the pandemic [4,6]. Although not specifi c for COVID-19, US fi ndings of peripheral interstitial viral pneumonias due to COVID-19 lung involvement are very characteristic. The characteristic sonographic pattern of multifocal confl uent B-lines with irregular pleural markings was seen on LUS in patients with COVID-19 pneumonia [7,8]. It was shown that the sensitivity and specifi city of bedside LUS in the diagnosis of atypical pneumonia were high enough to include in radiologic algorithm. The use of HLUS in COVID-19 atypical pneumonia is of critical importance due to its high diagnostic value in diagnosis and follow-up [8,9].

Discussion
Almost all scientifi c articles about LUS of COVID-19 pneumonia originating from Italy and China have been made in cooperation with Emergency physicians, Pulmonologists and Intensive care physicians. A big image database allowed COVID-19 LUS diagnostic scoring creation in this period [6].
Sonographic pattern of multifocal confl uent B-lines with irregular pleural markings was seen on LUS in patients with COVID-19 pneumonia. The accuracy of these fi ndings showed a high sensitivity (91%) and specifi city (86%) for COVID-19 pneumonia [8].
In another study with totally of 127 patients, it was shown that the sensitivity and specifi city of bedside lung US in the diagnosis of atypical pneumonia were 98.0% and 95.8%, respectively. In these cases where consolidation was not determined in LUS but B-3 line positivity or a diffuse interstitial pattern was present, the sensitivity and specifi city were 93.3% and 88.2%, respectively. This study showed that when consolidation was not observed in LUS, the presence of B-3 line positivity or diffuse interstitial pattern could be used for the diagnosis of pneumonia [9].

Conclusions
As a result, we can suggest a simple algorithm of HLUS at the bedside in the COVID-19 pandemic concerning these articles. After all, we cannot predict how much the COVID-19 pandemic will strain our health system in these pandemic times. Handheld pocket-sized US devices are cheap, easy to handle and equivalent to standard scanners for non-invasive assessment of severity and dynamic observation of lung lesions in COVID-19 patients with pneumonia [10]. Also HLUS can be used at the bedside, especially in emergency units, intensive care patients, children and pregnant women, can be performed by a single clinician, and can be repeated safely because it does not contain X-rays. The use of HLUS is of critical importance due to the reduction of burden in hospital care, CT units and the risk of transmission, and its high diagnostic value in diagnosis and follow-up [8,9].