الفهرس 
Covid-19 (laboratory diagnosis)Only 14 pages are availabe for public view
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Abstract
Coronavirus disease-19 (COVID-19) is the first pandemic infectious disease caused by a novel coronavirus, known as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Coronaviruses belong to the “Coronaviridae family”, which causes various diseases, from the common cold to SARS and MERS and they are naturally prevalent in mammals and birds.
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was first reported in December 2019 in Wuhan, China. Common symptoms include fever, dry cough, and fatigue, but in acute cases, the disease can lead to severe shortness of breath, hypoxia, and death. According to World Health Organization (WHO), the main transmission route is by inhalation of airborne droplets but direct contact with patients and feco-oral routes for COVID-19, also played a role in virus spread.
The SARS-CoV-2 infection molecular diagnosis depended on the detection of viral RNA on different biological samples (commonly nasopharyngeal swabs), using reverse transcriptase polymerase chain reaction (RT-PCR). The test takes about 6 h to be performed, but results may require up to 36 h to reach patients and healthcare practitioners when the samples have to be sent remotely or in the case of laboratory overload. The accuracy of such a test is still unclear, as false negative rates as high as 30% have been reported.
SARS-CoV-2 infection with pulmonary involvement shows typical computed tomography (CT) findings. With a reported sensitivity of 94% and specificity of 37%, CT scan is considered the most accurate, first-line imaging test to evaluate patients admitted to the ED with respiratory symptoms suggestive of SARS-CoV-2 infection. In these cases, CT scan is particularly useful if RT-PCR is negative.
The use of chest CT remains limited due to some notable drawbacks. For mild illness, radiation exposure, especially in children and pregnant women, overuse of health care resources, or lack thereof ability to get a CT scan seems to overshadow the need. In the critically ill, the transport of unstable patients and exposure to infective patients may also outweigh the clinical benefit. Therefore, alternative modalities to quickly characterize patients are needed.
Ultrasound machines are widely available and therefore Lung Ultrasonography (LUS) can be performed in few minutes, in mild or even unstable patients, at different hospital settings. Although there is an ongoing debate about how it should be applied, there is a general consensus about its usefulness. In this pandemic, the presence of subpleural consolidations, irregular pleural line and B-lines are highly suggestive for COVID-19 pneumonia
The aim of this work was to assess diagnostic performance of transthoracic ultrasound in covid pneumonia and correlations of these findings with clinical features, lab and chest CT findings.
This study was conducted on 100 patients (58males & 42females) with COVID-19 admitted at isolation unit (ward & ICU), Benha University Hospitals from June 2021 to January 2022.
All patients were subjected to the following:
a.Full clinical evaluation (including history and examination)
b.Lab tests (CBC, LDH, ferritin, D.dimer and ABG)
c.Nasopharyngeal and oropharengeal swabs for RT-PCR for SARS COV-2,
d.Non-contrast HRCT chest and
e.Transthoracic ultrasound
It was found that:-
The most frequent symptom among COVID patients was fever, followed by dyspnea, cough, and body aches.
LUS score significantly and directly correlated with respiratory rate and many laboratory markers (ferritin, LDH, D-dimer, CRP and TLC) while correlated significantly and inversely with oxygenation status (PO2 and SO2).
LUS score showed a significant positive correlation with CT scores and number of lobes affected.
The best cutoff of CT score to predict mortality was > 18, at which sensitivity and specificity were 100% and 87.3%, respectively while the best cutoff of LUS score to predict mortality was > 24, at which sensitivity and specificity were 95.2% and 96.2%, respectively.
CT and LUS scores were significant independent predictors of mortality.