Discussion
Acute dyspnoea could be a common symptom within the ED. the quality approach to dyspnoea often relies on radiologic and laboratory results, causing excessive delay before adequate therapy is started. Use of an integrated point-of-care ultrasonography (POCUS) approach can shorten the time needed to formulate a diagnosis, while maintaining a suitable safety profile (1).
Chest computerized tomography (CT) has significant limitations, like exposure to ionized radiation, limited application in certain patients, like pregnant women, the need of transferring a potentially unstable patient to the tomography unit and time consuming (2).
POCUS is employed by physicians at the bedside for rapid, focused and accurate evaluation to spot or rule out various pathologies. Several protocols for POCUS are currently available and employed in different clinical scenarios like undifferentiated dyspnoea, hypoxia or shock, and include the bedside lung ultrasound in emergency (BLUE), the rapid assessment of dyspnoea with ultrasound (RADIUS) and also the rapid ultrasound in shock (RUSH) protocols (3).
The bedside lung ultrasonography in emergency (BLUE) protocol is an algorithm developed by Lichtenstein as a systemic approach to the diagnosis of patients with dyspnoea in critical care units (ICUs) with 90.5% diagnostic accuracy. A (BLUE) protocol provides good step by step approach to diagnose acute dyspnoea (4).
The BLUE protocol started by checking Anterior lung sliding. Presence of sliding exclude pneumothorax. The B profile suggests pulmonary oedema. The A profile prompts an enquiry for thrombosis. The association of A profile with phlebothrombosis (venous scan) favours the diagnosis of pulmonary embolism with 81% sensitivity and 99% specificity (5).
At this point, adding a focus ECHO (FECHO) examination to BLUE protocol can confirm presence of embolism (PE) especially if it’s massive or sub-massive PE. Ultrasound signs of right heart strain include bowing of the IVS into the LV, right ventricular dilatation and systolic dysfunction including McConnell’s sign, possible tricuspid regurgitation, a dilated inferior vena cava and visual right heart thrombus (6).
Coronavirus disease 2019 (COVID-19) is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the World Health Organization (WHO) declared it an pandemic on 11 March 2020 (7).
The effect of SARS-CoV-2 on endothelial cells plays a vital role in vascular injury that contributes to pulmonary, cardiovascular and other manifestations. Endothelial dysfunction and endothelitis are considered the idea of thrombus formation and lead to COVID-19 associated thromboembolic insult of various organs and might partially explain the hypercoagulable state commonly related to patients infected with SARS-CoV-2 (7).
Thromboembolic manifestations of COVID-19 have been described in several reports. In the ED and critical care units, BLUE protocol plus FECHO in the appropriate clinical context is an effective tool to rapidly diagnose acute pulmonary embolism associated with right heart strain and possible thrombus in transit, and guide further treatment (8).
In our case the patient presented with acute dyspnoea with no clinical symptoms or signs that favour diagnosis of (COVID-19), using an Extended BLUE protocol by adding FECHO help in diagnosis acute massive PE with bilateral lower limb DVT. within the context of the present Pandemic with thrombosis everywhere, we diagnose this patient as (COVID-19) infection. Which was confirmed by positive nasopharyngeal swab for SARS-CoV-2 shortly.
We stress on the importance of BLUE protocol for assessment of patient with acute dyspnoea and recommend to include FECHO examination for more accurate diagnosis.