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.