Diagnosis
Diagnosis often follows a process of elimination. Diagnostic criteria
for FES are wide in the literature but none is routinely used in
practice.15 Most accepted are the modified Gurd’s
criteria.14 When using modified Gurd’s criteria, the
chance of underdiagnosis is greater, however fat droplets could be found
in many patients in lab results without any clinical significance.
In 1983 Schonfeld proposed a clinical score. He assigned scores to seven
clinical signs. A cumulative score >5 is required for a
diagnosis of FES. 15 (Table 1) Several other
scoring systems were still proposed but all these criteria are based on
small series and none of them are validated on prospective studies.
Arterial blood gas analysis will show hypoxia along with the presence of
hypocapnia. Thrombocytopenia, anaemia and hypofibrinogenemia are seen in
FES but are all nonspecific findings. ECG is usually non-specific, but
ECG changes can be detected if FES leads to myocardial necrosis.
On chest radiography bilateral pulmonary infiltrates, fleck-like
pulmonary shadows (snowstorm appearance) are seen.
High-resolution Computed Tomography (CT) shows patchy ground glass
opacities and consolidation with intralobular thickening. The extent of
the CT findings is well correlated with the disease
severity.15
POCUS (Point-of-care ultrasound) may aid to establish the diagnosis. Few
recent case reports have described that transthoracic echocardiography
(TTE) can detect fat emboli, seen as flowing hyperechoic particles in
inferior vena cava.16
Brain CT is mostly normal or may reveal diffuse white matter petechial
haemorrhages consistent with microvascular injury.
Bronchoalveolar lavage may also aid in the diagnosis, although fat in
the lungs is nonspecific and can be seen in multiorgan failure and
sepsis.