Clinical characteristics and management of patients with fat embolism syndrome in level I Apex Trauma Centre

Abstract

Purpose:
Fat embolism syndrome (FES) is systemic manifestation of fat emboli in the circulation seen mostly after long bone fractures. FES is considered a lethal complication of trauma. There are various case reports and series describing FES. Here we describe the clinical characteristics, management in ICU and outcome of these patients in level I trauma center in a span of 6 months.

Methods:
In this prospective study, analysis of all the patients with FES admitted in our polytrauma intensive care unit (ICU) of level I trauma center over a period of 6 months (from August 2017 to January 2018) was done. Demographic data, clinical features, management in ICU and outcome were analyzed.

Results:
We admitted 10 cases of FES. The mean age of patients was 31.2 years. The mean duration from time of injury to onset of symptoms was 56 h. All patients presented with hypoxemia and petechiae but central nervous system symptoms were present in 70% of patients. The mean duration of mechanical ventilation was 11.7 days and the mean length of ICU stay was 14.7 days. There was excellent recovery among patients with no neurological deficit.

Conclusion:
FES is considered a lethal complication of trauma but timely management can result in favorable outcome. FES can occur even after fixation of the fracture. Hypoxia is the most common and earliest feature of FES followed by CNS manifestations. Any patient presenting with such symptoms should raise the suspicion of FES and mandate early ICU referral.

Full text

Original Article
Clinical characteristics and management of patients with fat embolism syndrome
in level I Apex Trauma Centre
Richa Aggarwal
a
, Arnab Banerjee
b
, Kapil dev Soni
a
,
*
, Atin Kumar
c
, Anjan Trikha
d
a
Critical and Intensive Care, JPNATC, All India Institute of Medical Sciences, New Delhi, India
b
Department of Plastic Surgery, All India Institute of Medical Sciences, New Delhi, India
c
Department of Radiodiagnosis, All India Institute of Medical Sciences, New Delhi, India
d
Department of Anesthesiology, Critical Care and Pain Medicine, All India Institute of Medical Sciences, New Delhi, India
article info
Article history:
Received 11 December 2018
Received in revised form
29 January 2019
Accepted 1 March 2019
Available online 14 March 2019
Keywords:
Fat embolism
Trauma centers
Intensive care units
Patient outcome assessment
abstract
Purpose: Fat embolism syndrome (FES) is systemic manifestation of fat emboli in the circulation seen
mostly after long bone fractures. FES is considered a lethal complication of trauma. There are various case
reports and series describing FES. Here we describe the clinical characteristics, management in ICU and
outcome of these patients in level I trauma center in a span of 6 months.
Methods: In this prospective study, analysis of all the patients with FES admitted in our polytrauma
intensive care unit (ICU) of level I trauma center over a period of 6 months (from August 2017 to January
2018) was done. Demographic data, clinical features, management in ICU and outcome were analyzed.
Results: We admitted 10 cases of FES. The mean age of patients was 31.2 years. The mean duration from
time of injury to onset of symptoms was 56 h. All patients presented with hypoxemia and petechiae but
central nervous system symptoms were present in 70% of patients. The mean duration of mechanical
ventilation was 11.7 days and the mean length of ICU stay was 14.7 days. There was excellent recovery
among patients with no neurological deficit.
Conclusion: FES is considered a lethal complication of trauma but timely management can result in
favorable outcome. FES can occur even after fixation of the fracture. Hypoxia is the most common and
earliest feature of FES followed by CNS manifestations. Any patient presenting with such symptoms
should raise the suspicion of FES and mandate early ICU referral.
©2019 Chinese Medical Association. Production and hosting by Elsevier B.V. This is an open access article
under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
Introduction
Fat embolism is the presence of fat globules in the circulation
and fat embolism syndrome (FES) is the clinical manifestation of fat
emboli in the circulation characterized by specific signs and
symptoms. It is important to distinguish between fat embolism and
FES. Fat embolism is quite common occurring in more than 90% of
patients with long bone fractures
1
but not all the cases of fat em-
bolism progress to fat embolism syndrome. The incidence of FES is
variable ranging from <1% in retrospective studies
1
and 11%e29% in
prospective studies
2,3
and typically consists of a triad of neuro-
logical, pulmonary and cutaneous symptoms.
FES is commonly seen after orthopaedic trauma i.e. fracture of
long bones, pelvis or multiple fractures but can be seen in non-
trauma conditions also like after hip or knee arthroplasty, burns,
pancreatitis, liposuction and bone marrow transplant procedure.
4
All the patients who develop FES require intensive care unit
admission and critical management.
There are various case reports of FES published in the literature
but limited prospective case series. We report 10 cases of fat em-
bolism syndrome (FES) who were admitted in our polytrauma
intensive care unit (ICU) of level I trauma center in India over a
period of 6 months (from August 2017 to January 2018). Here we
described the clinical characteristics, course in ICU and outcome of
these patients.
Methods
The study was carried out in surgical ICU of level I trauma centre
of All India Institute of Medical Sciences (AIIMS) in India.
*Corresponding author.
E-mail address: kdsoni111@gmail.com (K. Soni).
Peer review under responsibility of Chinese Medical Association.
Contents lists available at ScienceDirect
Chinese Journal of Traumatology
journal homepage: http://www.elsevier.com/locate/CJTEE
https://doi.org/10.1016/j.cjtee.2019.01.007
1008-1275/©2019 Chinese Medical Association. Production and hosting by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://
creativecommons.org/licenses/by-nc-nd/4.0/).
Chinese Journal of Traumatology 22 (2019) 172e176

Prospective study and analysis of all the ten patients with fat em-
bolism was done. Demographic data, clinical features, course in ICU
and outcome were analyzed. We used Gurd's criteria for diagnosis
of FES. It consists of major and minor criteria.
Major criteria
Respiratory insufficiency
Cerebral involvement
Petechial rash.
Minor criteria
Tachycardia
Fever
Jaundice
Retinal changes
Renal changes
Microglobulinemia
Thrombocytopenia
Elevated erythrocyte sedimentation rate
Anemia
One major and four minor criteria must be present to formally
make the diagnosis of FES.
Results
We admitted 10 cases of fat embolism in 6 months (August 2017
to January 2018) in our ICU.
Demographic features
All patients were young males between 18 and 42 years (mean
age 31.2 years, standard deviation (SD) 12.38 yrs) except one female
who was 55 years old. The demographic profile of each patient is
given in Table 1. All the cases had fracture femur with or without
pelvis fracture except one who had tibial fracture. Most of them
were initially admitted and managed in the orthopaedic ward and
shifted to ICU once symptomatic. The time duration between the
time of injury and onset of symptoms varied among patients
ranging from 16 h to 7 days post injury (mean 56 h, SD 38.2 h).
Out of 10 patients, 4 patients presented with symptoms prior to
surgical fixation and 6 patients presented after the surgical pro-
cedure. Open reduction and internal fixation was done in 5 patients
and 1 patient underwent closed reduction. The time interval be-
tween the surgery and admission to ICU varied between 6 and 48 h.
Clinical features
The clinical features of the patients are presented in Table 2. All
the patients (100%) presented with hypoxemia and petechiae. The
petechiae were present in conjunctiva and upper chest (Figs. 1 and
2]. Central nervous system symptoms were present in 7 out of 10
i.e. 70% of patients. Other features like tachycardia, thrombocyto-
penia, and fever were present in varying degrees. Six patients
developed bilateral infiltrates mimicking acute respiratory distress
syndrome (ARDS) on chest X-ray (Fig. 3). Urine for fat globules was
positive in all patients.
ICU management and outcome
The management of these patients was primarily supportive.
ICU management and outcome are illustrated in Table 3. Out of 10
patients, 6 patients required intubation and mechanical ventilation,
2 patients were managed on non invasiveventilation and 2 patients
were managed with oxygen face mask. Duration of mechanical
ventilation ranged from 5 to 30 days (mean of 11.7 days, SD 11.45
days) and 5 patients required tracheostomy. Four patients with
prolonged ventilation developed ventilator associated pneumonia
(VAP), acinetobacter baumanni being the most common isolated
organism.
The mean length of ICU stay was 14.7 days ranging from 2 to 34
days (SD 12.1 days). There was no mortality and all the patients
survived. The neurological recovery was excellent and all patients
who had neurological symptoms recovered fully.
Discussion
FES is regarded as post traumatic complication associated with
long bone or pelvic fractures. Fat embolism was first described by
Zenker in 1861.
5
Even after 150 years of first definition, there is no
Table 1
Demographic profile of the patients.
Patient
No.
Age (year) Gender Mode of injury Diagnosis Time of presentation of
the symptoms after
trauma
Operative
procedure
Time of presentation of the
symptoms after the operative
procedure (h)
1 22 M RTA Left femoral shaft fracture 60 h CREF 24
2 41 M Fall from height Open Grade 1 tibia fracture 7 d ORIF 48
3 32 M RTA Bilateral femoral shaft fracture;
left olecranon fracture
42 h ORIF Before procedure
4 20 M RTA Left femoral shaft fracture 4 d ORIF 6
5 23 M RTA Grade 3 open distal end femoral
fracture
16 h ORIF Before procedure
6 38 M RTA Left femoral shaft fracture 72 h ORIF 48
7 55 F RTA Superior and inferior pubic
rami fracture; acetabulum
fracture; rib fracture
36 h Before procedure
8 18 M RTA Superior and inferior pubic
rami fracture; femoral neck
fracture
24 h ORIF Before procedure
9 21 M RTA Closed right femoral facture;
right distal femoral fracture;
Both bone right leg fracture
5 d ORIF 36
10 42 M RTA Bilateral femoral shaft fracture 4 d ORIF 24
RTA: road traffic accident, CREF: closed reduction and external fixation; ORIF: open reduction and internal fixation.
R. Aggarwal et al. / Chinese Journal of Traumatology 22 (2019) 172e176 173

definitive diagnostic test available. It is a diagnosis of exclusion
based on characteristic sign and symptoms with an underlying
cause. Fat embolism syndrome is common in trauma patients and
our being Apex Trauma Centre, we admitted 10 cases of fat em-
bolism in our ICU in 6 months period. Our center is a high volume
and tertiary referral center for trauma patients. This high occur-
rence of fat embolism has not been reported in previous reports.
As already established in the literature,
6
all our patients except
one were young patients. Fat embolism is most commonly associ-
ated with long bone fractures.
6,7
In our series, all patients had fe-
mur fracture with or without pelvis fracture except one who had
tibia bone fracture.
Fat embolism typically manifests 24e72 h after trauma but may
occur as early as 12 h and can be delayed up to 2 weeks of insult.
8
In
our study population, the time period varied from as early as 16 h to
7 days post injury. Six patients out of 10 presented after the fixation
of the fracture and 4 patients presented before operation. The time
gap between the injury and the surgery was between 24 and 96 h.
That is the time the patients are most prone to this complication
and should be kept under close observation. The timing of pre-
sentation after fixation varied from 6 h to 48 h.
According to the literature, pulmonary involvement is the most
common feature of FES and may be present in up to 92%e95% of
cases.
1,9
Similarly, in our study, hypoxemia was present in 100%
cases. Other causes of hypoxemia like pneumonia, pneumonitis,
transfusion related lung injury, effusion, basal atelectasis were
Table 2
Clinical features of the patients.
Patient No. Petechiae Hypoxaemia CNS depression Fever Urine fat Retinal fat Thrombocytopenia Bilateral infiltrates in chest X ray
1þþ þ þþee þ
2þþ þ þþeþþ
3þþ þ þþeþe
4þþ eeþeþþ
5þþ þ þþee þ
6þþ þ þþee þ
7þþ þ þþee þ
8þþ þ þþeþe
9þþ eeþeþe
10 þþ eeþee e
þ: present; : absent
Fig. 1. Multiple petechiae in the conjunctiva.
Fig. 2. Petechial rash on the anterior surface of the chest.
Fig. 3. Chest X-ray of the No. 6 patient shows bilateral infiltrates in upper and lower
lobes.
R. Aggarwal et al. / Chinese Journal of Traumatology 22 (2019) 172e176174

ruled out. Approximately 44%e50% cases of FES with long bone
fracture require mechanical ventilation.
10
In our study 60% of pa-
tients required mechanical ventilation. The characteristic finding of
bilateral infiltrates in chest X-ray were present in 6 patients, rest
had no specificfinding. Thorax computed tomography (CT) was
done in one case which revealed features suggestive of FES (Fig. 4).
CT scan chest of our patient depicted bilateral micronodular and
reticular opacities with areas of ground glass in a random distri-
bution. Though different studies report different times of
improvement of pulmonary symptoms ranging from 3rd day to
days of ventilation.
11
Many of our cases required prolonged
ventilation.
Petechial rash which is considered pathognomonic of FES usu-
ally develops in 20%e50% of cases.
1,10 ,12
In one study, the incidence
was as low as 8.3% and the authors
9
attributed this to retrospective
nature and delay in identification of rash in Asian population.
Various studies had reported less recognition in dark skinned pa-
tients. However in our series, all the patients i.e. 100% patients
developed petechial rash. The reason could be that we prospec-
tively looked for petechiae in all patients who had suspicion of fat
embolism. Other studies because of their retrospective nature may
have missed this finding. The petechiae were found mainly in the
conjunctiva, axilla and upper chest of the patients.
Neurological manifestations vary in cases of FES and may occur
in up to 86% of cases.
13
The symptoms may appear within 10 h or
may be delayed up to 5 days and range from acute confusion
14
to
altered level of consciousness and seizures.
1,14
In our series, 70% had
neurological involvement. The most common presentation was
altered sensorium. Four patients had drop in the neurological status
as documented by Glasgow Coma Score (GCS) but none had
Table 3
ICU course and outcome of the patients.
Patient No. Oxygen therapy Time on ventilator (d) Tracheostomy done Ventilator Associated
Pneumonia
Bacteria isolated
In BAL
Total ICU stay (d) Total hospital stay (d)
1 Venturi mask Nil ee Nil 2 8
2 Intubated 30 þþ Acinetobacter þKlebsiella 34 36
3 Intubated 26 þþ Acinetobacter 27 29
4 Intubated 16 þþ Staph. aureus 19 22
5 Intubated 7 ee Nil 14 21
6 NIV mask 6 ee Nil 8 14
7 Intubated 5 þeNil 7 9
8 Intubated 25 þþ Acinetobacter 30 37
9 NIV mask 2 ee Nil 4 10
10 Venturi mask Nil ee Nil 2 5
BAL: bronchoalveolar lavage; Nil: zero; þ: yes; : no.
Fig. 4. Axial CT scan images of the chest in lung window of the patient no. 6 shows extensive bilateral micronodular and reticular opacities with areas of ground glass in a random
distribution involving both the upper and lower lobes of the lung parenchyma. (A) Upper thoracic section at the level of carina; (B) Middle thoracic section at the level of heart.
Fig. 5. The T
2
weighted axial MR images of the brain (A, B) of the patient no. 8 shows bilateral asymmetrical patchy hyperintense lesions involving the subcortical and deep white
matter including the centrum semiovale. Note the involvement of splenium of corpus callosum (arrow in A). The presence of petechial microhemorrhages within most of these
lesions was seen on susceptibility weighted image (C).
R. Aggarwal et al. / Chinese Journal of Traumatology 22 (2019) 172e176 175

lateralizing signs. CT head was done in all patients with no specific
finding. As most of the patients were operated and had implants in
situ, magnetic resonance imaging (MRI) brain could be done in one
patient (Fig. 5). MRI revealed bilateral asymmetrical patchy
hyperintense lesions involving the subcortical and deep white
matter and the presence of petechial microhemorrhages. All pa-
tients with neurological involvement recovered completely
without any deficit.
The diagnosis of FES is mainly clinical. There is no standardized
validated diagnostic test for FES. Various authors have tried to
define diagnostic criteria like Gurd's criteria, Schonfeld and Lin-
deque
3,15,16
but none is validated. We used Gurd's criteria for
diagnosis of FES as mentioned in methodology section.
Chest radiography is normal in majority of patients. CT thorax
may show bilateral ground glass opacities which are well demar-
cated.
11,17
CT scan chest of our patient has already been described
above. Treatment is mainly supportive. Many strategies including
corticosteroids, albumin, heparin have been studied but none is
conclusive. Mortality in other studies varies from 5% to 15%
18
and
has been mainly attributed to progressive hypoxemia and ARDS.
Though many of our patients required prolonged ventilation but all
recovered. There was no mortality in our series.
FES is considered a lethal complication of trauma. However,
early diagnosis and timely management can result in favorable
outcome. Immobilization of the fracture segment and early fixation
of the fracture are assumed to be the best strategies to prevent FES
but FES can occur even after the fixation. In our study, most of the
patients presented after fixation of the fracture. All the patients
were immediately shifted and managed in ICU and all recovered
fully. Therefore, patients with long bone fractures should be kept
under strict vigilance even in the postoperative period and signs
like hypoxia or altered sensorium should raise the suspicion of FES
mandating early ICU referral.
Funding
Nil.
Acknowledgements
None at present.
Ethical statement
The study was performed in accordance with the ethical
guidelines of the Institute.
Conflicts of interest
All the authors declare no conflicts of interest.
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