EFFICACY OF FOCUSED ASSESSMENT SONOGRAPHY IN TRAUMA (FAST) IN PATIENTS WITH BLUNT ABDOMINAL TRAUMA

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Original Research Paper ISSN : e- ISSN 2395-3950, p-issn 2395-440X
IRPMS | VOL-2 | No. 5 | JAN-MAR | 2017
1
EFFICACY OF FOCUSED ASSESSMENT SONOGRAPHY IN TRAUMA
(FAST) IN PATIENTS WITH BLUNT ABDOMINAL TRAUMA.
1Krunalkumar Pancholi, 2Shreyas Patel, 3Rina Parikh, 4A.K.Saxena
1 Resident Doctor, 2&3Assistant Professor, 4Professor & Head, Department of Emergency Medicine,
SSG Hospital & Medical College, Baroda, Gujarat, India
Corresponding Author: Dr. Krunalkumar Pancholi, Resident Doctor, Department of
Emergency Medicine, SSG Hospital & Medical College, Baroda-390001, Gujarat, India. E-
mail: krunalpancholi90@gmail.com
INTRODUCTION
Abdominal injuries rank third as a cause of
traumatic death just after head and chest
injuries. Undetected hemoperitoneum is
one of the most common causes of death
in injured patients. Unrecognized
abdominal injuries are frequently the cause
of preventable death. The abdomen of
trauma victims is routinely evaluated with
ABSTRACT
Background & Objective: Unrecognized blunt
abdominal injuries are frequently the
cause of preventable death. Clinical examination is often inaccurate and therefore,
reliable,
accurate and repeatable bedside diagnostic test should be selected such as Sonography.
This study was undertaken to assess the efficacy of Focused Assessment Sonogra
phy in
Trauma (FAST)
examination for detection of free fluid in abdomen in patients with Blunt
Abdominal Trauma.
Methods: This study is a prospective and observational study,
conducted in the
Department of Emergency Medicine, S.S.G. Hospital and Medical College, Baroda.
All
patients who were brought to us
with definite or suspected blunt abdominal trauma
brought during the study period from October 2014 to February 2016 were included.
FAST with four standard views was performed using a low frequency curvilinear probe in
all the patients and repeated after 30 minutes. Results were compared with CT, s
urgical
findings, postmortem findings and the p
atient’s clinical status after 24 hours of
observation.
Results: Total of 256 patients were included in our study and the majority of
them were
males and the most common cause of injury was a Road Traffic Accident. The sensitivity
and specificity of FAST were 97.6% and 100%, respectively, with an accuracy of 99.2%.
Conclusion: Our study shows that the FAST is a
highly sensitive, specific, reliable and
accurate initial bedside investigation in patients with blunt abdominal trauma, which can
be performed rapidly even in haemodynamically unstable patients, making
it a very useful
tool in the Emergency Department.
Key-words: Blunt Abdominal Trauma, Emergency Department, FAST.

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physical examination and clinical signs
that have relatively low diagnostic
accuracy (47% to 87%),1 especially when
the patient had a decreased consciousness
level, neurological deficit, other associated
injuries, or was under the influence of
drugs or medications.Thus, diagnostic tests
must be selected, performed and
interpreted to reliably discriminate
between patients who require therapeutic
intervention or further study from those
who do not. One of the most important
tools for this purpose is sonography.
Sonography is designed to complement
other investigations: diagnostic peritoneal
lavage (DPL) is very sensitive, but not
without disadvantages, while CT will
remain the gold standard, but there is
usually some delay in obtaining a scan and
necessitates a haemodynamically normal
patient as it is not a bedside investigative
procedure and patient needs to be shifted
to the CT facility.2 Blunt abdominal
trauma (BAT) comprises 75% of all blunt
traumas. The majority occurs in vehicular
accidents, in which rapid deceleration may
propel the driver into the steering
wheel, dashboard, or seat belt causing
contusions in less serious cases, or rupture
of internal organs from briefly increased
intraluminal pressure in the more serious,
dependent on the force applied. Other
causes of BAT include fall, assault, sports
injury and accidental injuries with unusual
objects.3
The focused assessment sonography in
trauma (FAST) is a focused, goal directed,
sonographic examination of the abdomen
aimed at detecting the presence or absence
of hemoperitoneum. It provides a viable
alternative to other investigations in the
blunt abdominal trauma patient, and can be
integrated into the primary survey in
patients with signs of hemorrhagic shock
or suspicion of intra abdominal injury. It
has the additional advantages of being
noninvasive, reproducible, and is capable
of being rapidly performed at the patient’s
bedside by the Emergency Physician. A
standard 4 view examination can be
completed in approximately 2 minutes.
Bedside sonography not only increases the
speed of the patient management, but also
lowers the costs in the Emergency
Department, as well as it can be utilized in
haemodynamically unstable patients also.4
Our center is a tertiary care hospital and
one of the largest hospitals in central
Gujarat, where many patients of Blunt
Abdominal Trauma are referred from rural
parts of central and south Gujarat region as
well as from the border areas of nearby
states like Madhya Pradesh, Maharashtra
and Rajasthan also. Till date, no such
study on FAST has been conducted at our
center and perhaps in Gujarat. Therefore,
this study was undertaken to assess the
efficacy of FAST in patients with Blunt
Abdominal Trauma and to define the
utility of FAST as a screening test for
detection of free fluid in abdomen.
MATERIAL & METHODS
This prospective and longitudinal study
had been conducted in the Department of
Emergency Medicine, SSG Hospital &
Medical College, Baroda during the period
of one year from 1st October 2014 to 29th
February 2016. Total 256 patients, which
were brought to us with definite or
suspected blunt abdominal trauma during
this period were included in the study.
Ethical clearance from the institutional
review committee was taken before
starting the study and informed and written

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consent was taken from the patient or
relatives of the patient. The patient’s
general details, mechanism of injury,
primary survey details, examination
findings and initial management details
were filled in the predesigned proforma.
FAST protocol examination with four
standard views (subxiphoid, right upper
quadrant, left upper quadrant and pelvic)
was performed using a low frequency
curvilinear probe (3-5 MHz) in all the
patients and repeated after 30 minutes. In
some patients, a third FAST was also
performed according to the need. Any
anechoic strip or collection in the
peritoneal space was considered as free
fluid and the related solid organ injuries
were identified. In trauma patients, the
fluid is always assumed to be blood. As
many patients may be emergently
transferred to Operation Theatre and many
of the patients remain stable clinically,
third FAST was not required in many
patients. The results of the FAST were
compared with the findings of clinical
examination after 24 hours as well as with
the observations of CT scan findings or
surgical findings or postmortem findings.
Data collection was done and proforma
filled and data were analyzed using
Medcalc Version 12.5.0 Software and
appropriate statistical tests were applied.
The findings of this study were compared
with the similar type of studies done by the
Indian and foreign authors.
RESULTS
Table 1 shows that among 256 patients,
the majority of the patients were males
(66%) and the rest were females (34%).
Table 2 shows that the most common
mechanism of injury was RTA (65%) in
male patients, which was followed by fall
from height (24%), assault (9%), and
others (2%) while in case of female
patients the most common mechanism of
injury was fall from height (49%) followed
by RTA (39%) and assault (12%).
Table-1 : Distribution of Patients
According to Sex
Male
Female
Total
170
(66%)
86
(34%)
256
Table-2 : Distribution of Patients, According to Mechanism of Injury Causing BAT
Mechanism Of
injury Male
(% among
males) Female (% among
females) Total (% among total
patients)
Road Traffic
Accident (RTA) 111 (65%) 34 (39%) 145 (57%)
Fall from height 40 (24%) 42 (49%) 82 (32%)
Assault 16 (9%) 10 (12%) 26 (10%)
Others
3
(2%)
0
(0%)
3
(1%)
Total
170
86
256

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Table-3 : Distribution of Patients According to Clinical Examination Findings
Examination Male
(% among
total male
patients)
Female
(% among
total female
patients)
Total (% among total
patients)
Tenderness
77
(45%)
25
(29%)
102
(40%)
Rigidity
45
(26%)
15
(17%)
60
(23%)
Guarding
61
(36%)
27
(31%)
88
(34%)
Absent bowel
sounds 63 (37%) 27 (31%) 90 (35%)
Abdominal
Distension 34 (20%) 10 (12%) 44 (17%)
Dull note on
percussion 34 (20%) 10 (12%) 43 (17%)
Abrasion/
contusion 99 (58%) 49 (57%) 148 (58%)
blood at urethral
meatus 5 (3%) 0 (0%) 5 (2%)
swelling or bruise
over perineum,
vagina, rectum,
buttocks
0 (0%) 3 (3%) 3 (1%)
Figure-1 : Time Between Injury and Fast Examination
On abdominal examination,
abrasion/contusion (58%) was the most
common inspectory findings, while,
tenderness (40%) was the most common
palpatory finding, followed by guarding
(34%) and rigidity (23%). This time
duration is between injury and first FAST
performed in the Emergency Department,
which includes the time for transport from
the injury site. As most of the patients
were brought from the nearby area, most
(243) (96%) of the patients were examined
with FAST within 6 hours of injury. Out of
which, 68 (27%) patients had FAST within
1 hour and 66 (26%) patients had FAST
within 1-2 hours.
0- 1 hour
1-2 hour
2-6 hour
6-12 hour
>12 hours
Male
53
30
75
3
9
Female
15
36
34
1
0
0
10
20
30
40
50
60
70
80

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Figure-2 : Adverse Factor for Sonography
The most common adverse factor for
Sonography in males was bowel gas
(13%), followed by obesity (12%); while
in females, obesity (27%) was the adverse
factor in the majority. In the present study,
two serial FAST were performed in all 256
patients. Out of 177 patients in whom first
FAST was negative, second FAST (after
30 minutes of first FAST) turned out to be
positive only in 2 (1%) patients.
Table-4 : Sensitivity & Specificity of Fast
FAST
Positive
hemoperiton
eum
Negative
hemoperiton
eum
Tot
al
Positiv
e 81 0 81
Negati
ve 2 173 175
Total
83
173
256
• Sensitivity = 81 ×100
83
= 97.6% (95% CI = 91.5% -
99.7%)
• Specificity = 100% (95% CI = 97.9% -
100%)
• Positive Predictive value = 100% (95%
CI = 95.55% - 100%)
• Negative Predictive value = 173 ×100
75
= 98.8%
(95% CI =
95.9% -
99.88%)
• Positive Likelihood ratio- As
specificity is 100%, positive likelihood
ratio cannot be calculated
• Negative Likelihood ratio
= 1- sensitivity/specificity
= 0.024 (95% CI = 0.01-0.09)
• Accuracy
= True positive+ True negative/ Total
patients
= 254/256 =99.2%
(95% CI = 97.2%- 99.9%)
Among All (256) Patients irrespective of
FAST findings
• 44 (17%) patients had CT scan positive
for hemoperitoneum
• 25(10%) patients had operative
findings positive for hemoperitoneum,
out of them 11 (4%) patients had CT
scan done
• 7 (3%) patients had Post Mortem
reports positive for hemoperitoneum.
Obesity
Bowel gas
Un co operative
patients
Subcutaneus
emphysema
Male
21
22
2
2
Female
23
9
0
0
12% 13%
1% 1%
27%
10%
0% 0%
0
5
10
15
20
25

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• 18 (7%) patients were kept on
conservative management without any
CT scan.
• All 52 (20%) patients who were on
conservative management were stable
after 24 hours.
Among FAST Positive Patients (81)
• 42 (52%) patients had CT scan positive
for hemoperitoneum
• 24(30%) patients had operative
findings positive for hemoperitoneum,
out of them 10 (12%) patients had CT
scan done
• 18(22%) were patients were kept on
conservative management without any
CT scan.
• All 50 (62%) patients who were on
conservative management were stable
after 24 hours.
• 7 (9%) patients had Post Mortem
reports positive for hemoperitoneum.
DISCUSSION
During the period of our study, out of a
total 256; 66% patients were males and
34% were females. Almost similar
findings were noticed by Betul Gulalp et
al,5 Nauman Al Qamari et al2 and Navid
Farahmand et al6 showing that Blunt
Abdominal Trauma is more common in
males. The present study shows that Road
Traffic Accident (RTA) is the major
contributor in injuries causing Blunt
Abdominal Trauma. Brooks et al,7 J.
Branchley et al,8 M. Jawed et al9 and
Nauman Al Qamari et al.(2) also found
RTA as a most common cause of Blunt
Abdominal Trauma in their studies. In our
study, we observed that Road Traffic
Accident (RTA) was the most common
cause of injury in males (65%) while in
females fall from height (49%) was the
major contributor.
In the present study, the time elapsed
between injury and first FAST
examination (including transport from the
injury site) was less than 1 hour in 27%
patients, 1-2 hour in 26% patients, 2-6
hours in 43% patients, 6-12 hours in 1%
patients and >12 hours in 3% patients. The
study performed by Nauman Al Qamari et
al2 reviewed that the time elapsed between
injury and first FAST examination
(including transport from the injury site) is
less than 1 hour in 4% patients, 1-2 hour in
9% patients, 2-6 hours in 41% patients, 6-
12 hours in 29% patients and >12 hours in
18% patients. The present study also
shows, similar to the finding of J.
Branchley et al8 that around about one
third to one fourth patient have adverse
factor for sonography in blunt abdominal
trauma victims. Obesity and bowel gases
were the major contributors among these
adverse factors, but even after the presence
of these adverse factors for sonography,
the FAST results in our study were
accurate and no false positive or false
negative FAST results were obtained from
these patients.
This study is similar to the observations of
studies conducted by others, e.g. Ali Feyzi
et al10 showed the importance of serial
FAST examination. The present study
shows that FAST is a highly sensitive,
specific and accurate tool for detecting
free fluid in the abdomen and so can be
used as a rapid screening test in the
Emergency Department and almost similar
findings were observed by Richards JR et
al,11 Dolich MO et al12 Sanjeev Bhoi et
al,13 Majid Zamani et al,14 Nural MS et
al,15 Bowra J et al16 and Branchley et al.8

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This study may be helpful to form a
management protocol which includes
FAST as a screening test, in the
Emergency Department for the patients of
polytrauma in various health centers like
ours at SSG Hospital, Baroda.
CONCLUSION
FAST is proven to be highly sensitive,
specific, reliable and accurate initial
bedside investigation in patients with blunt
abdominal trauma. It can be done bedside
with least disturbance to the patients as
there is no need for patient shifting and
hence is useful in acute care settings and is
particularly useful as a screening test and
to triage patients who urgently need to
undergo CT scan and/or emergency
laparotomy. Reliance on a single FAST
examination can be misleading and hence
serial examination with FAST should be
done to rule out the false positive and false
negative results. This study needs to be
further evaluated in a larger group of
patients to validate the results at this center
as well as other centers.
Acknowledgement: Authors acknowledge
the immense help received from the
scholars whose articles are cited and
included in references of this manuscript.
The authors are also grateful to
Authors/Editors/Publishers of all those
articles, journal and books from where the
literature of this article has been reviewed
and discussed.
Source of Funding: Nil.
Conflict of Interest: None.
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