ABDOMINAL TRAUMA

ABDOMINAL TRAUMA
Blunt abdominal trauma is regularly encountered in the emergency department
(ED). The lack of historical data and the presence of distracting injuries or altered
mental status, from head injury or intoxication, can make these injuries difficult to
diagnose and manage. Victims of blunt trauma often have both abdominal and
extra-abdominal injuries, further complicating care.
The initial evaluation and management of patients with blunt abdominal trauma
are reviewed here. Discussions of penetrating abdominal trauma, the general
management of the acutely injured adult, and ultrasound evaluation in patients
with abdominal or thoracic trauma are found separately. (See "Initial evaluation
and management of abdominal stab wounds in adults" and "Initial evaluation and
management of abdominal gunshot wounds in adults"and "Initial management of
trauma in adults" and "Emergency ultrasound in adults with abdominal and
thoracic trauma".)
EPIDEMIOLOGY
Blunt abdominal trauma (BAT) accounts for the majority (80 percent) of abdominal
injuries seen in the Emergency Department [1], and is responsible for substantial
morbidity and mortality. The majority of BAT cases (75 percent) are related to
motor vehicle collision (MVC) or auto versus pedestrian accidents [2]. Blows to the
abdomen and falls are responsible for 15 and 6 to 9 percent, respectively [3]. Occult
BAT may occur with child abuse and domestic violence. (See "Physical child abuse:
Diagnostic evaluation and management".)
The prevalence of intra-abdominal injury among patients presenting to the
emergency department with BAT is approximately 13 percent [1]. The spleen and
liver are the most commonly injured solid organs in BAT [2,3]. Injuries to the
pancreas, bowel and mesentery, bladder, and diaphragm, as well as retroperitoneal
structures (kidneys, abdominal aorta), are less common but must also be
considered.
MECHANISM OF INJURY
Several pathophysiologic mechanisms can occur in patients with blunt abdominal
trauma [3,4]. A sudden and pronounced rise in intra-abdominal pressure created by
outward forces can rupture a hollow viscus. Passengers wearing a lap-belt without
a shoulder attachment can sustain injury from such a mechanism when the belt
forcefully compresses the abdomen.
Blunt forces exerted against the anterior abdominal wall can compress abdominal
viscera against the posterior thoracic cage or vertebral column, crushing tissue.
Solid organs (eg, spleen and liver) are particularly susceptible to laceration or
fracture by this mechanism. Older adults and alcoholic patients generally have lax
abdominal walls and are more likely to sustain such injuries. Delayed splenic
rupture can occur. Retroperitoneal structures, such as the duodenum or pancreas,
may be injured.
Shearing forces created by sudden deceleration can cause lacerations of both solid
and hollow organs at their points of attachment to the peritoneum. They may also
create tears at vascular pedicles or cause stretch injuries to the intima and media of
arteries, resulting in infarction of the susceptible organ. The kidney is most
susceptible to such stretch injury.
Fractured ribs or pelvic bones can lacerate intra-abdominal tissue.
HISTORY
Historical features traditionally associated with significant injury following blunt
trauma include those listed here, although the diagnostic utility of historical
features in blunt abdominal trauma (BAT) remains unclear:
●Fatality at the scene
●Vehicle type and velocity
●Whether the vehicle rolled over (roll-over mechanism is associated with
increased risk of serious injury)
●Patient's location within the vehicle (seat position on the side of impact is
associated with serious thoracoabdominal injury in side impact crashes) [5]
●Extent of intrusion into the passenger compartment (intrusion into
passenger space >6 inches [15 cm] is associated with increased risk of injury)
[6]
●Extent of damage to the vehicle
●Steering
wheel deformity (steering wheel deformity is associated with
increased risk of thoracoabdominal injury for front seat passengers) [7]
●Whether seatbelts were used and, if so, what type (eg, lap belt only increases
the risk of Chance fracture (image 1))
●Whether front or side air bags were deployed
Unrestrained victims are at higher risk of injury than those who are restrained [8].
Paradoxically, steering wheel deformity may be an independent predictor of
abdominal injury in front seat passengers, but not drivers [7,9].
The magnitude of injury to pedestrians varies with the speed and size of the
striking vehicle. Pedestrians often sustain a triad of injuries to the leg, torso, and
cranium; injury to any of these sites should prompt careful evaluation of the other
two [10,11].
Historical data are important, but mechanism alone cannot reliably predict the
need for emergent laparotomy and must be coupled with other information, such
as prehospital vital signs, fluctuations in vital signs, examination findings,
diagnostic test results (eg, ultrasound), and underlying medical conditions [9].
EVALUATION AND MANAGEMENT
Initial management of the trauma patient is directed at rapid stabilization and
identification of life threatening injuries, as described in Advanced Trauma Life
Support (ATLS) protocols. Primary assessment (ie, the primary survey) follows the
ABCDE pattern: Airway, Breathing, Circulation, Disability (neurologic status), and
Exposure. Details related to the initial management of blunt abdominal trauma
(BAT) are discussed below; basic algorithm for management of BAT is provided
(algorithm 1). The initial evaluation of the trauma patient is reviewed in detail
separately. (See "Initial management of trauma in adults" and "Trauma
management: Approach to the unstable child".)
Initial assessment and examination — BAT can manifest a wide range of
presentations, from a patient with normal vital signs and minor complaints to an
obtunded patient in severe shock. The initial presentation may be benign despite
the presence of significant intra-abdominal injury. If evidence of extra-abdominal
injury exists, the emergency clinician must assess for intra-abdominal injury, even
in hemodynamically stable patients without abdominal complaints. In the
hemodynamically unstable patient, concurrent resuscitation and assessment are
paramount. It is crucial that evaluating clinicians recognize that the absence of
abdominal pain or tenderness on physical examination does NOT rule out the
presence of significant intra-abdominal injury.
According to a systematic review of 12 studies involving 10,757 patients, the
physical examination findings most strongly associated with intra-abdominal injury
following BAT are the following [1]:
●Seatbelt sign (likelihood ratio (LR) range 5.6 to 9.9) (picture 1) (subsequent
observational evidence supports the association of the seatbelt sign with
intra-abdominal injury [12])
●Rebound tenderness (uncommon but substantially increases risk when
present; LR 6.5, 95% CI 1.8-24)
●Hypotension (defined as systolic blood pressure (SBP) <90 mmHg; LR 5.2,
95% CI 3.5-7.5)
●Abdominal distension (LR 3.8, 95% CI 1.9-7.6)
●Abdominal guarding (LR 3.7, 95% CI 2.3-5.9)
●Concomitant femur fracture (LR 2.9, 95% CI 2.1-4.1) (femur fractures are
significant distracting injuries, and may indicate BAT among pedestrians stuck
by automobiles).
Of note, although abdominal pain and abdominal tenderness did increase the
likelihood of intra-abdominal injury among patients with BAT, the negative
likelihood ratio for each is low, and thus as noted above the absence of either
finding cannot be used to exclude injury. In addition, while the absence of the
above signs and symptoms decreases the likelihood of intra-abdominal injury (LR
0.52-0.96), their absence, alone or in combination, is not sufficient to rule-out intraabdominal injury. This systematic review included only studies with a clear
reference standard (eg, computed tomography [CT], diagnostic peritoneal lavage
[DPL], laparotomy) and all were performed at major academic trauma centers.
The location of an abdominal seatbelt sign is worth noting. An observational study
of emergency department (ED) patients with BAT after motor vehicle collisions
found that an abdominal seatbelt sign above the anterior-superior iliac spine (ASIS)
was associated with a fourfold increase in the risk of intra-abdominal or lumbar
injury [13]. Patients with seatbelt signs at or below the level of the ASIS had a rate
of injury similar to those without a seatbelt sign.
The presence of an altered sensorium or painful extra-abdominal injuries in victims
of blunt trauma should raise suspicion for abdominal injury, even in the absence of
suggestive symptoms or signs [1]. Up to 10 percent of patients with an apparently
isolated head injury may have concomitant intra-abdominal injuries [14], and,
according to one prospective observational study, seven percent of blunt trauma
patients with distracting extra-abdominal injuries have an abdominal injury despite
the absence of abdominal pain or tenderness [15].
In alert patients free of distracting injuries, the most reliable symptoms and signs of
BAT are abdominal pain, abdominal tenderness, and peritoneal findings,
particularly when risk factors for abdominal injury are present. Patients with visceral
injury present with local or general abdominal tenderness in up to 90 percent of
cases. The presence of pain at the left costal margin has been associated with
splenic injury in up to 5.6 percent of patients [16]. However, such signs are not
specific, and may also be found with isolated thoracoabdominal wall contusions or
lower rib fractures. More importantly, the absence of abdominal tenderness in an
awake, hemodynamically stable patient without a distracting extra-abdominal
injury indicates that intra-abdominal injury is highly unlikely. Nevertheless, intraabdominal injury can occur in conscious patients without tenderness [1,17-20].
The results of a large prospective observational study suggest that use of a careful,
structured physical examination in alert patients following blunt trauma reduces
the risk of missing a clinically significant intra-abdominal injury due to an extraabdominal distracting injury [21]. However, we believe it is important to remain
cautious in such circumstances and to maintain a low threshold for obtaining
diagnostic imaging.
Intra-abdominal injury may cause referred pain. As examples, splenic injury
associated with blood adjacent to the left hemidiaphragm may cause referred pain
at the left shoulder (Kehr's sign) while a similar phenomenon associated with liver
injury may cause referred pain at the right shoulder.
The digital rectal examination (DRE) has poor sensitivity for bowel injuries and
should not be performed routinely. The examination is warranted in some cases,
including when urethral or penetrating rectal injury are suspected. The DRE is
discussed in greater detail separately. (See "Initial management of trauma in
adults", section on 'Rectum and genitourinary'.)
Hypotension following BAT most often results from hemorrhage from a solid
abdominal organ or intra-abdominal vascular injury. Although clinicians must look
for extra-abdominal sources of bleeding (eg, scalp laceration, thoracic injury, or
long bone fracture), an extra-abdominal source of hemorrhage never obviates the
need to evaluate the peritoneal cavity. Head injury alone cannot explain shock
except in rare cases of profound intracranial trauma or in infants who may have
significant intracranial bleeding or cephalohematoma [22].
Abdominal wall ecchymosis, abdominal distention, and decreased bowel sounds
may herald intra-abdominal injury. The proverbial "seatbelt sign" (ecchymosis over
the abdominal wall in the distribution of the seatbelt) indicates intra-abdominal
injury in up to one-third of patients [1,23,24]. Abdominal distention, resulting from
peritoneal irritation producing an ileus, pneumoperitoneum, or gastric dilation, can
indicate significant injury. Clinicians should never wait for such signs of
hemoperitoneum, as the blood volume required to create distention exceeds that
of the entire vasculature. Decreased bowel sounds can result from chemical
peritonitis caused by hemorrhage or from a ruptured hollow viscus. Bowel sounds
heard in the chest suggest the presence of diaphragmatic rupture.
Laboratory tests — Routine laboratory tests are generally of limited value in the
management of the acutely traumatized patient, but may be helpful in identifying
patients at low risk for significant injury when used in combination with other
clinical findings. Clinicians should consider laboratory tests adjuncts to diagnosis
and not substitutes for clinical assessment in BAT. We do suggest obtaining a
microscopic urinalysis in victims of BAT when the presence of intra-abdominal
injury is unclear, as microscopic hematuria (>25 red blood cells [RBCs] per high
power field) increases the likelihood of significant intra-abdominal injury (see the
discussion of Urinalysis immediately below). The appropriate use of laboratory tests
in the initial evaluation of trauma is reviewed separately; the use of tests of
particular relevance to blunt abdominal trauma is discussed here. (See "Initial
management of trauma in adults", section on 'Laboratory tests'.)
●Hematocrit – A hematocrit below 30 percent increases the likelihood of
intra-abdominal injury in the setting of BAT (LR 3.3, 95% CI 2.4-4.5) [1,25].
Anemia must be interpreted in light of the clinical context, including the
extent of hemorrhage, time since the injury, and the amount of exogenous
fluid administration. The clinician should not be reassured by a normal
hematocrit in the acute trauma patient with hypotension; internal
hemorrhage should be assumed in such cases.
●Leukocyte count – In BAT, the white blood cell (WBC) count is nonspecific
and of little value [17,26,27]. The positive and negative predictive value of,
respectively, an elevated or normal WBC is poor. Catecholamine release due
to trauma can cause demargination and may elevate the WBC to 12,000 to
20,000/mm3 with a moderate left shift. Solid or hollow viscus injury can cause
comparable elevations [28].
●Pancreatic enzymes – Normal serum amylase and lipase concentrations
cannot exclude significant pancreatic injury [29]. And while elevated
concentrations raise the possibility of pancreatic injury, they may be caused
by nonpancreatic abdominal injury as well, and alone are nondiagnostic. If
pancreatic injury is suspected, confirmatory studies (eg, CT scan) are needed.
●Liver
function tests – Hepatic injury is associated with elevations in liver
transaminase concentrations (LR 2.5-5.2), and there is some evidence that
higher elevations increase the odds for injury, and the likelihood of severe
injury [1,27,30,31]. In a retrospective study of 676 adult patients who
underwent CT imaging within three hours of BAT, of whom 64 were
diagnosed with hepatic injury, a threshold of 109 U/L for AST and 97 U/L for
ALT showed 84 percent sensitivity and 98 percent negative predictive value
for the detection of hepatic injury [31]. However, patients with comorbidities
such as alcohol-induced liver disease or hepatitis may have elevated
transaminase concentrations at baseline.
●Urinalysis – Gross hematuria suggests serious renal injury and mandates
further investigation (see "Blunt genitourinary trauma: Initial evaluation and
management").
According to a meta-analysis of 12 studies, microscopic hematuria (>25 RBCs
per high power field), increases the likelihood of significant intra-abdominal
injury (LR 3.7-4.1) [1]. Therefore, when the presence of intra-abdominal injury
is unclear, it is prudent to perform microscopic urinalysis in victims of BAT
[32]. In a prospective observational study of 196 patients with BAT, the
combination of abdominal tenderness and microscopic hematuria was 64
percent sensitive and 94 percent specific in predicting intra-abdominal injury,
as determined by abdominal CT [33].
Point-of-care (POC) urinalysis (ie, urine dipstick) is a reasonable screening
examination in patients felt to be at low risk of BAT based on their clinical
presentation. If the test is positive, it can be followed up with microscopic
urinalysis or with CT imaging. Patients with a negative formal urinalysis are at
low risk of intraabdominal injury [34]. However, POC urinalysis should be
interpreted cautiously. In one retrospective study, the sensitivity of POC
urinalysis for intra-abdominal injury (identified by CT) was 72 percent in
patients with demonstrated BAT [35]. Clinicians should not allow a negative
test to dissuade them from further investigation in the presence of
concerning clinical signs (eg, abdominal tenderness).
●Base
deficit and lactate – A prospective, nonrandomized study of BAT
patients in two trauma centers found that a base deficit less than -6 was
associated with intra-abdominal hemorrhage and the need for laparotomy
and blood transfusion [36]. Clinicians should be aware of these results in the
event that such laboratory studies are performed, but the studies are not
required in patients with BAT.
●Additional
tests – It is reasonable to obtain a pregnancy test in women of
childbearing age with BAT. Clinical circumstance should determine the need
for further testing (eg, patient taking anticoagulant or antiplatelet
medications would likely prompt coagulation studies).
Imaging studies
Warnings — Imaging studies can provide important information to guide the care
of patients with blunt abdominal trauma (BAT) but are not without risk. The
traumatized patient must be stabilized before most radiographic studies can be
performed, and clinicians must pay careful attention to potential spinal cord
injuries and guard against further injury during positioning and transfer for
radiographic studies.
The uncooperative patient may interfere with the performance of radiologic
studies, limiting study quality, while putting themselves at risk for cervical spine
injury. Clinicians must evaluate the patient to determine the likely cause for their
uncooperativeness (eg, hypoxia, traumatic brain injury). Combative patients may
require sedation in order to obtain needed studies.
A clinician familiar with trauma care must accompany any patient who has the
potential to deteriorate precipitously. Although many trauma centers have CT
scanners adjacent to the emergency department, this is not always the case.
Leaving a patient unattended in the radiology department for even a brief period
can have disastrous consequences. In addition to patients with likely intraabdominal injury, radiographic studies of the abdomen are indicated in stable
patients when the physical examination and laboratory tests are inconclusive and
the information will guide therapy.
Plain radiographs — Trauma series radiographs, typically including portable
radiographs of the chest and pelvis, are often obtained in an unstable patient with
BAT [37]. Patients who have sustained blunt trauma to the torso are at risk for
intrathoracic as well as intra-abdominal injury, and plain radiographs of the chest
may be helpful depending upon the clinical circumstances. The indications and use
of chest imaging in patients with blunt thoracic trauma is reviewed separately.
(See "Initial evaluation and management of blunt thoracic trauma in adults",
section on 'Chest computed tomography' and "Initial evaluation and management
of blunt thoracic trauma in adults".)
Findings on chest radiograph that suggest intra-abdominal injury include:
●Lower
rib fractures (image 2)
●Diaphragmatic
hernia (image 3)
●Free air under the diaphragm (image 4)
A portable radiograph of the pelvis can demonstrate unstable pelvic fractures
(image 5) and hip dislocation. Intra-abdominal injury should be suspected in any
patient with a fracture involving the pelvic ring. In these patients, plain films should
be followed with CT imaging of the abdomen and pelvis. (See "Pelvic trauma: Initial
evaluation and management".)
Computed tomography — Owing to its speed and accuracy, multidetector helical
computed tomography (MDCT) has become the primary method for identifying
intra-abdominal injury [1,38]. The sensitivity and specificity of MDCT for identifying
significant intra-abdominal pathology are high (97 to 98 percent and 97 to 99
percent, respectively)[1,39,40]. In patients with suspected BAT who have a negative
abdominal-pelvis MDCT, the rate of missed injury has been reported to be
extremely low (<0.06 percent) with a negative LR of 0.034 (0.017-0.068) [40].
The increased use and accuracy of CT have contributed to a shift to nonoperative
management and reduced morbidity for many patients with BAT. Evidence
supporting the use of MDCT in hemodynamically unstable trauma patients is
limited [41], and the study is largely restricted to stable patients at low risk for
decompensating while in the CT scanner [37].
Given the significant radiation exposure and expense associated with MDCT,
clinicians should carefully select the BAT patients most likely to benefit from MDCT
and avoid unnecessary studies. Observational studies report a low rate of positive
CT scans among BAT patients [42], suggesting that many studies are unnecessary.
In a prospective study involving nearly 5000 patients with blunt torso trauma, the
number of patients identified with intra-abdominal injuries requiring surgery was
below 5 percent [43]. A retrospective study of 147 blunt trauma patients presenting
with low-risk mechanisms of injury (fall from standing, seated position, or from
bed) in combination with an unremarkable physical examination (normal mental
status, no chest or abdominal pain, no shortness of breath, and no tenderness on
examination) reported a very low likelihood of positive findings on CT of the chest
or abdomen [44]. The clinical features most strongly associated with intraabdominal injury, and which warrant investigation with CT, as well as those unlikely
to be associated with clinically significant injury, are described above. (See 'Initial
assessment and examination' above.)
CT scanning's benefits include:
●Noninvasive
●Better
defines organ injury and potential for nonoperative management of
splenic and liver injuries [45,46]
●Detects not only the presence but the source and amount of
hemoperitoneum
●Active bleeding often detectable
●Retroperitoneum and vertebral column can be assessed in conjunction with
intra-abdominal structures
●Additional imaging can be performed when needed (eg, head, cervical spine,
chest, pelvis)
●Patients with negative imaging are at low risk for clinically significant injuries
CT scanning's disadvantages include:
●Despite
improvements in image resolution, MDCT remains an insensitive test
for mesenteric, bowel, and pancreatic duct injuries [47-53]
●IV contrast is needed; oral contrast is not needed as it rarely adds to
diagnostic accuracy and may delay imaging [54,55]
●Relatively high cost
●Can be unobtainable or delay critical care for unstable patients [56]
●Radiation exposure (see "Radiation-related risks of imaging")
CT protocols for trauma — Trauma CT protocols are designed to maximize the
detection of injury. During a multiphasic CT study for abdominal trauma, images
are obtained rapidly, and typically, a single bolus of intravenous (IV) contrast is
given, allowing identification and characterization of injuries to the vasculature,
solid organs, and genitourinary system. Occasionally, a split bolus technique
involving two or three boluses of contrast given sequentially prior to imaging is
used to improve the injury detection rate [57].
CT arteriogram of the abdomen and pelvis is performed to look for active arterial
bleeding or vascular injury, such as occlusion or pseudoaneurysm. CTA of the
abdomen has been shown to detect more splenic vascular and pelvic injuries
[58,59].
CT urography requires delayed imaging, at least five minutes after contrast
injection, of the abdomen and pelvis to capture the excretory phase and improves
visualization of both the upper and lower urinary tracts [37].
Ultrasound — Bedside ultrasound (US) is an integral component of trauma
management used primarily to detect free intraperitoneal blood after blunt trauma.
The trauma US examination focuses on dependent intraperitoneal sites where
blood is most likely to accumulate: the hepatorenal space (Morison's pouch), the
splenorenal recess, and the inferior portion of the peritoneal cavity (including
pouch of Douglas). These studies, when combined with evaluation of the
pericardium (which must not be neglected in the setting of BAT), are referred to as
the FAST exam (Focused Assessment with Sonography for Trauma). The use of the
FAST exam in the management of patients with abdominal trauma, and studies
pertaining to such use, are discussed in detail separately. (See "Emergency
ultrasound in adults with abdominal and thoracic trauma".)
Limitations of ultrasound in the setting of BAT include:
●Injury
to solid parenchyma, the retroperitoneum, or the diaphragm is not
well seen.
●Uncooperative patients, obesity, bowel gas, and subcutaneous air interfere
with image quality.
●Low sensitivity in comparison to CT, particularly in the absence of
hemoperitoneum and for non-hypotensive patients. Cannot reliably exclude
clinically significant injuries [60,61].
●Does not appear to improve diagnostic yield following negative CT [62].
●Blood cannot be distinguished from ascites or urine.
●Subcapsular injuries cannot be detected.
●Insensitive for detecting bowel injury.
Angiography — Unstable patients with BAT and a pelvic fracture may benefit from
angiography, although the order and timing of angiographic embolization versus
laparotomy with preperitoneal packing remains a matter of debate. Angiography
can be used to manage hemorrhage from solid viscera (eg, spleen) and to embolize
bleeding pelvic vessels, but it is time consuming and requires coordination with
interventional radiology services, which may not be immediately available at a
given institution. (See "Severe pelvic fracture in the adult trauma patient", section
on 'Arteriography and angioembolization' and "Management of splenic injury in
the adult trauma patient", section on 'Splenic embolization' and "Management of
hepatic trauma in adults", section on 'Hepatic embolization'.)
Diagnostic peritoneal lavage — Diagnostic peritoneal lavage (DPL), formerly a
mainstay in the diagnosis and management of blunt abdominal trauma (BAT), has
been almost entirely replaced by ultrasound and multidetector helical CT (MDCT)
scanning. As the role of nonoperative management and selective embolization for
abdominal injuries has expanded, the importance of DPL in modern trauma care
has dramatically declined, particularly with BAT. The procedure may be necessary in
some cases, such as the hypotensive BAT patient with equivocal results on FAST
examination and multiple potential sources of blood loss, and in resource poor
settings where advanced imaging is unavailable. The role and performance of DPL
is discussed separately. (See "Initial evaluation and management of abdominal
stab wounds in adults", section on 'Diagnostic peritoneal tap and diagnostic
peritoneal lavage'.)
MANAGEMENT BY CLINICAL SCENARIO
Overview — Patients with blunt abdominal trauma (BAT) require expeditious
evaluation to determine the need for operative care. After providing initial
resuscitation and management based upon protocols from Advanced Trauma Life
Support (ATLS), emergency clinicians determine the need for laparotomy using
some combination of physical examination, ultrasound (US), computed
tomography (CT), and diagnostic peritoneal tap and/or lavage (DPT/DPL). In some
instances, such as patients with a severe pelvic fracture, angiography may be
necessary to control hemorrhage and stabilize the patient [63]. A basic algorithm
for the management of BAT is provided (algorithm 1). (See "Initial management of
trauma in adults", section on 'Primary evaluation and management'.)
Hemodynamically unstable patient — In the unstable patient with BAT,
management hinges on determining the presence or absence of intraperitoneal
hemorrhage. Immediate trauma surgery consultation is required if the surgeon is
not already at the bedside. A FAST exam (Focused Assessment with Sonography for
Trauma) should be performed on all hemodynamically unstable BAT patients as
part of their initial evaluation, assuming US is available. (See "Emergency
ultrasound in adults with abdominal and thoracic trauma".)
Unstable patients with a positive FAST exam typically go directly to the operating
room for emergent laparotomy. If the FAST exam is limited (eg, poor image quality)
and the patient is unstable, the surgeon must decide whether suspicion for intraabdominal injury is sufficiently high to warrant emergent laparotomy. Diagnostic
peritoneal lavage (DPL) has largely been replaced by the combination of US and CT,
owing to their speed, sensitivity, and noninvasiveness, but DPL or DPT may be
performed in the hemodynamically unstable BAT patient to identify signs of intraabdominal injury. We suggest CT to evaluate for intra-abdominal (as well as extraabdominal injuries) in patients who can be resuscitated adequately to undergo
scanning. If this cannot be accomplished, an adequate FAST exam cannot be done,
and clinicians choose to perform a DPT or DPL, most experts agree that the
aspiration of 10 mL of gross blood confirms the presence of a significant intraabdominal wound that warrants emergent laparotomy. (See "Initial evaluation and
management of abdominal stab wounds in adults", section on 'Diagnostic
peritoneal tap and diagnostic peritoneal lavage'.)
Resuscitative endovascular balloon occlusion of the aorta (REBOA) is used as a
therapeutic adjunct in the management of some unstable BAT patients. While
promising in that it can be performed at the bedside as a bridging therapy to
control noncompressible hemorrhage, REBOA is associated with higher mortality
and higher rates of acute kidney injury and lower extremity amputation in some
studies [64]. Further research is needed to determine which patients benefit from
this approach. (See "Endovascular methods for aortic control in trauma", section
on 'Potential indications'.)
In unstable patients with no evidence of intra-abdominal injury (negative FAST
exam, negative abdominal CT), clinicians must search for alternative sites of
hemorrhage or other non-hemorrhagic causes of shock. (See "Initial management
of NON-hemorrhagic shock in adult trauma".)
When managing an unstable trauma patient with a major pelvic fracture, clinicians
should note that US cannot distinguish between hemoperitoneum and
uroperitoneum. If the patient can be stabilized, further evaluation of the intraabdominal cavity with CT may be warranted. (See 'Pelvic fracture' below.)
Hemodynamically stable patient — Management of the hemodynamically stable
patient with BAT depends upon the clinician’s assessment of their risk for
significant intra-abdominal injury. The approach selected will vary depending upon
many factors, including patient age and comorbidities, mechanism of injury,
examination findings, and hospital resources. In general, we follow the approach
outlined immediately below, but recognize that any basic plan must be adapted to
fit the clinical circumstances.
●For patients deemed low-risk by clinical presentation, vital signs, and
laboratory tests (no anemia, elevated transaminase concentrations [if
obtained], or hematuria), a nine-hour period of observation that includes
serial vital signs and abdominal examinations is generally sufficient to identify
patients with occult intra-abdominal injury [65]. Ultrasound may be
incorporated into the serial assessments, although the extent to which it adds
to the diagnosis of intra-abdominal injury in low-risk patients remains
unclear. (See "Emergency ultrasound in adults with abdominal and thoracic
trauma".)
For patients at low risk for intra-abdominal injury, including those with a
negative abdominal CT scan, an observation period shorter than nine hours
may be reasonable in many cases, but there is as yet no high quality evidence
to support this approach. Such decisions must be made by the clinician on a
case-by-case basis using their clinical judgement. Before discharge, all
patients should be instructed to return to the emergency department (ED)
immediately for any concerning symptom, such as new or worsening
abdominal pain, and informed about the limitations of the CT scan for
diagnosing injury.
●For
patients without a high-risk clinical presentation but with laboratory
findings associated with intra-abdominal injury (hematocrit <30 percent, AST
or ALT >130 units/L, microscopic hematuria >25 red blood cells [RBCs] per
high power field), CT is the preferred modality for identifying such injuries. If
a CT is obtained and is negative, a nine-hour period of observation that
includes serial vital signs and abdominal examinations is generally sufficient
to identify patients with injuries that CT may have missed (eg, bowel injury).
For patients with persistent pain or tenderness (eg, persistent tenderness on
examinations performed 30 minutes apart) despite a negative CT, admission
for observation and surgical consultation is warranted.
●For
patients who are hemodynamically stable but whose presentation or
examination includes one or more findings associated with an increased risk
for intra-abdominal injury, an abdominal CT is performed. Patients with
negative CT imaging are at low risk for clinically significant intraabdominal
injuries, and most can be discharged home. Patients with persistent pain or
tenderness despite a negative CT should be admitted for observation, and
surgical consultation is warranted in these cases. High risk examination
findings are reviewed above and include the following: hypotension,
peritoneal signs (eg, abdominal guarding, rebound tenderness), abdominal
distension, and seatbelt sign. (See 'Initial assessment and
examination' above.)
●Whether
routine whole-body imaging with CT leads to better outcomes
among high-risk patients than selective imaging (ie, directed by clinical
suspicion) is controversial. This issue is reviewed separately. (See "Initial
management of trauma in adults", section on 'Computed tomography,
including total body CT'.)
Evaluation of the hemodynamically stable patient with BAT incorporates diagnostic
imaging studies, serial physical examinations, or both. Each method of patient
evaluation has limitations, and there are a number of reasonable approaches.
In the stable BAT patient, ultrasound may miss clinically relevant injuries, and we do
not advocate its use as a single definitive screening test in this patient population
[60,66]. The accuracy of ultrasound evaluation for detecting intra-abdominal injury
improves with serial examinations [67]. If an ultrasound examination is performed
and detects intraperitoneal blood, the patient should undergo abdominal CT scan
to delineate intraperitoneal injuries and quantify the hemoperitoneum. The
surgeon may choose either admission with nonoperative management or
immediate laparotomy depending upon the injuries detected and the patient's
clinical status.
We recommend that CT imaging be performed for any patient with one or more
high risk clinical findings, and in any patient with persistent abdominal pain or
tenderness on serial examinations (eg, persistent tenderness on exams performed
30 minutes apart). Abdominal CT may also be needed for patients who are
hemodynamically stable, but whose sensorium or reliability is altered by closed
head injury, drug or alcohol intoxication, or significant distracting injury.
The decision of whether to perform an abdominal CT early on or follow the patient
with serial physical examinations is made largely on clinical grounds. Serial physical
examination is reserved for the patient whose examination is deemed reliable (ie,
patients with a normal sensorium and no severe distracting injury). Given increasing
concerns regarding the adverse effects of the radiation from CT scans, many
trauma centers are making increased use of serial examinations and standardized
clinical assessments [43]. (See "Radiation-related risks of imaging".)
Serial abdominal examinations and serial ultrasound evaluations may be useful in
select hemodynamically stable BAT patients. As an example, a non-intoxicated
patient who is not elderly and manifests no gross neurologic abnormalities (normal
Glasgow Coma Scale [GCS]) or high-risk clinical features would be a suitable
candidate for observation with serial assessments.
Clinical assessment of an alert, non-intoxicated BAT patient that depends solely on
abdominal examination findings is not infallible [15,68]. One prospective
observational study of such patients, with no signs of external trauma and a normal
abdominal examination, found clinically significant abnormalities in 7.1 percent of
patients using CT findings as the gold standard [18]. A subsequent, prospective
study of patients presenting to a major urban trauma center found intra-abdominal
injuries on CT imaging in 13.6 percent of asymptomatic patients with a GCS of 15
[68]. The use and limitations of the abdominal examination in BAT are discussed
further above. (See 'Initial assessment and examination' above.)
The accuracy of serial examinations continues to be debated, as has the period of
observation necessary to identify significant intra-abdominal injuries. One
retrospective cohort study performed at an academic trauma center found that all
patients with serious intra-abdominal injuries in whom initial imaging was deferred
were identified within nine hours using serial examinations [65]. In this study, all 80
patients whose injuries required intervention (surgery or embolization) manifested
clinical symptoms or signs within an average of 74 minutes of arrival. Another
retrospective study of trauma patients observed in the emergency department for
eight hours, whose vital signs, hematocrit measurements, and examinations
remained stable and within normal limits, reported that only 0.4 percent sustained
an intra-abdominal injury [69]. While a strategy of serial observation requires
careful selection of patients in whom reliable examinations can be performed, these
studies suggest that this approach is safe and feasible in patients deemed to be at
low-risk by virtue of their initial vital signs, diagnostic studies, and signs and
symptoms.
Clinical indications for laparotomy — Nonoperative management (NOM) has
become standard for all but the most severely injured BAT patients. Immediate
laparotomy after injury from a blunt mechanism is rarely based solely on clinical
parameters. Potential indications include the following:
●Unexplained signs of blood loss or hypotension in a patient who cannot be
stabilized and in whom intra-abdominal injury is strongly suspected
●Clear and persistent signs of peritoneal irritation
●Radiologic evidence of pneumoperitoneum consistent with a viscus rupture
●Evidence of a diaphragmatic rupture
●Persistent, significant gastrointestinal bleeding seen in nasogastric drainage
or vomitus
Establishing the need for urgent celiotomy on clinical grounds is particularly
problematic in the patient with multiple blunt injuries. Numerous extra-abdominal
sources of hemorrhage may exist. Head injury or intoxication often coexist with
abdominal trauma, further impairing the reliability of examination findings.
Laparotomy may imperil the patient when more crucial diagnostic and therapeutic
steps are delayed. Where confusion exists, we strongly prefer that corroborative
diagnostic tests be performed.
Special considerations
Pelvic fracture — In patients with a pelvic fracture and evidence of ongoing
bleeding (ie, hemodynamic instability), the presence or absence of
hemoperitoneum determines management. Detection of free fluid by US or gross
intraperitoneal blood by DPT accurately predicts active intraperitoneal hemorrhage
and the need for emergent laparotomy [66,70,71]. The absence of intraperitoneal
blood as determined by US or DPT suggests major retroperitoneal hemorrhage,
assuming there is no extra-abdominal source of bleeding. (See "Pelvic trauma:
Initial evaluation and management".)
There is an important exception when intraperitoneal fluid detected by US does not
represent hemorrhage. Major pelvic fracture can be associated with intraperitoneal
bladder rupture. In such cases, the free intraperitoneal fluid found on US is
uroperitoneum rather than hemoperitoneum. Intraperitoneal bladder rupture
requires surgical repair but not emergently.
Patients with a major pelvic fracture are at risk for life-threatening retroperitoneal
hemorrhage. As such, some clinicians perform a DPT in the hemodynamically
unstable patient with major pelvic fracture and a positive US in order to distinguish
hemoperitoneum, which requires exigent laparotomy, from uroperitoneum, and to
help decide whether to perform diagnostic and potentially therapeutic pelvic
angiography as the next step. Urgent laparotomy for bladder repair is performed
thereafter.
After carefully examining the perineum and rectum, clinicians should place a pelvic
stabilization device (prefabricated pelvic binder, or a bed sheet tied tightly around
the pelvis) on any potentially unstable pelvic fracture that may be contributing to
hemodynamic instability (image 6). External fixation devices are generally placed in
the operating room because placement can be difficult and time-consuming and
may interfere with other components of resuscitation. Following stabilization with
pelvic angiography and embolization, abdominal CT may be used to look further
for intraperitoneal injury.
Multiple system injury — Clinicians cannot approach the management of the
abdominal trauma patient with more than one life-threatening injury dogmatically.
At major trauma centers, clinicians regularly confront the problem of
intraperitoneal hemorrhage in a patient with apparent closed head injury and
suspected blunt aortic disruption. Traditionally, laparotomy to control
intraperitoneal hemorrhage takes precedence over operative management of head
or chest trauma. However, these situations are complex, and decision-making is
influenced by numerous dynamic variables. In general, a patient with known
hemoperitoneum who cannot be stabilized must first undergo laparotomy for lifesaving hemostasis before other injuries are addressed.
Closed head injury — In patients presenting with BAT and concomitant closed
head injury, the necessity and timing of neurosurgical intervention is directed by
the patient’s neurologic examination (Glasgow Coma Scale [GCS], presence of
lateralizing neurologic signs), and CT imaging results. Immediate consultation with
a neurosurgeon and trauma surgeon is needed. (See "Management of acute
moderate and severe traumatic brain injury".)
Patient transfer — A trauma patient at a small rural hospital may need a
laparotomy for hemorrhage control before being transferred to a trauma center for
definitive care [72]. Consultation with the trauma center should begin as soon as it
is apparent the patient has sustained injuries beyond the management capacity of
the hospital. (See "Initial management of trauma in adults", section on 'Patient
transfer'.)
Pregnant patient — Trauma remains the most common non-obstetric cause of
maternal death during pregnancy, and has been reported to complicate 6 to 7
percent of pregnancies. Initial evaluation and management of the pregnant trauma
patient is directed at determining the extent of maternal injury and directing
resuscitation towards the mother’s survival. Management of the pregnant trauma
patient is discussed separately. (See "Initial evaluation and management of major
trauma in pregnancy".)
Geriatric patient — Patterns of trauma in older adults are similar to those of adults
in general. However, the signs and symptoms of abdominal injury are often
attenuated in adults over 60 years, and therefore clinicians must maintain a high
index of suspicion for injuries in this population. (See "Geriatric trauma: Initial
evaluation and management".)
Obese patient — A retrospective trauma data bank study of over 100,000 BAT
patients found that class III obesity (body mass index [BMI] >40) was associated
with a lower rate of hollow viscus injury [73]. However, rates of abdominal solid
organ injury are comparable, and the eFAST and physical examinations are less
accurate in obese patients [74,75]. Given these findings, we maintain a low
threshold for obtaining CT imaging in obese patients with BAT.
SOCIETY GUIDELINE LINKS
Links to society and government-sponsored guidelines from selected countries and
regions around the world are provided separately. (See "Society guideline links:
General issues of trauma management in adults" and "Society guideline links:
Thoracic trauma" and "Society guideline links: Traumatic abdominal and non-
genitourinary retroperitoneal injury" and "Society guideline links: Thoracic and
lumbar spine injury in adults".)
SUMMARY AND RECOMMENDATIONS
●Emergency
clinicians managing blunt trauma must maintain a high degree
of clinical suspicion for intra-abdominal injury, particularly in patients with
suggestive mechanisms, signs of external trauma, or an altered sensorium
due to head injury or intoxication. Prompt resuscitation of the unstable
patient with blunt abdominal trauma (BAT) must coincide with the physical
examination and diagnostic testing aimed at determining the presence or
absence of hemoperitoneum and organ injury. A basic algorithm for the
management of blunt abdominal trauma is provided (algorithm 1).
●The spleen and liver are the most commonly injured solid organs in BAT.
Delayed splenic rupture can occur. Injuries to the pancreas, bowel, mesentery,
and diaphragm are less common but potentially dangerous and more difficult
to diagnose than solid organ injury. (See 'Epidemiology' above
and 'Mechanism of injury' above.)
●Noteworthy historical features include (see 'History' above):
•Fatality at the scene
•Vehicle type and velocity
•Whether the vehicle rolled over
•Patient's location within the vehicle
•Extent of intrusion into the passenger compartment
•Extent of damage to the vehicle; steering wheel deformity
•Whether seatbelts were used and what type (unrestrained victims are at
higher risk of injury); whether air bags deployed
Pedestrians often sustain a triad of injuries to the leg, torso, and cranium;
injury to any of these sites should prompt careful evaluation of the others.
(See 'History' above.)
The signs and symptoms of abdominal injury are often attenuated in adults
over 60 years, and clinicians must maintain a high index of suspicion for
injuries in this population. (See "Geriatric trauma: Initial evaluation and
management".)
●The clinical presentation of BAT varies widely, from minor complaints to
severe shock. The accuracy of the physical examination is limited. The initial
presentation may be benign despite the presence of major intra-abdominal
injury. Clinicians must look for intra-abdominal injury in all BAT patients with
an altered sensorium or extra-abdominal injuries. Examination findings
associated with intra-abdominal injury include:
•Seatbelt sign (picture 1), particularly if above the level of the anteriorsuperior iliac spine (ASIS)
•Rebound tenderness
•Hypotension
•Abdominal distension
•Abdominal guarding
•Severe distracting injury (eg, femur fracture)
Note that the absence of such findings does not exclude intra-abdominal
injury. If the patient is awake, alert, and hemodynamically stable, and is free
of abdominal pain or tenderness, intra-abdominal injury is unlikely.
(See 'Initial assessment and examination' above.)
●Notify the blood bank immediately and directly (ie, by telephone or in
person) of the need for transfusion should a BAT patient present with lifethreatening bleeding. Order a blood type and screen for any victim of
significant trauma. Routine hematology and chemistry laboratory tests are of
limited value in the management of the acutely traumatized patient, but may
be helpful in identifying patients at low risk for significant injury when used in
combination with other clinical findings. We suggest obtaining a microscopic
urinalysis in victims of BAT when the presence of intra-abdominal injury is
unclear, as microscopic hematuria (>25 red blood cells per high power field)
increases the likelihood of significant intra-abdominal injury. (See 'Laboratory
tests' above and "Initial management of NON-hemorrhagic shock in adult
trauma".)
●The traumatized patient must be stabilized before most abdominal
radiographic studies (eg, computed tomography [CT]) can be performed.
Clinicians must pay careful attention to potential spinal cord injuries and
guard against exacerbating such an injury during positioning. Patients must
be closely monitored while in the radiology area. The indications, advantages,
and disadvantages of the major modalities for imaging BAT are discussed
above. (See 'Imaging studies' above.)
●In the hemodynamically unstable patient with BAT, management hinges on
determining the presence or absence of intraperitoneal hemorrhage. The
emergency clinician performs a focused abdominal ultrasound (US) exam (or
in some instances a diagnostic peritoneal tap [DPT]), to make this
determination. Hemoperitoneum in the clinically unstable patient without
other apparent injury mandates laparotomy. For patients without
hemoperitoneum, clinicians search for extra-abdominal sites of hemorrhage.
(See 'Hemodynamically unstable patient' above and 'Clinical indications for
laparotomy' above and 'Diagnostic peritoneal lavage' above.)
●Management
of the hemodynamically stable patient with BAT depends upon
the clinician's assessment of their risk for significant injury. Patients at
increased risk based upon their presentation, examination findings, or
laboratory study results are evaluated by CT. Several approaches may be used
to assess low-risk patients and these are described in the text.
(See 'Hemodynamically stable patient' above.)
●Prompt consultation with a trauma center is paramount for those patients
with severe BAT presenting to a small emergency department without the
capacity to manage such injuries. (See "Initial management of trauma in
adults", section on 'Patient transfer'.)