Approach to Penetrating Abdominal Trauma 
Richard Davis and Caleb Van Essen 
 
OPEN MANUAL OF SURGERY IN RESOURCE-LIMITED SETTINGS 
www.vumc.org/global-surgical-atlas 
This work is licensed under a Creative Commons Attribution-ShareAlike 3.0 Unported License  
 
Background:  
Penetrating abdominal trauma can challenge 
even the seasoned clinician. Hemodynamically 
unstable patients cause stress to both the surgeon and 
the system, as they have ongoing bleeding and need 
immediate surgery. On the other hand, sometimes 
when patients present with penetrating abdominal 
injuries, it can be difficult to decide whether surgery 
is needed at all.  
The initial evaluation of these patients 
begins, as with all trauma patients, with a rapid 
primary and secondary survey, according to the 
principles of the Advanced Trauma Life Support 
(ATLS) course. Secondary survey is supplemented 
with carefully chosen adjuncts such as ultrasound 
and plain x-rays, bearing in mind that a poorly 
chosen study in our setting can cause a delay, 
potentially making the outcome worse.  
“Penetrating” trauma refers to stab wounds, 
shrapnel injuries, and gunshot wounds. The latter 
have much more tissue injury due to the velocity and 
cavitation effect of the bullet. Remember also that 
patients who present with apparent blunt trauma, as 
after a motor vehicle accident, can have penetrating 
trauma from vehicle fragments or stationary objects 
that they struck. Such wounds can be missed if all 
trauma patients are not thoroughly disrobed and 
examined.  
Most of the modern literature on decision-
making in penetrating trauma is written in resource-
rich environments. In this chapter we hope to address 
the limitations that we face, including:  
● Unavailability of advanced imaging technology 
● Difficulty in quickly mobilizing resources such 
as blood, anesthetists, and other operating room 
staff 
● More frequent delayed presentation 
● Lack of sufficient personnel and excessive 
fatigue or burnout in those who are present  
 
Anatomy:  
The 
abdominal 
cavity 
is 
lined 
with 
peritoneum, a thin lining that reacts in a unique way 
to irritation. When peritoneum is in contact with pus, 
succus, or blood, its irritation causes a reflex 
contraction of the adjacent muscles.  
 
Schematic cross-section of the lower abdomen: the peritoneum 
is represented by a Red line. When the peritoneum is irritated, 
the adjacent muscles contract in a reflexive manner, which can 
be detected by careful physical examination. Notice also that 
the ascending and descending colon are only partly 
intraperitoneal: injury to them from posteriorly, as a stab 
wound to the back, would not cause peritoneal irritation and 
thus would be harder to detect on physical examination. .  
 
In the anterior abdomen, reflex contraction of 
muscles is detectable as classic “Peritoneal Signs” 
The most obvious of these is rigidity of the muscles 
with 
severe 
tenderness, 
so 
called 
“Diffuse 
Peritonitis.” More subtle signs include a reflex 
tensing of the muscles when depressed steadily 
(“Involuntary Guarding”) or pain after sudden 
release of an examining finger that has slowly 
pressed into the abdomen (“Rebound Tenderness.”) 
These signs are sometimes present in one location 
but not another- when this finding is present, it is 
called “Localized Peritonitis.”  
In 
the 
posterior 
abdomen, 
localized 
peritonitis is more difficult to detect. It can be noted 
by pain on passive movement of the muscles that are 
adjacent to the posterior peritoneum, as through hip 
flexion (“Psoas Sign”) or hip rotation (“Obturator 
Sign.”)  
The abdominal cavity’s boundaries extend 
anteriorly from the inguinal ligaments and pubic 
symphysis to the nipples, and posteriorly from the 
upper buttocks to the inferior tips of the scapulae. In 
other words, the abdominal cavity can extend well up 
into the rib cage. The region of lower chest / upper 
abdomen is called the “Junctional Zone,” to denote 
the fact that penetrating objects in this area can cause 
Approach to Penetrating Abdominal Trauma 
Richard Davis and Caleb Van Essen 
 
OPEN MANUAL OF SURGERY IN RESOURCE-LIMITED SETTINGS 
www.vumc.org/global-surgical-atlas 
This work is licensed under a Creative Commons Attribution-ShareAlike 3.0 Unported License  
 
injuries in the chest, abdomen, mediastinum, or all of 
these areas simultaneously.  
 
The “Junctional Region,” an area where penetrating trauma 
can potentially injure intrathoracic, mediastinal, or intra-
abdominal contents, or both. The superior boundary is the 
nipples anteriorly, and the tips of the scapulae posteriorly. The 
inferior boundary is the costal margin. Remember to think 
about diaphragm injury, which can be difficult to detect.  
 
The retroperitoneum is an enclosed area 
posterior to the viscera, with the thick muscles of the 
flank and back shielding it from examination. The 
ascending and descending colon and the duodenum 
are partly or completely within the retroperitoneum. 
Penetrating injuries to these structures can be quite 
difficult to detect if spillage occurs only in the 
retroperitoneum. 
Abdominal 
examination, 
abdominal ultrasound, and even early CT scan may 
not detect these injuries. The aorta, vena cava, renal 
and iliac vessels are also contained in the 
retroperitoneum. Injury to these structures will 
usually be easier to detect, due to hemodynamic 
instability, though they can present in a delayed 
fashion.  
 
Retroperitoneum with vessels, kidneys, ureters, bladder and 
rectum shown. The ascending colon, duodenum and descending 
colon are found within the Red boxes. Stab wounds to the flank 
and back involving these organs can be undetected by physical 
examination or even during laparotomy.  
 
An isolated small bowel or colon injury that 
causes spillage into the peritoneum may not be 
detectable immediately; there may be a small amount 
of spillage that cannot be detected by either careful 
physical examination, ultrasound, or CT scan. Such 
injuries will usually cause peritonitis and early sepsis 
within 24-48 hours. This fact is the basis for Non-
Operative Management, which we describe further 
below. Briefly, this is careful serial abdominal 
examination, done frequently enough to detect intra-
abdominal spillage before it has irreversible 
consequences. If this strategy is done properly it is a 
very powerful screening tool, allowing the surgeon 
to operate on those who need it and avoid operation 
on those who don’t. If this strategy is undertaken 
poorly, patients will get the operation they need too 
late, or not at all, and will be in danger of death.  
 
Principles:  
 
Decision-making begins with the initial 
primary and secondary survey, paying special 
attention to the number of “holes” (even/odd) 
identified. Perform immediate operation on patients 
with penetrating abdominal trauma who present 
with:  
Approach to Penetrating Abdominal Trauma 
Richard Davis and Caleb Van Essen 
 
OPEN MANUAL OF SURGERY IN RESOURCE-LIMITED SETTINGS 
www.vumc.org/global-surgical-atlas 
This work is licensed under a Creative Commons Attribution-ShareAlike 3.0 Unported License  
 
● Hemodynamic instability 
● Peritonitis 
● Evisceration 
● Blood in the rectum 
● Bloody vomitus or NG aspirate 
● Bilious or feculent discharge from the wound. 
 
Evisceration after a stab wound to the upper abdomen. This 
patient is best treated by a midline laparotomy and exploration 
for other injuries in the area. Source: Desalegn M et al, East 
and Central African Journal of Surgery 
https://doi.org/10.4314/ecajs.v25i3.8  
 
Patients who have ongoing bleeding present with 
hemodynamic instability that does not respond to 
resuscitation,  or they will respond transiently and 
then become hypotensive and tachycardic again. 
They should undergo laparotomy as soon as possible. 
The only reason to delay operation is if such a delay 
would help you know where to operate. This 
situation arises in injuries to the “Junctional Region,” 
the area that extends from near the costal margin up 
to the mid-chest. In this situation, you may have a 
thoracoabdominal injury and be operating in the 
abdomen while bleeding continues uncontrolled in 
the chest. A chest tube can often assist in this 
decision making. We discuss this situation further 
below.  
Patients who are hemodynamically stable 
may or may not have an intra-abdominal injury that 
you have not detected yet. You do not want to miss 
an injury, but you also do not want to do a full 
laparotomy if such an injury is not present.  
In this situation, your toolkit includes Local 
Wound Exploration, Diagnostic Peritoneal Lavage, 
or Non-Operative Management. We discuss the 
principles behind all these techniques below, 
followed by principles of imaging. In the final 
section, Decision Making, we bring all these 
elements together into a cohesive strategy.  
In considering all these techniques, keep in 
mind that you are attempting to balance one bad 
outcome, a negative laparotomy, against a much 
worse outcome, a missed injury. Do not gamble with 
the patient’s life; if there is any change in the 
patient’s condition, do not hesitate to explore the 
abdomen. Find more on the thinking required here in 
the Chapter, “Detection of Post Operative Intra-
Abdominal Complications.”  
 
Local Wound Exploration 
This operation ranges from widening and 
exploring of a small stab wound under local 
anesthetic, to a full unroofing and debridement of a 
tangential gunshot wound tract in the operating 
room. In all cases, the main goal is to detect 
penetration, through the peritoneum, into the 
abdominal cavity. 
It is impossible to see the peritoneum on local 
wound exploration. So, we use the most superficial 
layer of fascia as a surrogate, as this breach can be 
detected at local wound exploration. (We accept a 
small false positive rate, for those rare cases where 
the tip of the missile went through the outer layer of 
the muscle fascia but no further.)  
It is obvious, therefore, that the operation must 
be conducted so that you can see the fascia clearly 
and do not miss a penetration. Follow these 
principles:  
● Do the operation with excellent lighting, at least 
one assistant to retract, and all the equipment you 
need. In some resource-limited settings, these 
conditions may only exist in the operating room.  
● Conversely, if you are able to perform this 
operation safely and well in the Casualty under 
local anesthesia, the patient can be discharged 
immediately after a negative exploration.  
● If you take the patient to the operating room, or 
if you put them to sleep for the exploration, have 
them sign consent for both wound exploration 
and laparotomy. Explain how you would deal 
with a bowel injury if you found one, including 
ostomy creation if that seems even remotely 
possible.  
● Open the wound enough to see as far down as you 
need to. For example, in an obese patient who 
was stabbed with a 2cm wide blade, you may 
Approach to Penetrating Abdominal Trauma 
Richard Davis and Caleb Van Essen 
 
OPEN MANUAL OF SURGERY IN RESOURCE-LIMITED SETTINGS 
www.vumc.org/global-surgical-atlas 
This work is licensed under a Creative Commons Attribution-ShareAlike 3.0 Unported License  
 
need to open the wound 10cm to definitely rule 
out penetration into the fascia.  
● Once you have finished, wash the wound well 
and close it loosely.  
● For gunshot wounds, consider local wound 
exploration only if it seems highly likely that the 
bullet passed through nothing more than skin and 
fat. In other words,  there must be an even 
number of holes (entry/exit), the trajectory 
pattern must be superficial, and there must be no 
hard signs of intraperitoneal violation as noted 
above. These patients will need debridement of 
clothing or shrapnel inside the wound at the same 
time, so do these explorations in the operating 
room with the appropriate anesthesia. Unroof the 
entire tract between the entrance and exit wound, 
debride any dead tissue, make sure there was no 
entry into abdominal wall muscle, irrigate and 
close the incision you made loosely, leaving the 
bullet holes themselves open. 
 
An apparently tangential gunshot wound (one wound is under 
the examiner’s gloved index finger.) Especially if a CT scan is 
not available, the tract between the two wounds should be 
unroofed, explored to verify no entry into the peritoneum, 
debrided, and loosely closed. Source: Bobjgalindo, CC BY-SA 
4.0 
https://creativecommons.org/licenses/by-sa/4.0 
 
via 
Wikimedia Commons 
 
Non-Operative Management 
 
As explained above, this strategy depends on 
the “window” that exists between initial injury and 
the serious consequences of that injury. This window 
lasts 24 hours at most. It has been described primarily 
for isolated solid organ injury, particularly the liver 
and spleen, in high resource settings. However  it is 
very useful for detecting intestinal injury as well. 
During this time, patients can deteriorate slowly or 
very quickly, depending on the size of the hole in 
their intestine. Therefore, to make this strategy work 
you must: 
● Watch these patients very closely 
● Intervene immediately at the first sign of 
peritoneal irritation, sepsis or hemorrhagic shock  
● Have blood products available, especially if there 
is a known injury to the liver or spleen. 
 
In a resource-limited hospital you may have 
difficulty with these requirements. Regarding the 
first requirement, you are committing that the same 
team will examine the patient’s abdomen very 
carefully every 4-6 hours for the next 24h. If you are 
the only surgeon, do not make a habit of placing this 
extra burden on yourself.  
Regarding the second requirement, you must 
be able to operate on this patient as soon as you 
detect a change in their condition. If you have limited 
operating theater space that is usually booked with 
elective operations, and then the whole team goes 
home to return at 8AM on the following day, this is 
not the strategy for you.  
The third requirement is also important when 
monitoring solid organ injury. A delay in operative 
intervention might ultimately require ongoing blood 
transfusions. A thorough assessment of one's 
resources is essential in making this decision.  
Recall that this strategy was originally 
described in high-resource settings. Most of these 
patients get a high-resolution CT scan with IV and 
sometimes oral contrast, then they are followed by a 
dedicated in-house trauma team with an operating 
room on standby. You may be enthusiastic about this 
approach after reading their literature, but consider 
whether their experience applies to you.  
Another 
caution 
to 
Non-Operative 
Management should be applied to patients with 
multiple injuries or head injuries. Any amount of 
hypotension may worsen the prognosis here. Often it 
is not clear where the injury is. Also, serial 
examination is more difficult with multiple injuries 
or decreased level of consciousness. We usually have 
a low threshold to explore the abdomen of such 
patients if there is any possibility of a missed injury: 
the consequences would be very grave.  
 
Diagnostic Peritoneal Lavage 
Approach to Penetrating Abdominal Trauma 
Richard Davis and Caleb Van Essen 
 
OPEN MANUAL OF SURGERY IN RESOURCE-LIMITED SETTINGS 
www.vumc.org/global-surgical-atlas 
This work is licensed under a Creative Commons Attribution-ShareAlike 3.0 Unported License  
 
 
This technique has fallen out of favor in high-
resource settings as imaging has become more 
advanced. Mention of this technique in textbooks 
and research articles has fallen at a similar rate. 
However, for a surgeon without a high-quality CT 
scan or rapid access to an ultrasound machine, this 
technique can be very useful. We have a separate 
chapter describing it in more depth (see “Diagnostic 
Peritoneal Lavage”).  
This technique is most suited to patients with 
back and flank penetrating trauma. Anterior 
abdominal penetrating injuries can be evaluated with 
local wound exploration. Consider it in patients who 
have:  
● Penetrating trauma to the back or flank and no 
access to CT scan.  
● Penetrating trauma to the back or flank with an 
unreliable examination due to head injury, spinal 
cord injury, intoxication, or other form of 
impaired consciousness making serial abdominal 
examination difficult 
● Extensive bruising or soft tissue trauma to the 
abdomen making examination unreliable.  
● Penetrating trauma to the back or flank who are 
in the operating room for another operation.  
● Patients who are hemodynamically unstable after 
any blunt or penetrating multiple trauma, where 
the source of bleeding is not clear. This 
indication has mostly been replaced by Focused 
Abdominal Sonography for Trauma (FAST, See 
Chapter.) If you do not have ready access to 
ultrasound, you will be using peritoneal lavage.  
 
Briefly, under general anesthesia a small 
incision is made just above the umbilicus. If blood 
returns immediately, proceed directly to laparotomy. 
If not, a catheter is inserted into the abdomen and 
directed towards the pelvis. 1L of Normal Saline is 
run in through IV tubing under gravity, then the IV 
bag is placed on the floor and the fluid runs back into 
the bag. If the fluid is so cloudy (but not bloody) that 
you cannot read a newspaper through the IV bag, 
proceed immediately with abdominal exploration.  
In resource-rich countries, the fluid is 
assayed for serum amylase, and if the level is 3x the 
serum amylase, the patient needs exploration. In our 
setting, this result probably won’t return soon 
enough to help with any decision-making, so the 
Lavage is mostly useful for the immediate presence 
of blood, or a positive “newspaper test.”  
 
Imaging 
 
You must know the limitations of each option 
in order to interpret the results. On both ultrasound 
and CT, blood and freshly spilled succus both have 
the same appearance, that of “fluid.” Patients who 
have a solid viscus injury such as spleen or liver 
injury will have fluid in the abdomen on imaging. 
You may be tempted to think that any intra-
abdominal fluid is only blood from these organs. We 
would recommend laparotomy in anyone with free 
abdominal fluid on initial presentation, unless you 
can do Non-Operative Management very well, as 
described above.  
The pitfall is, of course, thinking that the 
intra-abdominal fluid is only blood when it is, in fact, 
a mixture of blood and succus. This mistake is more 
likely to occur in non-operative management of solid 
organ injuries after blunt trauma.  
When using abdominal ultrasound to make 
management decisions, keep in mind that a patient 
will have a “normal” abdominal ultrasound until 
there is 600mL of fluid in the abdomen (an extremely 
skilled operator can detect as little as 400mL.) Also 
retroperitoneal injuries/blood may not be detected. 
The useful thing about ultrasound is that it can be 
easily repeated at the patient’s bedside. If a patient’s 
ultrasound was initially negative but they become 
unstable, repeat it. The amount of blood may have 
increased and now be visible to you.  
Blood, or freshly spilled succus, will look 
black on ultrasound. Any fluid that looks “cloudy” or 
has floating elements that can be made to move when 
pressure is applied to the probe, is probably purulent. 
Of course, this finding will happen in patients who 
present late, or in whom you have missed the injury 
previously.  
A high quality IV contrasted CT image will 
show other signs of viscus injury, such as thickening 
of bowel wall or stranding of mesentery or other 
adjacent fat. This depends on timing of injection and 
quality of the scanner. To assist identifying the 
penetration trajectory, place small metallic markers 
(EKG pads are useful) on all stab or gunshot wounds. 
Although it is helpful having CT imaging in 
operative planning, do not take a hemodynamically 
Approach to Penetrating Abdominal Trauma 
Richard Davis and Caleb Van Essen 
 
OPEN MANUAL OF SURGERY IN RESOURCE-LIMITED SETTINGS 
www.vumc.org/global-surgical-atlas 
This work is licensed under a Creative Commons Attribution-ShareAlike 3.0 Unported License  
 
unstable patient to the CT scanner! If you aren’t clear 
where the bleeding is, use ultrasound (or DPL if you 
don’t have ultrasound.) 
Plain x-rays should not be overlooked in 
assisting diagnosis of injury. Place metallic markers 
on all open wounds. Free air on upright or left lateral 
decubitus indicates need for a laparotomy. 
 
Decision Making: 
As with all trauma patients, start with ATLS 
primary and secondary evaluations. Often early, easy 
decisions can be made with hemodynamically 
unstable patients going straight to operation, without 
any delay for time-consuming imaging. Portable x-
rays and ultrasound (to confirm intra-peritoneal fluid 
and identify cardiac injury) can be considered if they 
can be performed quickly or performed without 
delay in the operating room.  
Beware the unstable patient with a junctional 
injury pattern or multiple penetrating wounds. 
Thoracoabdominal injuries requiring exploration of 
two cavities have extremely high mortality rates. 
You do not have time for imaging, but you do not 
know exactly where to operate! Completely 
exposing patients, rolling them and identifying the 
number and trajectory of injuries can assist in the 
operative approach. An early thoracostomy tube is 
diagnostic and possibly therapeutic, identifying 
which side of the diaphragm the injury is on.  
See the chapter on trauma laparotomy for 
details on performing the operation and decision 
making regarding exploration of hematomas. 
Briefly, in penetrating trauma, explore hematomas in 
zone 1, 2 and 3 whether they are expanding or not.  
Special considerations need to be made to 
prepare for any type of injury and the subsequent 
repair that is needed. Thus preparing and draping 
patients from neck to knees and elbows, with arms 
out, will allow exposure for central access, chest 
cavity exploration and vein harvest for grafting of 
vascular injury. Make plans for patients’ disposition 
as soon as possible due to constraints mobilizing 
support staff and equipment for ICU management.  
Be thinking about the possible need for 
damage control and temporary abdominal closure. 
Damage control is a strategy that focuses on 
immediate repair of life-threatening injuries, while 
delaying other measures (such as bowel anastomosis 
and abdominal closure) until the patient is more 
stable. Focus first on controlling hemorrhage and GI 
spillage. Once this is accomplished, consider 
whether you should reconstruct and repair at this 
time,  versus applying temporary abdominal closure 
and stopping the operation for rewarming and 
resuscitation. An experienced surgeon will often 
recognize the situation and choose damage control 
before the operation has even started.  
 
To summarize, take no chances with the 
patient. A negative laparotomy is better than a 
missed bowel or vascular injury. Unclear injury 
patterns can make management decisions difficult. 
When you are not sure what intra-abdominal injuries 
the patient might have, it is worth considering local 
wound exploration, non-operative management and 
diagnostic peritoneal lavage.  
Remember that injuries in the junctional zone 
can lead to ongoing bleeding in the chest, 
mediastinum or abdomen.  
Remember that both blood and spilled bowel 
contents initially look like dark fluid on ultrasound 
and CT scan. Do not mistake one for the other.  
The ideal local wound exploration patient 
includes: single anterior stab wound, known short 
bladed knife, cooperative patient, insufficient 
personnel for serial abdominal exam, experienced 
surgeon and no additional injuries.  
The 
ideal 
non-operative 
management 
(watchful waiting) patient includes: stab wound, in-
house on-call trauma team (residents,) ability to do 
an operation at any time,  an awake, alert and 
cooperative patient, initial exam is completely 
benign, and no advanced imaging available. 
Consider it also in a very obese patient, in whom 
local wound exploration would be morbid. 
Most patients with abdominal gunshot 
wounds will need laparotomy, unless it is quite clear 
that the wound is tangential and didn’t enter the 
peritoneum.  
 
Richard E. Davis MD FACS FCS(ECSA) 
AIC Kijabe Hospital 
Kenya 
 
Caleb Van Essen MD 
General Surgeons of Western Colorado 
Grand Junction, CO  USA 
