Abdominal Trauma

Abdominopelvic Cavity Ventral body cavity Thoracic Abdominopelvic Abdominal Liver Stomach Kidneys Pelvic cavity Bladder Some reproductive organs Rectum

Abdominopelvic Cavity The two cavities are continuous Most organs surrounded by a peritoneal cavity Visceral peritoneum Serous peritoneum Peritoneal cavity

Abdominal Quadrants 4 quadrants Right upper quadrant Left upper quadrant Left lower quadrant Right lower quadrant

Abdominal Trauma First aid Resuscitation Transport Diagnosis Treatment

Abdominal Trauma Penetrating abdominal taruma Blunt wounds Ballistic trauma stab wounds

blunt abdominal trauma

Blunt abdominal trauma is regularly encountered in the emergency department Victims of blunt trauma often have both abdominal and extra- abdominal injuries The integrity of the abdomen does not deteriorate

MECHANISM OF INJURY Several pathophysiologic mechanisms can occur in patients with blunt abdominal trauma. 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. Solid organs (eg, spleen and liver) are particularly susceptible to laceration or fracture by this mechanism Retroperitoneal structures, such as the duodenum or pancreas, may be injured.

HISTORY Important

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

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.

The physical examination findings most strongly associated with intra-abdominal injury following BAT are the following; Seat belt sign Rebound tenderness Hypotension Abdominal distension Abdominal guarding Concomitant femur fracture

Laboratory tests Hematocrit – A hematocrit below 30 percent increases the likelihood of intra-abdominal injury in the setting of BAT (blunt abdominal trauma) Leukocyte count – In BAT, the white blood cell (WBC) count is nonspecific and of little value Pancreatic enzymes – Normal serum amylase and lipase concentrations cannot exclude significant pancreatic injury Liver function tests – Hepatic injury is associated with elevations in liver transaminase concentrations Urinalysis – Gross hematuria suggests serious renal injury and mandates further investigation 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 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).

Radiologic studies 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

Computed tomography computed tomography has become the primary method for identifying intra-abdominal injury The use of MDCT remains largely restricted to hemodynamically stable patients who are at low risk for decompensating while in the CT scanner. CT scanning's benefits include: Noninvasive Better defines organ injury and potential for nonoperative management of splenic and liver injuries 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). CT scanning's disadvantages include: Despite improvements in image resolution, MDCT remains an insensitive test for mesenteric, bowel, and pancreatic duct injuries IV contrast is needed; oral contrast is NOT needed as it rarely adds to diagnostic accuracy and may delay imaging Relatively high cost Can be unobtainable or harmful to obtain in unstable patients Radiation exposure

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). 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 (82%, CI 75-89%); cannot exclude intra-abdominal injury based on normal study Blood cannot be distinguished from ascites or urine Subcapsular injuries cannot be detected Insensitive for detecting bowel injury

Diagnostic peritoneal lavage (DPL) 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 non-operative 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

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 GI bleeding seen in nasogastric drainage or vomitus

abdominal stab wounds

Any instrument that can impale may inflict a stab wound (SW). Typically these are narrow, sharp, knife-like implements, but items that can inflict stab wounds range from scissors to coat hangers to animal horns. The given instrument can injure any tissue it traverses, including skin, fascia, solid organ, hollow viscus, blood vessel, and bone.

ANATOMIC ZONES

HISTORY Answers to the following questions help to guide the clinician in assessing potential injuries from abdominal stab wounds: What instrument was used? How long and how wide was the instrument? How was the patient positioned during the stabbing? What path (or paths in the event of multiple wounds) did the implement travel?

EVALUATION It is important to completely undress any patient who sustains a stab wound (SW). SWs can often be obscured by body habitus, clothing, or bleeding, or be "hidden" in the axilla, scalp, perineum, or groin. Examine the patient carefully for evidence of more than one stab wound.

immediate laparotomy Patients with hemodynamic instability, evisceration, peritonitis, impalement, or frank blood from a nasogastric tube or on rectal examination typically undergo immediate laparotomy. Patients without apparent indications for laparotomy may be evaluated by a combination of the following: Local wound exploration (LWE) Plain radiograph Computed tomography (CT) Serial physical examinations (SPE) Diagnostic peritoneal lavage (DPL) Ultrasonography Laparoscopy

Local wound exploration Since the entire abdominal wall is encased in a layer of fascia, stab wounds (SWs) are often amenable to local wound exploration (LWE) to evaluate their depth and tract. This procedure is quickly and safely performed at the bedside in patients with SWs to the anterior abdomen. However, this approach should not be used for wounds over the chest wall due the risk of injury to the underlying viscera (lungs) and intercostal vessels.

Plain radiographs Plain radiographs typically add little to the management of abdominal SWs. If free intraperitoneal air is seen on an upright chest or lateral decubitus radiograph, then the peritoneal cavity has been violated, but this does not confirm hollow viscus injury. Thus, plain radiographs lack sensitivity and specificity for significant injuries and are rarely employed in this setting.

Computed tomography and magnetic resonance imaging triple contrast (intravenous, oral, and rectal), Multidetector computed tomography (MDCT) is a noninvasive and rapidly performed imaging study that enables clinicians to identify peritoneal penetration and delineate visceral injury advantage of MDCT is that it enables the identification of intraperitoneal injuries, such as hepatic lacerations, that may be amenable to nonoperative management magnetic resonance imaging (MRI) has greater sensitivity for some injuries and may play a useful role in the evaluation of hemodynamically stable patients MRI may also be useful for evaluating the stable pregnant patient in need of intraabdominal or thoracoabdominal imaging following penetrating injury

Serial physical examination It is well accepted that serial physical examination (SPE) is a safe and reliable means to detect significant intra-abdominal injuries after stab wounds to the abdomen, if performed by experienced clinicians on appropriate patients. Ideally, the same clinician should perform each examination.

Ultrasound Bedside Focused Abdominal Sonography for Trauma (FAST) examination is frequently used to determine the presence of hemopericardium, hemoperitoneum, pneumo or hemothorax, or some combination thereof. Overall, the specificity of the FAST examination for identifying signs of internal injury from a stab wound appears to be high but sensitivity is limited. The use of ultrasound in evaluating patients with abdominal trauma is described in detail separately.

diagnostic peritoneal lavage Although invasive, diagnostic peritoneal tap and lavage is a rapid and easily performed bedside procedure that offers information about peritoneal penetration and injury to solid organs, bowel, and the diaphragm. However, the widespread use of CT and ultrasound imaging has led to a diminishing role for this procedure In the setting of abdominal stab wounds, diagnostic peritoneal tap and lavage is generally used for one or more of three indications: Need to rapidly determine the presence of hemoperitoneum in unstable patients Need to identify intraperitoneal injuries that may require laparotomy in stable patients Need to diagnose diaphragm injury (eg, unclear if a stab wound to the lower chest has penetrated the peritoneum)

Diagnostic laparoscopy Diagnostic laparoscopy (DL) is most useful for inspecting the diaphragm in thoracoabdominal wounds, although some studies suggest it may be useful in evaluating the depth of wound tracts and identifying visceral injury in patients with equivocal peritoneal penetration

INITIAL MANAGEMENT General approach and indications for laparotomy

Prophylactic antibiotics Broad spectrum antibiotics are generally given to patients with penetrating abdominal injury requiring surgical management; routine antibiotic administration is not warranted in most injured patients, including those with penetrating abdominal injury, who are managed nonoperatively

SPECIAL CONSIDERATIONS Flank and back Identification of structures injured from penetrating wounds to the flank and back is difficult. Stab wounds (SW) to these regions can injure both retroperitoneal and intraperitoneal structures. Approximately 40 percent of penetrating flank wounds result in significant internal injury. Triple contrast CT (3CT) has become the diagnostic modality of choice for stable patients and may allow for safe triage to nonoperative management. Local wound exploration (LWE), ultrasound (US), diagnostic peritoneal lavage (DPL), and diagnostic laparoscopy (DL) are not ideal for evaluation of retroperitoneal structures.

SPECIAL CONSIDERATIONS Thoracoabdominal Thoracoabdominal wounds present a diagnostic challenge as movement of the diaphragm makes prediction of the Stab wounds (SW) tract difficult . If the wound is close to the lower chest, intrathoracic and diaphragmatic injuries must be considered and evaluated in addition to intraabdominal injury. Potential intrathoracic injuries include pneumothorax, hemothorax, and pericardial tamponade

SPECIAL CONSIDERATIONS Right upper quadrant injury Patients with a right upper quadrant stab wound who remain hemodynamically stable and remain free of abdominal tenderness on reliable, repeated examinations may be managed without laparotomy. Most patients with injuries of this nature have sustained grade I or grade II hepatic injuries and do not require operative intervention. However, these patients should be admitted for a period of observation.