It's no surprise that bellies get a lot of attention on television's perennial favorite ER. Unrecognized abdominal injuries are a major, preventable cause of morbidity and mortality. Trauma kills about 150,000 people annually, making it the fourth-leading cause of death for Americans after heart disease, cancer, and cerebrovascular disease.¹ Trauma is the most common cause of death for children and adults under 45 years.¹ In 2003, about 35% of the estimated 114 million visits to EDs were related to trauma,² About 25% of those cases involved injury to the abdomen.¹ Patients with abdominal trauma can rapidly progress to hypovolemic shock or death, making it an ED priority.¹

This module will provide nurses with information about the incidence of abdominal trauma in American EDs. The most common mechanisms of injury will be reviewed, as will the need for rapid diagnosis and stabilization. In addition, this module will discuss the important role nurses have during this critical period in managing patients and families in crisis.

Emergency assessment

A methodical approach is required to assess any trauma patient presenting to the ED because the most obvious injury is not necessarily the most serious one. Patients are assessed in a systematic fashion to quickly ascertain critical injuries.

• Primary assessment (ABCD): Immediate life-threatening problems are identified during the primary assessment. Airway, breathing, and circulation are evaluated while maintaining stability of the cervical spine. D is for neurological deficit, including level of consciousness and pupillary reaction.¹
• Secondary assessment (EFGHI): The secondary assessment is a brief (two to three minute) examination of the patient intended to detect and prioritize injuries. E is for exposure: Remove clothing to check for signs of injury while keeping the patient warm. F is for full set of vital signs and five interventions (cardiac monitor, pulse oximetry, urinary catheter if not contraindicated, nasogastric tube, and labs). F is also for facilitation of family presence. G: Give comfort measures (touch, pain control, verbal reassurance). H is for head-to-toe assessment and history as possible. I: Inspect and palpate posterior surfaces while maintaining cervical stability - turn the patient over to look for unseen injury.¹
• Focused assessment: At this point, a more detailed examination of injuries identified in the secondary assessment is performed, with concentration on problems with the pulmonary, cardiovascular, or neurological system, if any.

In the case of abdominal trauma, the abdomen is inspected for open wounds, external hemorrhage, foreign objects, or unusual patterns of bruising that might indicate internal bleeding. Auscultation will identify the absence or presence of bowel sounds or bruits. Auscultate prior to palpation because palpation may change the nature of the bowel sounds.³ Then palpate the abdomen for pain, guarding, and distention, keeping in mind that a patient under the influence of medication or alcohol may be incapable of normal response.³ Rigidity can indicate internal injury with hemorrhage or ruptured bowel. Abnormal findings on focused abdominal assessment may mean that a "surgical abdomen" is present and that rapid surgical intervention is indicated.³

Mechanisms of injury

Trauma is a disease process with the mechanism of injury being part of its etiology.¹ Experienced emergency health care providers recognize that knowing the mechanism of injury enables them to approach the patient with a high index of suspicion regarding specific injuries. Traumatic events tend to produce similar injuries that can be predicted and thus more rapidly located and treated. The severity of trauma depends on the wounding agent and its characteristics, such as acceleration, deceleration, velocity, and kinetic energy, as well as personal factors like age, gender, size, and existing comorbidities.¹

Penetrating injuries are caused by foreign objects in motion that penetrate the body, most commonly stabbings and gunshot wounds. Stab wounds are low-velocity injuries with minimal secondary trauma. Stabbings can result in massive blood loss and may damage organs in both the chest and abdomen. About 4.6% of trauma patients have been stabbed or cut.⁴

Gunshot wounds are high-energy injuries, causing extensive damage as the bullet cleaves a tunnel while traversing the body, displacing and destroying organs and tissues along its tract. The area of damage can be 30 to 40 times the diameter of the bullet.¹ In addition, the bullet creates a negative pressure, pulling contaminated materials, such as clothing and skin into the wound. About 5.85% of trauma patients present with gunshot wounds.⁴ Other penetrating abdominal injuries are caused by foreign bodies, such as wood or metal fragments from explosions and industrial accidents.

Blunt injuries are those with no break in the skin. Because injuries may not be readily apparent, blunt trauma injuries can be more difficult to diagnose and potentially have a greater mortality rate than penetrating trauma.¹ Energy is transmitted in all directions with blunt trauma, subjecting nearby organs to damage. Blunt trauma injuries occur most often with motor vehicle crashes (MVC) and falls from heights. Injuries, assaults, and other vehicular (i.e., motorcycle and boat) accidents are important causes of blunt trauma, but occur less often. MVCs account for more than 43% of trauma cases seen in the ED, while falls make up 26%.⁴

Abdominal injuries

Both blunt and penetrating abdominal trauma can cause life-threatening injuries. Abdominal trauma can occur alone or in combination with chest or skeletal injuries. Because inspiration lifts the diaphragm into the thoracic cavity, abdominal injury must be suspected whenever chest trauma occurs from the fourth rib downward. Organs in the abdominal cavity include the large and small intestines, liver, spleen, gallbladder, stomach, pancreas, and diaphragm. Hollow organs such as the intestines and stomach collapse or rupture when damaged. Solid organs, such as the liver and spleen, tend to fracture and bleed with trauma.

Patients with penetrating abdominal trauma require surgical intervention to repair the damage caused by blade or bullet. In some cases, an immediate "damage control laparatomy" is performed in the operating room to control hemorrhage, prevent bowel contamination, and continue vigorous resuscitation with blood and clotting factors.⁵ Additional surgeries will likely be necessary when the patient is stable. The small intestine, colon, and liver are the organs most frequently damaged by penetrating trauma.⁶ Hemorrhagic shock is the most common cause of death with these injuries.⁶ Even after successful surgery to repair the damage of a penetrating abdominal wound, a significant likelihood of infection exists because of fecal contamination.⁷

Blunt abdominal trauma injuries generally involve the spleen and liver.¹ Such injuries can lead to internal hemorrhage and shock. Liver injury should be suspected when trauma is applied to the right-upper quadrant in the region from the eighth rib down to the mid-abdomen.¹ Pain radiating to the right shoulder can signify liver injury.³ Kehr's sign, pain radiating to the left shoulder, indicates blood beneath the diaphragm, most often in the splenic region.³ Cullen's sign, a slight bluish discoloration around the navel, is generally a sign of blood in the peritoneum, often seen with pancreatic hemorrhage.^1,5

The stomach is not often injured with blunt trauma. If distended by a recent meal, the stomach acts somewhat like an airbag by absorbing the impact.⁸ This helps protect the liver, but if the distended stomach does rupture, it leads to an increased risk of infection.⁸

Diaphragmatic rupture can be caused by either penetrating or blunt trauma, especially if centered in the upper abdomen or lower chest. Rupture most frequently occurs on the left side because the liver partially protects the right diaphragm.^1,5 A damaged diaphragm can allow abdominal contents to spill into the thoracic cavity, putting the patient at jeopardy for immediate respiratory compromise and subsequent infection.¹

Patients involved in MVCs should be inspected for bruises, which could indicate abdominal injuries caused by seatbelts. In one study, nearly half of the children with seatbelt contusions had intra-abdominal injuries serious enough to require surgery.⁹ The small bowel was the organ most often damaged in children. ⁹

Major abdominal vascular structures include the aorta, vena cava, hepatic vein, iliac artery, and iliac vein. Vascular structures are damaged in about 10% of patients with blunt abdominal trauma.¹ Because the peritoneal cavity is a major reservoir for occult blood loss, vascular injury can rapidly lead to hemorrhage and death if not quickly identified, indicating the need for ongoing nursing assessment for as long as the patient remains in the ED.

Other injuries associated with abdominal trauma

Trauma that causes significant abdominal injury is likely to damage the urinary tract as well. Renal injuries are the most common injury of the urinary system.¹⁰ Trauma from blunt force injury causes 90 to 95% of renal injuries, while penetrating forces cause the balance.¹⁰ Even though the kidneys are well protected by ribs, vertebrae, and back muscles, they are frequently damaged by trauma.¹⁰ Injury to the right kidney often occurs in conjunction with liver injuries, while the left kidney may be damaged along with the spleen.¹⁰

The kidneys can be compressed between the 12th rib and lumbar spine with blunt trauma, resulting in contusion or laceration. During rapid deceleration (as in MVCs and falls and in sports such as skiing), the kidney may rotate in relation to the more stable aorta, causing lacerated renal arteries or veins.¹⁰ Because kidneys use up to 25% of the cardiac output, hemorrhage can rapidly compromise hemodynamic stability.¹⁰

Injury to the bladder occurs in about 2% of abdominal trauma cases.¹ Bladder injuries are most often associated with pelvic fracture.¹ About 1 in 10 patients with a pelvic fracture will have a ruptured bladder as well.¹ A distended bladder is more likely to rupture than an empty one and will often do so at the dome or posterior wall, releasing blood and urine into the peritoneal or retroperitoneal cavities.¹ A penetrating abdominal injury may damage the ureters and urethra, although they are injured less often than the kidneys and bladder.¹ Patients with abdominal trauma should have rectal and vaginal examinations to check for signs of bleeding.¹

Intervention

Because so many abdominal injuries can be life-threatening, the ED staff must make a rapid diagnosis. Injuries associated with penetrating trauma, such as stabbings or gunshot wounds, are generally more straightforward than with blunt trauma, in which internal injuries may be hidden. The goal of emergency care for abdominal trauma is to control bleeding, maintain blood volume, and prevent infection. While the exact order of diagnostic evaluation may vary by patient condition and facility protocol, the following components are likely to be included:

• A CT scan is the most sensitive diagnostic tool for the majority of patients with abdominal trauma.⁵ It may be performed first if the patient is stable enough to move to the CT suite and if a technician is immediately available. CT reveals the presence of free fluid or air in the abdomen. It can identify certain organ-specific injuries, especially splenic and liver injuries, allowing grading of those injuries.⁵ In addition, CT can demonstrate retroperitoneal and skeletal injuries. However, it cannot differentiate between blood and other fluids, and it inadequately identifies injuries of the small bowel, pancreas, and diaphragm.¹
• Bedside ultrasound (called FAST - focused abdominal sonography for trauma) to assess the abdomen for fluid and air after blunt injury has gained wide acceptance as a major diagnostic tool and is often the first diagnostic procedure performed. It's nearly 100% specific and 98% accurate in evaluating blunt abdominal trauma.³ The trauma physician performs FAST as an extension of the primary assessment in unstable patients and as part of the secondary assessment in stable patients. FAST can be quickly performed, it's portable and noninvasive, and in the hands of experienced physicians it approaches CT in accuracy. A newer, hand-held FAST unit is proving accurate and valuable when tested against larger models.¹¹
• Diagnostic peritoneal lavage (DPL) excels at detecting fluids in the abdominal cavity and differentiating blood from other fluids. The trauma surgeon inserts a large needle or small catheter either percutaneously or via a small incision through or below the umbilicus. If nothing is aspirated, normal saline or Ringer's solution is infused, then withdrawn and examined for blood. Limitations of DPL include its invasive nature and related complications (perforation of intestines or bladder), and the fact that it cannot determine the source of bleeding.³ CT and FAST have replaced DPL as the primary diagnostic procedures for abdominal trauma in some institutions and for certain patients.⁵
• While CT, FAST, and DPL are the most common diagnostic procedures for abdominal trauma, X-rays of the chest, abdomen, and pelvis are often required, and a laparoscopy may be performed in the event of penetrating trauma.¹
• Urinary catheterization decompresses the bladder and allows urine to be tested for blood and unrecognized pregnancy. It also facilitates monitoring of urinary output to gage the effectiveness of fluid resuscitation.
• Nasogastric intubation decompresses the stomach by removing gastric contents, thereby reducing the risk of aspiration. It may also reveal the presence of blood in the upper gastrointestinal tract.
• Blood will be drawn for complete blood count, type and cross-match, serial hemoglobin and hematocrit, coagulation studies, amylase, and alcohol and drug screening per institutional protocols or as indicated.
• Patients with abdominal trauma will have one or more large-bore intravenous lines inserted peripherally and/or centrally for administration of fluids, blood products, and medications like analgesics and antibiotics. A central line can be used for hemodynamic monitoring, as well.

Once the patient has been initially stabilized, plans for the next phase of care must be made. Of the estimated 114 million visits to the ED in 2003, about 13.9% resulted in hospital admission, 1.9% were transferred to another facility, 1.3% were admitted to ICU or CCU, and 0.3% died.² When only trauma patients are considered, approximately 40% are admitted to ICU.⁴ MVC and falls are by far the most common reasons for trauma admissions.⁴ If a trauma patient has critical injuries and the facility is not a Level 1 trauma hospital, he or she may be transferred to such a facility for further stabilization and treatment. Some patients will be discharged home after several hours of observation with detailed plans for follow-up care.

Nursing implications

While all nurses deal with patients and families in crisis, perhaps few do so as consistently as the ED nurse. Trauma is an insult to both body and mind. Patients are likely to be in pain, anxious, and fearful. The nurse should reassure the patient and explain procedures calmly and in easily understood language, remembering that anxiety and stress markedly reduce comprehension. Confused patients should be reoriented to time and place as often as necessary. Unconscious patients should always be treated as if they can hear everything being said around them.

Trauma patients do not exist in isolation. Today, most EDs recognize the importance of family-centered care. The Emergency Nurses Association supports the presence of family members at the bedside during invasive procedures and resuscitation.¹² Patients report that having family present provides comfort and helps to maintain family bonds.¹² For family members, presence at the bedside ensures that they recognize that everything possible is being done for their loved one.¹² They may also have important information about the patient's medical history to share with staff.¹²

If the patient dies, ED nurses can facilitate the grieving process and help bring closure. Nurses can encourage family members to view the body, if they wish to do so. They can take the family to see the body and urge them to say goodbye through touching and talking. The nurse can ensure that family members have privacy and as much time as they need for this painful process. Regardless of the cause of trauma, patients and family will look to ED staff for caring reassurance.