Patients on warfarin going to the operating

room may require reversal beforehand.

Type and screen (T&S). T&S should be obtained in

patients presenting with hemorrhage or going to the operating room. It is also necessary in determining the Rh status of females being evaluated for ectopic pregnancy.

..... Electrocardiogram

An electrocardiogram should be obtained as an initial

screening tool in patients with unexplained epigastric pain

or older patients with poorly localized pain. Cardiac markers can be ordered for additional risk stratification.

..... Imaging

Plain radiographs offer little diagnostic value in evaluating

nonspecific abdominal pain, but can serve as an initial

imaging study for perforated viscus, small bowel obstruction, volvulus, or foreign bodies. Radiographs offer the

advantage of being quick and portable, but owing to their

poor sensitivity, cannot be used to definitively rule out

disease. Upright chest x-ray can be used to screen for free

air under the diaphragm (Figure 26-2). When a patient is

unable to sit upright, a lateral decubitus may alternatively

be used.

Ultrasound plays a central role in evaluating patients

for disorders of the biliary tract, reproductive system, or

abdominal aorta. It is the primary radiologic modality in

investigating for cholecystitis, gonadal torsion, ectopic

pregnancy, and tubo-ovarian abscess. In children and

Figure 26-2. Radiograph showing free air under the

diaphragm in a patient with a perforated viscus.

pregnant women, it can serve as the initial imaging study

of choice in evaluating for appendicitis. In hemodynamically

unstable patients, bedside ultrasound enables the emergency physician to rapidly assess for the presence of an

abdominal aortic aneurysm, intrauterine pregnancy, or

free intraperitoneal fluid suggestive of hemorrhage.

Computed tomography (CT) is widely employed in the

diagnosis of abdominal diseases including infections

( appendicitis, diverticulitis, abscess), vascular events

(aortic dissection, mesenteric ischemia), bowel obstruction,

perforated viscus, and nephrolithiasis. It is the radiologic

study of choice when imaging is being pursued for undifferentiated abdominal pain. Its use is limited by contrast

nephropathy, contrast allergies, and exposure to ionizing

radiation.

The use of contrast agents is dictated by the study

indication. Noncontrasted CT is obtained when confirming nephrolithiasis. IV contrast is utilized in investigating neoplastic, infectious, and inflammatory diseases.

IV contrast accentuates areas of high blood flow ( eg,

appendicitis). IV contrast is furthermore utilized in

detecting vascular lesions such as intimal flaps (aortic

dissection), occlusion (mesenteric ischemia), and leakage (AAA). Oral contrast allows for visualization of the

bowel lumen. Variation in opinion exists over its use.

Conditions in which it can facilitate diagnosis include

bowel perforation, fistulas, and partial bowel obstruction. Both abscesses and loops of bowel appear as fluidfilled structures on CT, so oral contrast will help

discriminate between them, as only bowel should fill

with contrast.

MEDICAL DECISION MAKING

A primary survey guided by vital signs, general appearance, and a focused abdominal exam should be conducted to screen for a life- or organ-threatening disease

CHAPTER 26

Vital signs

General appearance

Focused abdominal exam

''The clin ical presentation of gonadal torsion - particu larly ovarian -

is variable and can be subtle. It is listed as an imminent diagnosis

due to the time sensitivity of organ viabil ity.

Hemodynamically stable

Non-toxic appearance

Non-peritoneal

Vascular

• AAA (non-ruptured)

Inflammatory /infectious

• Appendicitis

• Diverticul itis

• Cholecystitis

• Pancreatitis

• Pyeloneph ritis

• PID/TOA