Norm of Acute Abdominal Series
Requires individual interpretation.
Usage of Acute Abdominal Series
Differential diagnosis of the cause of an acute condition of the abdomen. Some examples are abdominal aortic aneurysm dissection, abscess, acute cholecystitis, acute ischemia, acute pancreatitis, appendicitis, bile duct obstruction, bowel strangulation, choledocholithiasis, gastric outlet obstruction, perforated abdominal viscus, peritonitis, pyelonephritis, ruptured ectopic pregnancy, Salmonella enterocolitis, and ureteral obstruction. Also useful for identifying the presence and location of (a) foreign body(ies).
Description of Acute Abdominal Series
An acute abdominal condition is characterized by the abrupt onset of abdominal pain, distention, diminished or absent bowel sounds, and, sometimes, guarding. There may be many causes of these symptoms, and the disorder within the abdomen is hidden. In addition to a routine external physical assessment, seven routes of diagnostic work-up are used. Less invasive testing is usually performed initially.
Laboratory studies include coagulation studies, hemoglobin and hematocrit tests, and blood volume determinations to rule out internal bleeding, leukocyte differential to determine whether an infectious or inflammatory process is present, amylase level to rule out pancreatic and other pathologic conditions, liver panels to rule out a hepatic disorder, blood urea nitrogen and creatinine determinations and urinalysis to rule out urinary tract infection, and stool examination to rule out Salmonella. Fine-needle aspiration cytologic testing provides clues to the type of process occurring.
Plain-film radiography is taking a radiograph without the use of an injected radiopaque agent. Plain-film radiography of the abdomen may identify compression fractures, intestinal obstruction, metastasis, perforated abdominal viscus, pancreatic calcification, and renal calculi.
Contrast radiography involves injection of a radiopaque agent into the vascular space. The contrast agent enhances the appearance of organ and vascular lumens and is more likely to reveal a pathologic condition than is plain film radiography. Vascular contrast examinations of the abdominal area, such as intravenous pyelography, help identify lumbar aortic aneurysms, urinary tract trauma, lesions, or other disorders.
Intestinal contrast examinations such as barium enema, oral cholecystogram, and upper gastrointestinal series may identify colonic lesions or perforation but should not be performed when obstruction is suspected. They may also rule out appendicitis.
Ultrasonography may help diagnose acute abscesses, cholecystitis, Crohn's disease, dilated bile duct, hepatic cancer, hepatic or splenic hematoma, splenomegaly, hydronephrosis, intussusception, pancreatitis, pancreatic pseudocyst, pancreatic carcinoma, urinary tract obstruction, and the presence of foreign bodies.
Computed tomography helps identify, differentiate, and evaluate hepatic, pancreatic, renal, and retroperitoneal abscesses, fluid accumulations, masses and cysts, and pancreatitis.
Nuclear medicine studies help identify intra-abdominal abscesses, sites of gastrointestinal bleeding, hematoma, and areas of abnormal tissue metabolism. Nuclear medicine scans may also help to rule out cholecystitis.
In extremely acute situations and when findings from any combination of the above tests are inconclusive, surgical exploration of the abdomen may be required.
Professional Considerations of Acute Abdominal Series
Consent form NOT required for the noninvasive studies. See individual listings for the invasive studies.
Allergic reaction to radiographic dye or nuclear medicine radiopharmaceutical for applicable tests (itching, hives, rash, tight feeling in the throat, shortness of breath, bronchospasm, anaphylaxis, death); renal toxicity.
Previous allergy to radiographic dye, iodine, or seafood or radionuclide for those tests involving injections; renal insufficiency.
During pregnancy, risks of cumulative radiation exposure to the fetus from this and other previous or future imaging studies must be weighed against the benefits of the procedure. Although formal limits for client exposure are relative to this risk-benefit comparison, the United States Nuclear Regulatory Commission requires that the cumulative dose equivalent to an embryo/fetus from occupational exposure not exceed 0.5 rem (5 mSv). Radiation dose to the fetus is proportional to the distance of the anatomy studied from the abdomen and decreases as pregnancy progresses. For pregnant clients, consult the radiologist/radiology department to obtain estimated fetal radiation exposure from this procedure.
- No preprocedural care is required for plain-film radiography.
- Intestinal contrast examinations often require clear liquids the day before the test and cathartics with or without cleansing enemas before the test. However, this requirement may be waived for a client with acute abdominal symptoms.
- Have emergency equipment readily available for tests involving injection of radionuclide or dye.
- Plain-film radiography: The client is positioned in supine, upright, oblique, and lateral decubitus positions, and radiographic films are taken from various angles. The best results are not obtained from portable films, especially in obese clients. The films should be taken in the radiology department, where the most powerful radiography is available, whenever possible. The lateral decubitus position is used for clients who are unable to stand, and the radiograph is taken horizontally across the table. A “kidneys, ureters, bladder film (KUB)” includes the majority of the abdomen and is taken from an anteroposterior angle. An anteroposterior scout film is used both before an intravenous pyelogram and in combination with an upright abdominal film for suspected intestinal obstruction. Subdiaphragmatic free air from a perforated abdominal viscus may be identified with an upright abdominal film or an upright chest film.
- Vascular contrast examinations: Radiographic dye is injected into an arm vein, and oblique films of the abdomen are taken 15 minutes later. A left posterior oblique position may help identify a lumbar aortic aneurysm because the position enhances visualization by rotating the aorta off of the spine. Arteriography and venography may also help identify blood vessel abnormalities such as aneurysm, hemorrhage, or occlusion.
- Intestinal contrast examination: The client is placed in a Sims' position. Barium with or without air is instilled into the lower gastrointestinal tract, and radiographic films are taken. In upper gastrointestinal series, the client must swallow barium, and radiographic films are then taken.
- Ultrasonography: The client is postioned on the side or supine, and a series of high-frequency sound waves are transmitted into the abdomen. The echoes reflected from the differing tissue densities are converted by a gel-coated transducer to form patterns of the abdominal structures on an oscilloscope screen.
- Computed tomography: The client is placed in a supine position on a platform table that moves the client through a circular computed tomography scanner. As several transverse films are taken, differing tissue densities are calculated based on varying absorption of the x-rays. Findings may indicate the need for further computed tomography after the administration of contrast medium.
- Nuclear medicine studies: At varying intervals after the intravenous injection of a radioactive tracer, scintigraphic scans, which detect areas of increased concentration of the tracer at sites of a pathologic condition, are taken of the abdominal area.
- Fluids should be encouraged after studies involving the administration of radiopaque dyes or barium.
- Cathartics may be prescribed after studies involving the administration of barium.
Client and Family Teaching
- Explain the purpose of each test as appropriate, the procedure for the test, and the results. See individual test listings for specific client teaching.
Factors That Affect Results
- The presence of gastrointestinal barium negates the value of plain-film radiography, vascular contrast examinations, ultrasonography, computed tomography, and nuclear medicine scintigraphy and so should be performed last.
- See also Barium enema; Radiography of the abdomen, Flat-plate radiography of the abdomen; Intravenous pyelogram; Upper gastrointestinal series; Computed tomography of the body.
- Health care professionals working in a nuclear medicine area must follow federal standards set by the Nuclear Regulatory Commission. These standards include precautions for the handling of the radioactive material and the monitoring of potential radiation exposure.
- Some extra-abdominal conditions that may cause acute abdominal pain include pneumonia, pulmonary or myocardial infarction, and pericarditis. Other conditions that may cause symptoms of an acute abdominal condition include acute intermittent porphyria, diabetic neuropathy, heavy-metal poisoning, sickle cell disease, and tabes dorsalis.