The physical examination helps establish baseline data about the physical dimensions of the patient’s situation.³ The abdomen is divided into four quadrants (left upper, right upper, left lower, and right lower), with the umbilicus as the middle point, to specify the location of examination findings (Fig. 29-1 and Box 29-2). The assessment should proceed when the patient is as comfortable as possible and in the supine position; however, the position may need readjustment if it elicits pain. To prevent stimulation of GI activity, the order for the assessment should be changed to inspection, auscultation, percussion, and palpation.⁴

Box 29-2

Anatomic Correlates of the Four Quadrants of the Abdomen

Right Upper Quadrant

• Liver and gallbladder

• Pylorus

• Duodenum

• Head of pancreas

• Right adrenal gland

• Portion of right kidney

• Hepatic flexure of colon

• Portion of ascending and transverse colon

Right Lower Quadrant

• Lower pole of right kidney

• Cecum and appendix

• Portion of ascending colon

• Bladder (if distended)

• Ovary and salpinx

• Uterus (if enlarged)

• Right spermatic cord

• Portion of left kidney

• Splenic flexure of colon

• Portions of transverse and descending colon

Left Lower Quadrant

• Lower pole of left kidney

• Sigmoid colon

• Portion of descending colon

• Bladder (if distended)

• Ovary and salpinx

• Uterus (if distended)

• Left spermatic cord

• Left ureter

From Barkauskas V, et al. Health & Physical Assessment. 3rd ed. St. Louis: Mosby; 2002.

FIGURE 29-1 A, Anatomic mapping of the four quadrants of the abdomen. B, Auscultation for bowel sounds. (From Barkauskas V, et al. *Health & Physical Assessment.* 3rd ed. St. Louis: Mosby; 2002.)

Inspection

Inspection should be performed in a warm, well-lit environment, and the patient should be in a comfortable position, with the abdomen exposed. Although assessment of the GI system classically begins with inspection of the abdomen, the patient’s oral cavity also must be inspected to determine any unusual findings. Abnormal findings of the mouth include temporomandibular joint tenderness, inflammation of gums, missing teeth, dental caries, ill-fitting dentures, and mouth odor.

Observe the skin for pigmentation, lesions, striae, scars, petechiae, signs of dehydration, and venous pattern. Pigmentation may vary considerably and still be within normal limits because of race and ethnic background, although the abdomen usually is of a lighter color than other exposed areas of the skin. Abnormal findings include jaundice, skin lesions, and a tense and glistening appearance of the skin. Old striae (stretch marks) usually are silver, whereas pinkish purple striae may indicate Cushing syndrome.⁴ A bluish discoloration of the umbilicus (Cullen sign) and of the flank (Grey-Turner sign) indicates retroperitoneal bleeding.¹

Observe the abdomen for contour, noting whether it is flat, slightly concave, or slightly round; observe for symmetry and for movement. Marked distention is an abnormal finding. In particular, ascites may cause generalized distention and bulging flanks. Asymmetric distention may indicate organ enlargement or a mass. Peristaltic waves should not be visible except in very thin patients. In the case of intestinal obstruction, hyperactive peristaltic waves may be observed. Pulsation in the epigastric area is often a normal finding, but increased pulsation may indicate an aortic aneurysm. Symmetric movement of the abdomen with respirations is usually seen in men.4,5

Auscultation

Auscultation of the abdomen provides clinical data regarding the status of the bowel’s motility. Initially, listen with the diaphragm of the stethoscope below and to the right of the umbilicus. The examination proceeds methodically through all four quadrants, lifting and then replacing the diaphragm of the stethoscope lightly against the abdomen (see Fig. 29-1). Normal bowel sounds include high-pitched, gurgling sounds that occur approximately every 5 to 15 seconds or at a rate of 5 to 34 times per minute. Colonic sounds are low pitched and have a rumbling quality. A venous hum may be audible sometimes.⁶ Table 29-1 provides a list of abnormal abdominal sounds.

TABLE 29-1

ABNORMAL ABDOMINAL SOUNDS

SOUND	CAUSE
Hyperactive bowel sounds (borborygmi), loud and prolonged	Hunger, gastroenteritis, or early intestinal obstruction
High-pitched, tinkling sounds	Intestinal air and fluid under pressure; characteristic of early intestinal obstruction
Decreased (hypoactive) bowel sounds	Possible peritonitis or ileus
Infrequent and abnormally faint sounds
Absence of bowel sounds (confirmed only after auscultation of all four quadrants and continuous auscultation for 5 minutes)	Temporary loss of intestinal motility, as occurs with complete ileus
Friction rubs	Pathologic conditions such as tumors or infection that cause inflammation of organ’s peritoneal covering
High-pitched sounds heard over liver and spleen (RUQ and LUQ), synchronous with respiration
Bruits	Abnormality of blood flow (requires additional evaluation to determine specific disorder)
Audible swishing sounds that may be heard over aortic, iliac, renal, and femoral arteries
Venous hum	Increased collateral circulation between portal and systemic venous systems
Low-pitched, continuous sound

LUQ, Left upper quadrant; RUQ, right upper quadrant.

From Doughty DB, Jackson DB. Gastrointestinal Disorders. St. Louis: Mosby; 1993.

Abnormal findings include the absence of bowel sounds throughout a 5-minute period, extremely soft and widely separated sounds, and increased sounds with a high-pitched, loud rushing sound (peristaltic rush). Absent bowel sounds may result from inflammation, ileus, electrolyte disturbances, and ischemia. Bowels sounds may be increased with diarrhea and early intestinal obstruction.⁶

The abdomen should be auscultated for the presence of bruits, using the bell of the stethoscope (Fig. 29-2). Bruits are created by turbulent flow over a partially obstructed artery and are always considered an abnormal finding. The aorta, the right and left renal arteries, and the iliac arteries should be auscultated.^5,6

FIGURE 29-2 Auscultation for bruits. The left illustration shows the correct placement of the stethoscope. (From Barkauskas V, et al. *Health & Physical Assessment.* 3rd ed. St. Louis: Mosby; 2002.)

Percussion

Percussion is used to elicit information about deep organs such as the liver, spleen, and pancreas (Fig. 29-3). Because the abdomen is a sensitive area, muscle tension may interfere with this part of the assessment. Percussion often helps relax tense muscles, and it is performed before palpation. Percussion in the absence of disease helps delineate the position and size of the liver and spleen, and it assists in the detection of fluid, gaseous distention, and masses in the abdomen.⁵

Percussion should proceed systematically and lightly in all four quadrants. Normal findings include tympany over the empty stomach, tympany or hyper-resonance over the intestine, and dullness over the liver and spleen. Abnormal areas of dullness may indicate an underlying mass. Solid masses, enlarged organs, and a distended bladder also produce areas of dullness. Dullness over both flanks may indicate ascites and necessitates further assessment.⁶

Palpation

Palpation is the assessment technique most useful in detecting abdominal pathologic conditions. Light and deep palpation of each organ and quadrant should be completed. Light palpation, which has a palpation depth of approximately 1 cm, assesses to the depth of the skin and fascia (Fig. 29-4A). Deep palpation assesses the rectus abdominis muscle and is performed bimanually to a depth of 4 to 5 cm (see Fig. 29-4B). Deep palpation is most helpful in detecting abdominal masses. Areas in which the patient complains of tenderness should be palpated last.⁶

Normal findings include no areas of tenderness or pain, no masses, and no hardened areas. Persistent involuntary guarding may indicate peritoneal inflammation, particularly if it continues even after relaxation techniques are used. Rebound tenderness, in which pain increases with quick release of a palpated area, indicates an inflamed peritoneum.⁴

Assessment Findings for Common Disorders

Table 29-2 presents a variety of common GI disorders and their associated assessment findings.

TABLE 29-2

ASSESSMENT FINDINGS OF COMMON GASTROINTESTINAL DISORDERS

CONDITION	HISTORY	SYMPTOMS	SIGNS
Right Lower Quadrant (RLQ) of the Abdomen
Appendicitis	Children (except infants) and young adults	Anorexia	Signs may be absent early
		Nausea	Vomiting
		Early vague epigastric, periumbilical, or generalized pain after 12-24 hours; RLQ at McBurney point	Localized RLQ guarding and tenderness after 12-24 hours
			Rovsing sign: pain in RLQ with application of pressure, iliopsoas sign
			Obturator sign
			White blood cell count of 10,000/mm³ or shift to left
			Low-grade fever
			Cutaneous hyperesthesia in RLQ
			Signs highly variable
Perforated duodenal ulcer	Prior history	Abrupt onset pain in epigastric area or RLQ	Tenderness in epigastric area or RLQ
Perforated duodenal ulcer	Prior history	Abrupt onset pain in epigastric area or RLQ	Signs of peritoneal irritation
			Heme-positive stool
			Increased white blood cell count
Cecal volvulus	Seen most often in older adults	Abrupt severe abdominal pain	Distention
			Localized tenderness
			Tympany
Strangulated hernia	Any age	Severe localized pain	If bowel obstructed, distention
	Women: femoral	If bowel obstructed, generalized pain
	Men: inguinal
Right Upper Quadrant (RUQ) of the Abdomen
Liver hepatitis	Any age, often young blood product user	Fatigue	Hepatic tenderness
Liver hepatitis	Any age, often young blood product user	Malaise	Hepatomegaly
	Drug addict	Anorexia	Bilirubin elevated
		Pain in RUQ	Jaundice
		Low-grade fever	Lymphocytosis in one third of cases
		May have severe fulminating disease with liver failure	Liver enzymes elevated
		May have severe fulminating disease with liver failure	Hepatitis A or B or antibodies to the viruses may be found
Acute hepatic congestion	Usually older adults with acute heart failure	Symptoms of acute heart failure	Hepatomegaly
	Pericardial disease		Acute heart failure
	Pulmonary embolism
Biliary stones, colic	“Fair, fat, forty” (90%) but can be 30 to 80 years old	Anorexia Nausea	Tenderness in RUQ Jaundice
		Pain severe in RUQ or epigastric area
		Episodes lasting 15 minutes to hours
Acute cholecystitis	“Fair, fat, forty” (90%) but may be 30 to 80 years old	Severe RUQ or epigastric pain	Vomiting
		Episodes prolonged up to 6 hours	Tenderness in RUQ
			Peritoneal irritation signs
			Increased white blood cell count
Perforated peptic ulcer	Any age	Abrupt RUQ pain	Tenderness in epigastrium, right quadrant, or both
			Peritoneal irritation signs
			Free air in abdomen
Left Upper Quadrant (LUQ) of the Abdomen
Splenic trauma	Blunt trauma to LUQ of abdomen	Pain: LUQ pain of the abdomen often referred to the left shoulder (Kehr sign)	Hypotension
	Blunt trauma to LUQ of abdomen		Syncope
			Increased dyspnea
			Radiographic studies show enlarged spleen
Pancreatitis	Alcohol abuse	Pain in LUQ or epigastric region radiating to the back or chest	Fever
	Pancreatic duct obstruction		Rigidity
			Rebound tenderness
	Infection		Nausea
	Cholecystitis		Vomiting
			Jaundice
			Cullen sign
			Turner sign
			Abdominal distention
			Diminished bowel sounds
Pyloric obstruction	Duodenal ulcer	Weight loss	Increasing dullness in LUQ
		Gastric upset	Visible peristaltic waves in epigastric region
		Vomiting
Left Lower Quadrant (LLQ) of the Abdomen
Ulcerative colitis	Family history	Chronic, watery diarrhea with bloody mucus	Fever
	Jewish ancestry
	Cachexia
		Anorexia	Anemia
		Weight loss	Leukocytosis
		Fatigue
Colonic diverticulitis	Older than 39 years	Pain that recurs in LUQ	Fever
	Low-residue diet	Pain that recurs in LUQ	Vomiting
			Chills
			Diarrhea
			Tenderness over descending colon

Modified from Barkauskas V, et al. Health & Physical Assessment. 3rd ed. St. Louis: Mosby; 2002.

Laboratory Studies

The value of various laboratory studies used to diagnose and treat diseases of the GI system has been emphasized often. However, no single study provides an overall picture of the various organs’ functional state, and no single value is predictive by itself. Laboratory studies used in the assessment of GI function, liver function, and pancreatic function are found in Tables 29-3, 29-4, and 29-5, respectively.

TABLE 29-3

SELECTED LABORATORY STUDIES OF GASTROINTESTINAL FUNCTION

TEST	NORMAL FINDINGS	CLINICAL SIGNIFICANCE OF ABNORMAL FINDINGS
Stool studies	Resident microorganisms: clostridia, enterococci, Pseudomonas, a few yeasts	Detection of Salmonella typhi (typhoid fever), Shigella (dysentery), Vibrio cholerae (cholera), Yersinia (enterocolitis), Escherichia coli (gastroenteritis), Staphylococcus aureus (food poisoning), Clostridium botulinum (food poisoning), Clostridium perfringens (food poisoning), Aeromonas (gastroenteritis)
	Fat: 2-6 g/24 hr	Steatorrhea (increased values) resulting from intestinal malabsorption or pancreatic insufficiency
	Pus: none	Large amounts of pus associated with chronic ulcerative colitis, abscesses, and anorectal fistula
	Occult blood: none (ortho-toluidine or guaiac test)	Positive test results associated with bleeding
	Ova and parasites: none	Detection of Entamoeba histolytica (amebiasis), Giardia lamblia (giardiasis), and worms
d-Xylose absorption	5-hr urinary excretion: 4.5 g/L	Differentiation of pancreatic steatorrhea (normal d-xylose absorption) from intestinal steatorrhea (impaired d-xylose absorption)
d-Xylose absorption	Peak blood level: >30 mg/dL
Gastric acid stimulation	11-20 mEq/hr after stimulation	Detection of duodenal ulcers, Zollinger-Ellison syndrome (increased values), gastric atrophy, gastric carcinoma (decreased values)
Manometry*	Values vary at different levels of the intestine	Inadequate swallowing, motility, sphincter function
Culture and sensitivity of duodenal contents	No pathogens	Detection of Salmonella typhi (typhoid fever)
Breath tests
Glucose or d-xylose breath test	Negative for hydrogen or carbon dioxide	May indicate intestinal bacterial overgrowth
Urea breath test	Negative for isotopically labeled carbon dioxide	Presence of Helicobacter pylori infection
Lactose breath test	Negative for exhaled hydrogen	Lactose intolerance

^*Use of water-filled catheters connected to pressure transducers passed into the esophagus, stomach, colon, or rectum to evaluate contractility.

From McCance KL, Huether SE, eds. Pathophysiology: The Biologic Basis for Disease in Adults and Children. 6th ed. St. Louis: Mosby; 2010.

TABLE 29-4

COMMON LABORATORY STUDIES OF LIVER FUNCTION

TEST	NORMAL VALUE	INTERPRETATION
Serum Enzymes
Alkaline phosphatase	13-39 units/L	Increases with biliary obstruction and cholestatic hepatitis
	Male 12-39 units/L
	Female 9-31 units/L
Aspartate aminotransferase (AST; previously serum glutamate oxaloacetate transaminase [SGOT])	5-40 units/L	Increases with hepatocellular injury (and injury in other tissues, i.e., skeletal and cardiac muscle)
Alanine aminotransferase (ALT; previously serum glutamate pyruvate transaminase [SGPT])	5-35 units/L	Increases with hepatocellular injury and necrosis
Lactate dehydrogenase (LDH)	0-250 units/L	Isoenzyme lactate dehydrogenase (LD₅) is elevated with hypoxic and primary liver injury
5′-Nucleotidase	2-11 units/L	Increases with increase in alkaline phosphatase and cholestatic disorders
Bilirubin Metabolism
Serum bilirubin
Indirect (unconjugated)	0-1.0 mg/dL	Increases with hemolysis (lysis of red blood cells)
Direct (conjugated)	0-0.3 mg/dL	Increases with hepatocellular injury or obstruction
Total	0-1.0 mg/dL	Increases with biliary obstruction
Urine bilirubin	0.2-1.3 mg/dL	Increases with biliary obstruction
Urine urobilinogen	0.3-2.1 mg/2 hr (male)	Increases with hemolysis or shunting or portal blood flow
Urine urobilinogen	0.1-1.1 mg/2 hr (female)	Increases with hemolysis or shunting or portal blood flow
Serum Proteins
Albumin	4.0-6.0 g/dL	Decreases with hepatocellular injury
Globulin	2.0-4.0 g/dL	Increases with hepatitis
Total	6-8 g/dL
Albumin-to-globulin (A/G) ratio	1.5-2.5 : 1	Ratio reverses with chronic hepatitis or other chronic liver disease
Transferrin	250-300 mcg/dL	Liver damage with decreased values, iron deficiency with increased values
Alpha-fetoprotein	<10 ng/dL	Elevated values in primary hepatocellular carcinoma
Blood Clotting Functions
Prothrombin time	10-14 sec or 90% of control	Increases with chronic liver disease (cirrhosis) or vitamin K deficiency
International normalized ratio (INR)	0.9-1.3	Increased values indicate high chance of bleeding; useful for monitoring effects of drugs such as warfarin
Partial thromboplastin time (PTT)	25-40 sec	Increases with severe liver disease or heparin therapy
Bromsulphalein (BSP) excretion	<6% retention in 45 min	Increased retention with hepatocellular injury

From McCance KL, Huether SE, eds. Pathophysiology: The Biologic Basis for Disease in Adults and Children. 6th ed. St. Louis: Mosby; 2010.

TABLE 29-5

COMMON LABORATORY STUDIES OF PANCREATIC FUNCTION

TEST	NORMAL VALUE	CLINICAL SIGNIFICANCE
Serum amylase	60-180 Somogyi units/mL	Elevated levels with pancreatic inflammation
Serum lipase	1.5 Somogyi units/mL	Elevated levels with pancreatic inflammation (may be elevated with other conditions; differentiates with amylase, isoenzyme study)
Urine amylase	35-260 Somogyi units/hr	Elevated levels with pancreatic inflammation
Secretin test	Volume 1.8 mL/kg/hr	Decreased volume with pancreatic disease because secretin stimulates pancreatic secretion
	Bicarbonate concentration: >80 mEq/L
	Bicarbonate output: >10 mEq/L/30 sec
Stool fat	2-5 g/25 hr	Measures fatty acids: decreased pancreatic lipase increases stool fat

From McCance KL, Huether SE, eds. Pathophysiology: The Biologic Basis for Disease in Adults and Children. 6th ed. St. Louis: Mosby; 2010.

Diagnostic Procedures

To complete the assessment of the critically ill patient with GI dysfunction, the patient’s diagnostic tests are reviewed. Although many procedures exist for diagnosing GI disease, their application in the critically ill patient is limited. Only procedures that are currently used in the critical care setting are presented here.

The nursing management of a patient undergoing a diagnostic procedure involves a variety of interventions. Nursing actions include preparing the patient psychologically and physically for the procedure, monitoring the patient’s responses to the procedure, and assessing the patient after the procedure. Preparing the patient includes teaching the patient about the procedure, answering any questions, and transporting and positioning the patient for the procedure. Monitoring the patient’s responses to the procedure includes observing the patient for signs of pain, anxiety, or hemorrhage and monitoring vital signs. Assessing the patient after the procedure includes observing for complications of the procedure and medicating the patient for any postprocedural discomfort. Any evidence of GI bleeding should be immediately reported to the physician, and emergency measures to maintain circulation must be initiated.

Endoscopy

Available in several forms, fiberoptic endoscopy is a diagnostic procedure for the direct visualization and evaluation of the GI tract. Endoscopy can provide information about lesions, mucosal changes, obstructions, and motility dysfunction, and a biopsy specimen can be obtained during the procedure. The main difference between the various diagnostic forms is the length of the anatomic area that can be examined. Esophagogastroduodenoscopy (EGD) permits viewing of the upper GI tract from the esophagus to the upper duodenum, and it is used to evaluate sources of upper GI bleeding (Fig. 29-5). Colonoscopy permits viewing of the lower GI tract from the rectum to the distal ileum, and it is used to evaluate sources of lower GI bleeding. Enteroscopy permits viewing of the small bowel beyond the ligament of Treitz, and it is used to evaluate sources of GI bleeding that have not been identified previously with EGD or colonoscopy. Endoscopic retrograde cholangiopancreatography (ERCP) enables viewing of the biliary and pancreatic ducts, and it is used in the evaluation of pancreatitis. During this procedure, contrast is injected into the ducts through the endoscope, and radiographs are obtained.⁷ Endoscopy also provides therapeutic benefits for a variety of conditions, including GI bleeding.⁸

FIGURE 29-5 Endoscopic appearance of a Mallory-Weiss tear with mild oozing. Note that the tear starts at the gastroesophageal junction *(large arrow)* and extends distally into the hiatal hernia *(small arrow)*. (From Feldman M, et al. *Sleisenger and Fordtran’s Gastrointestinal and Liver Disease.* 9th ed. Philadelphia: Saunders; 2010.)

Nursing Management

The patient should take nothing by mouth (NPO) for 6 to 12 hours before endoscopy of the upper GI tract. The patient should receive a bowel preparation before endoscopy of the lower GI tract.⁷ In some cases, the procedure is performed at the patient’s bedside, particularly if the patient is actively bleeding and too unstable to be moved to the GI suite. Fiberoptic endoscopy may present risks for the patient. Although rare, potential complications include perforation of the GI tract, hemorrhage, aspiration, vasovagal stimulation, and oversedation.⁷ Signs of perforation include abdominal pain and distention, GI bleeding, and fever.⁹

Angiography

Angiography is used as a diagnostic and a therapeutic procedure. Diagnostically, it is used to evaluate the status of the GI circulation (Fig. 29-6).⁷ Therapeutically, it is used to achieve transcatheter control of GI bleeding.¹⁰ Angiography is used in the diagnosis of upper gastrointestinal (UGI) bleeding only when endoscopy fails, and it is used to treat patients (approximately 15%) whose GI bleeding is not stopped with medical measures or endoscopic treatment.¹⁰ Angiography also is used to evaluate cirrhosis, portal hypertension, intestinal ischemia, and other vascular abnormalities.⁷

FIGURE 29-6 Arteriogram of superior mesenteric artery shows diverticular bleeding. Note the area of contrast extravasation. (From Doughty DB, Jackson DB. *Gastrointestinal Disorders*. St. Louis: Mosby; 1993.)

The radiologist cannulates the femoral artery with a needle and passes a guidewire through it into the aorta. The needle is removed, and an angiographic catheter is inserted over the guidewire. The catheter is advanced into the vessel supplying the portion of the GI tract that is being studied. After the catheter is in place, contrast medium is injected, and serial radiographs are obtained. If the procedure is undertaken to control bleeding, vasopressin (Pitressin Synthetic) or embolic material (Gelfoam) is injected after the site of the bleeding is located.¹⁰

Nursing Management

Complications include overt and covert bleeding at the femoral puncture site, neurovascular compromise of the affected leg, and sensitivity to the contrast medium. Before the procedure, the patient should be asked about any sensitivity to contrast. Postprocedural assessment involves monitoring vital signs, observing the injection site for bleeding, and assessing neurovascular integrity distal to the injection site every 15 minutes for the first 1 to 2 hours. Depending on how the puncture site is stabilized after the procedure, the patient may have to remain flat in bed for a specified length of time. Any evidence of bleeding or neurovascular impairment must be immediately reported to the physician.¹¹

Plain Abdominal Series

Although numerous radiologic studies are available to investigate GI dysfunction further, many of these studies are not performed on the critically ill patient. The radiologic study that is performed most often is the plain abdominal series (Fig. 29-7). An abdominal radiograph is useful in the diagnosis of a bowel obstruction and perforation.¹²

FIGURE 29-7 Abdominal flat plate radiograph. Note the air in the patient’s stomach. (From Mettler F. *Essentials of Radiology*. 2nd ed. Philadelphia: Saunders; 2005.)

Air in the bowel serves as a contrast medium to aid in the visualization of the bowel. Gas patterns (the presence of gas inside or outside the bowel lumen and the distribution of gas in dilated and nondilated bowel) are best revealed by plain radiographs. Common radiologic signs of free air in the abdomen include the presence of air on both sides of the bowel wall and the presence of air in the right upper quadrant anterior to the liver.¹² Table 29-6 lists common radiologic findings. Abdominal radiographs are used to verify nasogastric or feeding tube placement.

TABLE 29-6

PLAIN FILM FINDINGS

FINDING	APPEARANCE	ASSOCIATIONS
Pneumoperitoneum	Air seen under diaphragm on upright chest or overlying right lobe of liver on left lateral decubitus films	Most commonly associated with bowel perforation, although other causes exist
Peritoneal fluid	Medial displacement of colon separated from flank stripes by fluid density on flat plate	Ascites or hemorrhage
Adynamic ileus	Dilatation of entire intestinal tract, including stomach	Many causes, including trauma, infection (intra-abdominal and extra-abdominal), metabolic disease, and medications (e.g., narcotics)
Sentinel loop	Single distended loop of small bowel containing an air-fluid level	Represents localized ileus associated with localized inflammatory process such as cholecystitis, appendicitis, or pancreatitis
Small bowel obstruction	Dilated loops of small bowel (distinguished by valvulae conniventes, thin, transverse linear densities that extend completely across diameter of bowel) with air-fluid levels	Can be associated with other serious pathology such as incarcerated hernia, appendicitis, or mesenteric ischemia
Large bowel obstruction	Dilated loops, usually more peripheral in the abdomen (distinguished by haustra—short, thick indentations that do not completely cross-bowel and are less frequently spaced than valvulae conniventes)	Can be associated with diverticulitis and malignancy
Cecal volvulus	Usually found in middle or upper abdomen to the left; often kidney shaped
Sigmoid volvulus	Dilated loop of colon arising from left side of pelvis and projecting obliquely upward toward right side of abdomen
Early ischemic bowel findings	May resemble mechanical obstruction with dilated loops and air-fluid levels
Later ischemic bowel findings	May resemble a dynamic ileus; thumbprinting (edema of bowel wall with convex indentations of lumen) and pneumatosis intestinalis (linear or mottled gas pattern in bowel wall)
Gallbladder emergency findings	Ring of air outlining the gallbladder Air in biliary tree combined with signs of small bowel obstruction, possibly with visible calculus in pelvis	Emphysematous cholecystitis Gallstone ileus
Abdominal aortic aneurysm (AAA)	Usually appears left of midline on supine film and anterior to spine in lateral projection; calcification in wall of aneurysm is variable	Ruptured or leaking AAA may reveal loss of psoas shadows or large soft tissue mass

From Hendrickson M, Naparst TR. Abdominal surgical emergencies in the elderly. Emerg Med Clin North Am. 2003;21:937.

Computed Tomography of the Abdomen

Computed tomography (CT) is a radiographic examination that provides cross-sectional images of internal anatomy (Fig. 29-8). It may be used to evaluate abdominal vasculature and identify focal points found on nuclear scans as solid, cystic, inflammatory, or vascular.¹⁴ CT detects mass lesions more than 2 cm in diameter and allows visualization and evaluation of many different aspects of GI disease. It is particularly useful in identifying pancreatic pseudocysts, abdominal abscesses, biliary obstructions, and a variety of GI neoplastic lesions.¹⁵

FIGURE 29-8 Abdominal computed tomography (CT) in patient with abundant *(A)* and little *(B)* intra-abdominal fat. 1, Pancreas; 2, gallbladder; 3, crus of the diaphragm; 4, aorta; 5, superior mesenteric artery; 6, inferior vena cava with left renal vein; 7, left kidney; 8, right kidney; 9, liver; *10,* bowel; *11,* splenoportal confluence. (From Seeram E. *Computed Tomography: Physical Principles, Clinical Applications, and Quality Control.* 3rd ed. St. Louis: Saunders; 2009.)

The procedure involves taking the patient to the CT scanner, placing the patient on the table, and inserting the area to be studied into the opening of the scanner. Multiple scans are obtained at various angles, and a computer synthesizes images of the structures being studied. Intravenous or GI contrast may be used to facilitate the imaging of the blood vessels or the GI tract, respectively.¹⁴

Nursing Management

Before the procedure, the patient should be asked about any sensitivity to contrast. The procedure usually takes 30 minutes without contrast and 60 minutes with contrast, during which time the patient must lie very still. No special interventions are required before or after the procedure.¹¹

Hepatobiliary Scintigraphy

A hepatobiliary scan is a nuclear scan that is used to assess the status of the liver and the biliary system. It is valuable in detecting GI abnormalities such as acute and chronic cholecystitis, biliary obstruction, and bile leaks, and it yields additional information about organ size.¹⁶

The scan involves injecting an intravenous technetium 99m (^99mTc)–labeled iminodiacetic agent (radiotracer), such as disofenin (DISIDA) or mebrofenin (TMBIDA). Serial images are then obtained using a gamma (scintillation) camera. The liver cells take up 80% to 90% of the radiotracer, which is then secreted into the bile and transported throughout the biliary system, allowing visualization of the biliary tract, the gallbladder, and the duodenum.⁷ Pooling of the iminodiacetic agent around the liver indicates poor uptake and hepatocellular dysfunction.¹⁶

Nursing Management

The hepatobiliary scan is relatively noninvasive and safe, although the patient must be transported to the nuclear medicine department. The patient may need to maintain NPO status for 2 to 4 hours before the procedure. Sedation is usually not required, but the patient must be able to lie flat and remain still for 60 minutes during the scanning procedure. No special interventions are required after the procedure.¹¹

Gastrointestinal Bleeding Scan

A GI bleeding scan is used to evaluate the presence of an active bleed, to identify the site of the bleed, and to assess the need for an arteriogram.¹⁷ The GI bleeding scan is sensitive to low rates of bleeding (0.1 milliliters per minute [mL/min]), but it is reliable only when the patient is actively bleeding.^7,17

The scan is usually performed with intravenous ^99mTc-labeled sulfur colloid or ^99mTc-labeled red blood cells (radiotracers). To tag the red blood cells, a blood sample is taken from the patient. The red blood cells are separated, tagged with ^99mTc, and then returned to the patient. Serial images are obtained using a gamma (scintillation) camera. Extravasation and accumulation or pooling of radiotracers in the bowel lumen indicates active bleeding is occurring and facilitates identification of the site.7,17

Nursing Management

The GI bleeding scan is relatively noninvasive and safe, although the patient must be transported to the nuclear medicine department. Sedation usually is not required, but the patient must be able to lie flat and remain still for 60 minutes or longer during the scanning procedure. No special interventions are required after the procedure.¹¹

Magnetic Resonance Imaging

Magnetic resonance imaging (MRI) is used to identify tumors, abscesses, hemorrhages, and vascular abnormalities. Small tumors, whose tissue densities are different from those of the surrounding cells, can be identified before they would be visible on any other radiographic test.⁷ Magnetic resonance angiography (MRA) is a form of MRI that is used to assess blood vessels and blood flow.¹⁴ Magnetic resonance cholangiopancreatography (MRCP) is a form of MRI used to evaluate the biliary and pancreatic ducts.¹⁸

During MRI, the patient is placed in a large magnetic field that stimulates the protons of the body. Introduction of radiofrequency waves causes resonance of these protons, which then emit an image that a computer is able to reconstruct for viewing. Intravenous administration of a non–iodine-based contrast medium enhances the image by influencing the magnetic environment and signal intensity.¹⁴

Nursing Management

The MRI procedure is lengthy and requires that the patient be transported to the scanner. The patient must lie motionless in a tight, enclosed space (if a closed MRI scanner is used), and sedation may be necessary. Removal of all metal from the patient’s body is essential because the basis of MRI is a magnetic field. Patients with implanted metal objects are not candidates for the procedure. No special interventions are required after the procedure.¹¹

Percutaneous Liver Biopsy

Liver biopsy is a diagnostic procedure that is used to evaluate liver disease. Morphologic, biochemical, bacteriologic, and immunologic studies are performed on the tissue sample to diagnose liver disorders such as cirrhosis, hepatitis, infections, or cancer. A biopsy can also yield information about the progression of the patient’s disease and response to therapy.7,19

Percutaneous liver biopsy can be performed at the bedside or in the imaging department and involves the use of an imaging-guided needle.²⁰ Before the test, the patient should maintain NPO status for 6 hours and have blood drawn for coagulation studies. The procedure is performed by anesthetizing the pericapsular tissue, inserting a coring or suction needle between the eighth and ninth intercostal space into the liver while the patient holds his or her breath on exhalation, withdrawing the needle with the sample, and applying pressure to stop the bleeding.⁷