Chapter 28 Abdominal Pain and Emergencies

Abdominal pain is present in about 6% of approximately 100 million emergency department visits and is one of the most common chief complaints.¹ Although most abdominal pain is benign, as many as 10% of patients in the emergency department setting have a severe or life-threatening cause of abdominal pain or require surgery.²

Abdominal pain is categorized as visceral, parietal, or referred. The gastrointestinal (GI) tract contains both visceral and parietal pain receptors. The visceral receptors are located throughout the abdomen, while the parietal pain receptors are located in the peritoneum. Irritation of the somatic or parietal receptors causes more localized, sharper pain.

Visceral pain replaced by somatic pain often signals need for a surgical intervention.³

Pain can further be reduced to intra-abdominal or extra-abdominal; causes of abdominal pain can be classified as GI, genitourinary, cardiac, pulmonary, or neurogenic (Table 28-1). Because initial determination of pain etiology is frequently not possible, the patient presenting with abdominal complaints should be treated as urgent or emergent until proven otherwise. Initial treatment should be directed toward identifying and treating the cause of the pain.

TABLE 28-1 ABDOMINAL PAIN PATTERNS AND POSSIBLE ETIOLOGIES

Diffuse Pain	Epigastric Pain	Left Upper Quadrant
• Acute gastroenteritis • Sickle cell crisis • DKA • Peritonitis • IBS • Intestinal obstruction • Constipation	• Acute gastroenteritis • PUD • GERD • AAA • Early perforated viscus • Acute pancreatitis • Acute MI	• Gastritis or PUD • Left lower lobe pneumonia • Splenic infarct or rupture • Splenic enlargement: mononucleosis or leukemia • Left renal colic or pyelonephritis • Herpes zoster
Left Lower Quadrant	Right Upper Quadrant	Right Lower Quadrant
• Ovarian torsion or cyst rupture • PID or salpingitis • Inguinal hernia • Diverticulitis • Ruptured ectopic or mittelschmerz	• Hepatitis or biliary tract disease or abscess • Right lower lobe pneumonia • Right pyelonephritis or colic • Herpes zoster • Hepatomegaly	• Inguinal hernia • Acute appendix • Ovarian torsion, cyst, or mittelschmerz • Ruptured ectopic • PID, tubo-ovarian abscess, or salpingitis • Mesenteric adenitis or Meckel’s diverticulitis

AAA, Abdominal aortic aneurysm; DKA, diabetic ketoacidosis; GERD, gastroesophageal reflux disease; IBS, irritable bowel syndrome; MI, myocardial infarction; PID, pelvic inflammatory disease; PUD, peptic ulcer disease.

Initial Evaluation

History

• Focus on the patient’s pain history. The location of pain should drive the evaluation; also ask about pain radiation and the effect of movement or change in body position on the pain.² Pain preceding vomiting (as compared to vomiting before pain) and severe pain lasting 6 or more hours are more likely associated with a surgical condition.

Other considerations ³:

• Anorexia, nausea, and vomiting are directly proportional to the severity and extent of peritoneal irritation.

• Colic—sharp localized abdominal pain that increases, peaks, and subsides—may indicate a class of diseases of hollow viscera contracting related to a calculi, obstruction, etc.

• Determine the date of last bowel movement especially in the elderly and post-operative patient.

• Determine positive past medical history of abdominal surgery and infectious illnesses.

In the patient with abdominal pain, hypovolemia should always be considered if the patient’s heart rate is greater than 130 beats per minute, especially in the presence of anorexia, nausea, or vomiting.

Physical Assessment

Diagnostic Procedures

• Basic laboratory procedures, including complete blood count (CBC) and complete metabolic panel, are routinely ordered. Simultaneous amylase and lipase measurements are recommended in patients with epigastric pain.²

• The American College of Radiology recommends ultrasonography to assess right upper quadrant pain ⁶ and computed tomography (CT) to assess right and left lower quadrant pain.^7,⁸ These should also be considered in special populations, such as the elderly, who may present with atypical symptoms (“the atypical is typical in the elderly”).

Symptoms with abdominal pain that are suggestive of surgical or emergent conditions include ²:

• Fever

• Protracted vomiting

• Syncope or presyncope

• Evidence of GI blood loss

Specific Abdominal Emergencies

Peritonitis ^4,⁵

Primary peritonitis occurs when blood-borne organisms enter the peritoneal cavity. Secondary peritonitis, a much more common occurrence, results when abdominal organs perforate and release their contents (bile, enzymes, bacteria) into the peritoneal cavity. An initial chemical peritonitis is followed by bacterial peritonitis a few hours later. Possible causes include the following:

• Ruptured appendix

• Pancreatitis

• Trauma from a gunshot or knife wound

• Peritoneal dialysis

Signs and Symptoms

• Evidence of hypovolemic shock because of a massive fluid shift into the peritoneum.

• Tenderness over the involved area. However, if perforation exists, the patient can feel temporary relief from the release of the pressure, followed by a return of significant, generalized pain.

• “Guarding,” or protection of the area by positioning, or refusing to allow examination of the area.

• Rigid, “boardlike” abdomen (muscles spasm from the irritation).

Diagnostic Procedures

For all conditions, a history, physical assessment, and general laboratory work (CBC, electrolytes) are routinely prescribed. In addition to the routine diagnostic procedures, physical assessments include the following:

• Positive rebound tenderness: Apply deep palpation pressure. Pain is worse when released because of the irritation of the perineum.

• Heel drop (Markle test): Patient stands, rises on tiptoes with knees straight, and forcibly drops down on both heels to test for generalized peritoneal irritation. An alternative is to have the patient hop on one leg. When the patient is in severe discomfort, the same assessment can be made by firmly striking the supine patient’s heel to cause jarring in the peritoneum.

Therapeutic Interventions

Acute abdominal conditions require standard treatment:

• Keep patient nothing by mouth (NPO), insert nasogastric tube (NGT), and initiate bowel rest

• Obtain intravenous (IV) access and replace fluid and electrolytes as indicated

• Administer analgesics, antiemetics, and antibiotics as prescribed

• Anticipate surgical intervention

Acute Gastroenteritis ^7,⁸

Acute gastroenteritis can be bacterial, viral, or chemical in origin. The patient may present with dehydration; the very young or the elderly may experience hypovolemia.

Signs and Symptoms

• Diarrhea with nausea and vomiting.

• Pain is usually characterized as diffuse, sometimes crampy, lower abdominal pain.

• Fever.

• Signs of dehydration such as tachycardia and warm, dry skin.

• Splenomegaly may be noted, indicating gastroenteritis of bacterial origin.

Diagnostic Procedures

• Ova and parasite testing for stool as appropriate.

• Electrocardiogram is recommended for women, patients with diabetes, and the elderly as nausea and vomiting can be indicative of a cardiac event.

• Digoxin (Lanoxin) levels in the elderly population on this drug. Digoxin is excreted by the kidney, which decreases function by 1% every year of life after age 30 years. Early signs of toxicity are nausea and vomiting.

• Rule out appendicitis, as the conditions can imitate each other. See “Appendicitis” below.

• Differentiate from gastritis (left upper quadrant or epigastric pain or tenderness), which is a gastric mucosa irritation most commonly caused by smoking, alcohol, or medications.

Therapeutic Interventions

• Establish IV access to replace fluid and electrolytes as indicated.

• Administer antiemetics.

• Facilitate pain control if needed.

• Most gastroenteritis is self-limiting. The patient should be NPO until vomiting has ceased. As soon as tolerated, encourage oral intake of fluids with glucose and electrolytes (e.g., Pedialyte).

Appendicitis ^1,^2,^9,¹⁰

Appendicitis occurs when an obstruction of the appendiceal lumen results in a decrease in blood supply which, if left untreated, may progress to necrosis, perforation, and peritonitis.

Appendicitis is the most common surgical cause of abdominal pain. Overall, 7% of the population will be affected over their lifetime. One to three percent of emergency department visits for abdominal pain are appendicitis.¹ It is most commonly found in males between the ages of 10 and 30 years. The elderly and children are more likely to have atypical presentations.

Signs and Symptoms

• The classic presentation of appendicitis is a mild fever with dull steady periumbilical pain, anorexia, and nausea.

• Over the course of 12 to 48 hours, the pain typically moves to the right lower quadrant at McBurney’s point, the point on the lower abdomen that lies between the umbilicus and the right superior iliac spine.

• Anorexia; nausea and vomiting.

• Psoas sign may be present 6% to 30% of the time.

• To assess for the psoas sign, the nurse passively extends the right thigh of a patient lying on his or her side with knees extended or asks the patient to actively flex his or her right thigh at the hip. If right lower quadrant abdominal pain results, it is a “positive” psoas sign.

• Pain results because the psoas muscle borders the peritoneal cavity and moving it causes friction against the nearby inflamed tissues.

• Rebound tenderness.

• Abdominal rigidity.

Diagnostic Procedures ^2,⁵

Appendicitis can be difficult to diagnose, as the patient presents at various points in the protracted course or can be an atypical presentation. Misdiagnosis occurs with a frequency of 20% to 40% in some populations.¹

• CBC to detect leukocytosis (“shift to the left”)¹¹: One study of patients 15 to 83 years of age with suspected appendicitis found that a white blood cell count greater than 10,000/mm³ was 77% sensitive and 63% specific for the diagnosis. The white blood cell count is normal in 10% to 30% of patients with appendicitis.¹

• Urinalysis and a pregnancy test are routine.

• Imaging: CT with contrast is recommended by the current literature (70% to 94%) over ultrasonography for diagnosing appendicitis and can detect extracolonic causes of abdominal pain. It has a sensitivity of 92% to 98% and is specifically recommended for men with atypical presentation and for women in whom pelvic pathology may mimic appendicitis.