A 20-year-old woman with abdominal pain is evaluated in the emergency department. She describes the gradual onset of pain 24 hours previously, which has been persistent in its location in the lower abdomen. Shortly after the onset of pain, the patient developed nausea. She denies any diarrhea, dysuria, or previous abdominal symptoms. She had her last normal menstrual period 7 days ago, and she denies any abnormal patterns in her menses. The patient is sexually active with one partner. Her past medical and surgical history is unremarkable. She takes oral contraceptives and consumes alcohol socially. On physical examination, her temperature is 38.2°C (100.8°F) and her blood pressure, pulse, and respiration rate are normal. The cardiopulmonary examination is unremarkable. Her abdomen is soft, with tenderness to palpation in the right lower quadrant and suprapubic region. No peritoneal irritation or masses are detected. Her bowel sounds are hypoactive. The rectal examination reveals tenderness on the right side. Pelvic examination reveals no purulent discharge; however, there is tenderness in the right adnexal region. Laboratory studies reveal a white blood cell (WBC) count of 14,600/mm3, normal hemoglobin and hematocrit values, and normal electrolyte and amylase levels. Urinalysis reveals concentrated urine with 3 to 5 red blood cells (RBCs per hpf [high-power field]), 5 to 10 WBCs per hpf, and negative results for leukocyte esterase. The result from a serum pregnancy test is negative.
What should be your next step?
ANSWER TO CASE 17: Abdominal Pain (Right Lower Quadrant)
Summary: A 20-year-old woman has a 24-hour history of abdominal pain that is atypical for acute appendicitis. She has a low-grade fever and lower abdominal tenderness, with maximal tenderness in the right lower quadrant. Her laboratory tests are significant for leukocytosis, microscopic hematuria, and pyuria.
• Next step: Obtain a CT scan of the abdomen and pelvis.
1. Learn the pathophysiology of acute appendicitis.
2. Learn the diagnostic approaches for patients with suspected acute appendicitis.
The diagnosis of acute appendicitis is frequently made on the basis of clinical history, physical findings, and laboratory data. However, when a patient presents with an atypical history and atypical physical and/or laboratory findings, it is important to determine whether the atypical presentation is related to another disease process or to atypical positioning of the diseased appendix. Further diagnostic options (Table 17–1) for an “atypical” patient include imaging studies (a CT scan, ultrasonography), clinical observation with serial laboratory evaluations, and diagnostic laparoscopy. The CT scan is selected in this case because it is sensitive for identifying inflammatory changes and thickening of the appendix. In a patient with fever, lower abdominal tenderness, and leukocytosis, these radiographic changes should be present if the findings are indeed caused by appendicitis. A factor that favors the use of a CT scan over ultrasonography in this case is that the patient’s history and examination results are not suggestive of pelvic pathology, which is more effectively evaluated by ultrasonography. For this patient, clinical observation with serial laboratory evaluation is not a good option because she already has localized abdominal pain, fever, and leukocytosis, and therefore continued observation for regression of these symptoms would lead to a delay in diagnosis. Diagnostic laparoscopy is an operative procedure with associated morbidity and is mainly indicated for patients with nonspecific clinical or radiographic evidence of inflammation or pathology that cannot be further delineated by additional imaging studies.
Table 17–1 • DIAGNOSTIC OPTIONS FOR ACUTE APPENDICITIS
APPROACH TO: Suspected Acute Appendicitis
CHRONIC OR RECURRENT APPENDICITIS: Occurs in 5% of patients with appendicitis and may result from antibiotic administration in patients with early acute appendicitis.
INTERVAL APPENDECTOMY: This procedure generally is for the treatment of appendicitis complicated by abscess or phlegmon. The patient is treated initially with broad-spectrum antibiotic therapy and CT-guided drainage of the abscess to resolve the infectious process, followed by appendectomy after several weeks. Because some patients with appropriate nonoperative treatment do not develop appendicitis recurrences, the role of interval appendectomy remains unclear.
MESENTERIC ADENITIS: An inflammatory condition occurring with a viral illness, resulting in painful lymphadenopathy in the small bowel mesentery. This process can be associated with right lower quadrant pain and tenderness and is especially common in children.
ALVARADO SCORE: A 10-point scoring system that was initially introduced in 1986 to assist in the diagnosis of acute appendicitis. The scoring consists of symptoms, signs, and laboratory studies. Symptoms: migratory pain to RLQ (1), anorexia (1), nausea/vomiting (1). Signs: tenderness in RLQ (2), rebound tenderness in RLQ (1), (99.5°F) (1). Laboratory study: leukocytosis >100,000 (2), shift to the left (1). Scores: 0 to 4 (low probability); 5 to 6 (compatible with appendicitis); 7 to 8 (probable appendicitis); 9 to 10 (highly probable appendicitis). The Alvarado scores can be used in the following fashion: scores 0 to 4, observation; scores 5 to 8, imaging (CT or ultrasound) for definitive diagnosis; scores 9 to 10, appendectomy.
Pathogenesis and Clinical Presentation of Appendicitis
The appendix arises from the cecal diverticulum during embryonic development. During this process, it rotates from its posterior location toward the iliac fossa. Incomplete rotation occurs frequently, leading to variable appendiceal positioning and variations in clinical presentation. The development of appendicitis generally begins with luminal obstruction by a fecalith, lymphoid hyperplasia, or food matter. With this obstruction there is an increase in mucus secretion, venous and lymphatic congestion, and bacterial overgrowth (Table 17–2). When unabated, this process leads to ischemic necrosis and perforation. The classic history of acute appendicitis begins with vague pain in the periumbilical region, nausea, vomiting, and the urge to defecate; these symptoms are followed by localization of the pain in the right lower quadrant associated with localized peritonitis. Approximately 20% of patients with acute appendicitis experience perforation within 24 hours of the onset of symptoms. Recognition of appendicitis can be delayed because of atypical presentations caused by retrocolic or pelvic locations. Similarly, antibiotic administration during the early course of appendicitis may alter the clinical course. Only approximately 50% of patients with acute appendicitis show a classic presentation.
Table 17–2 • CLINICAL-PATHOLOGIC CORRELATION
Patients with the classic presentation generally require only a thorough history and physical examination, a CBC with a differential count, urinalysis, and a pregnancy test (women only) for diagnosis. When patients with an atypical history, physical examination, or laboratory findings are encountered, selective application of diagnostic imaging is indicated to avoid delays in therapy and minimize the occurrence of nontherapeutic operations. Over the past several years, there has been increased awareness of the potential harm related to radiation exposure from diagnostic studies such as CT scans. This issue should be discussed with the patients, as we plan diagnostic strategies for patients.
Appendectomy is the traditional treatment for the majority of patients with acute appendicitis. The procedure can be done either by an open approach or laparoscopic approach. Laparoscopic appendectomies are associated with less postoperative pain and improved recovery but are more costly than the open approach. Treatment of appendicitis with antibiotics alone has been evaluated in several randomized controlled trials, and the outcomes have been found acceptable. Therefore, nonoperative treatment could be considered a viable option in patients who accept the possibility of recurrence and are reliable for subsequent follow-up.
17.1 A 19-year-old woman presents with a 2-day history of right lower quadrant pain and no fever. She has a tender right adnexal mass, a normal WBC count, negative findings from a pregnancy test, and normal urinalysis results. Which of the following is the most appropriate management?
A. CT of the abdomen and pelvis.
B. Discharge the patient with reassurance.
C. Diagnostic laparoscopy.
D. Observation with serial laboratory studies.
E. Abdominal and pelvic ultrasonography.
17.2 A 24-year-old man complains of colicky intermittent umbilical and right lower quadrant abdominal pain of 24 hours’ duration. He complains of anorexia and nausea. His temperature is 36.7°C (98°F). Which of the following is the most likely diagnosis?
A. Acute appendicitis
B. Chronic appendicitis
D. Acute pancreatitis
17.3 An 18-year-old woman has a 1-day history of worsening lower abdominal pain, nausea and vomiting, and a low-grade fever. Her temperature is 37.2°C (99°F), and she has mild lower abdominal tenderness and no rebound. She has possible right adnexal tenderness. Which of the following tests would most definitively differentiate pelvic inflammatory disease from acute appendicitis?
A. CT scan of the abdomen and pelvis
B. MRI of the abdomen and pelvis
C. Ultrasound examination of the pelvis
E. Clinical response to antibiotics
17.4 A 43-year-old woman presents with 1-day history of right flank and right lower quadrant pain. She has a history of nephrolithiasis and indicates that the pain she experiences now is not similar to that she experienced before. Her temperature is 38.5°C (101.3°F), and her abdomen and right flank are tender to deep palpation. Her urinalysis shows 10 to 20 WBC/hpf and 10 to 20 RBC/hpf. Which of the following is the best management strategy?
A. Hospitalization, IV hydration, analgesics, and antibiotic therapy for urinary tract infection (UTI).
B. Perform pelvic ultrasound to rule out ovarian torsion.
C. Perform CT scan of the abdomen.
D. Diagnostic laparoscopy.
E. Cystoscopy and ureteral stent placement.
17.5 A 14-year-old boy present with right lower quadrant abdominal pain of 2-day duration. He indicates that he has been ill for the past 10 days with cough, runny nose, and fever, and over the past 2 days his lower abdomen has become painful. Over the past 12 hours the pain has been improving slowly. His temperature is 37.8°C (100.04°F). His abdomen is tender in the right lower quadrant, without masses or signs of peritonitis. His WBC is 11,000/mm3 and urinalysis is normal. CT of the abdomen reveals no inflammatory changes in the area around the cecum. There are several prominent lymph nodes measuring approximately 2 cm in size in the mesentery of the small bowel. The bowel wall is not thickened. What are your diagnosis and treatment?
A. Mesenteric adenitis. Discharge from ED with follow-up.
B. Probable mesenteric adenitis. Perform diagnostic laparoscopy to rule out appendicitis.
C. Crohn disease. Consult a gastroenterologist for definitive long-term management.
D. Mesenteric adenitis. Admit the patient for IV antibiotic therapy.
E. Perform CT-guided core-needle biopsy of the lymph nodes to rule out lymphoma.
17.1 E. For this patient with findings suggestive of pelvic pathology (an adnexal mass), ultrasonography is an accurate modality in defining the pathology. Reassurance and discharge without further delineation of the pathology is risky. Laparoscopy without further ultrasound imaging may potentially result in an unnecessary procedure. CT scan is less sensitive and specific for pelvic pathology.
17.2 C. Intermittent pain is not typical for appendicitis. Acute pancreatitis typically presents as constant boring pain radiating to the back. Gastroenteritis and intussusception could both present with intermittent abdominal pain. Because intussusception is quite rare in adults, the most likely diagnosis based on the frequencies of occurrence would be gastroenteritis.
17.3 D. Laparoscopy is the most accurate test to assess for acute pelvic inflammatory disease (an erythematous tube with purulent drainage from the fimbria) and to visualize the appendix.
17.4 C. Perform a CT scan of the abdomen. This patient has right flank and right lower quadrant pain and a history of kidney stones; however, the patient states that her pain now is dissimilar to her prior pain with kidney stones. A CT scan without contrast may be useful to help identify kidney stones, and, if this does not visualize kidney stones, a CT with contrast may also be performed to help rule out appendicitis and pyelonephritis.
17.5 A. This patient’s history, physical findings, and CT findings are compatible with mesenteric adenitis, which is nonspecific, and self-limiting inflammation of the mesenteric lymph nodes. No antibiotics treatment is necessary for the condition. Because CT of the abdomen has good negative predictive value in ruling out acute appendicitis, a diagnostic laparoscopy is unnecessary in this patient. Lymphoma could present with diffuse intraabdominal and retroperitoneal adenopathy. If this patient’s symptoms persist and the lymphadenopathy persists, biopsy to rule out lymphoma may become necessary.
The options in assessing atypical presentations for appendicitis include imaging tests, clinical observation with a serial laboratory evaluation, and diagnostic laparoscopy.
The classic history of acute appendicitis begins with vague pain in the periumbilical region, nausea, vomiting, and the urge to defecate; these symptoms are followed by localization of the pain in the right lower quadrant associated with localized peritonitis.
Only approximately 50% of patients with acute appendicitis have the classic presentation.
Ultrasonography is generally the best modality to assess pelvic pathology, whereas a CT scan is the best way to assess nongynecologic abdominal processes.
Brenner DJ, Hall EJ. Computed tomography—an increasing source of radiation exposure. N Engl J Med. 2007;357:2277-2284.
Jaffe BM, Berger DH. The appendix. In: Brunicardi FC, Andersen DK, Billiar TR, et al, eds. Schwartz’s Principles of Surgery. 9th ed. New York, NY: McGraw-Hill; 2010:1073-1134.
Maa J, Kirkwood KS. The appendix. In: Townsend CM, Beauchamp RD, Evers BM, et al, eds. Textbook of Surgery: The Biological Basis of Modern Surgical Practice. 18th ed. Philadelphia, PA: Saunders Elsevier; 2008:1333-1347.
Mason RJ. Surgery for appendicitis: is it necessary? Surg Infect (Larchmt). 2008;9:481-488.