A previously healthy 35-year-old man comes to the emergency department due to severe abdominal pain for the last 4 hours. The pain started in the periumbilical area but has now shifted to the right lower quadrant. The patient has also had nausea and 2 episodes of vomiting. He has no history of other medical conditions and takes no medications. Temperature is 38.3 C (100.9 F), blood pressure is 126/80 mm Hg, pulse is 100/min, and respirations are 20/min. Abdominal examination shows tenderness in the right lower quadrant that does not worsen with inspiration. Palpation of the left lower quadrant produces pain in the right lower quadrant. Urinalysis is normal. Laboratory results are as follows: Which of the following diagnostic imaging studies is most appropriate prior to definitive treatment of this patient?

Question

A previously healthy 35-year-old man comes to the emergency department due to severe abdominal pain for the last 4 hours.  The pain started in the periumbilical area but has now shifted to the right lower quadrant.  The patient has also had nausea and 2 episodes of vomiting.  He has no history of other medical conditions and takes no medications.  Temperature is 38.3 C (100.9 F), blood pressure is 126/80 mm Hg, pulse is 100/min, and respirations are 20/min.  Abdominal examination shows tenderness in the right lower quadrant that does not worsen with inspiration.  Palpation of the left lower quadrant produces pain in the right lower quadrant.  Urinalysis is normal.  Laboratory results are as follows:  Which of the following diagnostic imaging studies is most appropriate prior to definitive treatment of this patient?

Quizplus · Accepted Answer

Explanation: 11ec25c8_d8d9_5053_bc81_d77047608b3f_MD0003_00 This patient's migratory right lower quadrant (RLQ) pain, nausea, vomiting, fever, and leukocytosis are most concerning for acute appendicitis. A high clinical suspicion of appendicitis was historically considered sufficient to proceed to appendectomy, and a negative appendectomy (ie, removed appendix was noninflamed on pathology) rate (NAR) of approximately 10% was deemed acceptable. However, given its widespread availability and rapidity, diagnostic imaging is now typically performed when appendicitis is suspected (eg, modified Alvarado score ≥4). Imaging decreases the NAR and directs definitive management (Choice C). modified Alvarado score ≥4 For avoiding ionizing radiation exposure, abdominal ultrasound is the initial imaging modality used in children and pregnant women, and MRI may be necessary if ultrasound is nondiagnostic. However, CT scan of the abdomen and pelvis (with contrast) is the preferred study for evaluation of suspected appendicitis in nonpregnant adults, such as this man. CT has high diagnostic accuracy and is less likely to yield an indeterminate result (ie, nonvisualized appendix). In addition, CT is less operator dependent than ultrasound and is quicker, cheaper, and better tolerated by patients than MRI (Choices B and E). Management can be directed by CT findings: Normal appendix: Evaluate for other diagnoses (avoids unnecessary appendectomy). Nonperforated appendicitis: Treat with antibiotics and appendectomy within 12 hours. Perforated appendicitis: Treat with antibiotics and either percutaneous drainage (for stable patients with a contained RLQ abscess [ie, contained perforation]) or emergency appendectomy (for patients with diffuse intraabdominal contamination [ie, free perforation]). Several trials have studied antibiotic-based nonoperative management of patients with nonperforated appendicitis. Although most patients avoided appendectomy when treated with antibiotics only, there was no reliable way to predict which patients would fail treatment and which would require rescue appendectomy. At present, appendectomy remains the treatment of choice for nonperforated appendicitis. (Choice D) Plain abdominal (eg, supine, lateral decubitus) x-rays can be helpful in diagnosing some intraabdominal conditions (eg, air-fluid levels on lateral decubitus view in bowel obstruction). However, plain films do not visualize the appendix and cannot detect appendiceal inflammation. Educational objective: The evaluation of patients with suspected appendicitis (eg, modified Alvarado score ≥4) now includes imaging, which can visualize the appendix (eg, normal vs nonperforated or perforated appendicitis) and direct management. CT scan of the abdomen and pelvis is the recommended imaging study in nonpregnant adults. References: ACR Appropriateness Criteria® right lower quadrant pain-suspected appendicitis. (http://www.ncbi.nlm.nih.gov/pubmed/30392606) Computed tomography for diagnosis of acute appendicitis in adults. (http://www.ncbi.nlm.nih.gov/pubmed/31743429) Evolution and current trends in the management of acute appendicitis. (http://www.ncbi.nlm.nih.gov/pubmed/30243444)

A Previously Healthy 35-Year-Old Man Comes to the Emergency Department