A 28-year-old woman, G2P1, at 20 weeks gestation presents to the emergency department with a 12-hour history of worsening right lower quadrant abdominal pain, nausea, and anorexia. Her temperature is 38.1°C (100.6°F), heart rate is 108/min, and blood pressure is 112/72 mm Hg. Physical examination reveals tenderness superior and lateral to McBurney's point with localized guarding. Fetal heart tones are 145/min. Laboratory studies show a leukocyte count of 16,500/mm³ with 85% neutrophils. Assuming each diagnostic study is sequentially indicated due to inconclusive prior results, arrange the following steps in the most appropriate chronological order for evaluating and managing this patient.
- 1Initiate intravenous fluid resuscitation and empiric antibiotics.
- 2Perform graded compression ultrasonography of the abdomen and pelvis.
- 3Obtain a magnetic resonance imaging (MRI) scan of the abdomen and pelvis without contrast.
- 4Proceed with laparoscopic appendectomy.
Answer
The correct sequence is to first stabilize the patient with intravenous fluids and antibiotics, followed by graded compression ultrasonography as the initial imaging modality. Because the ultrasound is assumed to be non-visualizing, a non-contrast MRI is the next step to confirm the diagnosis. Finally, laparoscopic appendectomy is performed as the definitive surgical treatment.
The correct sequence follows the standard surgical algorithm for the acute abdomen in pregnancy. Stabilization (fluids/antibiotics) always precedes diagnosis. Ultrasound is the safest initial test. When ultrasound is non-diagnostic—which frequently occurs due to the anatomical shift of the appendix—non-contrast MRI is the gold standard next step. Once confirmed, laparoscopic appendectomy is the definitive treatment.
Step-by-Step Solution
Key Concept
The diagnostic and management algorithm for acute appendicitis in pregnancy prioritizes non-ionizing imaging (ultrasound followed by MRI) prior to definitive surgical intervention.