In a young, recently married, sexually active woman presenting with acute right lower quadrant pain, vomiting, and a normal urinalysis, what is the most appropriate next step in management?

Pelvic Ultrasound is the Next Step

In a young, recently married woman presenting with acute right lower quadrant pain and vomiting, pelvic ultrasound is the most appropriate next diagnostic step. This prioritizes the evaluation of gynecologic emergencies (ectopic pregnancy, ovarian torsion, tubo-ovarian abscess) that are life-threatening in this demographic, while avoiding radiation exposure in a woman of childbearing age. 1

Clinical Reasoning

Why Pelvic Ultrasound First

• Gynecologic causes are the priority in a sexually active woman of reproductive age with acute RLQ pain, particularly given the recent marriage suggesting active sexual activity and pregnancy risk. 1

• Transvaginal ultrasound provides superior diagnostic accuracy compared to transabdominal approaches, with 76-87% better image quality and the ability to detect pathology missed on other modalities. 2, 3

• Ectopic pregnancy must be excluded immediately as it can be life-threatening; transvaginal sonography is specifically noted as particularly helpful when exclusion of ectopic pregnancy is the clinical concern. 3

• Ovarian pathology (cysts, torsion, tubo-ovarian abscess) accounts for one-third of acute pelvic pain in reproductive-age women and requires urgent diagnosis. 4

• Pelvic inflammatory disease with tubo-ovarian abscess presents with fever and adnexal masses in 82% of cases, and ultrasound demonstrates thick-walled tubal structures and pyosalpinx with high sensitivity. 5

When to Proceed to CT

• CT should be reserved for after negative or equivocal ultrasound findings when appendicitis remains the primary concern or when ultrasound cannot adequately visualize the appendix. 1

• CT is appropriate when gynecologic causes have been clinically or sonographically excluded in women of childbearing age, given radiation exposure concerns. 1

• The ACR specifically states CT should be used judiciously in female patients of childbearing age until gynecologic etiologies are excluded. 1

Why Not Diagnostic Laparoscopy Initially

• Laparoscopy is invasive and requires general anesthesia, making it inappropriate as a first-line diagnostic test when non-invasive imaging can provide the diagnosis. 1

• Imaging must precede surgical intervention to guide appropriate management and avoid unnecessary operative risk. 1

Critical Pitfalls to Avoid

• Do not assume appendicitis without excluding ectopic pregnancy first in any sexually active woman of reproductive age—this is a potentially fatal error. 3

• Do not order CT as the initial test in reproductive-age women without first performing pelvic ultrasound, as this exposes the patient to unnecessary radiation and may miss early gynecologic pathology better seen on ultrasound. 1

• Do not dismiss the possibility of PID or tubo-ovarian abscess even with normal WBC count, as laboratory values can be nonspecific despite serious infection. 6

• Ensure both transabdominal and transvaginal components are performed when possible, as transvaginal imaging provides superior resolution of pelvic structures while transabdominal provides anatomic orientation. 3