Pelvic pain generally arises from gynecologic pathology but referred pain from extrapelvic conditions, such as inflammatory bowel disease, urinary tract infections or stones, diverticulitis, leaking abdominal aneurysm or appendicitis need to be considered. Pregnancy should be excluded in all women of reproductive age. Pelvic inflammatory disease is a common cause of pelvic pain and is discussed in Chapter 64.
Pelvic pain may be acute or chronic, intermittent or continuous. Attention to the characteristics of the pain will aid in determining etiologies. Sudden onset of unilateral pain suggests an ovarian cyst, adnexal torsion, obstruction, or renal lithiasis. Gradual onset suggests an infectious process or slowly enlarging mass. Other attributes, such as the relationship of the pain with the menstrual cycle, aggravating and relieving factors, and associated urinary, GI, and systemic symptoms assist in developing the differential diagnosis.
An abdominal and gynecologic examination, including speculum examination, and a vaginoabdominal examination (bimanual) should be performed. A pregnancy test should be done to rule out pregnancy. Other testing, such as urinalysis, CBC, and ultrasound are guided by the history and physical examination.
Diagnosis and Differential
Almost 90% of menstruating women experience dysmenorrhea at some point. Symptoms include mild to severe lower abdominal cramping during menses that diminishes as menstruation tapers. The pain can radiate to the thighs or lower back and may be accompanied by nausea and vomiting. Other gynecologic, urologic, or gastrointestinal conditions should be ruled out. NSAIDs, such as naproxen 500 milligrams twice daily PO or ibuprofen 400 milligrams every 6 hours PO, may alleviate symptoms. Further treatment, such as hormonal contraceptives, may be investigated at follow-up.
Mittelschmerz is a self-limited, unilateral dull, aching pain that occurs at mid cycle due to leakage of prostaglandin-containing follicular fluid. Patients frequently offer a history of previous similar pain. Treatment is symptomatic.
Pain results from 2 mechanisms: leak of contents causing tissue irritation or mechanical pressure on adjacent organs. Sudden onset of pelvic pain in a patient with ovarian cysts suggests acute rupture. A ruptured cyst can mimic a ruptured ectopic pregnancy. Pelvic/transvaginal ultrasound is the diagnostic imaging modality of choice (Fig. 58-1). Patients with cyst rupture who present with hemoperitoneum and hypotension require emergent gynecological surgery intervention. Hemodynamically stable patients with pain from cyst leakage or rupture can be treated as outpatients with NSAIDs. Patients with unruptured cysts less than 5 cm in size frequently require no treatment as these cysts usually involute within 2 to 3 menstrual cycles. All patients should follow-up with their gynecologic provider for further evaluation.
A 4-cm ovarian cyst demonstrated by endovaginal ultrasonography. (Reproduced with permission from Ma OJ, Mateer JR: Emergency Ultrasound, 2nd ed. © 2008, McGraw-Hill Inc., New York.)
Ovarian torsion results in the acute onset of severe adnexal pain from ischemia of the ovary. A history of intermittent pain, sometimes associated with exertion, preceding the severe symptoms may be obtained. Risk factors for torsion are pregnancy (enlarged corpus luteum), large ovarian cysts or tumors, and chemical induction of ovulation. Ultrasound with Doppler flow imaging is the diagnostic procedure of choice but is not 100% sensitive. Imaging early in the process may show congestion from venous outflow obstruction with preserved arterial flow and images obtained during a transient period of detorsion may appear normal. Analgesia, gynecologic consultation, and preparation for surgery are warranted if the diagnosis is suspected.
Endometriosis results from endometrium-like stroma implanted outside of the uterus, most commonly the ovaries. Symptoms include recurrent pelvic pain associated with menstrual cycle—secondary dysmenorrhea and dyspareunia. Nonspecific pelvic pain on examination is the usual finding but if the ectopic tissue ruptures, more severe pain may be present. Ultrasound may show endometriomas. The definitive diagnosis is usually not made in the ED. Treatment consists of analgesics and gynecologic referral.
Leiomyomas (uterine fibroids) are benign smooth muscle tumors, often multiple, seen most commonly in women in middle and later reproductive years. About 30% of women with leiomyomas will develop symptoms such as abnormal vaginal bleeding, dysmenorrhea, bloating, backache, urinary symptoms and dyspareunia. Severe pain can result with torsion of a pedunculated fibroid, or ischemia and infarction of a fibroid. Bimanual examination may demonstrate a mass or an enlarged uterus. Pelvic ultrasound is confirmatory. Treatment consists of NSAIDs or other analgesics for pain, hormonal manipulation for excessive bleeding, and referral to a gynecologist for definitive therapy.
Emergency Department Care and Disposition
Most patients are ultimately discharged from the ED even though there may not be a specific diagnosis. Patients should receive detailed discharge instructions about signs and symptoms to expect and warnings of when to return and when to follow-up. Reevaluation in 12 to 24 hours can be scheduled if any concern persists. Analgesics, such as NSAIDs, provide effective pain control for most outpatients, although some patients will require opioids, such as oxycodone/acetaminophen (5/325) 1 to 2 tablets every 4 to 6 hours PO for a few days.