In the evaluation of acute pelvic pain, early diagnosis is critical because significant delay increases morbidity and mortality. Central to correct diagnosis is an accurate history. The date and character of the last and previous menstrual periods and the presence of abnormal bleeding or discharge should be ascertained. The menstrual, sexual, and contraceptive history and any history of sexually transmitted conditions and previous gynecologic disorders are relevant. Pain history should include how and when the pain started, pregnancy-related symptoms (amenorrhea, irregular bleeding, nausea, breast tenderness), GI symptoms (anorexia, nausea, vomiting, constipation, obstipation, absence of ﬂatus, hematochezia), urinary symptoms (dysuria, urgency frequency, hesitancy, hematuria), signs of infection (fever, chills, purulent vaginal discharge), and symptoms attributable to a hemoperitoneum (orthostasis, abdominal distention, and right upper quadrant or shoulder pain). Document any past medical and surgical history, and current medications.
Baseline laboratory studies will include, at the least, a complete blood count with differential (CBC), clean catch mid-stream routine urine analysis (RUA), sensitive urine or serum pregnancy test, gonorrhea and chlamydia screening, and a transvaginal pelvic ultrasound. Other tests such as computerized tomography (CT) with and without contrast, chemistry panel, or blood type and screen (if transfusion is likely) may be indicated depending on the patient’s symptoms and the specific differential diagnosis.
Table 16.1 Differential Diagnosis of Acute Pelvic Pain 1. Complication of pregnancy a.
b.
Abortion, threatened or incomplete 2. Acute infections a.
b.
c.
3. Adnexal disorders a.
b.
Torsion of adnexa c.
Rupture of functional, neoplastic, or inﬂammatory ovarian cyst 1.
2.
3.
1.
2.
3.
4.
5.
6.
1.
2.
3.
1.
2.
1.
2.
3.
4.
Table 16.2 Nerves Carrying Painful Impulses from the Pelvic Organs
Reproductive Tract Causes of Acute Pelvic Pain
Ectopic Pregnancy All reproductive-aged women presenting with acute pain should be screened for pregnancy.
An ectopic pregnancy is defined as implantation of the fetus in a site other than the uterine cavity (see Chapter 20).
Symptoms of Ectopic Pregnancy
Implantation of the fetus in the fallopian tube produces pain with acute dilation of the tube. If tubal rupture occurs, localized abdominal pain tends to be temporarily relieved and is replaced by generalized pelvic and abdominal pain and dizziness with the development of a hemoperitoneum. A period of amenorrhea followed by irregular bleeding and acute onset of pain compose the classic triad of symptoms. A mass in the cul-de-sac may produce an urge to defecate. Referred pain to the right shoulder often develops if the intra-abdominal blood collection transverses the right colic gutter and irritates the diaphragm (C3 to C5 innervation).
Vital signs often reveal orthostatic changes in the case of a ruptured ectopic. Orthostasis is diagnosed by obtaining a patient’s pulse and blood pressure while they are supine, then after sitting for 3 minutes, and finally after standing for 3 minutes. If the systolic blood pressure decreases by 20 mm Hg or the diastolic blood pressure decreases by 10 mm Hg when standing from a supine position, orthostasis is confirmed. Although pulse rate is not specifically included in the definition of orthostasis, it is easy to obtain and an increase in pulse rate can be suggestive of orthostasis. Elevated temperature is generally absent with an ectopic.