Right Lower Quadrant Pain in Females
Authors: Larissa I. Velez, MD, FACEP, Associate Program Director, Emergency Medicine, University of Texas Southwestern, Staff Toxicologist, North Texas Poison Center, Dallas; Fernando Benitez, MD, FACEP, Department of Emergency Medicine, University of Texas Southwestern, Dallas; J. Clinton Lowry, MD, University of Texas Southwestern, Dallas; and Rolando Diaz, MD, University of Texas Southwestern, Dallas.
Peer Reviewers: Gary D. Hals, MD, PhD, Department of Emergency Medicine, Palmetto Richland Hospital, Columbia, SC; and Ralph Riviello, MD, MS, FACEP, Associate Professor and Associate Program Director, Department of Emergency Medicine, Jefferson Medical College, Philadelphia, PA.
Our public hospital emergency department (ED) has the "alley." Those of you of trained in public hospitals know what I mean: a place for ambulatory patients to be examined and treated, all the stretchers have stirrups, and the rooms are stocked with menstrual pads. You can often tell from the resident's facial expression that the next patient he or she is going to see is in the "alley." This area of the ED is supposed to be for more stable, less serious patients. However, over my years in emergency medicine, I've seen many patients deteriorate suddenly who were triaged to this area and I have learned to respect the "alley" and the patients who are seen there. This issue of Emergency Medicine Reports is dedicated to that area, those patients, and the emergency physicians who care for them.
—J. Stephan Stapczynski, MD, FACEP, FAAEM, Editor
Introduction
Abdominal pain in female patients can pose a diagnostic challenge to emergency physicians. There are a number of emergent clinical conditions that must be recognized in a timely fashion to reduce morbidity and mortality in these patients. This article will discuss these diagnoses and highlight critical points in the history and physical examination, as well as review current recommendations regarding treatment options and imaging modalities in this select group of patients. Both the pregnant and non-pregnant female patient will be discussed; however, traumatic causes of abdominal pain are beyond the scope of this review. Finally, miscellaneous causes of right lower quadrant pain that are not exclusive to females will also be discussed.
Emphasis is often placed on the initial history and physical examination of the patient, and with good reason. In most cases, the correct diagnosis can be established through a complete history, with careful attention to the gynecologic, obstetric, and sexual history. It should be noted, however, that patients often are reluctant to disclose their true sexual habits due to social stigmas. This is especially true among the lesbian, gay, bisexual, and transgender populations. It has been argued that self reports of sexual behavior are inherently unreliable and invalid due to multiple sources of bias, including underreports of stigmatized behavior and over reports of normative behavior.1 Salient historical features that should be asked and documented in the chart include presence of an intrauterine device (IUD), history of prior sexually transmitted diseases (STDs), and specific factors associated with pelvic inflammatory disease (PID). These factors include age younger than 25 years, age of first intercourse at younger than 15 years, lower socio-economic status, single marital status, multiple partners, frequent vaginal douching, and self-reported history of Chlamydia trachomatis.2
When presented with a female of child-bearing age whose chief complaint is abdominal pain, it is essential to obtain a screening urine pregnancy test early in the evaluation. This will often determine the clinical/diagnostic pathway that should be pursued and can have implications in management options (e.g. choice of medications and radiographic procedures). The diagnostic algorithm provided can help the clinician approach the female patient with right lower quadrant pain.
RLQ Pain in the Non-pregnant Patient
Pelvic Inflammatory Disease (PID). Pelvic inflammatory disease must be considered as a diagnosis in all female patients presenting with lower abdominal pain (LAP). This disease entity comprises a spectrum of processes such as salpingitis, endometritis, and tubo-ovarian abscesses (TOA), all of which begin as an ascending infection originating in the cervix and vagina.3
Each year in the United States, more than 1 million women experience an episode of acute PID and an estimated more than 100,000 women will become infertile as a result.4 A large proportion of this group is also at risk for subsequent ectopic pregnancies secondary to the adhesions and fibrosis that develop, which impede normal embryo migration through the fallopian tube.4-6 Early diagnosis (or at least suspicion of) and the initiation of appropriate antibiotic therapy are the primary goals of the emergency physician.
Neisseria gonorrhoeae and Chlamydia trachomatis are the most frequent organisms isolated in patients with PID, although other microbes have been isolated. These include anaerobes, Haemophilus influenza, Streptococcus agalactiae, Mycoplasma hominis, and Ureaplasma urealyticum. Co-existent HIV infection has also been associated with increased progression to TOA.7 This has been shown to be true regardless of CD4 T-lymphocyte count and is thought to be due to the impaired T-cell/macrophage signaling cascade and humoral mediated immunity. The causative agents in the HIV-positive population is also noteworthy. In a prospective observational study in which 162 female participants with lower abdominal were recruited, it was noted that HIV-positive women were less likely to be infected with either N. gonorrhoeae or C. trachomatis, or both, than were HIV-negative women.8
Clinical Presentation. The diagnosis of PID is principally based on clinical findings. The most common presenting complaint in patients with PID is lower abdominal pain that is often accompanied by a vaginal discharge.9 Direct visualization of the fallopian tubes by laparoscopy is the current gold standard for the diagnosis of PID, but procedure is not routinely used in clinical practice.10
The clinical diagnostic criteria published in 2006 by the Centers for Disease Control and Prevention (CDC) are divided into "minimum criteria" and "additional criteria." (See Table 1.) Empiric treatment should be initiated in young sexually active women or those with risk factors associated with STDs who have one of the minimum criteria and where no other etiology can be identified. The additional criteria were added to enhance the diagnostic specificity and support a diagnosis of PID, although with reduced sensitivity.4
| Table 1. Pelvic Inflammatory Disease: CDC Criteria (2006) |
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In one study, 189 patients diagnosed with PID by a gynecologist using clinical criteria were retrospectively studied in an attempt to describe the clinical basis for the diagnosis of PID and compare those to the CDC guidelines.11 They found abdominal pain to be the most commonly encountered presenting symptom (98% of patients), followed by vaginal discharge (45%), feeling of sickness (30%), dysuria (27%), and fevers and chills (25%). Examination of these patients revealed tenderness with manipulation of the cervix (cervical motion tenderness, or the Chandelier sign) and/or uterus and both adnexa in only 49% of patients.11 As a result, the clinical diagnosis of PID is not a precise one, and considering the morbidity/mortality associated with the complications such as ectopic pregnancy and infertility, there is a generally accepted low threshold for initiation of treatment.
The distinction between acute appendicitis and pelvic inflammatory disease is an important one because it affects further evaluation and consultations in the ED. While both conditions may present with very similar signs and symptoms, there are a few noteworthy differences that should be sought during the initial history and physical examination. In a retrospective study of 181 women aged 12-58 who presented to the ED with abdominal pain, 3 clinical factors were more likely to be associated with a low risk of appendicitis: no pain migration (OR 4.2), presence of bilateral tenderness (OR 16.7), and absence of nausea or vomiting (OR 8.4). This study found that a prediction rule based on the presence of all three factors had a 99% sensitivity (95% CI 94-100%) for excluding acute appendicitis.12
Often, distinguishing PID from appendicitis on clinical grounds alone can be impossible, and imaging is required to accurately identify the cause of the patient's symptoms when appendicitis is suspected.
Diagnostic Imaging. The decision to image the abdomen in these patients should be pursued when alternative diagnoses/potential surgical disease (such as acute appendicitis, ovarian torsion, pelvic abscess) cannot be excluded from a non-surgical disease (ovarian cyst, PID.).13
Ultrasound is considered by some to be the most practical imaging modality in female patients presenting with lower abdominal pain. The advantages of ultrasound are that it is widely available, relatively inexpensive, has high diagnostic accuracy, and can be brought to the patient's bedside if needed.14 Short of laparoscopy, pelvic ultrasound is considered the "gold standard" when making management and disposition decisions in patients with TOAs.14 However, the ultimate accuracy of ultrasound is dependent on an experienced technician, a quality machine, and the skill of the interpreting radiologist, and some emergency departments may not have access to ultrasound imaging after hours and on weekends. In these cases, and in situations where appendicitis is a true consideration, CT should be pursued.
Focused appendiceal CT scans with oral contrast only (sensitivity 93%, specificity 97%, accuracy 96%) and thin (5 mm) cuts (sensitivity 99%, specificity 98%, accuracy 99%) have both been found to be useful in the distinction between appendicitis and TOA/PID.15,16 When faced with the question of which imaging modality to begin with, one should use US if TOA is the suspected diagnosis and CT scan if appendicitis is the primary concern.
Treatment. The goal of PID treatment is to reduce the primary sequelae of chronic pelvic pain, ectopic pregnancy, and infertility. This results from the scarring and adhesion formation within the fallopian tubes as the inflammation resolves. Up to 18% of women treated for PID report chronic pelvic pain. The risk of infertility increases with each episode of PID: one episode is associated with a 13-21% risk, two episodes with a 35% risk, and three or more episodes with a 55-75% risk.17
The treatment options to be discussed in this article are based on the 2006 CDC recommendations for antibiotic use in PID. These guidelines were just updated in April 2007.18 The updates no longer include the use of fluoroquinolones to treat gonorrhea, due to high rates of antibiotic resistance. In general, antibiotic regimens should be effective against N. gonorrhoeae and C. trachomatis. Since anaerobes have been isolated from the upper reproductive tract of women with PID, the CDC currently advises that treatment should include anaerobic coverage.4 (See Table 2.)
| Table 2. Intravenous Antibiotic Recommendations for PID, CDC |
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Some experts have suggested that all patients with PID be hospitalized so that bed rest and supervised treatment with parenteral antibiotics can be initiated.4 The current consensus, although based on limited clinical data, is that women with PID of mild or moderate severity be treated as outpatients. Suggested criteria for hospital admission include:4
- Surgical emergencies cannot be excluded after imaging
- Pregnant patient
- Lack of clinical response to oral antibiotic therapy after 72 hours
- Patient is unable to tolerate outpatient oral regimen
- Severe illness with nausea, vomiting, and/or high fever
- Presence of TOA
- HIV patients with low CD4 counts or other immunosuppressed patients (chronic steroid use, diabetic, etc.)
- Patients with intrauterine device (IUD)
- Consider admission for adolescent patients (unreliable compliance, increased risk for future ectopic)
Special consideration should be given to patients with concomitant HIV infection and low CD4 counts (< 350 cells/mm3), as they are more likely to have complications and require admission. In one prospective study, 148 women with lower abdominal pain who were diagnosed with PID confirmed by laparoscopy (in which 39% were seropositive for HIV) there was no difference in clinical response to therapy in both seronegative and seropositive groups. However, there was a trend for increased risk of TOA in the seropositive group (2.8 fold increased odds), increased clinical severity scores, and longer hospitalizations. As opposed to the previously mentioned study by Bukusi, et al.,8 the study by Cohen, et al.,19 found no difference in microbiological etiology of PID comparing HIV-positive patients with those that were HIV negative.
If admission is deemed appropriate, the following parenteral regimen(s) should be initiated as soon as the diagnosis is made. (See Table 2.)
Patients who do not meet admission criteria and are clinically of mild to moderate severity may be discharged home with oral therapy. The current CDC recommendations (see Table 3) no longer recommend fluoroquinolones for the treatment of gonorrhea due to increasing resistance rates.
| Table 3. Outpatient Antibiotic Recommendations for PID, CDC |
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Clinical improvement should be seen within 3 days. If there is no response to therapy, an alternative diagnosis should be sought and/or the patient should be admitted for initiation of parenteral therapy. Male sex partners should be treated for presumed infection with agents effective against C. trachomatis and/or N. gonorrhoeae, due to the risk of re-infection of the patient. It is important to remember that these infections are often clinically silent in males, and the patient would otherwise not seek medical care. The presence of STDs is a significant risk factor for HIV infection, and all patients should be encouraged to have HIV testing performed when being treated for STDs.4 The patient should be referred to the health department if HIV testing in the ED is unavailable.
Adnexal Torsion (AT). Although relatively uncommon in the ED, adnexal torsion represents the fifth most common surgical gynecologic emergency.14 It is a surgical emergency because prompt operative detorsion is necessary to preserve ovarian viability.20 This condition is most commonly seen in women of child-bearing age, although it occurs in pre-menarche and post-menopausal women as well. Ovarian masses such as cysts (benign cystic teratomas or polycystic ovaries) or tumors increase the likelihood and risk of torsion21 due to the increased size of the ovary. Increases in ovarian size > 6 cm predispose the patient for torsion. Thus, women undergoing hormone injection therapy for assisted reproduction have very high risk for torsion, due to the large number of cysts induced.22 Risk of ovarian torsion also rises during the first trimester (6-14 weeks) and in the first 6-8 weeks after delivery, and 25% of cases are seen in pregnant patients.23
Adnexal torsion occurs because of the relative mobility of both supporting pedicles: the ovarian ligament connecting the ovary to the uterus and the suspensory ligament connecting the ovary to the intra-abdominal wall. During torsion, both pedicles are partially or completely strangulated, resulting in obstruction to venous outflow. This is soon followed by arterial flow obstruction. These events, if not corrected, lead to congestion, adnexal edema, and eventually ischemia and necrosis.20
Clinical Presentation. The typical presentation of a patient with a torsed ovary is usually described in texts as acute unilateral pelvic pain or a dull, aching pain with acute and sharp exacerbations if the torsion is intermittent. Case reports and large-scale reviews, however, have shown that the presenting signs and symptoms are usually less specific.24 In fact, presenting symptoms of ovarian torsion are widely varied and can be very subtle. Thus, it is no surprise that many physicians fail to accurately diagnose this condition in a timely fashion, often because the physician did not consider this disorder in the differential of potential diagnoses.
In a published retrospective chart review, the average duration of pain lasted from several hours to weeks (mean 7.8 days). Thirty patients (35%) had mild tenderness on abdominal examination; 15 (17%) had severe tenderness. Twenty-five patients (29%) had no tenderness on pelvic examination, while 16 (18%) had severe tenderness.24 Only 13 patients (16%) had a white blood cell (WBC) count greater than 15,000/mm3, and most were afebrile and without nausea and vomiting. Interestingly, most of the diagnosed cases of adnexal torsion reported in the literature occur on the right side.25
The length of time required to render an ovary non-viable is unknown. The ability to retain viability despite prolonged ischemia as shown by preservation of ovarian function in even necrotic appearing ovaries indicates that complete arterial obstruction does not usually occur.21
Diagnostic Imaging. As with most gynecologic complaints, pelvic ultrasound should be the initial imaging modality in suspected cases of adnexal torsion. Visualization of the ovaries and any adnexal masses, in addition to color flow Doppler imaging, make ultrasound the imaging modality of choice in the diagnosis of ovarian torsion.14,26 However, in one study, normal Doppler flows were found in 60% of cases of ovarian torsion diagnosed by laparoscopy.27 Thus, abnormal Doppler flows are highly predictive of AT, but a normal flow does not reliably exclude AT. This could be due to dual ovarian blood supply, intermittent nature of the torsion, and subtorsions. A case series demonstrated abnormally large ovaries in all patients with AT, a small amount of fluid in the cul-de-sac in 32%, and small cystic structures around the ovary (presumed to be follicles) in 74% of cases.28 In the setting of an abnormally enlarged ovary, it is reasonable to consult a gynecologist, since this finding can be the only one in the setting of an AT.
Treatment. If the diagnosis is made or cannot be reasonably excluded, emergent consultation with a gynecologist should be undertaken, as definitive treatment is manual detorsion with or without ovarian resection.20,21 In the meantime, the patient should receive analgesics, intravenous fluid resuscitation, and anti-emetics as needed.
Ruptured Ovarian Cyst/Ovarian Masses. Physiologic ovarian cysts are the most common gynecologic masses to occur in the female pelvis.29 Ovarian cysts develop as a result of failure of a follicle to rupture or regress after completion of the follicular phase in the normal menstrual cycle. About two weeks into the normal menstrual cycle, the follicle ruptures and releases an ovum. This process can be a source of discomfort and is referred to as "mittelschmerz"—a German word translating as "middle pain," referring to the mid-cycle pain of ovulation. After release of an ovum, the follicle now involutes and becomes the corpus luteum. This structure will begin to produce progesterone, which will prepare the uterus for embryo implantation. The vast majority of ovarian cysts are physiologic in origin, unilocular, and non-neoplastic.14
Cystic structures identified on ultrasonic imaging are referred to as cysts if their diameter is equal to or greater than 2.5-3 cm. If they are less than this value, then they are simply referred to as follicles. During the course of the menstrual cycle, a mature graafian follicle or the corpus luteum ordinarily may reach a size of up to 2.5 cm. Therefore, the term ovarian cyst is reserved for structures larger than this size.30
Clinical Presentation. Most ovarian cysts are asymptomatic and may be discovered incidentally on a routine well-woman examination or encountered during a work-up in a female presenting with lower quadrant abdominal pain. When the cyst becomes symptomatic, it is typically due to cyst rupture or hemorrhage into the cyst. The most common presenting complaint is abdominal pain.14,31 The pain can be sharp, intermittent, sudden in onset, and severe with associated nausea and vomiting. In some cases, cyst rupture can lead to life-threatening hemorrhage. Ovarian cysts also predispose patients to ovarian torsion.
Treatment. The sudden onset of abdominal pain with peritoneal findings would suggest ovarian cyst rupture, but the clinician should also consider an ectopic pregnancy and other causes of a surgical abdomen in this setting. Patients with symptomatic ovarian cysts should be referred to a gynecologist for outpatient work-up and follow up. All pre- and post-menopausal women with adnexal masses should have a prompt outpatient work-up for malignancy. The following ultrasound findings should raise the suspicion of an adnexal malignancy: masses larger than 7 cm; masses that persist beyond one menstrual cycle; and masses that have solid internal components or a complex cystic structure.32 Warnings should be given to all, since there is always a risk of ovarian torsion or cyst rupture with hemorrhage.
RLQ Pain in the Pregnant Patient
Pregnant patients with right lower quadrant pain pose additional diagnostic challenges. In this patient population, it is important to consider both pregnancy-related and non-obstetrical etiologies of RLQ pain.
Relevant questions in the history include last menstrual period, previous STDs, previous or current IUD use, surgical history, previous pregnancies and any complications, presence or absence of vaginal spotting or discharge, and passage of tissue. Attempts should be made to quantify the amount of vaginal bleeding if present (ie., how many pads/tampons used in last 12-24 hours). Additionally, if the patient is aware of the pregnancy, a history of any prenatal visits is another important aspect of the history.
The physical examination should be guided by the patient's presentation and history and also by the gestational age. If bleeding after the 20th week of gestation is present, bimanual and speculum examination should be deferred until placenta previa is ruled out with an ultrasound evaluation. Like speculum examination, transvaginal US is NOT safe in a bleeding patient with suspected previa and should also be avoided.
Ectopic Pregnancy (EP). Accurately identifying ectopic pregnancy is essential in the patient who presents with abdominal pain in the first trimester, as EP is the most common cause of maternal death in this trimester.33,34 The incidence of ectopic pregnancy in the United States has risen in recent decades to almost 2% of all pregnancies.33 Risk factors for ectopic pregnancy include previous PID, previous or current IUD use, previous tubal surgeries, and previous ectopic pregnancies.35 Additional factors associated with an increased frequency of ectopic pregnancy include: in utero diethylbestrol (DES) exposure, infertility, current smoking, three or more spontaneous abortions, induced abortions, and more than one lifetime sexual partner.36
Clinical Presentation. The "classic triad" of symptoms in ectopic pregnancy is amenorrhea, abdominal pain, and irregular vaginal bleeding.37 However, less than 50% of patients with ectopic pregnancy will present with all three complaints.36 Moreover, the above symptoms may also be found in an intrauterine pregnancy (viable or non-viable) as well as with cervicitis, PID, cervical irritation, or trauma.36 Women may complain of nausea and/or vomiting, breast tenderness, and fatigue, symptoms that often occur with normal pregnancy. Physical examination findings of cervical motion tenderness, adnexal tenderness, and peritoneal signs may be present, but are neither sensitive nor specific for ectopic pregnancy.33 An adnexal mass is palpable in only 10% of cases of ectopic pregnancy. Finally, a normal physical examination does not rule out an ectopic.33,36
Diagnostic Imaging. Transvaginal ultrasound is the current diagnostic modality of choice when ectopic pregnancy is suspected. With a high resolution ultrasound machine and a skilled ultrasonographer, intrauterine pregnancy (IUP) can be detected on transvaginal ultrasound with serum beta-HCG levels between 1000-1500 mIU/mL.33,36 Variations in the discriminatory zone (lowest serum beta-HCG level at which a gestational sac can be visualized) are institution-dependent and related to the ultrasound equipment used and the skill of the ultrasonographer.33 One should be aware of the discriminatory zone used at each hospital where one practices. In general, serum beta-HCG levels between 1000-1500 mIU/mL correlate with a gestational age of 4.5 to 5 weeks.33 Multiple gestations are an exception in which an IUP may not be visualized at this discriminatory zone.
One important limitation of ultrasound is related to the location of the ectopic implant. Conventional 2-dimensional (2-D) US has variable sensitivity depending on the location of the ectopic. Interstitial pregnancy occurs with implantation of the gestational sac in the most proximal aspect of the fallopian tube. Interstitial pregnancies account for a small portion of ectopic pregnancies (2-6%) but carry an increased mortality risk due to the vasculature in the area, as there is increased potential for significant hemorrhage.38 Seventy-one percent of interstitial pregnancies can be accurately diagnosed by ultrasound.38 A cornual pregnancy is intrauterine by definition, with implantation occurring in the upper and lateral aspects of the uterus.39 The distinction between interstitial and cornual implantations is therefore an important one, and if any ambiguity exists after 2-D ultrasound, obstetrical consultation is appropriate. Newer technologies such as 3-Dimensional and 4-Dimensional US may be superior to traditional ultrasound techniques in distinguishing interstitial from cornual implantations, although these modalities may not be readily available at many institutions.38,39
Definitive diagnosis of an ectopic pregnancy on ultrasound requires visualization of a gestational sac with yolk sac or fetal pole outside of the endometrial cavity. However, other ultrasound scenarios strongly suggest the diagnosis of ectopic pregnancy without providing a definitive diagnosis:
- An empty uterus with a beta-HCG level above the discriminatory zone;
- Presence of fluid in the cul-de-sac, especially if the fluid is echogenic or the amount of fluid is large;40
- Presence of an ill-defined adnexal mass.33,34
Any of the above findings should prompt obstetrical consultation for definitive diagnosis and further treatment.
Treatment. Patients with a confirmed early pregnancy (detection of beta-hCG in the urine or serum) who are hemodynamically unstable should be considered to have an ectopic pregnancy until proven otherwise. In these patients immediate resuscitation and obstetrical consultation are critical. The patient's clinical condition should guide fluid resuscitation and early transfusion, and transfusion should not be delayed awaiting consultation. Laboratory workup should include urinalysis, complete blood count, type and crossmatch, Rh status, coagulation panel, and a quantitative serum beta human chorionic gonadotropin (beta-HCG). The quantitative beta-HCG, while unimportant in the initial management of the unstable patient, will be useful for the consulting obstetrician in monitoring resolution of the ectopic pregnancy after intervention.33
Once an ectopic pregnancy is diagnosed or strongly suspected, further management decisions should be guided by an obstetrician. Treatment options for ectopic pregnancy in stable patients include medical therapy with methotrexate or emergent operative intervention. Although methotrexate has not received FDA approval for medical therapy in ectopic pregnancy, this treatment method has been endorsed by the American College of Obstetrics and Gynecology and is widely used at many institutions.41 Treatment decisions depend on serum quantitative beta-HCG levels, gestational age, ectopic size, and presence or absence of fetal heartbeat. Importantly, 50 mcg of anti-Rho immunoglobulin should be given to all Rh-negative women presenting with an ectopic pregnancy or any vaginal bleeding in pregnancy.33
Heterotopic pregnancy is the presence of both an intrauterine pregnancy and an ectopic pregnancy. Estimates of the incidence of heterotopic pregnancy range from 1/2600 to 1/8000 in women who have not used assisted reproduction, and a reported incidence as high as 1-3% in patients using fertility drugs or in vitro fertilization.34 In a woman without the aforementioned risk factors for ectopic pregnancy and signs and symptoms suggestive of an ectopic, this risk of heterotopic pregnancy is low and this condition can essentially be excluded if an IUP is visualized on ultrasound. Conversely, for patients with risk factors for ectopic pregnancy, the detection of an IUP by ultrasound does not eliminate the possibility of a heterotopic pregnancy. Therefore, depending on the risk for ectopic, consultation with a gynecologist would be prudent.
Miscarriage. Miscarriage should always be considered in the differential diagnosis of the pregnant patient with abdominal pain presenting in the first 20 weeks of gestation. Approximately 15% of pregnancies end in miscarriage, with most occurring before 12 weeks of gestation.42 In addition to abdominal pain, vaginal bleeding is commonly present. The following definitions are useful in such scenarios:
Threatened miscarriage is defined as vaginal bleeding during the first 20 weeks gestation when fetal heart tones are present, without dilatation of the cervix.
Inevitable miscarriage is dilatation of the cervix with no history or evidence of passage of tissue in the first 20 weeks.
Incomplete miscarriage is passage of parts of the products of conception, in the presence of a closed cervical os, with retained fetal or placental tissue visualized on ultrasound.
Complete miscarriage is passage of all fetal tissue and subsequent closure of the cervical os before 20 weeks gestation.
Septic miscarriage is evidence of infection during any stage of miscarriage.42
Intrauterine fetal demise (IUFD) is defined death prior to the complete expulsion or extraction from its mother of a product of human conception, and further classified as early (< 20 weeks' gestation), intermediate (20-27 weeks' gestation), or late (> 28 weeks' gestation). To separate early pregnancy loss (spontaneous abortion) from later pregnancy loss, a threshold gestational age (e.g., 20 weeks) or fetal weight (e.g., 350 g) is generally used. Most patients with IUFD report no pain, but may describe an absence of fetal movement. The diagnosis of IUFD is established by visualization of the fetal heart without any cardiac activity. Occasionally, patients with IUFD may present with abdominal pain and/or uterine bleeding. The available therapeutic options, including expectant, surgical, as well as medical management should be discussed with a gynecologist once IUFD is confirmed in the ED.
To evaluate vaginal bleeding and abdominal pain in the first 20 weeks, a pelvic examination should be performed to quantify the amount of vaginal bleeding, passage of tissue, and to examine for presence of cervical dilatation. Any tissue discovered in the vagina or cervical os should be sent for pathologic examination. Laboratory workup should include urinalysis, complete blood count, blood type, Rh factor and antibody screen, and a quantitative beta-HCG. Transvaginal ultrasound should be performed to evaluate for fetal viability, identify retained products of conception, and to evaluate for ectopic pregnancy.42
Treatment. Patients with a threatened miscarriage can be safely discharged home with warnings and instructions to follow up with an obstetrician in 2-3 days for repeat beta-HCG measurement.42 Patients with the diagnosis of inevitable miscarriage or IUFD should have a gynecologist called to evaluate the patient in the ED; the discussion of treatment options and the risk of complications are best handled by this expert. Avoidance of tampons and sexual intercourse should be advised to prevent infection. If complete miscarriage is diagnosed, discharge with obstetric follow up is appropriate if vaginal bleeding is minimal.42 If there is any concern for the possibility of retained fetal parts (incomplete miscarriage), an obstetrical consultation is appropriate, as these patients have the potential for a septic miscarriage and/or significant hemorrhage. The febrile patient with missed miscarriage should raise the concern for septic miscarriage, and mandates emergent obstetrical consultation, as well as blood and cervical cultures and Gram stain, intravenous antibiotics, and admission.42 A commonly used antibiotic regimen in this scenario includes ampicillin (Omnipen) 1-2 grams IV q4-6 hours; gentamycin (Gentacidin, Garamycin) 3-5 mg/kg/day q6-8 hours adjusted for renal function; and metronidazole (Flagyl) 500 mg IV q8h or 750 mg IV q12h.42 However, there are many other alternative regimens. Whichever antibiotic regimen is used, one must ensure adequate coverage for both aerobic and anaerobic organisms.
Administration of Rh immune globulin to Rh-negative women with first trimester spontaneous miscarriage is a common practice and supported by many expert opinions.43 However, there are no studies that demonstrate that first trimester fetomaternal hemorrhage results in Rh sensitization.43 From a risk/benefit standpoint, the administration of Rh immune globulin is a low-risk intervention, and could potentially lead to substantial benefits in future pregnancies. Dosing for Rh immune globulin is 50 mcg in the first 12 weeks of gestation and 300 mcg after 12 weeks.42 If there is any doubt regarding gestational age, the 300 mcg dose should be administered.
Appendicitis In Pregnancy. The incidence of appendicitis in pregnancy is approximately 1 in 1500 pregnancies, a rate not different from non-gravid patients.44 Numerous studies have reported a higher frequency of appendicitis in the second trimester as compared to the first and third trimester.44,45
Clinical Presentation. Early in pregnancy the presentation will not differ considerably from the non-gravid patient. However, differentiating between tubo-ovarian abscess, appendicitis, ectopic pregnancy, ovarian torsion, and ovarian cysts is impossible based solely on physical examination. Later in the pregnancy, the physical examination findings are often obscured, as the abdominal wall becomes stretched and the underlying inflamed appendix may not be in direct contact with the peritoneum.34 Peritoneal signs may be absent as a result. Based on a small study from 1932, the classic teaching has been that abdominal pain from appendicitis may not be in the right lower quadrant as pregnancy progresses as the appendix is displaced upward by the growing uterus. One recent study disputes this long held belief.46 A large retrospective study found that right lower quadrant pain was the most common presenting symptom in pregnant patients presenting with appendicitis regardless of gestational age.47
White blood cell count has limited utility in diagnosing appendicitis due to the physiologic leukocytosis of pregnancy. As with the non-gravid patient, a normal white blood cell count does not rule out appendicitis. Additionally, presence or absence of a left shift is not useful in predicting appendicitis.44
Diagnostic Imaging. The utility of ultrasound to diagnose appendicitis in pregnancy is often limited in the second or third trimester. The gravid uterus, obesity, the presence of a retrocecal appendix, and overlying bowel gas are all potential limitations when using ultrasound.44 Studies have reported sensitivity as low as 75%, with specificities consistently above 95%.34 Positive findings on ultrasound are reliable, while a negative or equivocal ultrasound study cannot reliably exclude appendicitis from the differential diagnosis. Thus, ultrasound has some value in the detection of acute appendicitis in the pregnant patient, but it also has real limitations.48 Therefore, one should be aware that a normal US does not rule out appendicitis.
Just as with US, a CT scan that does not adequately visualize a normal appendix also does not rule out appendicitis. When abdominal ultrasound results are negative, equivocal, or ultrasound is unavailable, helical CT scan should be considered to rule out appendicitis. The diagnosis of patients who present early (< 12 hours) into their course of appendicitis remains a clinical one.
If CT scan is being considered it should first be discussed with a radiologist to select a protocol to minimize fetal radiation exposure. With a proper protocol selected to minimize fetal radiation exposure, helical CT scan of the abdomen involves a fetal radiation exposure of only 0.3 rads.48,49 Diagnostic studies with fetal exposure of less than 5 rads are not believed to be associated with increased fetal risk of birth defects, growth retardation, or spontaneous abortion, regardless of trimester at the time the study is performed.49 When helical CT scan or other imaging involving radiation exposure is indicated, the pregnant patient should be counseled regarding this information. This is consistent with guidelines set forth by the American College of Obstetricians and Gynecologists.49
One recent study using magnetic resonance imaging (MRI) to diagnose appendicitis in pregnancy shows promise, although further studies are necessary and this is not the current standard of care, primarily due to cost and limited availability.50
Treatment. Once appendiceal perforation occurs, both maternal and fetal mortality increase substantially. Maternal mortality rises to 4% with advanced gestation and perforation, while fetal mortality rises to as high as 20-25% after perforation has occurred.51 Thus, early surgical consultation is appropriate when appendicitis is suspected or cannot be reliably excluded. It is also reasonable to discuss with the consultant the choice of diagnostic imaging in pregnancy, or the option of admission for serial examinations and observation. Additionally, parenteral antibiotics should be given early for suspected appendicitis, as this may reduce morbidity and mortality.48,49 Penicillins and cephalosporins are considered to be safe in pregnancy—the exceptions being cefaclor and cephradine, which should be avoided.49
Once believed to be contraindicated during pregnancy, laparoscopic appendectomy has been used with increased frequency, particularly in the first trimester, with some institutions performing laparoscopic surgery in the second and third trimesters.52,53
Urolithiasis in Pregnancy. Kidney stones are a frequent cause of non-obstetric abdominal pain during pregnancy, with incidence estimates ranging from 1/1100 to 1/1500.54,55 This does not differ substantially from rates seen in non-pregnant patients.54 Elevated urine calcium levels and urinary stasis are believed to contribute to calculi formation in pregnancy. To counter this, ureteral dilatation and hydronephrosis naturally occur as the uterus becomes progressively enlarged, which may lead to fewer symptoms during pregnancy and easier passage of calculi.54,55
Clinical Presentation. The presentation of urolithiasis during pregnancy is similar to that of the non-pregnant patient: hematuria, nausea, vomiting, and flank or abdominal pain are the most common symptoms.56
The laboratory workup should be similar to the non-pregnant patient with suspected kidney stones. Serum creatinine levels are typically lower during pregnancy due to the increased glomerular filtration rate. The serum creatinine is of particular importance, as uremia increases the risk of fetal demise.
Diagnostic Imaging. Ultrasound should be used as a first-line diagnostic study, as it carries no potential risk of fetal harm from radiation.34,55,56 Ultrasound will not show the stone but will show other features of the disease including hydroureter and hydronephrosis. The commonly used renal CT scan should be avoided when possible, especially during early pregnancy to prevent fetal exposure to unnecessary ionizing radiation.34 Whenever ordering radiographic studies in a pregnant patient, it is useful to remember the guidelines set forth by the American College of Obstetrics and Gynecology:
1. Counseling that exposures < 5 rads have not been associated with increased fetal anomalies or spontaneous abortion.
2. Maternal health should not be compromised by fears of the dangers of radiation. However, alternative imaging procedures (such as US and MRI) should be employed whenever feasible.
3. Ultrasound and MRI are not associated with any known fetal adverse effects.
4. Radiologic consultation is advisable when necessary to estimate fetal radiation doses, especially when multiple radiographic tests are being performed.
5. Therapeutic radioactive iodine isotopes are contraindicated.
6. Radio-opaque and paramagnetic contrast agents are unlikely to cause harm, but the benefit versus the potential risk must be assessed prior to their use.57,58
Treatment. Most pregnant patients with kidney stones can be managed conservatively and will respond to intravenous isotonic crystalloids and analgesia.55 However, kidney stones in pregnancy do carry an increased risk of premature delivery.59 If urolithiasis is diagnosed or strongly suspected, consultation with a urologist and/or obstetrician (if viable pregnancy) is appropriate.
The febrile patient with urolithiasis should raise suspicion for concomitant pyelonephritis. The workup in these patients should also include blood and urine cultures and admission for intravenous antibiotics. Infected stones may need to be removed to cure the infection and avoid catastrophic complications such as gram-negative sepsis.60
When the Fetus is Viable. When abdominal pain is present in a woman with a viable fetus (usually considered more than 24 weeks gestation or an estimated fetal weight of 500 g or more), a detailed and accurate history is important. Vaginal bleeding is of particular concern in this population, as it may be indicative of placenta previa or abruptio placentae. Additionally, vaginal bleeding could represent the "bloody show" that often is present in labor. It is important to ascertain by history the presence or absence of leakage of fluid that may represent premature rupture of membranes. Ideally, all patients with a viable fetus should be evaluated while undergoing fetal monitoring, especially if the patient is reporting abdominal pain or vaginal bleeding. If such a patient is being evaluated in the ED, portable fetal monitoring equipment and the appropriate staff should be requested to come to the patient's bed and apply the monitoring devices. In addition to this, it is important to remember that caution should be exercised when performing a pelvic examination in the second half of pregnancy. In most instances, the emergency practitioner should not perform pelvic examinations in pregnant patients with a viable fetus.
Placenta previa should first be ruled out with abdominal ultrasound prior to performing a digital or speculum examination. If a digital exam is performed, sterile gloves should always be used to prevent infection, which may lead to an increased risk of premature rupture of membranes. If a speculum examination is performed, any fluid present in the vaginal vault should be tested for pH to rule out premature rupture of membranes, defined as the rupture of membranes prior to the onset of labor. Fluid in the vaginal vault with pH > 6.5 is indicative of amniotic fluid. Microscopic examination should also be performed to look for ferning, which is also indicative of amniotic fluid. If premature rupture of membranes is diagnosed, consultation with an obstetrician is appropriate to guide further management.61
Abruptio placentae deserves special mention due to its often catastrophic outcomes, although isolated right lower quadrant pain would be unusual in this setting. Placental abruption is premature separation of the placenta from the uterine wall.62 Risk factors for placental abruption include: maternal hypertension (the most common cause of abruption), maternal trauma, smoking, use of ethanol, use of cocaine, sudden decompression of the uterus, a short umbilical cord, post-amniocentesis, and advanced maternal age. Women with abruptio placentae typically present with vaginal bleeding, increased resting uterine tone, uterine tenderness, and hypertonic contractions. Fetal distress is common. Often, abruption is mistaken for the onset of labor, and delays in its diagnosis lead to increased maternal and fetal morbidity and mortality.
The diagnosis of placental abruption is a clinical one. Vaginal bleeding may or may not be present, depending on the size of the abruption.62 A concealed abruption involves only partial placental separation and does not lead to vaginal bleeding. Abdominal ultrasound findings in abruption are highly variable and unreliable when no abruption is visualized.34 Sensitivity and specificity have been reported as 24% and 96% based on a retrospective cohort study.57 As many as 50% of placental abruptions may not be visualized on ultrasound, and this modality should never be used as a "rule out" study.34,57 Patients with suspected placental abruption warrant immediate fetal monitoring and urgent obstetrical consultation and should not be sent outside of the emergency department for any diagnostic imaging.34 Laboratory workup should include a CBC, coagulation panel, type and crossmatch, Rh status, and renal function studies.
Miscellaneous Causes of RLQ Pain in Females
Tables 4-6 include diagnoses that can result in right lower quadrant pain but are not exclusive to females. An in-depth discussion of each of these conditions is beyond the scope of this article, but some highlights are included.
Conclusion
Abdominal pain in females, especially in either lower quadrant, poses unique diagnostic challenges due to the presence of the reproductive organs and the possibility of a complication of pregnancy. A careful history, coupled with a thorough physical examination and the thoughtful use of the laboratory and imaging studies, will very often yield the correct diagnosis. As always, it is paramount to ensure that life-threatening diagnoses are considered and excluded first.
The accompanying algorithm (see Figure 1) should assist clinicians when approaching female patients with right lower quadrant abdominal pain.
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Abdominal pain in female patients can pose a diagnostic challenge to emergency physicians. There are a number of emergent clinical conditions that must be recognized in a timely fashion to reduce morbidity and mortality in these patients.You have reached your article limit for the month. Subscribe now to access this article plus other member-only content.
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