This article is the second in an on-going series of columns about abdominal pain. The patient in the first article complained of right lower quadrant pain.
Abdominal pain is the most common cause of hospital admission in the United States.[1] The ability to build a differential diagnosis and subsequent treatment plan relies on the quality of both the patient history and physical exam.
One of the first steps in diagnosing abdominal pain is to understand the nature of the pain and to think about the anatomical structures in the area the pain is located. Ask questions about how pain changes with movement, inspiration and palpation for additional clues about the cause of the discomfort.
Primary and secondary assessment
Julia presents with an increase in abdominal pain accompanied by some vaginal bleeding. Based on her recent history of a positive pregnancy test and missed menstrual cycle it is clear that pregnancy-related complications must be considered for the remainder of her assessment. She has a history of miscarriage and this seems like a reasonable diagnosis to include miscarriage as you proceed with your assessment.
Her pain is located in the left lower quadrant (LLQ) an area commonly associated with reproductive structures in female patients. The mention of shoulder pain when lying flat is particularly interesting and should trigger thoughts of another differential diagnosis.
While patients often experience pain at the location of their disease or injury, pain may also be referred to another location. When a patient has fluid in her abdomen lying flat causes the fluid to migrate upward and can irritate the lining of the diaphragm. This, in turn, causes pain in the shoulder. Left shoulder pain like Julia is experiencing may also be associated with gallbladder or pancreas problems, as well as blood in the abdominal cavity.
Julia’s heart rate is slightly elevated and her blood pressure is normal which indicates that she may be in compensated shock. This finding, along with the referred shoulder pain when lying flat, should result in a differential diagnosis of intra-abdominal bleeding. The history of a positive pregnancy test should further refine that diagnosis to a ruptured ectopic pregnancy.
Ectopic pregnancy
Any fertilized egg which implants outside of the uterus is considered an ectopic pregnancy with most implanting in the fallopian tube. It is estimated that ectopic pregnancy occurs one to two times per hundred live births.[2] Patients using assistance to become pregnant (like in vitro fertilization) or those who have had a tubal ligation are at increased risk.[2]
The range of symptoms of an ectopic pregnancy vary widely with up to 10 percent of patients having no symptoms at all.[2] The symptoms associated with an ectopic pregnancy can also be found in presentations of appendicitis, ovarian cyst, miscarriage and urinary tract infection.[2]
As the rate of women receiving prenatal care has increased, ectopic pregnancies are caught earlier and an acute rupture is less likely to be the first indication of implantation outside of the uterus. Still, since a ruptured ectopic pregnancy may be a life-threatening condition, it is important that all women of childbearing age with acute abdominal pain have ectopic pregnancy listed as a must-not-miss diagnosis.
Traditionally, ectopic pregnancy was ultimately diagnosed during surgery to remove the tissue from the implanted location. Now, however, an ectopic pregnancy can effectively be diagnosed by ultrasound.[2]
A ruptured ectopic pregnancy will likely require emergency surgery to repair or remove the affected fallopian tube. For non-emergency cases, surgery may still be required but there are also medical options allow the cells to dissolve and simply be passed from the body.
Treatment of the patient
Based on your assessment findings you determine that Julia is at a high risk for a ruptured ectopic pregnancy. Since her vital signs are indicating a state of compensated shock and ALS is not yet on scene, you elect to begin transport and request that an ALS crew intercept you on the way to the hospital. You advise your receiving hospital early in your transport to allow them ample time to prepare and transport non-emergent to the ED.
Once at the hospital, Julia undergoes transvaginal ultrasound and is diagnosed with a tubal ectopic pregnancy. Ultrasound reveals blood in her abdomen and she is taken for surgical repair of her ruptured fallopian tube. The procedure goes well and she is discharged home two days later.
References
1. Stern, S. D., Cifu, A. S., & Altkorn, D. (2006). Abdominal pain. In Symptom to diagnosis: An evidence-based guide(pp. 9-31). New York: Lange Medical Books.
2. Kirk, E, C Bottomley, and T Bourne. “Diagnosing Ectopic Pregnancy and Current Concepts in the Management of Pregnancy of Unknown Location.” Human Reproductive Update 20.2 (2014): 250-261. Web. 1 May 2015.
