Sonographic free fluid in patients with ectopic pregnancy

Abstract

Study objectives: Many emergency physicians currently use abdominal and endovaginal ultrasonography to evaluate pregnant patients for ectopic pregnancy. Emergency physician–performed pelvic ultrasonography is generally used to rule out ectopic pregnancy by detecting an intrauterine pregnancy. However, when an ectopic pregnancy is present, free fluid in the pelvis or hepatorenal recess (Morison's pouch) can be easily recognized. The amount and location of free fluid in patients with ectopic pregnancy is used to make important management decisions, such as whether to proceed with methotrexate therapy or surgery. Our objective is to assess whether physicians who interpret ultrasonographs in patients with ectopic pregnancy note the presence or absence of pelvic or abdominal free fluid. We hypothesized that some of these physicians overlook free fluid in either the pelvis or Morison's pouch because they do not fully understand the significance of these findings. Methods: This study was a retrospective medical record review of all emergency department (ED) patients diagnosed with ectopic pregnancy during 2000 to 2004. The setting was an urban teaching hospital with an ED census of more than 100,000 patient visits per year. In our hospital, all ultrasonography for suspected ectopic pregnancy is performed by either an emergency physician or by radiology. Our electronic charting systems (EmSTAT and IRIS) were used to identify and review the records of 134 patients with ectopic pregnancy. Information was collected about the evaluation, management, and outcome of all patients. Endovaginal and abdominal ultrasonographic interpretations by emergency physicians and radiologists were recorded and compared. Results: Ectopic pregnancy was diagnosed in 134 patients during the study dates; all received ultrasonographic examinations. Twenty unstable patients had emergency physician–performed abdominal ultrasonography demonstrating free fluid in Morison's pouch and went directly to the operating room. Sixty-seven stable patients had emergency physician– and radiology-performed endovaginal studies. Emergency physicians recognized an empty uterus in all cases and noted pelvic free fluid in 27 (41%) patients. Subsequent radiology studies confirmed the finding of an empty uterus in all cases but noted pelvic free fluid in 58 (88%) patients. Ultrasonography of Morison's pouch was performed by emergency physicians in 45 (42%) of the stable patients and by radiologists in only 10 (9%). Emergency physicians found free fluid in Morison's pouch in 17 patients; radiologists noted this in only 9 patients. Every patient with free fluid noted in Morison's pouch was either admitted or required immediate surgery. The presence or absence of free fluid in Morison's pouch did not correlate well with the amount of free fluid noted in the pelvis. Three patients with pelvic free fluid were discharged home without an ultrasonograph of Morison's pouch and later returned and required surgery. Conclusion: In stable patients with ectopic pregnancy, emergency physicians are more likely to find and report free fluid in Morison's pouch, whereas radiologists are more likely to find and report free fluid in the pelvis. Stable patients with suspected ectopic pregnancy should have an ultrasonograph of the pelvis and Morison's pouch. Physicians who interpret ultrasonographs in patients with ectopic pregnancy should understand the significance of free fluid in the pelvis and Morison's pouch so that the assessment and treatment of patients with ectopic pregnancy can be more consistent.