When pain (perceived or real) makes patients almost impossible to examine, ultrasound can give you the diagnostic edge that you need.
“Never let them see you sweat.” You roll your eyes at the antiperspirant commercial blaring on the TV in a nearby patient’s room as you ask your nurse to push another miligram of epinephrine and turn on the transcutaneous pacer. This is in response to the flat line you have produced on the cardiac monitor after defibrillating the octagenerianin front of you. It’s the third cardiac arrest you’ve seen during your shift, and you have a sneaking suspicion that your “black cloud” isn’t about to dissipate any time soon.
Just as you finish uttering the time of death, the new charge nurse grabs you by the arm and pulls you over to see a young woman who is wailing at about 120 decibels. You recognize her immediately. She’s been one of your “frequent fliers” for years and you know her chart like the back of your hand. She’s allergic to morphine, codeine, ketorolac, and compazine, with a history of fibromyalgia and chronic migraines. She comes in with either a headache or abdominal pain almost every week. If you give her at least 2-mg of dilaudid two or three times she’ll be sure to let you know what a “great doctor” you are when she leaves.
Today, however, something looks different. As you greet her familiar face, you can’t help but notice that she is as diaphoretic as you were during that last resuscitation. Her arms are folded across her abdomen as she rocks rhythmically in a fetal position. You quickly note her triage vital signs—not pretty. You ask your best nurse to start two large bore peripheral IV’s. You let out a sigh of reliefas you note the flash of venous blood in the catheter at your patient’s left antecubital fossa. With access secured, you ask the nurses to grab some fentanyl while you try to figure out what is going on. Attempts to question your patient are met with hysterical screams. She won’t bring her knees away from her abdomen long enough for you to examine her and if you persist, she pushes you away.
You grab your ultrasound machine and quickly scan her right upper quadrant using a lateral/midaxillary approach. Her hyperventilation is prohibiting you from getting ideal views of Morrison’s Pouch, but you think you catch a hypoechoic sliver of fluid surrounding her right kidney.
“Ma’am, when was your last period?”
Your patient wails back “I don’t know! I don’t know! Oh my God! I’m going to die!”
As you have the nurse administer 50-mg of fentanyl, which you have chosen knowing it is less likely than other narcotics to cause hypotension, you ask your unit secretary to put a page out to the OB/Gynecologist on call.
Given her age, you are of course suspicious for an ectopic pregnancy. Nevertheless, you run through a differential diagnosis in your head. Did she suffer from some abdominal trauma? Possibly. Does she have a ruptured hemorrhagic ovarian cyst? Not unlikely. Could it be ascites? Probably not. How about hemorrhagic pancreatitis? Could be.
Knowing that it’s going to be nearly impossible to get a urine pregnancy test on this patient, and that a serum pregnancy test is going to take too long, you explain to your patient that you need to examine her lower abdomen with the ultrasound machine. She refuses to extend her hips because of pain, and unfortunately, your transabdominal views are impeded by a combination of her habitus and her position. You encourage her to allow you to do a quick transvaginal scan at the bedside, and she yells out “I don’t care what you do! Just please give me more dilaudid!”
You gently insert your probe with the indicator marker pointing towards the pubic symphysis. In this sagital plane, you get the two images below. You angle the probe towards the patient’s left adnexa and see the bottom image.
The mass you note sitting just outside the uterine fundus, coupled with the free fluid noted on your scans, leads you to believe that it is a ruptured ectopic pregnancy and Miss Frequent needs an emergency trip to the operating room. You express your concerns to the OB/Gynecologist over the phone who mutters “send her up to the OR” before she slams down the phone. You type and cross 6 units of PRBC’s, and double-check your work. Fifteen minutes later the transport team arrives and about an hour after that the OB/GYN comes down to compliment you on a job well done. Your lady’s serum quantitative beta-HCG was only 700, but they couldn’t salvage her left ovary or fallopian tube.
Just after you finish patting yourself on the back, the radio nurse lets you know that your fourth cardiac arrest of the evening is 5 minutes out. You gown up, grab your trusty ultrasound machine, and smile at the charge nurse and say with conviction, “Never let them see you sweat.”
For common pearls and pitfalls of using ultrasound to detect an ectopic pregnancy, see the next page.
Pearls and Pitfalls for ultrasound of an ectopic pregnancy
—When you scan for alternate indications, practice looking at the pelvis with trans-abdominal ultrasound. The more normals you look at, the more likely you are to recognize when something is not right.
—Do not send an unstable patient to radiology. If you have the skills, perform a bedside ultrasound yourself and call your surgeon early. A formal study is preferred if the delay is not likely to jeopardize care. Again, if the patient is unstable, it should be done at the bedside.
—Any patient with a positive pregnancy test and free fluid visible on bedside ultrasound should be suspected of having a ruptured ectopic pregnancy until proven otherwise. In many ectopic pregnancies, free fluid is the only sonographic abnormality appreciated.
—Begin by scanning the hepatorenal recess (Morrison’s Pouch). This is the most dependent position when the patient is lying supine and free fluid may be noted here first.
—If Morrison’s Pouch is clean, evaluate the pelvis via a transabdominal approach. In order to obtain adequate transabdominal views, the patient must be cooperative and ideally have a full bladder to serve as an acoustic window. Look for hypoechoic free fluid in the vesicouterine and rectouterine spaces.
—Assess the uterus for the presence or absence of an intrauterine pregnancy.
—If adequate images are not able to be obtained via the transabdominal approach, a transvaginal ultrasound can be performed at the bedside.
—Cover the endovaginal transducer with a gel filled sheath and apply a copious amount of sterile gel to the outside of the sheath.
—Insert and advance the transducer with the indicator marker pointing anteriorly towards the patient’s pubic symphysis. Alternatively, you may let the patient insert the probe herself as this method is often less uncomfortable. Scan through the uterus in this sagital plane, noting the presence or absence of an intrauterine pregnancy. If the patient has a positive urine or pregnancy test, and the uterus is appears empty, an ectopic pregnancy should be suspected.
—It is often possible to visualize the ectopic pregnancy during a quick transvaginal bedside scan. Rotate the probe 90° counter-clockwise and point the indicator marker towards the patient’s right side. Trace the broad ligament of the uterus out towards the ovaries, which lie just medial to the iliac vessels.
—In this coronal plane, assess for any complex adnexal masses or tubal rings. Remember that it is not always necessary to visualize these subtle adnexal findings in order to diagnose an ectopic pregnancy. A comprehensive pelvic scan should only be performed if additional diagnostic information is required and if it does not delay patient management.
Brady Pregerson, MD, oversees QI for ED Ultrasound at Cedars-Sinai Medical Center in Los Angeles. For more images, check out Real-Time Readings at www.epmonthly.com. Teresa Wu, MD, a clinical assistant professor in EM at Florida State University, completed her ultrasound fellowship at Stanford University Medical Center.