You are midway through an extremely busy overnight shift when you go in to see a 24-year-old female who has been waiting four and a half hours in the waiting room. You introduce yourself and apologize for the wait, hoping to improve a challenging Press-Ganey situation. During the history, she states she was feeling fine until around 10pm when she suddenly developed abdominal pain and “bloating”. She describes the pain as generalized, but mentions that it feels more severe around the edges of her abdomen, in the suprapubic area, and at both costal margins. The upper abdominal pain is most severe in the midline and is worse when she breathes in or presses on it. It also radiates into her neck, shoulders and chest. She did have one episode of vomiting and has had three episodes of diarrhea, but all were without any signs of blood. She denies fever, dysuria, vaginal discharge and any other systemic complaints.

She is otherwise healthy with no significant past medical or surgical history. Her only medication is a birth control pill. She is sexually active with one male partner who has accompanied her to the ED. Her review of systems is essentially negative with the exception of some very mild dyspnea.

On exam her vital signs are all within normal limits. Her skin is warm and dry and her head and neck exam are completely normal. Her lungs are clear and her heart sounds are unremarkable. Her abdominal exam is notable for diffuse mild tenderness and mild voluntary guarding but no rebound. There is no focal area of tenderness. Her legs are without swelling, chords or erythema. She politely refuses the pelvic exam and states she just saw her gynecologist last week for her annual check up.

Due to the protean nature of the patient’s complaints, and the fact that you are swamped, you decide to take more of a “shotgun approach” to her diagnostic testing. You have a feeling that “something just ain’t right,” even though you can’t put your finger on exactly what the problem is. You decide that’s it’s better to be comprehensive than take the risk of missing something big. An EKG done for the chest pain shows a normal sinus rhythm at a rate of 75 without any ischemic changes or evidence of strain. A chest X-ray was also done and was read as normal. Her pregnancy test comes back negative, as does the metabolic panel, LFTs and lipase. Her urinalysis appears positive with 44 white cells and 1+ bacteria and her CBC is normal except for a white count of 13. The D-dimer eventually returns elevated at 385, above the 250 cutoff in the lab.

By the time all of these tests are back and you do your re-evaluation, you are getting ready to sign out to the morning doctor. You have already tried Maalox for the upper abdominal pain and morphine for the lower pain, neither of which helped. You order a VQ scan secondary to the elevated D-dimer. You figure it has a lot less radiation than a CT scan and with a normal chest X-ray you should not end up with an indeterminant result. But how do you explain the diarrhea? How about the UTI in a young woman with no dysuria or flank pain or tenderness? And furthermore, you shouldn’t have pain and tenderness in the lower abdomen from a PE. What is going on here? You want to make some sort of contingency plan so your relief doesn’t have to get too involved in the case if the VQ comes back negative. You don’t want to order an unnecessary CT scan in someone who is so low risk, but you just get an uneasy feeling about everything. Then you remember the one symptom among many that she had mentioned, which might be important: “Bloating.”

Bloating is rarely a red flag for anything serious. The differential diagnosis usually includes the five “F’s”: Fat – no emergency, flatus – no emergency unless it’s a bowel obstruction, fetus – you’ve ruled that out, feces – no emergency, and fluid – she certainly has no liver disease. But then you think about the other type of fluid – BLOOD.

You certainly don’t want to miss that, but with no trauma and with normal vital signs, a normal hemoglobin and a negative pregnancy test, it’s pretty unlikely. However you decide to do a quick check of the pelvis and of Morrison’s pouch with the ultrasound machine before you’re ready for sign-outs. Below are two ultrasound images. What do they show? What changes in management should you make before you sign out?

What changes in management should you make before sign out? See NEXT page for case conclusion.

Dx: Significant Free Fluid, Likely Blood

The ultrasound shows free fluid. In the absence of trauma or cirrhosis, this is likely blood, and in a young female it is most likely from a gynecologic source. The blood is acute and therefore appears anechoic (black). It can be seen posterior to the uterus on the pelvic view. There is also a significant amount of fluid in and around Morrison’s pouch between the liver and right kidney; this means there is a large amount of blood present. This finding could explain all the mysteries in this case: multifocal abdominal pain, non-specific bloating, and a little vomiting and diarrhea, plus even the elevated D-dimer and the pleuritic chest pain and arm pain from irritation of the underside of the diaphragm. To proceed, you:

• Cancel the VQ scan of her chest
• Order a comprehensive pelvic ultrasound and a repeat CBC, and
• Consult the gynecologist on-call

You learn the next day that the repeat hemoglobin was 2 grams lower, and the pelvic ultrasound showed only moderated free fluid and no source of bleeding. Your colleague decided to consult surgery and, of course, the surgeon requested a CT scan, which showed a 3.5cm splenic artery aneurysm that was bleeding. The vascular surgeon ended up taking her to the OR for repair of the aneurysm, and although her hemoglobin eventually dipped below 8, she fortunately she got away without needing a blood transfusion.

Spontaneous Hemoperitoneum
from Quick Essentials: Emergency Medicine, EMresource.org
Symptoms: Pain may radiate to chest or shoulder/arm & be pleuritic, bloating, weakness
Causes: Ovarian cyst, endometrioma, ectopic, uterine rupture. AAA, splenic artery aneurysm, Pancreatitis, ruptured hepatic cyst, ruptured neoplasm, DIC, spontaneous splenic rupture

Splenic Artery Aneurysm
from Quick Essentials: Emergency Medicine, EMresource.org
Risks: pregnancy, tobacco, female, HTN.
Complications: rupture if >2-3cm or pregnant (mortality 10-25%)
Treatment: refer, surgery, embolization, stent

Facts About Splenic Artery Aneurysm:

• Incidence is 0.7% - 10%, and in females is four times the rate in males
• It is the second most common intra-abdominal aneurysm after aortic and iliac
• The peak time of detection is in the sixth decade of life
• Half of ruptures occur during pregnancy
• The mortality of a ruptured splenic artery aneurysm is ~80%
• Rupture risk is highest for symptomatic aneurysms, those more than 30mm in size, and those detected in women who plan to become pregnant
• 50% of all ruptures occur in pregnant patients
• Fetal mortality is as high as 97%

Continue Next for Pearls for Using Ultrasound to Scan for Free Fluid

1. Remember that patients can develop intraperitoneal free fluid from a variety of etiologies. Use the principles and concepts of the FAST exam to help you in situations where you are trying to rule-out free fluid from non-traumatic causes, too.

2. Blood appears anechoic (black) when acute and free flowing, but hypoechoic (gray) when subacute or clotted. When blood is gray it is much easier to miss, especially if you are not looking for it. Always obtain multiple views and perform serial scans when you can.

3. The sensitivity of the FAST exam improves with Trendelenberg positioning, repeat imaging, and if you know how and where to look (experience).  Always image the inferior tip of the liver, as this area may be positive when Morrison’s pouch is not. Likewise, blood can also accumulate near the inferior border of the spleen, even when the splenorenal recess appears normal. Turn down the gain on the pelvic view if the bladder is full, otherwise the enhancement behind the bladder may “white out” a small pocket of fluid. If you think you see a small sliver of free fluid, reposition the patient to see if the anechoic area changes or fluctuates.  The sensitivity of the FAST for blood is ~85% if serial exams are performed, but it can be as low as 24% in some studies.  Usually >200ml of fluid can be detected

4. The specificity of the FAST exam is about 95%.  False positives may include fluid mimics such as the prostate, psoas, a perinephric fat pad, severe hydronephrosis or a large blood vessel.  They may also include other causes of free fluid such as ascites, urine, physiologic fluid, and inflammatory fluid from infection, pancreatitis or ischemic bowel. Remember that it is beyond your scope of practice to rely on ultrasound to help you determine what type of fluid you see in the peritoneum. Bedside ultrasound should only be used to tell you whether or not free fluid is present. Always correlate your bedside ultrasound findings with the physical exam and clinical picture.

Brady Pregerson manages a free on-line EM Ultrasound Image Library and is the author of the Tarascon Emergency Department Quick Reference Guide. For more information visit www.EMresource.org.

Teresa S. Wu is the Associate Residency Director, and Director of Ultrasound and Simulation Based Training for the Maricopa Emergency Medicine Program in Phoenix, Arizona.