Jelly Belly

Your next ED patient is a 47 year old male with a history of diabetes, hypertension, coronary arterial disease and CHF who presents with 2 weeks of gradually worsening leg swelling, abdominal swelling, and trouble sleeping due to orthopnea. He states that he has had the leg swelling and trouble breathing in the past from his CHF, but he has never had a “jelly belly” before. He denies any change in his medications or dietary indiscretion. He has not had any chest pain, abdominal pain other than feeling “fat and bloated” or any vomiting, diarrhea or fever. His main concern seems to be his abdomen and his request is simple. “Doc, can you fix me?”

On physical exam, he is in no acute distress but is a bit hypertensive and tachypneic. His temperature is 96.8°F with a respiratory rate of 24 and a pulse ox of 96% on room air. His pulse and blood pressure are 68 and 179/96, respectively. His head and neck appear normal except for his eyes, which have just the slightest tint of yellow. His lungs are clear, but he has decreased breath sounds bilaterally. His heart is regular, without murmur or gallop. His abdomen is quite distended, but non-tender, and he has a positive fluid wave. His extremities have symmetric 2+ edema, without redness or tenderness.

You order some basic tests and none of the results surprise you much. His EKG and chest X-ray show nothing acute, just poor inspiration. His potassium is a bit low and his bicarb a bit high from the Lasix he is taking, but otherwise his metabolic panel looks good. His CBC is fine except for low platelets at 111,000. His troponin is normal, but his BNP and LFT’s are all slightly out of whack.

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You call his internist to admit him for a mild CHF exacerbation with new onset ascites, likely due to a combination of the CHF and previously undiagnosed liver disease. His internist agrees, but wants you to tap his abdomen first – conditions, conditions.

“This guy is breathing fine,” you think to yourself. “He doesn’t really need the tap done now, and the ED is pretty busy. I don’t really want to give myself more work, but it is Saturday evening, and if I don’t do it, it probably won’t be done till midday on Monday.”

You tell the internist, “sure,” then, after getting off the phone, you ask one of your trusty ED techs to set you up for a paracentesis. As an afterthought you add, “Better get the ultrasound machine in there as well.” You might as well confirm 100% that there is actually fluid in there, that there is enough to tap, and where the safest puncture location is.

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When the time is ripe, you turn on your ultrasound machine, add a small dab of gel to the curvilinear probe and take the following image (below) in the right lower quadrant.

What do you see? Is there ascites?
If so, how much? Does this look like a promising location or should you look elsewhere?
Would repositioning your patient help?

Image 1 does indeed show ascites. The ascites appears anechoic (black) and is in the nearfield (top of the image) as opposed to the intestine, which appears hyperechoic (white) and is in the farfield (bottom of the image). In real time, you can also often see the bowel moving within the ascitic fluid during peristalsis. You may even see the bowel contents moving within the bowel walls. It’s hard to estimate the total amount of ascitic fluid in the abdomen with just one view, but you could estimate how much you see in just the image above by using the centimeter markers at the bottom and left side of the screen. The pocket appears to be between 5-7cm deep and at least 14cm across. A second view with the probe rotated 90° (not shown) noted a maximal depth of 10cm. If the pocket were a rectangle that was 6 X 14 X 10 cm, then the total volume of just this part of the pocket would be about 840ml. This pocket looks like a quite promising location to do your tap, but it always makes sense to compare sides before making your final choice.

Factors other than pocket size are important to consider as well. For example, you want to avoid puncturing an enlarged liver or spleen. Find adjacent organs while you are performing your scan. You also would want to avoid any surgical scars, because adhesions in the area may tether down bowel and increase the risk that you will perforate them with your needle. Proper positioning for paracentesis is also important. Since bowel floats, it is recommended that the patient be positioned with the head of the bed elevated between 45 and 60 degrees. The bowel will rise and the fluid will collect in the lower abdomen. Repositioning the patient after the ultrasound, but before the tap however, is ill advised. Any repositioning may cause the bowel and fluid to shift and increases the risk of hitting bowel. The one botched tap I have done was due to repositioning a patient. He had a belly full of fluid by an ultrasound that was done in the supine position. I then sat him up to do the tap and could not get any fluid at all. I ended up aspirating peritoneal gas. When I ultrasounded him again, all the fluid had mysteriously disappeared. As it turned out, the patient’s “ascitic fluid” was actually all urine due to a ruptured bladder, and when I had repositioned him, it had all siphoned off into the Foley catheter that the nurse had placed. This scenario is rare, but it reinforces the importance of doing the ultrasound right before you do the tap, with no repositioning in between.