bp drop during paracentesis

loveofrn, BSN, RN · Feb 12, 2017

Well, you have to first understand how osmotic, albumin and hydrostatic pressure works.

There are many reasons why patients develop ascites and the most common causes is liver problem.

Patients with cirrhosis have low albumin level because the liver cant produce them anymore or produce little.

Albumin helps to keep fluid in the circulatory system, so when there is low albumin fluid tends to leak around the cell ( third spacing) which cause ascites.

The recommended fluid removal is less than 5, when more than 5 is removed it usually cause hypotension because even though the fluids that was removed is in the third space, fluid continues to leak into the third space from the vasculature because low albumin cant keep the fluid in the circulatory system

Thats why we usually check Bp to see if the patient can tolerate the procedure and we give albumin to prevent hypotension which helps to draw fluid into the circulatory system before the procedure.

So the answer to the question is, paracentesis can cause hypotension and you should always be alert and prevent it by giving albumin and remove fluids gradually.

I hope this helps.

Wuzzie · Feb 12, 2017

So, when i was on med surg rotation in telemetry, my preceptor was always asking me questions. she asked me one that i had to think about. We had a patient who had a paracentesis and she asked me why we don't have a drop in BP if they are removing fluid from the body. It's because you are not taking it from the vasculature, which made sense. Now as I am doing Kaplan, there was a question, on the ONE thing you need to monitor during paracentesis, and it is of course BP, because shock may occur due to removal of fluid. So, is it just because of the drop in pressure then or was she incorrect? I am a little confused.

You should be confused because she was wrong. There are two reason for hypotension. The previous poster discussed the post-procedure causes but during the procedure is a different process. I'm not going to tell you the answer because I want you to look it up yourself but I will point you in the right direction. Think about what might be affected when the intra-abdominal pressure is elevated and then when it drops suddenly. What circulatory structures might be affected? Think about the impact on venous return. Fluid boluses are generally not particularly successful in treating paracentesis related hypotension during and immediately after the procedure but vasopressors are. Why do you think that is? A quick Google search brought up some reliable articles that will be very helpful in answering your question.

A note about procedure time. It is recommended that the procedure is limited to 4 hours or less to decrease risk of infection. We do ours in less than an hour but we also limit it to 5 liters as ours are primarily palliative. However, it is not unusual to remove 10 liters in an emergent situation.

Lev, MSN, RN, NP · Feb 12, 2017

Any time fluid is removed from the body, even if not taken directly from the bloodstream, there is risk of decreased BP.

As another poster correctly stated, all that fluid in the abdomen (4, 5 + liters) is providing pressure against the abdominal vasculature. What do you know about causes of hypertension? Whenever there is decreased compliance of a vessel, the pressure inside the vessel increases. When all that fluid is drained, sometimes rather rapidly, the vessels can now expand fully and dilate to their regular capacity. Now the blood has more room to flow and therefore there is decreased pressure in the vessels.

However, fluid in the abdomen (depending on volume and size of the patient) can increase intrathoracic pressure which can decrease blood pressure (especially in patients who are dehydrated) because the increased pressure reduces preload and afterload and impairs cardiac output. You will see this with patients on BIPAP too. So I guess things balance themselves out at times.

The other point to bring up is that of fluid shifting. The fluid shifting effect is more of a factor when large volumes of fluids 5+ liters are removed and especially in patients with cirrhosis. In this case, infusion of a volume expander such as albumin may be indicated.

AliNajaCat · Feb 12, 2017

The previous two posters have given you some good hints (and some actual answers, how generous). You know how to think about blood pressure in terms of how you get a low one with hypovolemia. Remember that's what's inside the blood vessels (your instructor was right about that); that's hemodynamics.

However, you have by now figured out that even if the amount of blood in the blood vessels is completely unchanged (paracentesis does not result in immediate hypovolemia), there's a reason why blood pressure could drop during the procedure; think of that as mechanical.

And yes, over time, if somebody develops ascites or a pleural effusion, he will probably do it again after his tap empties it out, losing intravascular volume as he puts protein-laden fluid into his peritoneal or pleural space. That will take a little time, though, and the NCLEX question is what happens DURING the procedure.