bp drop during paracentesis

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.

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.

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.