Cardiac Question Help

What did they say the rationale was? I'm confused myself because the pt would at least need a pulmonary artery catheter to track that, and a pt admitted for GI issues is not going to have one of those. Actually I used to work in a CVICU and don't remember ever calculating a preload myself...we looked at cardiac output, stroke volume, cardiac index, SVR (again, not something that your GI pt is going to have such an invasive line to be able to track)...

I would have answered heart rate too. Out of those four parameters, that's the only one that you can "monitor more closely" in someone that's admitted to the floor for re-hydration and Zofran. Now all those other hemodynamic values will be affected too because your pt is clearly dry from all that vomiting and diarrhea, and therefore has less circulating volume. But again, he's not going to have a line that can tell you what any of those values are.

His heart rate will be a quick indicator of his fluid status in the medical floor setting; it will increase in someone who is dry. You'd expect BP to decrease also.

Someone please correct me if I'm wrong...if I am you can teach me something today too. :)

I would worry about fluid loss.

And when you have big enough fluid loss, you have decreased BP, even if you have an attempt to compensate by increasing heart rate; and heart rate will not be able to keep up at some point. Why is that? Preload, that's why. Less venous return coming to the heart makes less coming out of the heart.

Sure, you might need a CVP line (at a minimum) to quantify preload with a number. But didn't you learn about jugular distension (and, in this case, lack thereof) in physical exam class? If someone has a fat jugular at 45 (or 30, 60, or 90) degrees, you know he has more preload going on than someone whose jugular is flat.

2.3 kg is 2.3 liters of fluid. That's a lot of juice missing. This guy is DRY.

Gross analogy, but it works...Think about flushing a toilet......you flush, and then flush again right away......nothing happens right? This is because the tank doesn't have time to fill....PRELOAD is decreased in the tank.

What if the toilet is plugged up? When you flush, it backs up....this is too much afterload.

Awesome analogy - this totally makes sense to me!

HR is affected by the preload, but it wouldn't be affected right away. A change in preload would come before any changes in HR related to volume gain or loss.

Stroke volume would not be an entirely accurate factor to look at, because it can be improved by changes in HR, even if the patient is hypovolemic.

The preload is the blood going back to the heart after it has gone through systemic circulation and after volume loss has occurred. Therefore, it makes sense to look at preload.

Patient would have fluid volume deficit. Preload = volume. You don't NEED a PA to measure preload, you can transduce a central line to get a CVP.

And if there's no big CVP line you look at JVD. Check your physical exam textbook or look that up.