Perfusion

Don't be ungrateful to a healthy body that God gave you, okay? But what are the six Halloween limb salvage lessons we should take away from this? Tissue viability is not determined by appearance alone.

Perfusion is fundamental for wound healing.

That's why we love vascular I love vascular, but this gentleman was a very bad person.

And I'm just going to call it like it is, okay? If you don't agree with me and say, oh, we have to be sympathetic towards them, don't contact me.

You can think about...

Perfusion, you can think about building just so many different types of hardware for every part of the protocol that you can imagine.

For every one of those, there's multiple angles.

It's like folks building the perfusion devices.

The waveform gives us important hemodynamic information, while toe pressure can provide additional information about distal perfusion.

Also, TCPO2 can be extremely useful.

Perfusion is not a number.

It is a clinical condition.

Yes, no, absolutely.

And with that, you can actually cut off the blood supply to the muscle.

So the treatment of that is basically releasing all of that tension, all that pressure, so that the muscles can breathe and get more oxygenation and blood flow.

And so that's a really, unfortunately, a common problem, but if it's addressed early, it's very fixable.

And Brett, so from your perspective?

Rather than just accepting problems, we tried to come up with a solution.

And we spent the time since 2008 and 2009 when we first met and started working on that other grant uh developing our solution to negative pressure wound therapy and wound therapy in general and that's uh where we're at today that's what we call the prevent uh because it prevents a lot of the negative effect of negative pressure wound therapy and in doing so it delivers a level of care that's been unmatched and we've been so happy to see that it's like uh our baby uh our baby's finally got legs and starting to walk and We're seeing amazing clinical responses for the thing you talked about, peripheral artery disease or peripheral vascular disease.

And these wounds really thrive with the prevent because we do it at low negative pressure, which really helps with the blood flow to the wound base.

But even where it came from, what's its trauma? In Ukraine right now, they're using our dressing to save soldiers injured in that war front with large open wounds like the ones we treated when I was in the army.

Turning the patient prone or on their stomach shifts the heart and abdominal contents so that their weight, their presence is off the lungs, allowing previously compressed areas to reopen and participate in gas exchange.

We also get with that better ventilation perfusion

matching.

Now, if you've not heard this term before, ventilation perfusion matching, you've probably also then never heard of a VQ mismatch.

And V stands for ventilation, Q stands for perfusion.

And when we have a mismatch, the patient is not doing well respiratory-wise.

Now, if you want to dive into this in more detail, Go and check out episode 46, so an episode from the way back time machine, and you definitely want to dive into that so that you can understand this type of respiratory problem.

Basically, there's a mismatch between the patient ventilating and the perfusion that is going on.

It's not saying what's been delivered at the tissue bed.

So what's been delivered at the tissue? Because by definition, shock is inaccurate tissue perfusion and oxygenation.

Inadequate, yeah.

Yeah.

Only for so long.

That's right.

But that's not telling you necessarily at the tissue level because the tissue perfusion is a combination of the pressure difference between the arterial and the venous end.

Yes.

This is Matthew Sun, Assistant Professor of Neurosurgery, brain tumor surgeon, and at UT Southwestern in Dallas, Texas.

Today, I have the pleasure of speaking with Dr. Alexandra Toldea and Dr. Riccardo Ludovichetti at University Hospital Zurich about their paper recently published in Neuro-Oncology Advances titled Prediction of Treatment Failure in Patients with Glioblastoma with Perfusion MRI and Molecular Biomarkers.

Alexandra and Ricardo, thank you for joining us today.

First, I'll just start out with an introductory question.

MGMT methylation, not early imaging progression, predicted long-term survival.

So this suggests a hierarchical approach.

Perfusion MR reflects early failures for closer monitoring, while MGMT status determines who actually lives longer.

Thank you so much for that summary, Ricardo.

Clinically, I look for congestion and for perfusion.

Congestion, orthopnea, raised jugular venous pressure, a positive hepatojugular reflux, peripheral edema, crackles, ascites.

Perfusion, cold peripheries, narrow pulse pressure, confusion, oliguria, rising lactate.

This gives the classic profiles warm and wet, the commonest cold and wet, which signals low output and possible cardiogenic shock, warm and dry, and cold and dry.

The profile determines urgency and treatment.

Why? This drug only works on the blood that can get to the nephron.

So if the patient has decreased perfusion...

What does perfusion mean? Perfusion is the ability of the body to actually, um, um, use those resources, use up the oxygen, the vitamins, the nutrients, the minerals that are in the blood.

Okay? That's what perfusion is.

So if the patient's perfusion is decreased, the drug's not gonna work because only the blood that can get to the nephron will only, will, will, uh, be effective, okay? Let me make this bigger for you.