Відео

Thank you for the feedback :)

So kind of you :) I'm glad you found the video useful!

Yes! So to understand the concept of reciprocal changes, you'll have to be familiar with the direction (vector) that each of the leads are pointing to. In the video example at 19:35, the ECG wave drawn roughly represents what we would expect to see in lead II. If we were to take the same MI scenario but looked at how lead aVR (which roughly points in the opposite direction as Lead II) would have looked like, the ST segment would actually look like a depression since the constant "noise" that shifted the ECG wave downwards in lead II would have shifted the ECG wave upwards in lead aVR. The ST depression seen in aVR would be considered a reciprocal change to the ST elevation seen in lead II. Essentially reciprocal changes are ST depressions seen in the leads pointing in the opposite direction of the leads that have ST elevations. A real life example of a full-thickness inferior wall MI, the overall "noise" vector ends up being pointed away from the inferior (downward) pointing leads (II, III, aVF), so you see ST segment elevations in those inferior leads (II, III, aVF). Instead of looking at that overall "noise" vector as pointing AWAY from the INFERIOR direction, you can say that the "noise" vector is pointing TOWARD the SUPERIOR direction. Therefore the ECG waves in the leads pointing upwards in the SUPERIOR direction (I, aVL) will show ST depressions. You'll notice that lead I is not actually pointing downward (it's rather pointing horizontally) but still shows ST depression in this case since likely the "noise" vector in an inferior wall MI is pointing away from somewhere in between leads III and aVF (not exactly pointing downward 90 degrees). Hope that helps clear that up?

Very true!

The PAO2 that's noted in the equation is the alveolar O2 left in the alveoli once the inhaled O2 that was destined to enter the blood has gone into the blood. Maybe it might be more intuitive if we rearrange the equation so it's like PIO2 = PAO2 + PO2delivered to blood. The total inhaled O2 (PIO2) will either stay in the alveoli (PAO2) or will be delivered into the blood (PO2delivered to blood). The output O2 (PO2delivered to blood) is calculated by seeing how much CO2 is in the alveoli since there's the specific exchange ratio between CO2 and O2. The inhaled CO2 is almost zero so all the CO2 seen in the alveoli essentially all came from the blood.

@@medrounds101 Thank you so much! But I feel the PaCO2 should be drawn from the VBG instead of the ABG since VBG has CO2 rich blood and that CO2 in VBG is what is going to be readily picked up by aveoli? Also I feel the PO2 delivered to blood can also be drawn from ABG directly because it's O2 rich blood and the PaO2 reading from ABG should reflect the PO2 delivered to blood? Sorry about all the questions....and again thank you so much for making these videos!

I've had some brilliant teachers and also happened to come across this, essentially, basics of cardiology book a while back that went though some concepts of electrophysiology and echocardiograms. It was in Japanese, and I can't quite remember to title at the moment but I'll come back to mention it if I find it. I have been recommended "The only EKG book you'll ever need" by Malcolm Thaler a lot but I personally have not had the opportunity to go through that yet.

​@@medrounds101 I have a copy of that book I found online so ill definitely give that a look too. Thanks a bunch for this video and the response.

It's definitely a tricky concept to grasp! If we were met in a euvolemic hypoosmolar hyponatremia due to potomania, it means we're taking in a lot of extra free water when the serum osm is already really low. In that scenario, our kidneys would want to excrete lots of free water to keep the serum osmolarity from going down any further. ADH would be very low to accomplish this. RASS would probably be hanging around in a happy medium since we're euvolemic. Regular kidneys can dilute urine a lot so they can dump all that free water we just took without losing too much sodium with it. With impaired kidneys with less ability to dilute, in order for the impaired kidneys to accomplish getting rid of the same amount free water that was consumed, more sodium would be lost compared to normal (urine osm would be low..but higher than the urine osm of a healthy kidney).

@@medrounds101amazing! When you have time, could you make videos about understanding ventilator settings? And also concepts about intrathoracic pressure and stuff 😅😅😅

I'm glad you found it helpful :)

Thank you so much! I'm not aware of a condition that would do that... if there is one, I'd love to hear about it!

Good luck on your exam!

EXACTLY!!! You said it all

Hey! Thank you so much :) I'd love to, but unfortunately I currently don't quite have the time... I will be making more at some point though!

Haha very kind of you. Much appreciated :)

Thanks so much! Really appreciate it :)

I'm glad you found it useful!!

So happy you found it useful!!

i agree 1000% 😂 thank you for making this video and sharing with us