Dr. Farsi explains PEEP, the pressure that keeps lungs open after breathing out. It recruits collapsed air sacs to improve oxygen, but in asthma or COPD it can trap air dangerously, reducing blood return to the heart. If PEEP goes above 5 or 10, disconnect the patient to release the pressure.
Questions this video answers
He verbally suggests concern for high PEEP at "anything over 5 or 10" (as stated in the talk).
Chapters
Foreign.
Hi, everybody. Dr. Farsi here. And today we're going to talk about PEEP, positive and expiratory pressure. So what is PEEP? And just to kind of use a analogy that I kind of love to do, we're going to use this, our lovely glove, right? And we're going to think of it as our lung, right? So our lung.
This is where we live. We live at an inflated lung. Our lung at any time is always inflated, right? And that's the what's called the end expiratory volume or the reserve capacity. So the lung is never deflated. And so when we breathe, we're going to breathe at this level.
In, out. But lungs never collapse in a disease state, any disease state. Car accident, trauma, CHF, MI. The lung goes all the way to full collapse, right? And respiratory arrest, cardiac arrest, anything, the lung collapse. And so imagine the amount of energy the body requires to inflate the lung. Yeah, it's gonna have to use the first 50% of the force to just re inflate the lung, just to re inflate to a point where we can have gas exchange.
And that is what PEEP is. Right? So PEEP is really that volume that we're gonna use to prevent the lung collapse. Right. And it's really, really important to understand PEEP because pipa has a lot of positive effect and a lot of negative effect. Today we're going to focus on those two effects. The positive effect first and then the negative effect. So the positive effect of PEEP is it's going to promote lung recruitment. And what is lung recruitment is all those small bags of alveoli that are claps. PEEP will promote recruitment. And then to show this, we're going to do my. We're going to use my balloon again.
And if you think of recruitment, I'm going to go and try to see if we can focus on this. But you see all the fold in the gloves or these fold. With time, people allow all those fold to reopen up and become as smooth as this. That is the gas exchange core recruitment. And that is what PEEP is at the end of expiratory, it will promote recruitment. Why recruitment? That promotes gas exchange, oxygenation, meaning oxygen comes in and ventilation, meaning CO2 gets out. We need those units. So now we're going to talk about the negative aspect of peep. And the negative aspect of PEEP is when we're inflated, right?
And then suddenly, you know, the air comes out and we have a disease state. Now take a disease state like asthma, copd emphysema. We'll focus on asthma first because asthma is a bronchoconstriction, meaning the air, the smooth muscle, right. We have two, we have three style of muscle, but we're focused on the smooth muscle is constricted. So the lung cannot really get air. Can get air in, cannot get air out. So now you have peep, right? And now we're giving, we're bagging the patient or the patient's taking is on the vent and it get 500 title volume.
So 500 and now 200 comes out. Instead of 500, then we give another 500.
And then 200 comes out, give another 500.
You don't have to. I don't. I'm not going to go to show you till the balloon blows up. But you understand that we have retention of gas into the lung. Well, what that retention does, it does multiple physiological effect. One, it's gonna create what generally we have a negative intrathoracic pressure, meaning the pressure in our chest is negative. Now suddenly that pressure is gonna turn into positive. By creating a positive pressure in the chest, it's gonna decrease the return of the blood to the right side of the heart. Now, as a pause, let's think of the heart as a pump, right? Divided into right and left. The right side, it's paper thin. It's made to accommodate a lot of volume. Right. The left side is the strength. Right. It's the, the powerhouse thick ventricle is to blow the send the blood all the way to the rest of the body. So in elevated peep, where we have a dangerous level of air trapping, right, gas trapping, then the blood return to the right heart is decreased and then you see sudden hypotension. So that should always be your first indicator. Any change or fluctuation in blood pressure. With high peep, anything over 5 or 10 should be indicator that something is going on. The first thing you need to do, the first is whatever you're doing, if it's cpap, if it's on bagging or if it's on a vent, you must disconnect the patient. Disconnect the patient and gently press on the chest because you want all that gas trapping to leave. And what you're gonna hear is this.
You're gonna hear all that air coming out and suddenly you'll see the blood pressure coming right back to normal at that moment. That should indicate you two things. Patient is being bagged too fast, right? So if you're bagging too fast, we have an inspiratory phase, meaning the time it takes to breath to get in and the expiratory phase, the time it takes the gas to get out. In asthma, emphysema and severe copd, we need a short inspiratory time and a very long expiratory time. So.
Short and long time to come out and this will prevent the negative effect of heap.
