Refractory Hypoxemia – Changes in the Exudative Phase (Nursing)

00:01 Refractory means stubborn or unmanageable or resistant to a process or stimulus.

00:07 That's what that word means inside and outside of medicine.

00:11 Stubborn, unmanageable, resistant to process or stimulus.

00:17 Now, we say stubborn, unmanageable resistant to processor stimulus, low oxygen in the blood.

00:25 So, no matter how we try to ventilator oxygenate this patient, we just can't make it work that PaO2/FiO2 level is still too low.

00:36 Take a look at that Berlin definition you see right there.

00:39 Remember we talked about that in the beginning.

00:41 We talked about the PaO2/FiO2 ratio.

00:44 We've got the breakdown there for mild to moderate to severe.

00:48 Now, which category do you think refractory hypoxemia would fall into? Right, severe.

00:55 This is when we're in big trouble for our patient.

00:58 So, that refractory hypoxemia is low levels of oxygen in the blood despite increasing the delivery of oxygen.

01:06 It's rare, but very serious and a life-threatening complication of ARDS.

01:12 So, is there anything we can do? Yes, there's some things I'll get to those in just a minute, but I want to make sure you are clear on what this definition is.

01:22 So physiologically, it's been defined as an increase in partial pressure of oxygen in arterial blood.

01:29 Yes, you already know that is PaO2.

01:32 So, in looking at as a increase in the PaO2 of less than 5 millimeters.

01:39 If the fraction of inspired oxygen the FiO2 is increased by 0.1 or 10 %.

01:47 Okay, so what does that mean? Well, that means if I have a patient who is on 75% oxygen, right.

01:55 So let's say you're on a ventilator, they're on 75% oxygen which is higher than I would want them to be look at that definition.

02:05 So if we increase the oxygen by 0.1, then I would bump that patient up to 85%.

02:12 But the PaO2 change I saw was less than 5.

02:17 So, if my PaO2 before this ventilator change was set at 75 when I Increased it to 85% FiO2 and only bumped up to 77 that would be considered refractory hypoxemia.

02:32 So for practical purposes, there's various criteria been applied most commonly is considered as one of these other things, right.

02:40 Because that was a lot for me to talk you through.

02:42 Look at these, it's either a PaO2 of less than 60.

02:46 Hello, because remember normal is 80 to 100 or it's the defiinition you see here that we just talked about.

02:55 PF of less than or equal to 100 on FiO2 of 80% to a 100% with peep positive end pressure of greater than 30 centimeters.

03:09 Okay, this is wow.

03:11 We're going to add on to that a plateau pressure of 30.

03:14 Now, if your eyes just glazed over and you said, I don't even know what you are talking about.

03:19 That is okay, all right.

03:20 I just want you to know takeaway point from this.

03:23 Refractory hypoxemia means we're doing some pretty fancy ventilator settings and oxygen support and we're not making that big a difference in the PaO2.

03:34 So, easier than memorizing all this is just think been an easy one to go with is PaO2 less than or equal to 60.

03:41 And refractory means no matter what we're trying, it doesn't seem to be making a difference in the PaO2.

03:48 Why are we looking at that number? Because the PaO2 helps us quantify the lungs ability to get oxygen from the lungs into the blood stream.