TTHealthWatch is a weekly podcast from Texas Tech. In it, Elizabeth Tracey, director of electronic media for Johns Hopkins Medicine in Baltimore, and Rick Lange, MD, president of the Texas Tech University Health Sciences Center in El Paso, look at the top medical stories of the week.
This week's topics include eye training to prevent myopia worsening, nurse intervention to manage blood pressure post-stroke, preoxygenation before intubation, and risk of a second cancer after CAR T-cell therapy.
Program notes:
0:40 Cancers subsequent to CAR-T therapy
1:40 Only one person with a T cell cancer
2:40 Must do large populations to identify risk
3:15 Preoxygenation before intubation
4:15 More hypoxemia in oxygen mask group
5:15 Takes a little more time
6:09 Can nurses control blood pressure post stroke in Black and Hispanic patients
7:10 450 participants who'd had a stroke
8:10 Nurses talked about lifestyle in addition to blood pressure
8:50 Training eyes to slow down myopia in kids
9:50 Occurring globally
10:50 Myopia is nearsightedness
11:50 Employ computers to treat
12:31 End
Transcript:
Elizabeth: Can we train eyes so myopia doesn't get worse?
Rick: The risk of a second cancer after T-cell therapy for the first cancer.
Elizabeth: What's the best way to preoxygenate someone who is going to be intubated?
Rick: And can nurses help manage home blood pressure in Black and Hispanic patients after they have had a stroke?
Elizabeth: That's what we're talking about this week on TTHealthWatch, your weekly look at the medical headlines from Texas Tech University Health Sciences Center in El Paso. I'm Elizabeth Tracey, a Baltimore-based medical journalist.
Rick: And I'm Rick Lange, president of Texas Tech University Health Sciences Center in El Paso, where I'm also dean of the Paul L. Foster School of Medicine.
Elizabeth: Rick, how about if we turn right to the New England Journal of Medicine and let's talk about this issue of cancers subsequent to CAR T-cell therapy.
Rick: We have used different immune therapies to treat cancer for a while. Now, we have what's called CAR T-cell therapy. That stands for chimeric antigen receptor T-cells. These are genetically modified immune cells from the person's own body. We modify them to recognize and attack cancer cells by inserting genes into the T-cell with the use of a virus.
As of early 2024, we have treated more than 34,000 patients with CAR T-cell therapy. There have been 20 to 25 reported cases of T-cell cancer after that. Is the therapy we are using to treat these initial cancers actually causing a secondary cancer? To address that, we have an author that describes the risk of second cancers in 724 consecutive recipients of CAR T-cell therapy. They were treated at a single institution.
What they reported is, there was only one person that ended up with a T-cell cancer. By the way, they did very deep genetic analysis and determined that it wasn't related to the CAR T-cell therapy at all. In fact, remember that these patients, before they get the T-cells, they get chemotherapy; that could possibly do it. You also have a patient that's already predisposed to cancer because they have had one already. So it looks like the CAR T-cell therapy, although there have been a couple of -- a handful of cases of second cancers after CAR T-cell therapy, it doesn't appear to be related to the CAR T-cell therapy.
Elizabeth: There are a few things I would say about this. Even if we look at the numbers where it precipitated the investigation by the FDA, they are also really small. The other thing I would note is that there are other technologies that are emerging that are likely going to supplant CAR T therapy that may very well obviate this problem.
Rick: Right. But I think what this highlights is whenever you have a therapy that looks initially beneficial in small numbers of patients, you actually need a large population to identify the unique risk or side effects from any type of therapy. With the new therapies you're mentioning too, Elizabeth, they are unlikely to come without some side effects or risks associated with them that won't be known until we have used them in thousands of patients.
Elizabeth: I would also point out that for folks in this situation, the unfortunate situation of having an intractable cancer, this may offer the best hope for a treatment.
Rick: This CAR-T therapy is often used for relapsed or refractory cancers like myeloma. It's expensive. It takes some time. There are technical limitations, but the results can be quite dramatic and satisfying.
Elizabeth: Staying in the New England Journal of Medicine, let's turn to a study that's taking a look at, "Gosh, how should we preoxygenate someone who is going to end up with emergency intubation?" These were largely folks that -- and of course, I spend a lot of time in the ICU in the chaplain role -- who are in the ICU, but also in EDs around the country.
They had in this study a multicenter randomized trial at 24 emergency departments and intensive care units in the United States. Critically ill adults who were going to undergo tracheal intubation were preoxygenated either with noninvasive ventilation, or what is frequently called BiPAP, or an oxygen mask. Their outcome measure was hypoxemia.
In these 1,301 patients who were enrolled, they had hypoxemia occur in 57 of 624 patients (9.1%) in the noninvasive ventilation group or BiPAP, and in 118 (18.5%) of their other folks who were in the oxygen mask group. They also looked at cardiac arrest that occurred in 1 person in the BiPAP group and 7 in the oxygen mask group.
It's looking pretty persuasive that the way to preoxygenate folks is with BiPAP, if you can. They offer the caveats that, of course, you have to have this stuff on hand. It's a little bit more time-consuming. That's one of the caveats if you're thinking of employing BiPAP versus an oxygen mask for this particular part of this procedure.
Rick: Even with those caveats, BiPAP is pretty routinely available. Obviously, we use it to treat individuals that have respiratory problems. We don't want to put them on a ventilator where we intubate and put a tube down their throat, so putting a very tight-fitting mask and hooking it to a ventilator that puts positive pressure is fairly routine in most hospitals. As you said, it does take a little bit more time to set up than putting a mask on someone, but really not that much more time. As you mentioned, the study shows that it's much more effective in preventing hypoxemia -- that is, low oxygen -- while you're getting ready to actually intubate somebody.
Now, the other thing that was concerned with BiPAP is, these are oftentimes individuals that haven't been fasting for a while. The concern was if we put the BiPAP on and then we intubated them, would they have a higher risk of aspirating -- that is, coughing up their gastric contents and causing lung problems? That wasn't the case. There were no bad side effects from using BiPAP and, in fact, just an upside.
This is good news. I say it's good news because most of the time when intubation is going to be done we usually use a mask. We don't usually use BiPAP. But this study should put to rest the fact that BiPAP is actually beneficial and it has no ill effects.
Elizabeth: Yep. Absolutely. As we know, these innovations that are established in these emergency departments and in ICUs frequently trickle down into the other areas of medicine. My suspicion is that everyone will be doing it this way.
Rick: Yeah. Speaking of things that people should be doing, Elizabeth, can nurses help control high blood pressure in Black and Hispanic patients who have a stroke? The reason why I set that up is these individuals, Blacks and Hispanics, have high rates of both recurrent stroke and uncontrolled hypertension in the United States. Now, we know that home blood pressure telemonitoring can be very effective. We can actually give people home blood pressure devices and those blood pressure devices can actually transmit the information to the doctor's office.
Let's add one other thing, telephonic nurse case management. Instead of just sending them to the doctor's office and waiting for a call, let's get a nurse actively involved where after the patient has had a stroke, they go home. For the first month or two, the nurse calls a couple of times a week and then for the next several months calls once a week, then after that calls on a monthly basis. Over the next 6 months, the nurses are helping the patient actually manage their blood pressure. Do they offer an advantage [over] just home blood pressure alone?
That's the study that took place in 8 different stroke centers and ambulatory practices in New York City where 450 participants, African Americans or Blacks who had a stroke, were randomized to just either home blood pressure telephonic monitoring or having the telephonic nurse case management in addition to that. They asked two questions. One is, is blood pressure better controlled? The second is, can it prevent recurrent strokes?
In the individuals who have just the home blood pressure monitoring, the blood pressure went down about 6 mm. For those individuals that had that and the telephonic nurse case management, it went down 15 mm. That's huge, Elizabeth.
Now when they looked at the rate of recurrent stroke over the next 24 months, there was no difference. It was 4% in both groups. That's lower than it usually is. This is a practice that can be applied to these low-income Black and Hispanic stroke survivors that have uncontrolled hypertension.
Elizabeth: I like this. What about the cost of such an implementation?
Rick: You're talking about a phone call. Obviously, it takes a nurse to do that. It would be no different than calling the patient back and having them followed up. Here is what it accomplished. The nurses not only talked about blood pressure, but they talked about lifestyle changes, physical activity, weight loss, dietary changes, and making sure they were taking their medications. They were more likely to intensify the medical regimen if the person's blood pressure wasn't controlled. Although there wasn't a cost-effectiveness study done, it seems like this is actually pretty easy to do and it doesn't cost a lot of extra money.
Elizabeth: I guess the final thing I would ask about this is, were there any quality of life measures? I would think that patients who got followed up with a phone call would feel more cared for.
Rick: Well, they didn't do that. There was no measure of quality of life or no measure of patient satisfaction, just hard endpoints.
Elizabeth: Let's mention that that's in JAMA. Finally, let's turn to JAMA Pediatrics. We have this looming problem of the development of myopia in young people. This is a worldwide problem, which is why I picked this study.
The authors start out their preamble with myopia a common cause, of course, of visual impairment and its prevalence is continuing to increase globally. According to current research, they say that by 2050 almost 50 million people will experience myopia, accounting for half of the world's population. Another assertion they make is that early onset of myopia increases the risk of high myopia and that can lead to irreversible retinal damage and even loss of central vision.
We're seeing this happening more often with kids because kids are spending a whole lot more screen time and they are also spending less time outdoors. We're seeing this myopia incidence going up not just in China, where this study took place, but also everywhere around the world.
This study assesses efficacy and safety of something called naked-eye 3-dimensional vision training. This is a technique that is a computer implementation where the eyes are asked to follow moving things that are on the screen. I would say that my bias against it is it's yet one more exposure to a screen.
They had 227 patients who completed their 6-month follow-up, 102 in their intervention group and 125 in the control group. They looked at axial length and another measure called spherical equivalent refraction in these folks, in these children, at 6 months. Sure enough, they were able to show that this computer-based intervention, abbreviated as NVT treatment, was able to reduce the rate at which myopia was progressing in these kids.
Rick: For our listeners that may not be familiar with the term myopia, it's also called nearsightedness. We can see things near pretty clearly, but things that are far away look blurry. This is a progressive condition where the eye continues to elongate and it makes it even blurrier. If we can prevent that just by retraining the eye, that's much easier than trying to do some corrective surgery or actually putting eyedrops in. What you described, by the way, is a computer-based program that trains the eye -- it does eye exercises, that's what it does -- and it prevents the eye from actually elongating.
Elizabeth: Yep. As you already pointed out, what are the alternatives? Well, atropine drops, but these are associated with adverse outcomes after they have been used for really a long period of time. I imagine there is probably some level of resistance on the part of kids, and then there are procedures to help with it.
I think that this international increase in myopia is very concerning. If we can actually employ one of the factors, computers, that are involved in the genesis of this condition in order to ameliorate it, that's a good thing.
Rick: It is, and these kids had to view this computer program for just 20 minutes a day. Kids are not averse to watching things on the computer. The only thing I had mentioned, Elizabeth, is the results looked fairly promising at 6 months and that's good, but it's a relatively short time period. What you'd like to do is to extend these studies for a longer period of time to make sure the results are robust and last long.
Elizabeth: On that note then, that's a look at this week's medical headlines from Texas Tech. I'm Elizabeth Tracey.
Rick: And I'm Rick Lange. Y'all listen up and make healthy choices.