SCCMPod-546 PCCM: Finding Better Ventilation Strategies for Pediatric ARDS

Dr. Mack: Hello and welcome to the Society of Critical Care Medicine podcast. I'm your host, Dr. Elizabeth Mack, and today I'll be speaking with Dr. Anil Sachdev, MD, FICCM, about the article "Transpulmonary Pressure Guided Mechanical Ventilation and Severe Acute Respiratory Distress Syndrome in the PICU: A Single Center Retrospective Study in North India, 2018 to 2021," published in the September 2024 issue of Pediatric Critical Care Medicine. To access the full article, visit pccmjournal.org.

Dr. Sachdev is the Director of Pediatric Emergency Critical Care and Pulmonology and Chairman of the Department of Pediatrics at the Institute of Child Health, Sir Ganga Ram Hospital in New Delhi, India. Welcome, Dr. Sachdev.

Dr. Sachdev: Thank you. Thank you for the opportunity.

Dr. Mack: All right. Before we start, do you have any disclosures to report?

Dr. Sachdev: No, I have no disclosures to make.

Dr. Mack: Okay. Well, thank you so much for this contribution to the literature. I'm curious, how did you come up with the idea for this study?

How did you identify your collaborators? What was that beginning like for the study?

Dr. Sachdev: See, I am working at Ganga Ram Hospital for the last 35 years, and I have built up the Pediatric Intensive Care Unit myself, you know, and it has started from a 4-bedded unit to now 14-bedded unit. And we have a state-of-the-art equipment. So, there was a need for more ventilators in the ICU.

So, then I thought that why should I go for the, you know, the basic thing, which let's have some advanced models and started searching about it and started working on it and started reading about it. So, I started reading about it and then I came to know about, you know, the physiology we already knew, but I came to know that such equipments are available. So, I started talking to the company and I'm thankful to the management of my hospital that they agreed to purchase this machine in 2018, you know, we started with one machine.

And then after the initial learning curve, then I planned this study and there was a learning curve, a little steep curve and then we started working on a protocol and started working on the research. Regarding the collaborators, you know, we are an academic unit, we have a teaching hospital also. So, I have fellows with me who are under trainees, like they have three years training course with me and we have other intensives.

So, we had, you know, classes initially to understand the concepts and the working of the equipment. And then I trained a few of my nurses also, so that they can collect the data and my fellows also. So, that is how we started and we followed the protocol during this study period of 2018 to 21.

Dr. Mack: Wonderful. Thank you. So, if you don't mind, just tell us a little bit about your esophageal pressure monitoring research protocol for pediatric ARDS patients.

Tell us a little bit about the device, the cost. I noticed that the family pays. So, was there a difference in the patients whose families consented?

You know, how is it used? I would love to hear a little bit more about that.

Dr. Sachdev: Yeah, yeah, yeah. So, we are working in a developing country. So, the infections are the main, you know, the Indian indications for their admissions.

And most of the ARDS patients are mild to moderate and few are severe or refractory hypoxemia sometimes. So, these are the patients where we use high PEEP. So, it is always hesitant, you know, to use PEEP above 10 without any physiological markers.

The PEEP titration we do, but once the patient is on high PEEP, then once he had the transformative pressure monitoring, so we thought let's, you know, start using transformative monitoring in patients who require, you know, 8 or more than 8 PEEP for ventilation. So, started offering this to the patients. Now, being a developing country, all the patients, my hospital is a charitable trust hospital.

It is not a corporate hospital. So, we offer to the parents that this is a modality which is available with us and it is likely to help the patient with the ventilation. So, that is how the cost factor was explained to them.

And then the advantages and the disadvantages, everything was explained and the consent was taken for that. And then we go ahead with that. That is why there were patients who I have taken as, you know, as controls, I would say that where the TPP was not done and few patients, you know, they refused the use of transformative pressure.

So, we went ahead with the conventional ventilation in these patients. So, that is how we, you know, the protocol was followed throughout the study. So, the cost is, in my unit, the cost is per catheter is about 15 to 20,000 Indian rupees.

Dr. Mack: Thank you for that. You had mentioned that the monitoring was not necessarily the intensivist choice but rather based on availability and it sounds like you really were advocating for availability and of course, depended also on the parents' consent. Can you tell us a little bit about what the availability was like?

Dr. Sachdev: As I said, we used a particular company transformative pressure device, which is a balloon device. And fortunately, the company was providing us with different size catheters, you know, for the small kids to the adults. So, in our unit, we are admitting a pediatric patients 1 month to 18 years of age.

So, obviously, you need different size catheters for the monitoring. And regarding the use, as I said that the first was the availability, I started with one machine. And now have I currently I have three machines with me.

So, the availability is better. But at that time, if somebody was already on the transformative pressure monitoring, then I could not offer to the other patient. So, that was a big limitation with me.

And second was the cost factor, which I have already explained to you that the patients were told about that this is a chargeable monitoring device and they will have to pay for it. So, that is how, you know, this was not a choice of the intensivist but availability of machine and the acceptability or the consent by the parents.

Dr. Mack: Gotcha. Thank you for that. If you don't mind, I would love to hear a little bit about your results.

Dr. Sachdev: The results are, you see, in the study, we had initially 28 patients, out of which 13 patients received transformative pressure, and the 15 patients received conventional ventilation. But after 24 hours of the transformative pressure, there were one patient who, you know, was shifted to high frequency oscillator on the discretion of the intensivist available on that particular day. And the other patient was upgraded to BV ECMO.

Similarly, in the non-conventional group, two patients, you know, for some reason, you know, they left against the medical advice, and one patient was switched to high frequency oscillator. So, after 24 hours, out of 13 patients in the TP group, I had 11 patients in the TP group, and I had 12 patients in the in the in the in the conventional this thing a patient. So, this is how it is.

So, final analysis, we have done the 13 patients in the first 24 hours, and 11 patients in the 48 and 72 hours. And similarly, 13 patients were there in the in the non-conventional group in the sorry, in the conventional group. And after 24 hours, there were 12 patients.

So, that is how we have taken the results as a baseline, 24 hours, 48 hours and 72 hours. So, this was the enrollment of the of the patients. And patients who are monitored for hemodynamic monitoring, they all had, you know, invasive blood pressure monitoring and central lines and everything.

And they were monitored with the like, like to monitor any very sick critical patient, that is how they were monitored. So, as far as the results are concerned, the results are quite encouraging, but the sample size was small. So, the results of our study show that there was a higher tips were used in the TP group as compared to non-conventional group.

And that was basically because we had an objective criteria in front of us, we were monitoring the transmonary um PEEP and the transmonary ah plateau pressure. And we were confident that ok, we are not crossing the limit, we are not over distending or we are not allowing the alveoli to collapse. So, that gave us confidence of using higher PEEP in these patients.

And that resulted in a better oxygenation, the the the improvement in the PF ratio, improvement in the oxygenation index in these patients. The other results like ventilation results, though there was no significant values, but yes the the the alveolar dead space fraction reduced. And again the the higher plateau pressures were achieved with the with the ah TP monitoring.

So.

Dr. Mack: Thank you. Thank you so much for sharing. Sounds like incredibly important work.

I am curious, what sort of illnesses did these children mostly have? Were they mostly viral infections or was it pretty heterogeneous? Love your thoughts on that.

Dr. Sachdev: Yeah, we had a heterogeneous group. As I said in the beginning that ah in our country the infections is the are the main culprit for the admissions septicemia or serious viral infections or as you know the clinical diagnosis in our study was that we had a few patients of H1N1, we had RFC pneumonia, influenza, then one case of polytrauma was there in the TP group. Then of course, we had septicemia patients, we had dengue patients.

So, all these are infections were there. I mean majority of the patients had infections and two patients had polytrauma and then quite a few had you know the two patients had dengue, severe dengue with multi-organ dysfunction. So, we had about 16-17 patients who had multi-organ dysfunction on arrival to the hospital and those very sick patients were there.

Dr. Mack: I bet so. So, curious what you all are doing going forward? Are you continuing to use this technology?

What are your next steps from a research perspective? Would love your thoughts.

Dr. Sachdev: Yeah, we are we are using transpiratory pressure, but again I would say that we are selective. We have a criteria that the patients who require PEEP more than eight and we are unable to meet targets in these patients. In such patients, we are using transpiratory pressure and especially in patients where we are clinically suspecting they have a poor chest compliance.

In these patients also we prefer to use transpiratory pressure because it helps in partitioning the understanding the compliance of the chest wall and the lungs. So, it helps us using higher PEEP in these patients and understanding the avoiding the overinflation or the underinflation or the you know at electro trauma in these patients. So, we are continuing to use now as I told you I have three machines.

So, the frequency of use of transpiratory pressure has increased in my unit. Yeah.

Dr. Mack: So, anything else that we have not touched on that you wanted to share?

Dr. Sachdev: Yeah, the one thing which I you know when we were started using this especially these the catheters for the young kids you know the infants are two or three years. They are very pliable, they are very pliable, they are very soft. So, we had the issue of you know inserting these catheters through the nose.

So, the so the we the one usually many a times you know these catheters coiled inside the pharynx. So, we had the problem. So, we innovated one idea that you know in the eye of the feeding tube that is Ryle's tube we inserted or we you know inserted the tip of the transpiratory catheter and because the Ryle's tube is little stiff.

So, we inserted both together through the nostril and once we were in the stomach we little jerk with a little jerk we pulled out the transpiratory pressure and then bring it to the correct position. So, that way we you know we overcame this problem of coiling of this soft pliable transpiratory catheters especially in the kids. For older kids that was not the issue that was never a problem for us but for the infants and the young kids where we are using the small size catheters that is one. 

And second is the positioning is very important in transpiratory pressure you have to ensure before you take any reading you have to ensure that you know the position is correct. So, that was ensured by the by the by looking at the x-rays or looking at the cardiac oscillations that we get on the on the screen and that way it is very important or you can put little pressure on the epigastrium and in a deeply sedated or paralyzed patient you can see a positive deflection. So, that ensures that your catheter is in the correct position.

So, correct position before you make any reading or you put the patient on inspiratory hold or expiratory hold is extremely important. Yeah.

Dr. Mack: That that makes sense making sure that you are interpreting data from the proper position.

Dr. Sachdev: Yes.

Dr. Mack: For sure and thank you for sharing your lessons learned about the very pliable catheters as well.

Dr. Sachdev: Yeah.

Dr. Mack: Anything else that you wanted to share?

Dr. Sachdev: One thing was there that this study took very long because of the COVID period in between. So, at that time you know.

Dr. Mack: Yes.

Dr. Sachdev: I had no ventilators and practically there was just one machine left with me in the PICU and all the machines were you know moved to the to the COVID wards. So, that was a you know almost more than a year there were no recruitment during this or no patient was put on the transpiratory pressure. So, because the times were like that during the pandemic you know and the everything was on the COVID and you know you can't even ask your nurses or fellows or you know you can use transpiratory pressure in this because they all were so deeply involved with the COVID care patients care.

So, that that was a that was one thing why the study was prolonged for three years and we could you know enroll also such a small number.

Dr. Mack: Yes. Totally understand. Nobody was planning on that disruption for sure.

Dr. Sachdev: Yes.

Dr. Mack: Makes sense why you could not recruit. Well, I really appreciate this very important contribution to the literature. I know that our readers, our listeners will as well.

This concludes another episode of the Society of Critical Care Medicine podcast. If you're listening on your favorite podcast app and you liked what you heard, consider rating and leaving a review. And for the Society of Critical Care Medicine podcast, I'm Dr. Elizabeth Mack.

Announcer: Elizabeth H. Mack, MD, MS, FCCM, is a professor of pediatrics and chief of pediatric critical care at Medical University of South Carolina Children's Health in Charleston, South Carolina.

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