Welcome to PICU Doc On Call, a podcast dedicated to current and aspiring intensivists. My name is Pradip Kamat.
And my name is Rahul Damania, we come to you from Children's Healthcare of Atlanta/Emory University School of Medicine. Today's episode is dedicated to Noninvasive and Invasive ventilation in children post-hematopoietic cell transplantation.
We are delighted to be joined by Dr. Courtney Rowan, MD, MSCR, Associate Professor of Pediatrics, and the Director of the Pediatric Critical care Fellowship at Indiana University School of Medicine/Riley Children’s Health.
Dr. Rowan's research interest is in improving the outcomes of immunocompromised children with respiratory failure. She is active in this field of research and has led and participated in multi-centered studies. She is the co-chair of the committee of the hematopoietic cell transplantation subgroup of the Pediatric acute lung injury and sepsis investigators network. In our podcast today we will be asking Dr. Rowan about the findings of her recent study published in the journal-Frontiers in Oncology reporting on the risk factors for noninvasive ventilation failure in children post hematopoietic cell transplant.
She is on twitter @CmRowan.
I will turn it over to Rahul to start with our patient case...
Dr. Rowan, welcome to our PICU Doc on-call podcast.
Dr. Rowan: Thanks Rahul & Pradip for having me. I am delighted to be here to discuss one of my favorite topics. I have no conflicts of interest but I have funding from the NHLBI.
Today we will be discussing the up-to-date evidence for NIV (HFNC and NIPPV) use in children who have had BMT. Additionally, we will also be discussing the use of invasive MV strategies including HFOV in the pediatric BMT population. To start us off, Dr. Rowan, why is the BMT cohort different from other patients admitted to the PICU?
There is an increase in the # of patients undergoing BMT as indications for BMT are being expanded to different disease processes. The Etiologies for lung disease in BMT patients can be infectious (common organisms as well as opportunistic organisms). They can have lung disease from non-infectious causes and even fluid overload from renal dysfunction/medications given and there is a constant threat of alloreactivity which can manifest as GVHD or engraftment syndrome. 75% of PICU admits of immunocompromised children come from the heme-onc inpatient services. BMT patients have a higher risk to progress to ARDS. Recent reports show the incidence of ARDS in the intubated BMT population reaching upwards of 92%. These patients are also at high risk for MODS and can have a mortality rate close to 60%.
💡 To summarize, the BMT population is a unique ever-growing population that represents a relatively large cohort of immunocompromised children in the PICU with a risk of high mortality. As we have set this basis, we will be focusing the rest of our episode on the need for early recognition and intervention in this special population.
Dr. Rowan: This is a great question. We have had a few studies examining this very question. In a paper we published in Pediatr Blood Cancer in 2017, we evaluated 87 allogeneic HCT recipients to investigate the association of clinical risk factors with the development of respiratory failure.
Of the 87 allogeneic HCT recipients, 22 (25%) developed respiratory failure. The group with respiratory failure had a significantly higher percent weight gain increase at multiple time points.
The odds ratio, (OR) for respiratory, failure increased with increasing percentage peak weight gain. We also found that the OR for respiratory failure in patients requiring more than 1 liter supplemental O2 is 25.3 (6.5, 98.7).
We concluded that the percent weight gain and need for supplemental oxygen is highly associated with the development of respiratory failure in pediatric HCT recipients. Additionally, Dr. Algunik et al, have reported (PCCM 2016) that Pediatric Early Warning Score is highly correlated with the need for unplanned PICU transfer in hospitalized oncology and hematopoietic stem cell transplant patients. Additionally, the authors also reported an association between higher scores and PICU mortality. In another study, Dr. Algunik et al (Cancer 2017)reported that PEWS accurately predicted the need for unplanned PICU transfer in pediatric oncology patients in this resource-limited setting, with abnormal results beginning 24 hours before PICU admission and higher scores predicting the severity of illness at the time of PICU admission, need for PICU interventions, and mortality.
Cater et al (PCCM 2018) showed that adding weight gain to PEWs (cutoff of 8) score can increase specificity as well as the AUC to predict children with BMT at risk for clinical deterioration.
💡 Key points from these studies which we can clinically apply — trending of weights and attention to respiratory support and PEWS. Contingency planning and prompt recognition of when to initiate a transfer from floor to PICU is essential in intervening early.
A controlled transfer with the pediatric patient not in extremis allows for opportunities and time for in-depth multidisciplinary discussion.
This also allocates time for goals of care discussions.
We need to balance this with bed availability, familial stress of transitioning their stay from the floor to the PICU and introduction of a new care team being us in the PICU.
Dr. Rowan: In the case above, our patient was started on non-invasive PPV and antibiotics prior to transfer to the PICU. Could you comment on the ideal interface to provide respiratory support in our patient in this case?
💡 Yes from both the adult and pediatric literature It seems like there is a trend towards worsened outcomes with non-invasive ventilation in a BMT patient with acute respiratory failure.
💡 This is a great summary point that answers the question when do these patients need to be considered for intubation:
Dr. Rowan, If a BMT patient needs intubation, what does your study using search data inform us of?
💡 This high percentage of ARDS in intubated pediatric patients with BMT is close to the incidence in adult studies.
Our strategy, once the patient is intubated, should be surrounding lung-protective ventilation.
These include close attention to:
Our goal is to decrease ventilator-induced lung injury. (Rowan PCCM 2018).
💡 Summary: limit peak pressures, initiate high PEEP early, and limit FiO2.
Dr. Rowan: Our patient now is intubated and has an OI of 28. The patient is starting to have increased peak pressures to 35. She has saturations ~87% with high-mean airway pressures. How would you approach the management in this case?
Dr. Rowan, would you mind commenting on the data related to early vs. late oscillator initiation?
💡 The summary for our listeners here is to consider if HFOV is indicated within 48hrs from CMV to allow for peak survival.
Unfortunately, the patient in the above case died during her stay in the PICU. If we reflect, were there opportunities for us to improve her outcome?
This is a great question and as there are many factors that are patient-specific. Here are some general rules to consider:
Dr. Rowan, we appreciate your insights on today's podcasts, as we wrap up, would you mind highlighting your personal clinical pearls related to the critically ill pediatric BMT population?
This concludes our episode today on Noninvasive and Invasive ventilation in children post-hematopoietic cell transplantation. We hope you found value in this short podcast. We welcome you to share your feedback & place a review on our podcast. PICU Doc on Call is co-hosted by Dr. Pradip Kamat and myself Dr. Rahul Damania. Stay tuned for our next episode! Thank you.