(From the November 2015 Issue of PediatricsOnline)
Children who receive extracorporeal membrane oxygenation (ECMO) while waiting for a lung transplant are typically sicker than children who don't receive this mechanical support, but long-term chances of surviving appear to be similar in both groups, research from Nationwide Children's Hospital shows.
Survival of children on ECMO is an important consideration for public policy, as use of this support technology has been growing, says Don Hayes Jr., MD, MS, MEd, medical director of the Lung and Heart-Lung Transplant Programs at Nationwide Children's.
A possible reason for this growth is that the use of ECMO can improve a patient’s position on the transplant waiting list if the patient has the potential for a good outcome after transplant, based on the current donor organ allocation system in the United States.
With no differences in long-term survival, Dr. Hayes and colleagues question if using ECMO to determine priority for donor lungs is well-founded.
"Donor organs are a limited resource," says Dr. Hayes, who, with a team of researchers, has reported on ECMO and long-term survival in recent papers published in The Journal of Heart and Lung Transplantation and Pediatric Transplantation.
Dr. Hayes, who is also an associate professor at The Ohio State University College of Medicine and The Ohio State University College of Public Health, says there is more research to be done, but the data raise the question, "Would it be better to transplant someone who is not at as great a risk?"
The team analyzed data from lung transplant patients from 2000 to 2013 registered in the national Organ Procurement and Transplant Network Standard Transplant Analysis and Research database administered by the United Network for Organ Sharing.
The team found 17 children who were on ECMO and compared them to more than 500 children awaiting a lung transplant while not on ECMO. They found no statistically significant differences in long-term survival between these groups following transplantation.
Other important findings from this research include a lower risk of death after lung transplant for patients who were on ECMO in more recent years. The researchers suggest improvements to ECMO technology and protocols may be responsible.
Dr. Hayes and his collaborators also examined the outcomes in adult lung transplant recipients who were on and off ECMO, using this database over the same time period. They found that negative effects centered on older patients. Therefore, Dr. Hayes says, age should definitely be a factor when a patient on ECMO is being considered for lung transplantation.
Factors that may benefit children receiving a lung transplant include fewer comorbidities compared to adults and their relatively immature immunological systems, Dr. Hayes suggests.
Nationwide Children's protocols for ECMO may also provide a benefit, Dr. Hayes says. At the hospital, children on ECMO are awake, undergo physical therapy and interact with family for months before they receive the transplant.
After the transplant, these children spend less time in rehabilitation compared to similar children who were unconscious and on a ventilator prior to transplant. The benefits of this pre-operation activity are an important direction for further study, the researchers say.
To explore these and other factors affecting survival after organ transplantation, Nationwide Children's created the Center for Pediatric Transplant Research and joined with The Ohio State University Wexner Medical Center and The Ohio State University Colleges of Medicine and Public Health to form the Center for the Epidemiological Study of Organ Failure and Transplantation in August. Ongoing work by researchers in these centers aims to improve the success of transplantation in children and adults.
Hayes D Jr, Whitson BA, Black SM, Preston TJ, Papadimos TJ, Tobias JD. Influence of age on survival in adult patients on extracorporeal membrane oxygenation before lung transplantation. Journal of Heart Lung Transplant.2015 Jun;34(6):832-838.
Hayes D Jr, McConnell PI, Tobias JD, Whitson BA, Preston TJ, Yates AR, Galantowicz M. Survival in children on extracorporeal membrane oxygenation at the time of lung transplantation. Pediatric Transplantation. 2015 Feb;19(1):87-93.