Neonatal hemodynamics: a ‘transformative’ change in care
In keeping with University of Iowa Stead Family Children’s Hospital’s history of medical innovation, neonatology experts believe that the use of ultrasound technology to evaluate hemodynamics—a technique that helps doctors understand and improve blood flow and function of the heart—could further boost survival rates and improve outcomes of premature and critically ill infants.
Inside the womb, a fetus receives oxygen through the placenta, which allows time for the lungs to adequately develop. When a premature baby is born, it’s critically important to ensure that the infant’s heart makes the necessary transitions to allow the lungs to both mature and receive the blood they need to function correctly. One way to do this is to monitor an infant’s blood pressure. However, medical research has shown that normal blood pressure does not equate to normal blood flow.
The use of ultrasound to view a premature infant’s heart and observe how it functions is more accurate and can help prevent bleeding in the brain, which is a major contributor to death and brain injury among premature babies. At UI Stead Family Children’s Hospital, all newborns under 27 weeks receive their first echocardiogram by the end of their first day after delivery. The sickest infants are evaluated within minutes or hours of birth, if needed. Focusing on hemodynamics to stabilize heart and lung function also can reduce the use of extracorporeal membrane oxygenation (ECMO), or cardiac bypass, in full-term critically ill newborns, which often means a shorter stay in the NICU and a lower risk of complications.
This past year, neonatologist and neonatal hemodynamics expert Regan Giesinger, MD, used echocardiography to perform roughly 800 ultrasounds on sick or premature babies. About 75% of NICU patients were examined. Moving a tiny ultrasound wand over a newborn’s chest, Giesinger can quickly and efficiently capture 120 images of a baby’s heart, valves, and vessels in 10 to 15 minutes. She follows a strict assessment protocol to ensure that she captures a complete and comprehensive picture.
“It’s important to take images of the heart from many angles because it is a very complex organ,” says Giesinger, a clinical assistant professor in the Division of Neonatology in the Stead Family Department of Pediatrics. “Our assessment is designed to evaluate heart function and blood flow both to the body and to the lungs. We use this information to provide the baby’s primary doctor with a customized treatment plan. If structural heart defects are identified incidentally, a referral to a pediatric cardiologist for their prompt review and consultation is facilitated.”
Giesinger came to Iowa with her mentor, Patrick McNamara, MB, BCh, director of the Division of Neonatology in the Stead Family Department of Pediatrics and leader of the neonatal hemodynamics initiative that monitors fragile newborns using echocardiography, along with near-infrared spectroscopy and electroencephalogram (EEG), to assess brain health.
For example, an enhanced understanding of neonatal hemodynamics helps doctors treat brain asphyxia, or lack of oxygen to the brain prior to birth. In these cases, standard of care is the use of therapeutic hypothermia to cool the infant’s body. However, 40% to 50% of babies still suffer brain damage. Research by McNamara and his team shows that right heart dysfunction (identified by ultrasound) seems to be a precursor to this outcome.
In his previous post at The Hospital for Sick Children in Toronto, Canada, Patrick McNamara, MB, BCh, and his team increased the total number of annual neonatal hemodynamic consultations from 30 to 1,500 in a decade. The program enables enhanced diagnostic precision leading to optimization of medical therapy. Today, neonatal hemodynamic review is standard of care in all 15 of Canada’s academic medical centers.
“In the United States, there are probably only two or three other programs that offer some form of neonatal hemodynamic care,” says McNamara, director of the Division of Neonatology in the Stead Family Department of Pediatrics and leader of the neonatal hemodynamics program at Iowa. “These other programs are looking to us at the University of Iowa to guide them in developing comparable programs that hopefully will benefit patients in their region.”
In the U.S., physicians trained in neonatology receive limited training in cardiovascular physiology, says McNamara, which is why so few Neonatal Intensive Care Units (NICU) in the nation use echocardiography to monitor premature or critically ill newborns. At UI Stead Family Children’s Hospital, the goal of the neonatal hemodynamics program is to eventually offer two to three fellowships per year, which could help to increase the number of experts nationwide and save more lives. The first neonatology hemodynamic fellow at Iowa arrived in summer 2019.
“What we saw in Canada was that once we built our training program and started to take the most talented neonatal trainees and put them through a dedicated year of training, those individuals then went on to start programs in other sites and the program really grew across the country,” says McNamara, who has pioneered standardized training in neonatal hemodynamics in the U.S. and Europe. “Almost every week, there's someone who contacts me to ask if we have someone trained who can come build a neonatal hemodynamics program at their hospital.
“I think over the next five to 10 years, this field will expand significantly, and the program here is going to play a major role in transforming neonatal care in this country,” he says.
Danielle Rios, MD, MS, who trained at The Hospital for Sick Children in Toronto and the Baylor College of Medicine, will aggregate the data collected through monitoring the babies to create predictive algorithms that will help the team further understand the factors influencing patient outcomes.