Working against the clock to save the sickest babies
The sickest babies in the neonatal intensive care unit are those with persistent pulmonary hypertension, an increase in blood pressure in the arteries or capillaries of the lung. This condition occurs in two to six of every 1,000 live births. Of the babies who receive current available treatments, about a third do not survive.
Dr. Shyamala Dakshinamurti , an associate professor of pediatrics and physiology at the University of Manitoba, is investigating the lack of oxygen caused by a delayed first breath, and an inflammation molecule called thromboxane, which causes the blood vessels in the lungs to tightly constrict. Inflammation from this molecule forces the heart to pump harder in its effort to push blood into a tightly constricted lung.
With a research grant from the Heart and Stroke Foundation, Dr. Dakshinamurti and her team are looking at medications that can reduce the sensitivity of thromboxane receptors and allow blood vessels to relax, reducing pressure on the heart.
The stakes couldn’t be higher. Newborn pulmonary hypertension is the fastest moving of all hypertensive diseases. Hypertension in an adult may result in death in a matter of years, but the longest a newborn can survive under these conditions is two weeks.
“The newborn heart is very strong, it’s a valiant heart,” says Dr. Dakshinamurti. “But it cannot pump against high pressure for very long. If these babies are not treated very quickly, they will die of heart failure within the first two weeks of life.”