Routine caregiving in NICU may affect blood flow in premature babies

Diaper changes and other routine caregiving procedures done on critically ill premature babies in the neonatal intensive care unit (NICU) are associated with major changes in blood flow, according to a recent study. This can lead to problems with oxygen delivery to the brain during this critical period of brain development. Nurses can try to reduce these risks through gentle care.

The importance of blood flow and oxygen to the brain

“One of the most important problems that occurs in the very immature newborn baby is bleeding into the ventricles of the brain, called intraventricular hemorrhage (IVH). Another important problem is white matter injury in the brain. Very immature newborn babies cannot regulate the flow of blood to their brain. Changes in blood flow in the brain are associated with hemorrhages, and reduced delivery of oxygen to the brain may lead to white matter injury,” said Dr. Andrew James, a neonatologist at Toronto’s Hospital for Sick Children.

The mechanisms underlying circulatory changes in premature babies are multiple, complex, and poorly understood. This study, reported in the November 2008 issue of Pediatrics, set out to determine what types of caregiving interventions in the NICU might interfere with a preemie’s blood flow and delivery of oxygen to the brain.

The effect of NICU caregiving interventions on blood flow and oxygenation

The study evaluated 82 infants who weighed less than 1500 grams at birth and who required intensive care and continuous blood pressure monitoring. All infants entered the study before they were 24 hours of age. The researchers used various tests to continuously monitor any circulation changes, meaning changes in blood flow and oxygenation to the brain and throughout the body.

They studied the circulation changes that occurred during various types of caregiving interventions, such as

• minor manipulations such as using a stethoscope to listen to the baby’s heart and lungs
• diaper changes
• suctioning of the endotracheal tube (ET), which is the tube placed in the baby’s windpipe to deliver oxygen into the lungs
• repositioning of the ET, which involves stabilizing the baby’s head and neck while gently lifting the adhesive tape used to attach the ET to the baby’s skin
• more complicated caregiving interventions: two or more of the above interventions occurring within a 10-minute period

The researchers found all the caregiving interventions mentioned above had a significant effect on blood flow and oxygenation. These circulatory changes were greatest during complicated interventions and during ET repositioning. This study is also the first to show important changes in circulation during diaper changes. The researchers suggest that certain abrupt changes that occur when a baby’s legs are raised, such as increases in the flow of blood back to the heart, could be the reason for this finding.

Nurses have known for many years that diaper changes and other caregiving interventions can lead to disruptions in oxygenation, but the study provides objective evidence of this. “This study will reinforce views that nurses have held for some time. In order to minimize changes in oxygenation, nurses change diapers, reposition the ET, and carry out other caregiving interventions as gently as they can,” says Dr. James.

Will these findings affect current practice in the NICU?

The study concluded that “routine caregiving procedures in critically ill premature babies are associated with major circulatory fluctuations that are clinically underappreciated and underdetected by current bedside monitoring. The data underscores the importance of continuous monitoring of blood flow and oxygenation to the brain in critically ill premature babies.”

However, according to Dr. James, while all NICUs monitor oxygen, blood pressure, and heart rate, some NICUs do not have the capabilities to monitor blood flow and oxygen delivery to the brain.

Also, before changes in practice can be made, more research is needed. While this study showed certain caregiving interventions are associated with changes to the circulation, it did not show a definite cause and effect relationship. More studies are needed to prove whether certain caregiving interventions actually cause disruptions to blood flow and oxygenation. “We may eventually learn which events cause these problems and then have evidence to change practice,” says Dr. James.