Babies born prematurely are in exceptionally delicate health and are often at risk for a wide range of serious complications. Two major risk factors for neonates are conditions called intraventricular hemorrhage (IVH) and periventricular leukomalacia (PVL). IVH is a condition in which the blood vessels break or leak inside or around the ventricles of the brain within the first days following birth. PVL is the necrosis of the white matter around the ventricles, which is responsible for helping transmit signals between nerve cells and different parts of the brain.
Both of these conditions are serious and have prematurity as a factor for development, so it’s especially important that NICU personnel understand IVH and PVL so they can identify and manage them.
What Causes Intraventricular Hemorrhage?
Most intraventricular hemorrhage causes can be traced back to capillary bleeding. The two primary contributing factors for neonatal intraventricular hemorrhages are:
- Increased vascular fragility combined with a loss of cerebral autoregulation
- Abrupt changes in cerebral blood flow or pressure
Most babies who are born premature but otherwise healthy tend to have some ability to regulate blood flow through their delicate and still-developing brain. If cerebral autoregulation processes should fail, the subsequent shift to a systemic pressure-passive circulatory pattern is key to the development of IVH. Studies on the subject have found that hemorrhages can develop when fluctuating cerebral blood flow and pressure occurs when a pressure-passive circulatory pattern is present within the germinal matrix.
Intraventricular Hemorrhage Grading
In terms of anatomic classification, some cases of IVH are short-term and relatively harmless, while other more serious cases can lead to neurological issues in later life, including developmental issues like cerebral palsy. IVH can occur without clinical signs and present with symptoms similar to those of other conditions, which makes screening and serial examinations a critical part of proper diagnoses. Doctors diagnose IVH via brain imaging studies and cranial ultrasonography.
Intraventricular hemorrhage grading includes four levels of severity — a classification that can be useful for helping parents and caregivers understand the condition. These classifications are determined based on radiological appearance, not by the pathophysiological sequence of events leading to the development of IVH. These grades and their outcomes are:
- Grade 1: There is minimal hemorrhaging, contained to a small area of the subependymal region and/or germinal matrix. There is approximately a 10% chance of developing a major neurodevelopmental disability.
- Grade 2: There is moderate subependymal hemorrhaging that extends into the lateral ventricles but does not enlarge the ventricles. There is approximately a 40% chance of developing a major neurodevelopmental disability and a mortality rate of 10%.
- Grade 3: There is severe bleeding extending into the lateral ventricles, significantly enlarging them.
- Grade 4: There is intraparenchymal hemorrhaging into the white matter adjacent to the ventricles. For Grades 3 and 4, there is an 80% chance of developing a major neurodevelopmental disability, a mortality rate of 50% or higher, and hydrocephalus is common in survivors.
Risk Factors for Intraventricular Hemorrhage in Preterm Infants
- Unstable cerebral blood flow. Maintaining hemodynamic balance is critical for reducing NICU patients’ risk for developing IVH and PVL.
- Birth weight of less than 700g. In one study, 97% of the lesions examined by researchers in infants with BWs under 700g met the conditions for Grade 3 IVH. It also appeared earlier and was more likely to coincide with late and lethal intracranial hemorrhages.
- Less than 32 weeks gestation. While all premature infants should be considered to be at risk, the chance of developing IVH is inversely proportional to gestational age. Neonates delivered before 32 weeks are significantly more at risk for IVH, as the germinal matrix has yet to regress.
- Hypoxic events. Hypoxic-ischemic encephalopathy (HIE) can also lead to IVH, as oxygen-deprivation injuries (whether from trauma or other cause) can cause bleeding within the brain.
What Is Periventricular Leukomalacia?
PVL is a disorder of the brain’s white matter similar to a periventricular hemorrhagic infarction, but one that operates through non-hemorrhagic ischemic necrosis. This means a lack of blood flow has damaged the brain tissue. Both PVL and IVH can lead to significant neurological disorders and outcomes. Sequelae of PVL vary based on both the size of the initial lesion and the amount of time that has passed since the initial injury.
PVL is diagnosed at six to ten weeks through cranial ultrasound, tomography scan, or MRI. Periventricular leukomalacia symptoms often present as irritability, frequent tremors, hypertonicity, and abnormal Moro reflex. Long-term effects can include intellectual, motor, and visual deficiencies, spastic diplegia, and weakness in the lower limbs.
Can You Treat IVH and PVL?
While IVH and PVL cannot be prevented or treated directly, there are a number of supportive prenatal and postnatal strategies that NICU staff can follow to reduce the risks for IVH/PVL development. This effort involves establishing potential best practices (PBPs) for both pre and postnatal care, including strategies for the “golden hour” in the delivery room and the NICU. These PBP’s are often referred to as “bundling” and are being implemented by many NICUs.
NICU staff should also closely monitor neonates for the first week post-delivery. Half of IVH cases occur within the first 24 hours of delivery, and 90% within the first 72. That said, IVH can appear after the first three days, especially if the neonate experiences a significant illness. If hemorrhaging does occur, it often manifests worst at approximately five days post-delivery. This is why most programs recommend screening neonates for IVH at seven days of age.
NICU staff can further help to mitigate the risks of IVH and PVL by ensuring they avoid events that create sudden changes in arterial and venous flow and pressure. That's where Kentec Medical's products come in.
Kentec Medical: Your Partner In IVH/PVL Risk Reduction
Designed specifically to help reduce the risk of IVH and PVL occurring, the Kentec Medical Hummi Micro Draw system allows you to safely take blood samples from a neonate’s umbilical catheter. The Hummi micro-draw device offers the lowest volume clearance (0.5mL) and flush volume (0.3mL) of any blood sampling system available on the market. The Micro Draw closed sampling system reduces infection risk and reduces blood volume movement by over 70%. This helps reduce the risk of significantly disrupting cerebral blood flow and creating hemodynamic change, a known contributing factor to the development of IVH.
Kentec Medical believes in a customer-first approach, and we work hard to ensure that each of our clients receives proper support and reliable access to medical supplies and devices. Visit our website to learn more about how to get high-quality NICU products into your hospital. Contact us today to learn more.