How much post-operative bleeding is normal in babies? Blood Research Institute Investigator Debra Newman, PhD, is working hard on new research to help our tiniest patients.
Think about the last time you cut yourself shaving, or nicked a fingertip while making dinner. How much did you bleed? A lot? A little? It’s likely that what you might consider “a lot” is actually “a little” to others. Measuring a “normal” amount of bleeding is relatively easy in adults. One study conducted by Blood Research Institute investigators, including Debra Newman, PhD, attempted to give it a number in infants, in whom measuring bleeding is much more difficult.
Dr. Newman and her colleagues at the Blood Research Institute, Children’s Hospital of Wisconsin and the Medical College of Wisconsin sought to understand why babies bleed so badly during heart surgery. Their study, “Validation of a definition of excessive postoperative bleeding in infants undergoing cardiac surgery with cardiopulmonary bypass,” attempted to quantify how much post-operative bleeding is normal for infants who had heart surgery accompanied by cardiopulmonary bypass (a technique in which a machine temporarily takes over the function of the heart and lungs during surgery).
After these infants underwent surgery, physicians put in chest tubes to allow for fluids to drain. Some of this drainage is natural fluids, but some is blood. In some cases, however, babies experienced cardiac tamponade, or pressure that builds up in the chest cavity because of trapped fluids. In other words, these babies were bleeding internally, and required further surgery to understand why. By measuring chest tube output and determining the incidence of cardiac tamponade, investigators had easy ways to compare the amount of fluid (some of which is blood) that drained from the heart after surgery.
Dr. Newman and her team asked whether certain amounts of chest tube output, and whether the need for more surgery because of cardiac tamponade, were associated with poor recovery after surgery. They found that chest tube outputs of ≥7 mL/kg/hour for ≥2 consecutive hours in the first 12 hours after surgery, or ≥84 mL/kg total for the first 24 hours after surgery, and/or having to perform additional surgery because of cardiac tamponade within the first 24 hours after surgery were all associated with longer hospital stays, increased re-admission rates and increased post-operative blood transfusions in infants, and were therefore indicative of excessive bleeding.
Dr. Newman and her team plan to apply this definition of excessive bleeding to identify the patients who bleed excessively after heart surgery. Coupled with their knowledge of the hemostatic system, they can determine how the hemostatic system is failing in these babies and causing them to bleed excessively.
Dr. Newman is interested in whether certain subsets of babies are at greater risk than others to bleed excessively after heart surgery. Of particular interest to her are infants with 22q11.2 Deletion Syndrome (or DiGeorge Syndrome), which can cause a variety of health issues, including congenital heart defects, platelet defects and, in some cases, a severe bleeding disorder. Dr. Newman wants to know whether platelet defects cause patients with 22q11 Deletion Syndrome to bleed excessively under normal circumstances and after heart surgery.
The results of this research are expected to advance Precision Medicine & Expertise at Versiti by guiding diagnosis and management of bleeding problems associated with cardiac surgery in infants.
About the expert: Debra Newman, PhD, is a senior investigator at the Blood Research Institute and professor within the Departments of Pharmacology & Toxicology and Microbiology & Immunology at the Medical College of Wisconsin (MCW). Learn more about Dr. Newman.