Targeted Neonatal echocardiography (TnECHO) offers a non-invasive assessment of cardiovascular health and illustrates the underlying pathophysiology otherwise unseen. The practice of TnECHO has become rapidly disseminated in Canadian NICU’s and is now considered standard of care, in certain situations, in some centers. Our goal is to evaluate and demonstrate the presumed benefits of TnECHO relate to clarification of cardiovascular physiology, earlier identification of disease states, more focused cardiovascular decision making and avoidance of treatment in certain situations.
Efficacy of rectal acetaminophen for avoiding surgical ligation of a hemodynamically significant ductus arteriosus (HSDA)
Cyclooxygenase inhibitors (COXI) are the primary pharmacotherapy to treat HSDA in preterm infants but are contraindicated in gastrointestinal disorders such as necrotizing enterocolitis & intestinal perforation. Both oral (PO) & intravenous (IV) acetaminophen have demonstrated efficacy for PDA closure. No studies have evaluated the efficacy of per rectum (PR) acetaminophen in cases where PO administration is contraindicated, bioavailability is compromised or when IV formulation is unavailable. PR acetaminophen has been trialed as a rescue therapy in infants who would otherwise be considered for surgical ligation. The objective of this study was to evaluate the efficacy of PR acetaminophen in modulating the risk of surgical ligation. The study fount that a course of PR acetaminophen led to improvement in echo indices of PDA shunt. Avoidance of PDA ligation in over 50% of cases where medical therapy was contraindicated. Future larger prospective studies should define the pharmacology of this new indication enabling randomized treatment comparisons.
Accuracy and reliability of qualitative echocardiography assessment of right ventricular size and function in neonates.
Assessment of right ventricular (RV) size, pressure (septal wall flattening) and function is complex and limited by a lack of normative data. Currently, diagnostic impressions are formulated on the basis of ‘eyeballing’ echocardiography images. Although used clinically to guide decision making, these methods lack validation against objective echocardiography measures of RV function. Our objective is to determine reliability and validity of qualitative assessment of RV size and function in a representative cohort of patients with a wide spectrum of RV function measurements in infants with pulmonary hypertension (PH) and healthy infants. From this study we have learned that qualitative assessment of RV size, function and septal flattening revealed poor agreement amongst all raters . Accuracy of a qualitative diagnosis of septal flattening or RV dysfunction varied within/between experts and novices . This further supports the use of quantitative measures of RV size and function to aid in clinical decision-making.
Validation of right ventricular output in a cohort of healthy neonates.
Right ventricular output (RVO) is routinely used as a surrogate of right ventricular (RV) systolic performance to guide clinical decision making. It is possible to image the right ventricular outflow tract and estimate RVO from different imaging planes, but the reliability and precision of each technique is unknown. We have found that the RVO may be calculated from different imaging planes with acceptable bias and low intra/interobserver variability. Although certain imaging planes showed the lowest median bias and interobserver variability, the optimal method used clinically to estimate RVO should be based on the quality of the imaging plane.