Chest compression in newborn infants: what anatomical structures are we compressing?

OBJECTIVE: To identify the location of the left ventricle (LV) and identify the structures below the lower third of the sternum when chest compressions (CCs) are performed using transthoracic echocardiography. DESIGN: Prospective observational cohort study. SETTING: The Lois Hole Hospital for Women and the Grey Nuns Community Hospital, Edmonton, Alberta, Canada. PATIENTS: weeks' gestation admitted to postnatal unit. Newborns of diabetic mothers, large or small for gestational age and with known congenital anomalies were excluded. INTERVENTIONS: Transthoracic echocardiogram to obtain views as per the American Society of Echocardiography guidelines including (1) parasternal long axis, (2) parasternal short axis, (3) apical four chamber and (4) subcostal view. MAIN OUTCOME MEASURES: To assess the positions of the right ventricle and LV and their perception on the chest wall when CCs are performed. RESULTS: A total of 50 newborn infants were recruited with a mean (SD) gestational age of 39 (1) weeks and birth weight of 3409 (347) g. The LV was located at the third left sternal border in one (2%) newborn infant. In 22 (44%) infants, the LV was located at the fourth left sternal border, in 25 (50%) infants the LV was located at the fifth and in 2 (4%) infants, it was located at the sixth left sternal border. CONCLUSIONS: In newborn infants, CC delivered at the currently recommended lower third of the sternum is likely to compress the right heart, great veins and aorta and not the LV.