Endotracheal epinephrine. Theoretical concerns regarding endotracheal epinephrine administration in perinatal asphyxia. Asphyxia and acidosis lead to a decrease in systemic vascular resistance by dilating the peripheral vascular bed. Coronary perfusion pressure is low. High fetal pulmonary vascular resistance may lead to right to left shunting at the PDA level limiting pulmonary blood flow. Presence of fetal lung liquid may dilute tracheal epinephrine and absorption may be limited by low pulmonary blood flow. The proposed path of intratracheal epinephrine is shown by a hyphenated green line. A higher dose of endotracheal epinephrine may compensate and achieve higher plasma levels. LV left ventricle, PA pulmonary artery, PDA patent ductus arteriosus, PVR pulmonary vascular resistence. Copyright Satyan Lakshminrusimha.