Impact of Oxygen Saturation Targets and Oxygen Therapy during the Transport of Neonates with Clinically Suspected Congenital Heart Disease

Background: Although guidelines for mechanical ventilation, cardiovascular support and intravenous prostaglandin are well established, there is a lack of consensus regarding SpO 2 targets and safety of oxygen administration during transport of neonates with suspected congenital heart disease (CHD). In many centers, an SpO 2 range of 75–85% is targeted but there is no published evidence of the clinical consequences of this approach. Objective: To determine the effect of average SpO 2 range and oxygen administration during neonatal transport on clinical markers of cardiovascular instability. Methods: A retrospective study was conducted on neonates with suspected CHD who presented at community hospitals. Based on average SpO 2 during transport, neonates were categorized into three distinct groups: group I (SpO 2 85%). The severity and proportion of neonates with hypoxemia, metabolic and lactic acidosis on arrival at level III NICU were compared. A comparison was also made between oxygen requirement and indicators of cardiorespiratory instability. Results: Seventy-five neonates were studied and 14 (19%), 38 (50%) and 23 (31%) neonates were allocated to groups I, II and III, respectively. Therapeutic interventions during the transport stabilization process included oxygen (n = 53, 71%), mechanical ventilation (n = 56, 75%) and prostaglandin E1 (n = 63, 84%). The severity or proportion of neonates with hypoxemia, elevated lactate or metabolic acidosis was similar between the groups. Neonates receiving an oxygen requirement of FiO 2 >70% had lower arterial SpO 2 on arrival. A provisional diagnosis of CHD and/or PPHN (p = 0.01) and neonates receiving inotropes (p = 0.005) were independent risk factors for cardiovascular instability. Conclusion: If congenital heart disease is strongly suspected oxygen should be cautiously weaned to maintain a minimum SpO 2 >75%. Neonates receiving >70% oxygen are at greatest risk of metabolic acidosis or critical hypoxemia and may benefit from expedited transfer to a cardiac center.