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) <75%), group II (SpO(2) 75-85%), group III (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.


CONCLUSIONS
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.
Acute Care Transport Services, University of Toronto, Toronto, Ont., Canada.
Sandesh
S
Shivananda
Joel
J
Kirsh
Hilary E
HE
Whyte
Koshy
K
Muthalally
Patrick J
PJ
McNamara
D000140:Acidosis, Lactic / Q000453:epidemiology / Q000517:prevention & control; D006330:Heart Defects, Congenital / Q000097:blood* / Q000453:epidemiology / Q000628:therapy*; D006764:Hospitals, Community; D006801:Humans; D006976:Hypertension, Pulmonary / Q000097:blood / Q000628:therapy; D000860:Hypoxia / Q000453:epidemiology / Q000517:prevention & control; D007231:Infant, Newborn; D007363:Intensive Care Units, Neonatal; D010100:Oxygen / Q000097:blood*; D010102:Oxygen Inhalation Therapy / Q000379:methods*; D011237:Predictive Value of Tests; D012121:Respiration, Artificial; D012189:Retrospective Studies; D012307:Risk Factors; D014187:Transportation of Patients
D010100:Oxygen