2022 Eastern Regional Meeting

2022 Journal of Investigative Medicine  
Purpose of Study The use of 100% supplemental O 2 is not recommended in the resuscitation of preterm neonates due to the risk of systemic oxygen toxicity. A recent meta-analysis suggests that more than 50% of preterm infants are born with a heart rate < 100 bpm. Not achieving an HR of 100bpm and saturation (SpO 2 ) of 80% by 5 min places a preterm infant at a higher risk of morbidity/mortality. Ventilation with an intact cord improves hemodynamic transition in a preterm neonate. In an
more » ... d preterm neonate, the use of 100% O 2 with an intact cord could improve alveolar oxygenation with less systemic toxicity due to buffering by umbilical venous return. Our objectives are to study the effect of initiating positive pressure ventilation (PPV) with 100% O 2 with and without an intact umbilical cord in asphyxiated and non-asphyxiated preterm lambs. Methods Used Preterm lambs (125-127d gestation) were randomized to 4 groups a) AXDCCasphyxiated (to HR < 100 bpm) and ventilated with an intact cord, b) AXECCasphyxiated, early cord clamping and PPV, c) NoAXDCCnon-asphyxiated delayed cord clamping, d) NoAXECCnonasphyxiated, early cord clamping. The cord clamping is delayed in all DCC groups for 5 min. The primary outcome is the incidence of HR of 100 bpm and SpO 2 of 80% by 5 min. The secondary outcomes were measures of gas exchange, hemodynamics, and oxidative stress (oxidized to reduced glutathione ratio in the blood). In all the groups PPV was initiated with 100% O 2 for 2 min and titrated proportional to the difference in observed and targeted SpO 2 every min. Summary of Results Asphyxia led to lower PaO 2 , SpO 2 , HR and higher PaCO 2 at the initiation of PPV. The primary outcome was achieved in 4/7 (AXECC), 6/7 (AXDCC), 5/6 (NoAXECC) & 7/7 (NoAXDCC). By 5 min, the preductal SpO 2 was higher in DCC groups despite lower O 2 exposure compared to other groups (figure 1B & figure 1C ). Intact cord resuscitation led to lower PaCO 2 in asphyxiated lambs along with higher peak pulmonary and carotid flow (figure 2 ). At 5 min, there was Abstract #1 Figure 1 Groups -AXasphyxiated (HR < 100 bpm), NoAXnon-asphyxiated, ECCearly cord clamping, DCCdelayed cord clamping. A * p<0.01 by ANOVAsignificantly higher than other groups. B * p<0.01 significantly higher than the rest of the groups. C p<0.01significantly lower O 2 requirement than other groups. D *p<0.01 -highest PaO 2 compared to rest of the groups Abstracts
doi:10.1136/jim-2022-erm fatcat:44n3rbijszapjadughnt52b7ny