ABSTRACT

The present study aimed to analyse the effects of exogenous surfactant administration in premature lambs on oxidative stress profile, oxygenation and lung histology. Preterm lambs (n = 22) were randomly assigned to: Control (n = 5), Single Surfactant (n = 5; single intratracheal administration of 100 mg/kg surfactant), Double Surfactant (n = 6; two equal doses of surfactant at 0 and 30 min) and Triple Surfactant (n = 6; three doses at 0, 20 and 40 min). Lambs were subjected to vitality score, oximetry, arterial blood pH, lactatemia, oxidative stress and antioxidant profile during 24 h. Lambs that died were subjected to pulmonary histology. Double group survived longer than Triple group. However, Control presented higher survival time, vitality, oxymetry and blood pH in comparison to surfactant groups. Fractionalized groups had higher vitality, oxymetry and blood pH in comparison to single group. Lactatemia of Control was lower in comparison to surfactant groups, while single group was higher than fractionalized groups. Catalase concentration was higher in fractionalized groups compared to single group. Treated groups had higher superoxide dismutase concentration compared to Control. In conclusion, single dose of intratracheal surfactant in preterm lambs compromises pulmonary adsorption and impairs neonatal antioxidant performance, leading to poor clinical and respiratory outcome, besides being preventive for excessive invasive manipulation.

摘要

本研究旨在分析早产羔羊外源性表面活性剂给药对氧化应激分布，氧合和肺组织学的影响。早产羔羊（n  = 22）被随机分配给：对照（n  = 5），单一表面活性剂（n  = 5；气管内单次施用100 mg / kg表面活性剂），双重表面活性剂（n  = 6；两次相等剂量的表面活性剂0和30分钟）和三重表面活性剂（n = 6; 在0、20和40分钟时服用三剂）。在24小时内，对羔羊进行活力评分，血氧饱和度，动脉血pH，乳酸血症，氧化应激和抗氧化剂曲线。死亡的羔羊接受肺组织学检查。双组比三组存活时间更长。然而，与表面活性剂组相比，对照具有更高的存活时间，活力，血氧测定法和血液pH值。与单独组相比，分级组具有更高的活力，血氧测定法和血液pH值。与表面活性剂组相比，对照组的乳酸血症较低，而单一组的则高于分级组。分馏组的过氧化氢酶浓度高于单组。与对照组相比，治疗组的超氧化物歧化酶浓度更高。总之，ş早产羔羊气管内表面活性剂的单剂量添加会损害肺部吸附并损害新生儿的抗氧化性能，从而导致不良的临床和呼吸结果，此外还可以防止过度的侵入性操作。