Jefferies A L, Dunn M S, Possmayer F, Tai K F
Department of Paediatrics, Mount Sinai Hospital, London, Ontario, Canada.
Am Rev Respir Dis. 1993 Oct;148(4 Pt 1):845-51. doi: 10.1164/ajrccm/148.4_Pt_1.845.
Surfactant therapy and high-frequency oscillatory ventilation (HFO) may minimize damage to the pulmonary epithelium of surfactant-deficient newborns. Using pulmonary clearance of insufflated, aerosolized 99mTc-DTPA (molecular weight 492) as an index of lung epithelial permeability, we examined the effects of 300 mg bovine lipid extract surfactant (S) administered at birth to preterm lambs ventilated by either HFO or conventional mechanical ventilation (CMV). Four groups of lambs, delivered by cesarean section at 129 to 133 days of gestation, were studied: (1) HFO + S, (2) CMV + S, (3) HFO, and (4) CMV. 99mTc-DTPA clearance was assessed at 2, 4, and 5.5 h after birth. Surfactant treatment improved oxygenation and lung pressure-volume relationships, with oxygenation best maintained by the combination of HFO + S. All groups had similar biexponential clearance curves at the three time points, however, and there was no significant difference in the mean rates of clearance (k) between the four groups at 2 h (k = 6.03 +/- 0.60 [SEM], 7.04 +/- 1.46, 5.67 +/- 0.91, and 7.23 +/- 0.97 %/min for Groups 1, 2, 3, and 4, respectively), 4 h (k = 6.95 +/- 0.77, 5.60 +/- 0.51, 6.39 +/- 0.64, and 6.78 +/- 1.71 %/min), and 5.5 h (k = 7.43 +/- 0.78, 6.08 +/- 0.80, 7.86 +/- 0.90, and 7.95 +/- 0.66 %/min). These data suggest that neither surfactant nor HFO significantly alters pulmonary epithelial permeability to a small radiolabeled molecule in preterm lambs.
表面活性剂疗法和高频振荡通气（HFO）可能会将对表面活性剂缺乏的新生儿肺上皮的损伤降至最低。我们以雾化吸入的99mTc-DTPA（分子量492）的肺清除率作为肺上皮通透性的指标，研究了出生时给早产羔羊气管内注入300mg牛肺脂质提取物表面活性剂（S）后，采用高频振荡通气（HFO）或传统机械通气（CMV）的效果。研究了四组在妊娠129至133天经剖宫产出生的羔羊：（1）高频振荡通气+表面活性剂组（HFO + S），（2）传统机械通气+表面活性剂组（CMV + S），（3）高频振荡通气组（HFO），（4）传统机械通气组（CMV）。在出生后2、4和5.5小时评估99mTc-DTPA清除率。表面活性剂治疗改善了氧合和肺压力-容积关系，高频振荡通气与表面活性剂联合应用时氧合维持最佳。然而，所有组在三个时间点的双指数清除曲线相似，四组在2小时（分别为1、2、3和4组，清除率k分别为6.03±0.60[标准误]、7.04±1.46、5.67±0.91和7.23±0.97%/分钟）、4小时（k = 6.95±0.77、5.60±0.51、6.39±0.64和6.78±1.71%/分钟）和5.5小时（k = 7.43±0.78、6.08±0.80、7.86±0.90和7.95±0.66%/分钟）的平均清除率（k）无显著差异。这些数据表明，表面活性剂和高频振荡通气均未显著改变早产羔羊肺上皮对小分子放射性标记物的通透性。
