Rootwelt T, Løberg E M, Moen A, Oyasaeter S, Saugstad O D
Institute for Surgical Research, University of Oslo, Rikshospitalet, Norway.
Pediatr Res. 1992 Jul;32(1):107-13. doi: 10.1203/00006450-199207000-00021.
To study whether room air is as effective as 100% O2 in resuscitation after hypoxia, hypoxemia (PaO2 2.3-4.3 kPa) was induced in newborn pigs (2-5 d old) by ventilation with 8% O2 in nitrogen. When systolic blood pressure had fallen to 20 mm Hg, animals were randomly reoxygenated with either 21% O2 (group 1, n = 9) or 100% O2 (group 2, n = 11) for 20 min followed by 21% O2 in both groups. Controls (group 3, n = 5) were ventilated with 21% O2 throughout the experiment. Base deficit peaked at 31 +/- 5 mmol/L (mean +/- SD) for both hypoxic groups at 5 min of reoxygenation and then normalized over the following 3 h. There were no statistically significant differences between the two groups during reoxygenation concerning blood pressure, heart rate, base deficit, or plasma hypoxanthine. Hypoxanthine peaked at 165 +/- 40 and 143 +/- 42 mumol/L in group 1 and 2 (NS), respectively, and was eliminated monoexponentially in both groups with an initial half-life for excess hypoxanthine of 48 +/- 21 and 51 +/- 27 min (NS), respectively. Blinded pathologic examination of cerebral cortex, cerebellum, and hippocampus after 4 d showed no statistically significant differences with regard to brain damage. We conclude that 21% O2 is as effective as 100% O2 for normalizing blood pressure, heart rate, base deficit, and plasma hypoxanthine after severe neonatal hypoxemia in piglets and that the extent of the hypoxic brain damage is similar in the two groups.
为研究在新生儿缺氧后复苏过程中，室内空气是否与100%氧气一样有效，通过用8%氧气和氮气混合气体对2 - 5日龄新生猪进行通气诱导低氧血症（动脉血氧分压2.3 - 4.3 kPa）。当收缩压降至20 mmHg时，将动物随机分为两组，一组用21%氧气复氧（第1组，n = 9），另一组用100%氧气复氧（第2组，n = 11），持续20分钟，之后两组均用21%氧气。对照组（第3组，n = 5）在整个实验过程中用21%氧气通气。复氧5分钟时，两个缺氧组的碱缺失峰值均为31±5 mmol/L（均值±标准差），随后在接下来的3小时内恢复正常。复氧过程中，两组在血压、心率、碱缺失或血浆次黄嘌呤方面无统计学显著差异。第1组和第2组次黄嘌呤峰值分别为165±40和143±42 μmol/L（无统计学差异），两组中多余次黄嘌呤均呈单指数消除，初始半衰期分别为48±21和51±27分钟（无统计学差异）。4天后对大脑皮层、小脑和海马进行盲法病理检查，结果显示两组在脑损伤方面无统计学显著差异。我们得出结论，对于仔猪严重新生儿低氧血症后血压、心率、碱缺失和血浆次黄嘌呤的恢复正常，21%氧气与100%氧气一样有效，且两组缺氧性脑损伤程度相似。
