Sato M, Severinghaus J W, Powell F L, Xu F D, Spellman M J
Department of Anesthesia, University of California, San Francisco 94143.
J Appl Physiol (1985). 1992 Jul;73(1):101-7. doi: 10.1152/jappl.1992.73.1.101.
To test the hypothesis that the hypoxic ventilatory response (HVR) of an individual is a constant unaffected by acclimatization, isocapnic 5-min step HVR, as delta VI/delta SaO2 (l.min-1.%-1, where VI is inspired ventilation and SaO2 is arterial O2 saturation), was tested in six normal males at sea level (SL), after 1-5 days at 3,810-m altitude (AL1-3), and three times over 1 wk after altitude exposure (PAL1-3). Equal medullary central ventilatory drive was sought at both altitudes by testing HVR after greater than 15 min of hyperoxia to eliminate possible ambient hypoxic ventilatory depression (HVD), choosing for isocapnia a P'CO2 (end tidal) elevated sufficiently to drive hyperoxic VI to 140 ml.kg-1.min-1. Mean P'CO2 was 45.4 +/- 1.7 Torr at SL and 33.3 +/- 1.8 Torr on AL3, compared with the respective resting control end-tidal PCO2 of 42.3 +/- 2.0 and 30.8 +/- 2.6 Torr. SL HVR of 0.91 +/- 0.38 was unchanged on AL1 (30 +/- 18 h) at 1.04 +/- 0.37 but rose (P less than 0.05) to 1.27 +/- 0.57 on AL2 (3.2 +/- 0.8 days) and 1.46 +/- 0.59 on AL3 (4.8 +/- 0.4 days) and remained high on PAL1 at 1.44 +/- 0.54 and PAL2 at 1.37 +/- 0.78 but not on PAL3 (days 4-7). HVR was independent of test SaO2 (range 60-90%). Hyperoxic HCVR (CO2 response) was increased on AL3 and PAL1. Arterial pH at congruent to 65% SaO2 was 7.378 +/- 0.019 at SL, 7.44 +/- 0.018 on AL2, and 7.412 +/- 0.023 on AL3.(ABSTRACT TRUNCATED AT 250 WORDS)
为验证个体的低氧通气反应（HVR）是一个不受习服影响的常数这一假设，在海平面（SL）对6名正常男性进行了等碳酸5分钟阶梯式HVR测试，以ΔVI/ΔSaO₂（升·分钟⁻¹·%⁻¹，其中VI为吸入通气量，SaO₂为动脉血氧饱和度）表示，在海拔3810米处停留1至5天（AL1 - 3）后进行测试，并在海拔暴露后1周内进行3次测试（PAL1 - 3）。通过在高氧状态下超过15分钟后测试HVR，在两个海拔高度寻求相等的延髓中枢通气驱动，以消除可能的环境性低氧通气抑制（HVD），选择终末潮气二氧化碳分压（P'CO₂）升高到足以将高氧状态下的VI驱动至140毫升·千克⁻¹·分钟⁻¹来实现等碳酸。海平面时平均P'CO₂为45.4±1.7托，AL3时为33.3±1.8托，而各自静息对照终末潮气二氧化碳分压分别为42.3±2.0托和30.8±2.6托。海平面时HVR为0.91±0.38，在AL1（30±18小时）时为1.04±0.37无变化，但在AL2（3.2±0.8天）时升至1.27±0.57（P＜0.05），在AL3（4.8±0.4天）时为1.46±0.59且在PAL1时保持在1.44±0.54，PAL2时为1.37±0.78，但PAL3（第4 - 7天）时未保持。HVR与测试的SaO₂（范围60 - 90%）无关。高氧状态下的HCVR（二氧化碳反应）在AL3和PAL1时增加。在约65% SaO₂时，海平面时动脉pH为7.378±0.019，AL2时为7.44±0.018，AL3时为7.412±0.023。（摘要截断于250字）
