Rigatto H, Brady J P, de la Torre Verduzco R
Pediatrics. 1975 May;55(5):614-20.
We studied nine "healthy" preterm infants (birthweight, 1,000 to 2,000 gm) 58 times during postnatal life to define the effects of gestational and postnatal age on the ventilatory response to carbon dioxide. The infants were given air and 2% and 4% carbon dioxide in air to breathe for five minutes each. We determined respiratory minute and tidal volumes, frequency,heart rate, and alveolar PCO2 and PO2. We measured ventilation with a nosepiece and a screen flowmeter, using a constant flow-through to eliminate valves and reduce diad space. Analysis were made during the fifth minute while the baby breathed the various gas mistures. The slope of the carbon dioxide response increased 42% from 32 to 37 weeks gestation (P smaller than .05) and 62% from 2 to 27 days of age (P smaller than. 025). However, the intercept at .3 liter/min/kg was the same at different gestational ages, but significantly greater at 2 compared with 27 days of age (P smaller than.05). We sugest that the unresposiveness primarily dependent on the mechanical abnormalities of the lung.
我们对9名“健康”早产儿（出生体重1000至2000克）在出生后的不同时期进行了58次研究，以确定胎龄和出生后年龄对二氧化碳通气反应的影响。给这些婴儿分别吸入空气、含2%和4%二氧化碳的空气，每次呼吸5分钟。我们测定了呼吸分钟量、潮气量、频率、心率以及肺泡二氧化碳分压和氧分压。我们使用鼻罩和屏幕流量计测量通气量，采用恒定的流通方式以消除阀门并减少死腔。在婴儿呼吸各种气体混合物的第5分钟进行分析。二氧化碳反应的斜率从妊娠32周时的32增加到37周时的42%（P小于0.05），从出生后2天到27天时增加了62%（P小于0.025）。然而，每分钟0.3升/千克的截距在不同胎龄时相同，但在出生后2天与27天时相比明显更大（P小于0.05）。我们认为这种无反应性主要取决于肺部的机械性异常。
