Upton C J, Milner A D, Stokes G M, Carman P G
Neonatal Research Laboratory, City Hospital, Nottingham, UK.
Pediatr Pulmonol. 1990;9(3):136-9. doi: 10.1002/ppul.1950090303.
In 21 studies on 15 infants an additional dead space tube produced a significant rise in end-tidal PCO2 and fall in end-tidal PO2, associated with a rise in minute ventilation (228 +/- 77 mL/kg/min at zero, 348 +/- 85 mL/kg/min at one, and 437 +/- 128 mL/kg/min at two anatomical dead spaces). The differences between end-inspiratory and end-expiratory PCO2 and PO2 did not change significantly, suggesting an increase in dead space, but not in alveolar ventilation. In a further 9 babies the rise in ventilation was unchanged when measurements were repeated in 30% oxygen (361 +/- 65 vs. 340 +/- 54 mL/kg/min at one anatomical dead space). Studies on 8 babies, with the added tube ventilated by a fan, showed that a mean 28% of the rise in minute ventilation was due to increased resistance. Although the response to tube breathing in neonates is complex, carbon dioxide appears to be the major factor producing increased ventilation.
在针对15名婴儿的21项研究中，增加一根死腔管会导致呼气末PCO2显著升高、呼气末PO2下降，同时分钟通气量增加（零根死腔管时为228±77 mL/kg/min，一根死腔管时为348±85 mL/kg/min，两根解剖死腔管时为437±128 mL/kg/min）。吸气末与呼气末PCO2和PO2之间的差异无显著变化，提示死腔增加，但肺泡通气量未增加。在另外9名婴儿中，当在30%氧气浓度下重复测量时，通气量的增加没有变化（一根解剖死腔管时为361±65 vs. 340±54 mL/kg/min）。对8名婴儿进行的研究显示，用风扇对添加的管子进行通气时，分钟通气量增加的平均28%是由于阻力增加。尽管新生儿对管内呼吸的反应很复杂，但二氧化碳似乎是导致通气增加的主要因素。
