Stark A R, Frantz I D
Pediatr Res. 1979 Apr;13(4 Pt 1):261-4. doi: 10.1203/00006450-197904000-00010.
End-expiratory lung volume increased 17.5 +/- 5.4 ml (mean +/- SD) in full term infants and 7.7 +/- 2.1 ml in premature infants when 5--7 cm H2O continuous negative pressure (CNEG) was applied around the thorax. In the full term infants, respiratory rate decreased from 52--43 min-1 (P less than 0.001), mean inspiratory duration (ti) was unchanged, and mean duration of expiration (te) increased from 0.62 +/- 0.14 (SE)-0.84 +/- 0.22 sec (P less than 0.001) after application of CNEG. Te of occluded efforts on CNEG was also prolonged (P less than 0.005), although less than te of spontaneous breaths on CNEG (P less than 0.005). Te increased in four of eight premature infants when CNEG was applied. We conclude that phasic vagal feedback regulates Ti and te is controlled by tonic vagal activity.
Premature infants may have an optimum functional residual capacity (FRC) which can be achieved with continuous distending pressure, resulting in regularization of respiration.
当在胸廓周围施加5-7 cm H2O的持续负压（CNEG）时，足月儿的呼气末肺容积增加17.5±5.4 ml（平均值±标准差），早产儿增加7.7±2.1 ml。在足月儿中，呼吸频率从52-43次/分钟下降（P<0.001），平均吸气持续时间（ti）不变，施加CNEG后平均呼气持续时间（te）从0.62±0.14（标准误）-0.84±0.22秒增加（P<0.001）。CNEG时阻塞性用力的te也延长（P<0.005），尽管短于CNEG时自主呼吸的te（P<0.005）。施加CNEG时，8名早产儿中有4名的te增加。我们得出结论，阶段性迷走神经反馈调节ti，而te由持续性迷走神经活动控制。
早产儿可能具有最佳功能残气量（FRC），可通过持续扩张压力实现，从而使呼吸规律化。
