Page M, Jeffery H E, Marks V, Post E J, Wood A K
Department of Obstetrics and Gynaecology, University of Sydney, Australia.
J Appl Physiol (1985). 1995 May;78(5):1942-9. doi: 10.1152/jappl.1995.78.5.1942.
The airway protective mechanisms evoked after infusion of fluids into the pharynx were examined in the intact and healthy newborn piglet during sleep. Thirteen healthy normothermic piglets (3-6 days of age) were examined on 4 consecutive days during sleep. The fluids infused (0.05-1.5 ml) were 0.9% saline, distilled water, and HCl (pH 3 and pH 2). Respiratory rate, heart rate, oxygen saturation (SaO2), swallowing, and arousal were compared pre- and postinfusion during active (AS) and quiet sleep (QS) for each test fluid. The most common response in AS and QS was swallowing (90%) and then arousal (24%); however, no apnea occurred, and respiratory rate and SaO2 were always maintained. A significant difference occurred between HCl infusions of pH 2 and pH 3; at pH 2, the frequency of swallows and latency to the first swallow were reduced (P < 0.05) and the frequency of arousal was reduced in AS compared with that in QS (P < 0.01). Airway protection after pharyngeal fluid stimulation is achieved primarily by swallowing and arousal, without any effect on respiratory rate and SaO2. Attenuation of protective mechanisms occurred, however, when the infusate was at pH 2.
在睡眠状态下，对完整健康的新生仔猪注入液体后诱发的气道保护机制进行了研究。连续4天，在睡眠状态下对13头健康的体温正常的仔猪（3 - 6日龄）进行了检查。注入的液体（0.05 - 1.5毫升）包括0.9%生理盐水、蒸馏水和盐酸（pH 3和pH 2）。针对每种测试液体，在主动睡眠（AS）和安静睡眠（QS）期间，比较了注入前后的呼吸频率、心率、血氧饱和度（SaO2）、吞咽和觉醒情况。在AS和QS中最常见的反应是吞咽（90%），然后是觉醒（24%）；然而，未出现呼吸暂停，呼吸频率和SaO2始终保持稳定。pH 2和pH 3的盐酸注入之间存在显著差异；在pH 2时，与QS相比，AS中的吞咽频率和首次吞咽潜伏期降低（P < 0.05），觉醒频率降低（P < 0.01）。咽部液体刺激后的气道保护主要通过吞咽和觉醒实现，对呼吸频率和SaO2无任何影响。然而，当注入液的pH值为2时，保护机制会减弱。
