Investigation on upper airway collapsibility and postoperative nocturnal breathing in children

本研究的目的是评估儿童术后晚期夜间由上呼吸道阻塞引起的低饱和度的发生率和意义，并比较儿童和成人的上呼吸道塌陷性。虽然由于这些小孩子的血氧饱和度测量不可靠，我们未能完成手术后夜间去饱和度的研究，但我们完成了对全身麻醉下肌肉麻痹小儿童咽部塌陷的评估。我们发现，婴儿的咽部比成年人更容易塌陷，咽部的呼吸道在出生一年内就稳定了。最有趣的是，俯卧位增加了婴儿和儿童的咽部塌陷。我们的研究结果表明，成熟度和体位是术后夜间呼吸异常的重要原因。此外，俯卧位增加的咽部塌陷可能是小岛屿发展中国家患者患病率较高的关键证据。由于我们的研究是在全身麻醉下进行的，并伴有全身肌肉麻痹，因此我们对神经肌肉机制在补偿上呼吸道阻塞中的作用缺乏了解。未来的研究应该针对这些儿童的神经肌肉机制的贡献进行研究。

The purposes of this investigation were to assess prevalence and significance of late post-operative nocturnal desaturations caused by upper airway obstruction in small children, and to compare upper airway collapsibility in small children with adults. While we failed to complete the study on post-operative nocturnal desaturations because of unreliable measurements of oxygen saturation in these small children, we completed the evaluation of pharyngeal collapsibility in small children under general anesthesia with muscle paralysis. We found that infants had more collapsible pharynx than adults, and the pharyngeal airway was stabilized within the first year of life. Most interestingly, prone position increased the pharyngeal collapsibility in infants and small children. Our findings indicate that maturation and body position significantly contribute to post-operative nocturnal breathing abnormality. Furthermore, increased pharyngeal collapsibility by the prone position may give a key evidence for the higher prevalence of SIDS victims. Because our study was performed under general anesthesia with total muscle paralysis, we lack knowledge on a role of neuromuscular mechanisms compensating the upper airway obstruction. Future studies should be directed to investigate contribution of the neuromuscular mechanisms in these small children.