BASIC AND CLINICAL STUDY OF PERIOPERATIVE RESPIRATORY MANEGEMENT ON ORAL AND MAXILLOFAICIAL SURGERY

为探讨手术中颌间固定对全麻后呼吸功能的影响，特别是术前呼吸途径的不同对呼吸功能的影响，选择14例呼吸功能正常的健康成人（对照组）和29例全麻下行矢状截骨联合颌间固定的患者（患者组）。测定鼻呼吸、口呼吸、各呼吸道潮气量（VT）、每分钟呼吸量（min）、呼吸频率（RR）、呼气末CO_2浓度（EtCO_2）、血氧饱和度（SpO_2）等指标。NO - N组术后潮气量和每分钟呼吸量均下降.这表明，在涉及颌间固定的正颌手术中全身麻醉后，口腔呼吸被颌间固定消除，并且表明鼻呼吸途径中补偿这种消失的呼吸量不会增加。然而，呼吸量的减少不足以改变SpO_2。认为EtCO_2的减少是由于呼吸容量改变后死腔的影响。NO-N组患者呼吸量减少的可能原因是正颌手术改变了上气道的形状。本研究提示，术前经口呼吸时，应密切关注全麻后颌间固定术的呼吸状况。

We studied the effects of intermaxillary fixation during surgery on respiratory function after general anesthesia, expecially differences caused by differences in preoperative respiratory routes.The subjects in this study were 14 healthy adults with normal respiratory function (control group) and 29 patients (patient group) subjected to sagittal osteotomy accompanied by intermaxillary fixation under general anesthesia. Measurement items were the presence of nasal breathing and oral breathing, tidal volume (VT) in each respiratory route, respiratory minute volume, respiratory rate (RR), end-tidal CO_2 concentration (EtCO_2), and oxygen saturation (SpO_2).In the control NO - N group, there were no changes in any of the measurement items before and after intermaxillary fixation except in the case of respiratory routes. In the patient NO - N group, however, the postoperatively measured tidal volume and respiratory minute volume decreased. This suggested that, after general anesthesia during orthognathic surgery involving intermaxillary fixation, oral breathing was eliminated by intermaxillary fixation, and it was suggested that the respiratory volume in the nasal breathing route compensating for this disappearance would not increase. However, the decrease in the respiratory volume was not large enough to change SpO_2. The decrease in EtCO_2 was thought to be due to the effect of dead space following the respiratory volume change. The possible causes of the decreased respiratory volume in the patient NO -N group were a change in the form of the upper airway by orthognathic surgery. This study suggested that when oral breathing is recognized before surgery, close attention should be paid to respiratory conditions after general anesthesia during intermaxillary fixation.