以術前胸腔X光片估計左側雙腔式氣管內管之置放深度

Estimation of the Depth of Left-sided Double-lumen Endobronchial Tube Placement Using Preoperative Chest Radiographs

背景：對單側肺部換氣患者而言，將雙腔式氣管內管放至正確位置是必要的。本實驗目的是試圖由病人術前的胸腔X光片去預估左側雙腔式氣管內管所需放置的深度。方法：以接受胸腔手術並放置左側雙腔式氣管內管的病人四十五人為本實驗的研究對象。在胸腔X光片上測得第六頸椎上緣至氣管隆突的距離(Dc-c)。插完管後，以氣管內視鏡確定深度。利用線性迴歸統計分析左側雙腔式氣管內管的放置深度與Dc-c的相關性。結果：左側雙腔式氣管內管放置的深度分別與胸腔X光片上測得第六頸椎上緣與氣管隆突的距離(y= 0.5304x + 19.646)以及身高(y= 0.1022x + 10.525)在統計上皆有明顯的相關(P< 0.001和P< 0.01)。結論：雙腔式氣管內管放置不當會使胸腔外科手術無法順利進行，甚至引起致命性的低血氧症。手術前測得胸腔X光片上第六頸椎上緣與氣管隆突間距將有助於左側雙腔式氣管內管深度的預測與評估。

Background: Accurate placement of the double- lumen endobronchial tube (DLETs) is essential for optimal gas exchange during one-lung ventilation. The present study was designed to estimate the insertion depth of left-sided DLET using a preoperative chest radiograph. Methods: Forty-five patients who underwent thoracic operations requiring intubation of a DLET were studied. The distance between the cephalic edge of the sixth cervical vertebra and the carina of the trachea (Dc-c) was measured from the anterior-posterior view of preoperative chest radiograph. After the tube was positioned in the main bronchus, a fiberoptic bronchoscope was introduced into the tracheal lumen to ensure the appropriate position of the DLET. Simple regression analysis for the insertion depth of the DLETs and Dc-c was performed. Results: There was a highly significant correlation between the insertion depth of the DLET and both the Dc-c (y = 0.5304x + 19.646) and the body height (y = 0.1022x + 10.525), with P < 0.001 and P < 0.01, respectively. Conclusions: To get the distance from the cephalic edge of the 6th cervical vertebra to the Dc-c from the chest radiograph preoperatively would be helpful for the evaluation of the proper insertion depth of the placement of DLET.