小儿气道困难课件.ppt

In contrast to adults,most children with difficult airways are recognised　before induction of anaesthesia. The choice of the LMA is based on the lean body weight of the child.It is common to inflate the cuff partly during insertion. The estimated size of the endotracheal tube can be chosen from a table and compared with the distal phalanx of the fifth finger of the child, which often correlates well with the tube size. From the age of 2 years, the formula Tube size=4+(age/4), may be used as guidance. If cuffed tubes are used, the formula is changed to 3.5+(age/4). The first flexible pediatric bronchoscopy was described by Wood in 1978.Fibreoptic bronchoscopes small enough for use in infants and children became widely available in 1981. Monitoring of heart rate, respiration and oxygen saturation is mandatory.Breath sounds can be monitored using a precardial stethoscope. Continuous end-tidal carbon dioxide(CO2) The first flexible pediatric bronchoscopy was described by Wood in 1978.Fibreoptic bronchoscopes small enough for use in infants and children became widely available in 1981. The first flexible pediatric bronchoscopy was described by Wood in 1978.Fibreoptic bronchoscopes small enough for use in infants and children became widely available in 1981. 据统计由LMA 引导的FOB 插管成功率在90 %～100 % ,明显高于经LMA 的直接盲探插管。操作可在保证建立供氧 通道下进行,软组织损伤小,能准确定位插管位置,并发症少。 以往上感患儿进行术前评估时,麻醉医师会建议延迟手术至症状消失,以降低围术期气道并发症的发生率。 喉罩能方便置入并维持稳定可靠的气道,避免反复多次插管造成的损伤及气道并发症 LMA组气道高敏反应和并发症的发生率低。 喉痉挛发生的危险因素主要有三类：患者相关的、手术相关的和麻醉相关 最重要的麻醉相关因素就是麻醉过浅，拔管时麻醉过浅的患者容易诱发喉痉挛，任何浅麻醉下的刺激诸如疼痛、颈椎移位和放置鼻胃管也会诱发喉痉挛，吸入麻醉药对声带的刺激、分泌物、粘液、血液、喉镜片、吸引管都可能诱发喉痉挛的发生。麻醉医生经验不足、多次插管操作和喉罩操作也会增加喉痉挛的发生率。 气道手术包括支气管镜都有较高的喉痉挛的发生率。扁桃体和增殖腺切除手术的喉痉挛发生率为21-27% 年龄，并发上呼吸道感染的患者发生喉痉挛的比率增加2.3-5倍。吸烟的年轻人也更易发生喉痉挛，气道反应性过高的被动吸烟者和儿童，包括哮喘者，易感率为正常人的10倍。其他影响因素包括ASAIV级、1岁以内的早产儿、百日咳、阻塞性睡眠呼吸暂停、肥胖、呼吸道异常、胃食管反流性疾病、悬雍垂过长和睡眠中气哽病史。电解质紊乱如低镁低钙也可能诱发喉痉挛 气道管理包括维