不同头颈位对LMA-Supreme^(TM)间歇正压通气时口咽漏气压的影响

Influence of head and neck position on oropharyngeal leak pressure with LMA-Supreme^(TM) during intermittent positive pressure ventilation

目的评价不同头颈位对LMA-SupremeTM(SLMA)间歇正压通气时口咽漏气压(OLP)的影响。方法妇科全麻手术患者60例,麻醉诱导后插入SLMA行间歇正压通气,设定喉罩气囊压(ICP)为60 cm H2O。喉罩插入即刻,机械通气后60 min分别测量正中位、前屈位、旋转位、后仰位四个头颈位时的OLP和ICP。统计各头颈位正压通气时漏气率。分别在四个头颈位通过引流管插入润滑后的胃管,记录胃管插入成功率并经通气导管插入纤维支气管镜(FOB),采用FOB分级法评价喉罩解剖位置。结果喉罩置入即刻和机械通气后60 min的OLP,前屈位>正中位>后仰位,旋转位与正中位比较无明显差异(P<0.05)。ICP在前屈位大于正中位,后仰位小于正中位,旋转位与正中位比较无明显差异。各种头颈位下患者喉罩解剖位置FOB分级无差异;前屈位时胃管插入成功率低于其他头颈位。结论头前屈位可改善SLMA气道密闭性,适度前屈患者头部是改善SLMA正压通气效果的有效方法。相对于正中位,旋转位不影响SLMA通气效果,而后仰位降低SLMA气道密闭性。

Objective To evaluate the influence of head and neck position on oropharyngeal leak pressure with LMA-SupremeTM during intermittent positive pressure ventilation.Methods Sixty anaesthetized adult female patients were studied.The laryngeal mask airway was inserted into each patient and the cuff was inflated to an intra-cuff pressure（ICP）of 60cm H2O.The oropharyngeal leak pressure（OLP）,intra-cuff pressure,and leakage rate were determined at four different head and neck position（neutral,flexion,rotation and extension） at the time after the insertion and 60min after operation.Also,the anatomical position of the airway tube and drainage tube were also documented.Results Compared with the neutral position,the oropharyngeal leak pressure and intracuff pressure were higher in flexion,but lower in extension in 0 and 60min.Changes in head and neck position did not alter the anatomical position of the airway tube,but the drainage rate was lower in extension than the others.Conclusion Head flexion can improve airway sealing.Appropriate head flexion is an effective way to improve positive pressure ventilation.Caution should be warranted when using LMA-SupremeTM in extension as airway sealing is decreased in this position.