动态量化通气指标评估老年患者右双腔支气管导管管端位置

Estimation of the position of right-sided double-lumen endobronchial tubes with spirometry in elderly patients

目的探讨吸气峰压(Ppeak)、肺顺应性数值(Cdyn)变化的量化指标和肺顺应性环的改变评估老年患者无隆突钩右双腔支气管导管(DLT)管端位置的准确性。方法96例行胸科手术老年患者根据回归方程计算的插管深度插入Mallinckrodt右DLT,在单肺通气(OLV)时出现Ppeak超过双肺通气(TLV)的1.5倍,Cdyn低于TLV的0.5倍,且Ppeak超过22cmH2O共22例。在TLV15min后(S1),右侧OLV5min(S2),以纤维支气管镜(FOB)观察并调整管端至正确位置,右侧OLV15min(S3)。结果FOB发现19例DLT管端位于右中间支气管,3例管端进入右下肺支气管,需退出0.5～1.9cm。S2OLV后124±39s患者脉搏血氧饱和度(SpO2)开始下降。S2的Ppeak比S1增加91.0%,S3比S1仅增加43.4%;S2的Cdyn比S1减少62.7%,S3比S1仅减少33.6%。S2的压力-容量环曲线斜率向右明显移位,流速-容量环体面积减少。结论老年患者单肺通气时采用上述量化指标,在SpO2下降前以FOB观察调整DLT管端位置,使FOB的应用时机提前。

Objective To study the accuracy of position estimation of fight-sided double-lumen endobronchial tubes （DLTs） without carinal hook in elderly patients according to the changes of inspiratory peak airway pressure （Ppeak）, lung compliance （Cdyn）, pressure-volume loop （P-V loop）, and flow-volume loop （F-Vloop）. Methods Ninety-six elderly patients undergoing thoracic surgery were intubated with fight-sided Mallinckrodt DLTs, the depth of which was determined based on the regressive equation. After 15 min of two lung ventilation （TLV）, the Ppeak showed a more than 50% increase from the baseline in 22 patients when switching to one lung ventilation （OLV） with Cdyn less than 50% of the baseline and Ppeak in excess of 22 cmH2O. In these 22 cases, the position of the DLT was determined by fiberoptic bronchoscope （FOB） and adjusted to the precise position at 15 min of OLV. Results DLTs were inserted into the fight middle bronchi in 19 cases and the fight lower lobe bronchi in 3 cases. At 124±39 s after OLV, the SpO2 began to decrease, and the Ppeak of OLV increased by 91.0% and Cdyn decreased by 62.7%. The slope of P-V curve was reduced and the P-V loop extended, with reduced increment of the expiratory limb and the area of the F-V loop, so that the tips of the DLT were withdrawn by 0.5 to 1.9 cm. The Ppeak of OLV increased only by 43.4% when DLT was in correct position, and was Cdyn decreased by 33.6% （P〈0.01）. Conclusion When changes of Ppeak and Cdyn in excess of above guidelines occurs after switching from TLV to OLV in the elderly patients, FOB should be applied to determine the tip position of DLT before SpO2 reduction takes place.