呼吸对全腔肺动脉吻合术后肺循环血流的影响

Influence of respiration on pulmonary blood flow patterns after total cavopulmonary anastomosis

目的 探讨呼吸对全腔肺动脉吻合术后肺循环血流的影响。 方法 对 15例全腔肺动脉吻合术后的患儿进行超声检查 ,观察在静息及深呼吸条件下肺循环血流的变化特征。 结果 应用外管道的患儿 ,静息状态下 ,肺动脉为持续性前向血流 ,血流速为 (38 0± 2 3)cm/s ;深吸气时前向流速增大为 (6 7 0± 3 5 )cm/s;深呼气时前向流速减小为 (2 6 0± 2 3)cm/s,与静息状态时相比 ,差异均有极显著性意义 (P <0 0 1)。应用内隧道的患儿 ,其肺动脉血流同时要受心动周期的影响 ,静息状态下 ,上腔静脉为持续性血流 ,血流速为 (4 2 0± 2 1)cm/s;深吸气时流速增大为 (71 0± 4 3)cm/s;深呼气时流速减小为 (2 1 0± 1 0 )cm/s ,与静息状态时相比 ,差异均有极显著性意义 (P <0 0 1) ,且无反向血流。应用人工血管外管道的患儿 ,吸气时 ,下腔静脉为峰值 (37 0± 2 3)cm/s的前向血流 ,呼气时为峰值 (33 0± 1 7)cm/s的反向血流 ;应用带瓣的同种血管外管道的患儿 ,吸气时下腔静脉为峰值 (4 7 0± 1 9)cm/s的前向血流 ,呼气时无前向流 ,且无明显反向血流。 结论 呼吸是全腔肺动脉吻合术后肺循环的另一能量来源 ;

Objective To determine whether respiration influences the pulmonary blood flow in patients after total cavopulmonary anastomosis (TCPA). [WT5”HZ]Methods[WT5”BZ] Doppler echocardiography was employed to assess superior vena cava (SVC), inferior vena cava (IVC) and pulmonary artery blood flow patterns at rest and during deep respiration in 15 children after TCPA for treatment of complex heart malformation. [WT5”HZ]Results[WT5”BZ] For patients with extracardiac conduit, the pulmonary artery blood flow pattern was continuous forward flow. Deep inspiration resulted in an increase in peak forward flow velocity from (38 0±2 3) cm/s to (67 0±3 5) cm/s ( P <0 01) and deep expiration a decrease in the peak velocity from (38 0±2 3) cm/s to (26 0±2 3) cm/s ( P <0 01). For patients with intra arterial tunnel, the pulmonary artery blood flow pattern was mainly affected by cardiac cycle. For all the 15 patients, blood flow of SVC was continuous with a velocity of (42 0±2 1) cm/s. During deep inspiration, the flow velocity was increased to (71 0±4 3) cm/s ( P <0 01. The forward flow velocity was reduced to (21 0±1 0) cm/s during deep expiration ( P <0 01). For non valved extracardiac conduit TCPA, the flow in IVC was forward flow with a velocity of (37 0±2 3) cm/s during inspiration and there was an obvious reversal flow with a peak velocity of (33 0±1 7) cm/s during expiration. For valved conduit TCPA, the flow in IVC was forward flow with a peak velocity of (47 0±1 9) cm/s during inspiration but there were no forward flow and reversal one during expiration. [WT5”HZ]Conclusions[WT5”BZ] Respiration is another origin of energy supply for pulmonary circulation after TCPA because it can enhance forward flow for pulmonary circulation. The valved conduit can prevent retrograde flow in IVC, which is beneficial to the recovery of patients.