死腔、肺内分流及气体交换对肺栓塞辅助诊断价值的研究

The investigation of the adjuvant diagnosis value of dead space,shunt and gas exchange in pulmonary thromboembolism

目的研究肺栓塞(PTE)的死腔(VD/VT)、肺内分流(QS/QT)及气体交换的变化特点,探讨其临床意义。方法对22例PTE患者(PTE组)、39例非PTE患者(非PTE组)及25例健康者(对照组)进行了研究。PTE组男13例、女9例,年龄52±10岁。非PTE组男23例、女16例,年龄56±17岁。选择25例健康者作对照组,男17例、女8例,年龄46±15岁。对PTE组急性期、恢复期,非PTE组及对照组的VD/VT、潮气末二氧化碳分压(ETCO2)、动脉血肺泡气二氧化碳分压差(P(aA)CO2)、动脉血二氧化碳分压(PaCO2)、QS/QT、肺泡气动脉血氧分压差(P(Aa)O2)及动脉血氧分压(PaO2)进行了测定。结果研究发现PTE组急性期VD/VT明显增大,而ETCO2及PaCO2则下降,与非PTE组及对照组相比有显著性差异(P均<0.01);P(aA)CO2增大,但与非PTE组及对照组相比无显著性差异(P均>0.05);QS/QT及P(Aa)O2明显增大,而PaO2明显下降,与非PTE组及对照组相比有显著性差异(P均<0.01)。研究还显示,PTE组恢复期的VD/VT、ETCO2、P(aA)CO2、PaCO2、QS/QT、P(Aa)O2及PaO2均较急性期明显恢复好转(P均<0.01),但是P(Aa)O2及PaO2水平仍然分别高于和低于对照组(P均<0.01)。结论作为无创手段VD/VT及ETCO2具有辅助评价可疑肺栓塞的意义,如结合其它无创手段则更能加强彼此间的辅助诊断价值。同时提示VD/VT、ETCO2、QS/QT及其它气体交换指标可用于监测PTE临床症状的变化。

Objective To investigate the characteristics of dead space（VD/VT）, pulmonary shunt fraction（QS/QT ）, gas exchange in pulmonary thromboembolism （PTE） and evaluate their clinical implications. Methods Twenty-two patients with PTE （PTE group） and 39 without PTE （non PTE group） underwent the study. PTE group included 13 male and 9 female patients, with an age of 52 ± 10 years. Non-PTE group included 23 male and 16 female patients, with an age of 56 ± 17 years. The control group comprised 25 healthy subjects, male 17 and female 8, with an age of 46±15 years. VD/VT ,end-tidal CO2 （ET-CO2）,arterial-alveolar CO2 gradient （P（a-A）CO2 ）, carbon dioxide partial pressure in arterial blood （PaCO2）, QS/QT, alveolar-arterial O2 gradient （P（A-a）O2 ）, oxygen partial pressure in arterial blood （PaO2） were obtained and recorded at both acute and remissive stages in two groups. Results The results showed that VD/VT increased and ET-CO2 and PaCO2 declined significantly in patients with PTE at acute stage, compared with non-PTE group and the controls（all P 〈0.01）. Although P（a-A）CO2 increased in PTE group at acute stage compared with non-PTE group and the controls, the difference was not significant （8.13 ± 5.64 vs 6.25±4.71 mmHg, P 〉0.05）. Furthermore,QS/QT and P（A-a）O2 also enhanced and PaO2 decreased significantly in patients with PTE at acute stage compared with non-PTE group and the controls （all P 〈 0.01）. The study also demonstrated that all VD/VT, ET-CO2, P（a-A）CO2, PaCO2, QS/QT, P（A-a） O5 and PaO2 were improved significantly in patients with PTE at remissive stage compared with those at acute stage （all P〈0.01）. However P（A-a）O2 and PaO2 were still abnormal in patients with PTE at remissive stage compared with the controls （ P 〈 0. 01, 0. 01 ）. Conclusions The study demonstrated the ability of VD / VT and ET-CO2 to evaluate and potentially noninvasively diagnose PTE in combination with other techniques. The results also indicated potential utility of VD/VT ,ET-CO2, QS/QT and parameters described as above to imply and monitor the clinical situation of PTE.