El-Khatib Mohamad F, Jamaleddine Ghassan W
Department of Anesthesiology, School of Medicine, American University of Beirut, PO Box 11-0236, Riad El Solh, Beirut 1107 2020, Lebanon.
Chest. 2004 Feb;125(2):592-6. doi: 10.1378/chest.125.2.592.
To assess the reliability of new and traditional oxygenation measurements in reflecting intrapulmonary shunt.
Prospective study.
Cardiac surgery unit at a university hospital.
Fifty-five patients undergoing coronary artery bypass grafting.
Simultaneous blood samples were collected from an indwelling arterial line and a catheter for determination of blood gases. Standard accepted formulas were utilized to measure a new oxygenation index: PaO(2)/fraction of inspired oxygen (FIO(2)) x mean airway pressure (Paw). The standard formulas used were the oxygenation ratio (PaO(2)/FIO(2)), PaO(2)/alveolar partial oxygen pressure (PAO(2)), alveolar-arterial oxygen tension gradient (P[A-a]O(2)), and intrapulmonary shunt (venous admixture [Qsp/Qt]). There were significant negative (p < 0.05) correlations between the PaO(2)/(FIO(2) x Paw) and Qsp/Qt (r = - 0.85), between the PaO(2)/FIO(2) and Qsp/Qt (r = - 0.74), and between the PaO(2)/PAO(2) and Qsp/Qt (r = - 0.71). There was a significant positive (p < 0.05) correlation between the P(A-a)O(2) gradient and Qsp/Qt (r = 0.66). However, the correlation was strongest between the PaO(2)/(FIO(2) x Paw) and Qsp/Qt.
In this group of patients, PaO(2)/(FIO(2) x Paw) might be more reliable than other oxygenation measurements in reflecting intrapulmonary shunt.
评估新型和传统氧合测量方法在反映肺内分流方面的可靠性。
前瞻性研究。
一所大学医院的心脏外科病房。
55例接受冠状动脉旁路移植术的患者。
从留置动脉导管和一根导管同时采集血样以测定血气。采用标准公认公式测量一种新型氧合指数：动脉血氧分压（PaO₂）/吸入氧分数（FIO₂）×平均气道压（Paw）。所使用的标准公式包括氧合比（PaO₂/FIO₂）、PaO₂/肺泡氧分压（PAO₂）、肺泡 - 动脉氧分压差（P[A - a]O₂）以及肺内分流（静脉血掺杂[Qsp/Qt]）。PaO₂/（FIO₂×Paw）与Qsp/Qt之间存在显著负相关（p < 0.05）（r = - 0.85），PaO₂/FIO₂与Qsp/Qt之间存在显著负相关（r = - 0.74），PaO₂/PAO₂与Qsp/Qt之间存在显著负相关（r = - 0.71）。P(A - a)O₂梯度与Qsp/Qt之间存在显著正相关（p < 0.05）（r = 0.66）。然而，PaO₂/（FIO₂×Paw）与Qsp/Qt之间的相关性最强。
在这组患者中，PaO₂/（FIO₂×Paw）在反映肺内分流方面可能比其他氧合测量方法更可靠。
