Stein P D, Goldhaber S Z, Henry J W, Miller A C
Henry Ford Heart and Vascular Institute, Detroit, MI, USA.
Chest. 1996 Jan;109(1):78-81. doi: 10.1378/chest.109.1.78.
The utility of arterial blood gas levels in excluding the diagnosis of acute pulmonary embolism (PE) was evaluated.
Data are from the Prospective Investigation of Pulmonary Embolism Diagnosis (PIOPED). PE was diagnosed or excluded by pulmonary angiography. Among 330 patients with no prior cardiopulmonary disease, 130 patients had PE and 200 did not. Among 438 patients with prior cardiopulmonary disease, 147 had PE and 291 did not. Definitions were low PaO2 (< 80 mm Hg), low PaCO2 (< 35 mm Hg), and high alveolar-arterial oxygen gradient (P(A-a)O2 [> 20 mm Hg]).
Among patients with no prior cardiopulmonary disease who had values of the PaO2 and PaCO2 that were not low and a P(A-a)O2 that was normal, 16 of 42 or 38% (95% confidence interval [CI] = 24 to 54%) had PE. Among patients with prior cardiopulmonary disease who had PaO2 and PaCO2 values that were not low and a P(A-a)O2 that was normal, 4 of 28 or 14% (95% CI = 4 to 33%) had PE. Other combinations of blood gas levels and the P(A-a)O2 gradient, failed to exclude PE in larger percentages of patients.
With various combinations of the PaO2 of 80 mm Hg or more, the PaCO2 of 35 mm Hg or higher, and the P(A-a)O2 gradient of 20 mm Hg or less, PE could not be excluded in more than 30% of patients with no prior cardiopulmonary disease and PE could not be excluded in more than 14% of patients with prior cardiopulmonary disease. Blood gas levels, therefore, are of insufficient discriminant value to permit exclusion of the diagnosis of PE.
评估动脉血气水平在排除急性肺栓塞（PE）诊断中的作用。
数据来自肺栓塞诊断前瞻性研究（PIOPED）。通过肺血管造影诊断或排除PE。在330例无既往心肺疾病的患者中，130例患有PE，200例未患。在438例有既往心肺疾病的患者中，147例患有PE，291例未患。定义为低氧分压（<80 mmHg）、低二氧化碳分压（<35 mmHg）和高肺泡-动脉氧梯度（P(A-a)O2 [>20 mmHg]）。
在无既往心肺疾病且氧分压和二氧化碳分压值不低、肺泡-动脉氧梯度正常的患者中，42例中有16例（38%，95%置信区间[CI]=24%至54%）患有PE。在有既往心肺疾病且氧分压和二氧化碳分压值不低、肺泡-动脉氧梯度正常的患者中，28例中有4例（14%，95%CI=4%至33%）患有PE。血气水平和肺泡-动脉氧梯度的其他组合未能排除更大比例患者的PE。
对于氧分压80 mmHg或更高、二氧化碳分压35 mmHg或更高以及肺泡-动脉氧梯度20 mmHg或更低的各种组合，在无既往心肺疾病的患者中，超过30%无法排除PE；在有既往心肺疾病的患者中，超过14%无法排除PE。因此，血气水平的鉴别价值不足以排除PE的诊断。
