Detection of disturbances in pulmonary gas exchanges during exercise from arterialized earlobe PO2

作者：Aguilaniu Bernard^*; Maitre Jocelyne; Diab Samia; Perrault Helene; Peronnet Francois

来源：Respiratory Physiology & Neurobiology, 2011, 177(1): 30-35.

DOI：10.1016/j.resp.2011.03.005

• Exercise testing
• Arterialized blood gas
• Alveolar-capillary oxygen gradient
• pH
• Bayes theorem

Blood sampling from the arterialized earlobe is widely used in clinical exercise testing but Fajac et al. (1998) (Eur. Respir. J. 11,712-715) have shown that arterialized P-O2(Pc-CO2) is not a valid surrogate for Pa-O2. In the present study, in order to detect disturbances in pulmonary gas exchanges during clinical exercise testing from the alveolar-arterial gradient of P-O2 (P[Ai-a](O2)), a correction factor for Pc-O2 was validated from data on a large cohort (107 patients at one or two levels of exercise: 172 pairs of samples). Pulmonary gas exchanges and pH, P-O2, P-CO2, PA(iO2) and P(Ai-a)(O2) from arterial and arterialized blood were measured or computed. Arterial and arterialized pH and P-CO2 (and thus PA(iO2)) were similar but Pc-O2 was lower than arterial P-O2 (Pa-O2). However, when corrected for the systematic bias between Pao, and Pc-O2. which increased with Pc-O2, Pc-O2 adequately detected disturbances in pulmonary gas exchanges with a very high sensibility and specificity (predictive values of a negative or positive test similar to 95%).

• 出版日期2011-6-30