Differences in PO 2 and PCO 2 between arterial and arterialized earlobe samples. A. Sauty, C. Uldry, L-F. Debétaz, P. Leuenberger, J-W. Fitting. ©ERS Journals Ltd 1996. ABSTRACT: Arterialized ear lobe blood samples have been described as adequate to gauge gas exchange in acute and chronically ill patients. It is a safe procedure, usually performed by medical technicians. We have conducted a prospective study to verify the validity of this method.One hundred and fifteen consecutive adult patients were studied. Blood samples were drawn simultaneously from arterialized earlobe and radial artery. Values of partial pressure of oxygen (PO 2 ) and of carbon dioxide (PCO 2 ) were measured by means of blood gas electrodes.The correlation coefficients between the two samples were 0.928 for PO 2 and 0.957 for PCO 2 values. In spite of a highly significant correlation, the limits of agreement between the two methods were wide for PO 2 . Earlobe values of PO 2 were usually lower than arterial values, with larger differences in the range of normal arterial PO 2 . On the other hand, the error and the limits of agreement were smaller for PCO 2 .We conclude that, in adult patients, arterialized earlobe blood PO 2 is not a reliable mirror of arterial PO 2 . Eur Respir J., 1996, 9: 186-189 Blood gas values can be measured using arterialized earlobe blood samples, instead of arterial samples, in order to gauge pulmonary gas exchange in acute or chronically ill patients. This method, described many years ago [1], is a simple and safe procedure which can be performed by medical technicians. Comparing values for partial pressure of oxygen (PO 2 ) and of carbon dioxide (PCO 2 ) from arterialized earlobe blood samples with arterial blood samples, several authors have concluded that the earlobe site was suitable for routine clinical purposes [1][2][3][4][5][6][7][8][9]. This idea was again advocated by two recent studies. PITKIN et al. [10] compared PO 2 , PCO 2 , and pH values from 40 blood samples simultaneously drawn from the radial artery and hyperaemic earlobe. Using the method of BLAND and ALTMAN [11] for the assessment of agreement, these authors also concluded that arterialized earlobe blood gas values were accurate enough to be used in clinical application. Finally, DAR et al. [12] reported that earlobe sampling was significantly less painful than arterial sampling in 55 patients, whereas blood gas values were not different with the two techniques.For several years, the arterialized earlobe technique has been the standard practice for measuring arterial blood gases in our pulmonary function laboratory. However, in some instances, we have noticed a marked discrepancy between arterial and relatively lower arterialized earlobe values of PO 2 . We, therefore, conducted a prospective study to compare arterial and arterialized earlobe blood samples in 115 consecutive adult patients. Material and methodsOur study group included 115 consecutive adult patients investigated in our pulmonary function laboratory for various conditions. No...

Between 1979 and 1984, 321 patients received 354 St. Jude Medical prostheses (194 aortic, 94 mitral, 1 tricuspid, and 32 multiple valve replacements). Follow-up was 96% complete (2967 patient-years; mean 9.5 years per patient). Actuarial event-free rates at 10 years and linearized rates (in parentheses) of late complications were as follows: embolism, 85.0% +/- 2.3% (2.3% per patient-year); anticoagulant-related hemorrhage, 74.8% +/- 2.7% (3.3% per patient-year); cerebrovascular accident, 81.8% +/- 2.5% (2.6% per patient-year); prosthesis thrombosis, 98.5% +/- 0.7% (0.1% per patient-year); endocarditis, 97.2% +/- 1.1% (0.4% per patient-year); prosthesis dysfunction, 97.1% +/- 1.0% (0.4% per patient-year); hemolytic anemia, 98.5% +/- 0.7% (0.1% per patient-year); reoperation, 97.4% +/- 1.0% (0.4% per patient-year); overall mortality, 63.3% +/- 2.7% (4.2% per patient-year); and valve-related death (including sudden death), 84.7% +/- 2.2% (1.4% per patient-year). Independent preoperative risk factors were as follows: (1) for embolism, cardiac failure as indication for operation and history of prior systemic embolism; (2) for cerebrovascular accidents, the same two factors and age; (3) for endocarditis, diabetes, chronic alcoholism, and aortic valve replacement; (4) for overall mortality, age, ejection fraction (or cardiac index or cardiothoracic index), chronic alcoholism, and history of systemic embolism; and (5) for valve-related death, chronic alcoholism, degenerative cause of valve disease, and prosthetic diameter 23 mm or smaller. Ninety percent of survivors were in New York Heart Association functional class I or II at the end of follow-up. In conclusion, this study confirms the excellent durability of the St. Jude Medical valve and the remarkable functional benefit for the majority of the patients. However, prosthesis-related complications are still common, particularly for small-diameter prostheses. Outcome is strongly related to the patient's preoperative cardiac condition and to the adequacy of anticoagulation control.