Adrenal Vein Sampling in a Patient With Primary Hyperaldosteronism and Severe Contrast Allergy.

We report on a case of a 50-year-old female patient with primary hyperaldosteronism, in whom adrenal venous sampling was required to differentiate between unilateral and bilateral disease. Because of a history of severe allergy to iodinated contrast media, premedication with glucocorticoids was indicated. Exogenous glucocorticoids, however, can affect measurements of serum cortisol. To avoid this potential confounding effects on the cortisol assay, we decided to use dexamethasone instead of prednisolone or hydrocortisone. A high-dose adrenocorticotropin (ACTH) stimulation test with the simultaneous use of dexamethasone revealed an adequate adrenal cortisol response. ACTH-stimulated adrenal venous sampling showed reliable results, which provided a solid basis for further clinical decision-making.

Validation of the blood gas analyzer for pH measurements in IVF culture medium: Prevent suboptimal culture conditions.

Measurement of pH in IVF-media using the blood gas analyzer (BGA) requires validation, because IVF-media is outside the intended scope of the BGA. To determine whether the Siemens Rapidpoint 500 BGA is suitable for pH measurements in IVF-media this study will validate the BGA and assess its accuracy. In this method comparison study, the pH of over three hundred IVF-media samples was measured with the BGA and a pH electrode (Hanna pH checker). The precision of both the BGA and the pH electrode were excellent (coefficient variation <1.4%). However, the closeness of agreement between measured values of both devices were not equivalent to each other in the tested IVF-media, showing 15% to 85% accordance between devices. The pH measured with the blood gas analyzer was also significantly higher in the tested media, compared to that measured by the pH electrode. One of the tested media did not reach its target pH when it was measured with the BGA, even at 9% CO2. The results show that the validated blood gas analyzer produces excellent results in terms of precision but not in terms of accuracy. Inaccurate measurement may lead to misinterpretation of results and consequently to suboptimal culture conditions. Therefore, each laboratory is encouraged to perform a validation of their BGA.