THU120 Validation Of A Novel Automated System, Fluispotter®, For Serial Sampling Of Dried Blood Spots

Disclosure: J. Krogh: None. P. Plomgaard: None. R. Frikke-Schmidt: None. S. Velschow: None. J. Johannesen: None. L. Hilsted: None. M. Schrøder: None. U. Feldt-Rasmussen: None. Repeated blood sampling is required in certain clinical and research settings, which is currently performed by drawing blood from venous catheters requiring manual handling of each sample at time of collection. Collecting samples in a stressful environment, e.g. during the night or admission as inpatient to hospital potentially influences the hormone concentrations to be studied. The hypothesis of this study was that a novel body-worn device for repeated serial samples, Fluispotter®, with automated extraction, collection and storage of up to 20 venous dried blood spot samples over the course of 20 hours may overcome problems with current methods for serial sampling. The purpose of the study was to assess the performance and safety of Fluispotter for the first time in healthy subjects and perform cortisol measurements from the blood spots by mass spectrometry. Fluispotter consists of a cartridge with tubing, reservoir for flushing solution, pumps and filter-paper and a multi-lumen catheter placed in the brachial vein. We recruited healthy subjects for testing in an in-hospital setting. Fluispotter was attached to 22 healthy subjects of which 9/22 (40.9 %) participants had all 20 samples taken, which was lower than the expected 80% (p = 0.02). The main reason for sample failure was clogging of blood flow which was observed in 11/22 (50 %) of the participants. No serious adverse events occurred, and the participants rated the pain from insertion and removal of catheter as very low. A cortisol profile showed nadir values at midnight and highest values at 5 a.m. Although full sampling was not successful in all participants, the Fluispotter technology proved safe and highly acceptable to the participants producing the expected cortisol profile in an undisturbed environment without the requirement of staff during sample collection. The minor technical problems of blood clotting can be solved by increasing the flow of the rinsing fluid between samples. The Fluispotter may thus facilitate future circadian hormone assessments e.g. in patients on pituitary cortisol replacement with a perspective of improving management of patients with pituitary insufficiency. Presentation: Thursday, June 15, 2023