On the dynamic performance of the Abbott Safeset (TM) blood-conserving arterial line system

Objective. Critically ill patients frequently have indwelling arterial line s placed during their Intensive Care Unit stay. The lines are used to monit or blood pressure continuously, administer drugs and to draw blood for a va riety of physiologic tests. Several blood-conserving arterial line systems have been developed to eliminate the need to discard blood in the process o f obtaining undiluted and uncontaminated blood samples. The purpose of this study was to evaluate the dynamic performance of one such system - the Abb ott Clinical Care System Safeset(TM) blood conserving arterial line system - in comparison to a conventional arterial line system. Methods. We studied ninety-nine patients who had indwelling arterial lines placed during surge ry and who were admitted to our Surgical Intensive Care Unit (SICU). The pa tients were randomly placed into one of two groups. The control group recei ved a conventional indwelling arterial line system; the experimental group received the Abbott Safeset(TM) system. We measured the damping coefficient and resonant frequency daily in order to evaluate and compare the dynamic performance of the two systems. We also measured discard volumes (in the co ntrol group) and blood sample sizes during the patients' stays in the SICU. Results. The two patient groups were similar in regards to demographics an d baseline clinical characteristics. A median 3 ml of blood per draw and 17 .5 ml of blood per patient was discarded in purging the conventional arteri al line system while, by design, no blood was discarded with the experiment al system. There was no difference between the two groups with regard to da mping coefficient. Both systems were underdamped. However, the conventional arterial line system had a significantly higher resonant frequency (16.7 H z) compared to the Safeset(TM) system (12.5 Hz). Conclusions. Because the A bbott Safeset(TM) blood-conserving arterial line system is underdamped and has a lower resonant frequency compared to the traditional arterial system, it may overestimate systolic blood pressure, particularly in patients with high heart rates.