BACKTRACKING SERUM LITHIUM .2. CLINICAL VALIDATION OF THE LITHIUM ION-SELECTIVE ELECTRODE ANALYZER (LI-ISE)

The lithium ion-selective electrode (Li-ISE) provides a means of rapid analysis of blood lithium in the lithium clinic in the presence of th e patient and increases the capability of the physician to manage the treatment. With accurate and up-to-the-minute information both patient and physician are motivated to maintain the progress of the therapy. One further improvement may be to 'backtrack' the blood lithium concen tration to a standard '12 hour Standard Lithium level' and the advent of the Li-ISE makes this a useful and realistic possibility. In this p aper we validate the use of the Li-ISE in studies carried out in perip heral psychiatric clinics and also in a large-scale pharmacokinetic tr ial. Both studies afforded us the opportunity to analyse a large numbe r of blood samples both by Li-ISE and by standard Atomic Absorption an d Flame Emission Spectroscopic techniques. We confirm that there is su bstantially no difference between the techniques in terms of accuracy and that the Li-ISE technique is suitable for routine clinical monitor ing of patients receiving lithium prophylaxis.