is the potassium of patient 51858 last measured on the current hospital visit less than the value second to last measured on the current hospital visit.
select ( select labevents.valuenum from labevents where labevents.hadm_id in ( select admissions.hadm_id from admissions where admissions.subject_id = 51858 and admissions.dischtime is null ) and labevents.itemid in ( select d_labitems.itemid from d_labitems where d_labitems.label = 'potassium' ) order by labevents.charttime desc limit 1 ) < ( select labevents.valuenum from labevents where labevents.hadm_id in ( select admissions.hadm_id from admissions where admissions.subject_id = 51858 and admissions.dischtime is null ) and labevents.itemid in ( select d_labitems.itemid from d_labitems where d_labitems.label = 'potassium' ) order by labevents.charttime desc limit 1 offset 1 )