what was the total amount of protonix of patient 15794 that had received on the current icu visit?
select sum(inputevents_cv.amount) from inputevents_cv where inputevents_cv.icustay_id in ( select icustays.icustay_id from icustays where icustays.hadm_id in ( select admissions.hadm_id from admissions where admissions.subject_id = 15794 ) and icustays.outtime is null ) and inputevents_cv.itemid in ( select d_items.itemid from d_items where d_items.label = 'protonix' and d_items.linksto = 'inputevents_cv' )