how many times has patient 1561 recieved a .45% normal saline intake on the last hospital encounter?
select count(*) 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 = 1561 and admissions.dischtime is not null order by admissions.admittime desc limit 1 ) ) and inputevents_cv.itemid in ( select d_items.itemid from d_items where d_items.label = '.45% normal saline' and d_items.linksto = 'inputevents_cv' )