whats patient 3229 minimum arterial bp mean on the first icu visit?
select min(chartevents.valuenum) from chartevents where chartevents.icustay_id in ( select icustays.icustay_id from icustays where icustays.hadm_id in ( select admissions.hadm_id from admissions where admissions.subject_id = 3229 ) and icustays.outtime is not null order by icustays.intime asc limit 1 ) and chartevents.itemid in ( select d_items.itemid from d_items where d_items.label = 'arterial bp mean' and d_items.linksto = 'chartevents' )