how many hours have passed since patient 17667 stayed during their current hospital encounter in the careunit micu for the last time?
select 24 * ( strftime('%j',current_time) - strftime('%j',transfers.intime) ) from transfers where transfers.hadm_id in ( select admissions.hadm_id from admissions where admissions.subject_id = 17667 and admissions.dischtime is null ) and transfers.careunit = 'micu' order by transfers.intime desc limit 1