what is the number of hours since patient 76332 received the last vancomycin hcl prescription during the current hospital encounter?
select 24 * ( strftime('%j',current_time) - strftime('%j',prescriptions.startdate) ) from prescriptions where prescriptions.hadm_id in ( select admissions.hadm_id from admissions where admissions.subject_id = 76332 and admissions.dischtime is null ) and prescriptions.drug = 'vancomycin hcl' order by prescriptions.startdate desc limit 1