how much hydromorphone (dilaudid) has been prescribed in their first hospital encounter to patient 26995 overall?
select sum(prescriptions.dose_val_rx) from prescriptions where prescriptions.hadm_id in ( select admissions.hadm_id from admissions where admissions.subject_id = 26995 and admissions.dischtime is not null order by admissions.admittime asc limit 1 ) and prescriptions.drug = 'hydromorphone (dilaudid)'