how many times did patient 17638 receive insert endotracheal tube in the first hospital encounter.
select count(*) from procedures_icd where procedures_icd.icd9_code = ( select d_icd_procedures.icd9_code from d_icd_procedures where d_icd_procedures.short_title = 'insert endotracheal tube' ) and procedures_icd.hadm_id in ( select admissions.hadm_id from admissions where admissions.subject_id = 17638 and admissions.dischtime is not null order by admissions.admittime asc limit 1 )