ในการเข้ารับการรักษาในห้องไอซียูปัจจุบัน คนไข้ 021-111547 วัดการหายใจครั้งสุดท้ายเมื่อใด?ไม่จำเป็นต้องใช้ตารางทั้งหมด
on the current icu visit, when was the last time that patient 021-111547 had a respiration measured?It is not neccessary to use all the tables.
 patient:  uniquepid [ text]  patienthealthsystemstayid [ number]  patientunitstayid [ number]  gender [ text]  age [ text]  ethnicity [ text]  hospitalid [ number]  wardid [ number]  admissionheight [ number]  admissionweight [ number]  dischargeweight [ number]  hospitaladmittime [ time]  hospitaladmitsource [ text]  unitadmittime [ time]  unitdischargetime [ time]  hospitaldischargetime [ time]  hospitaldischargestatus [ text] 
SELECT vitalperiodic.observationtime FROM vitalperiodic WHERE vitalperiodic.patientunitstayid IN (SELECT patient.patientunitstayid FROM patient WHERE patient.patienthealthsystemstayid IN (SELECT patient.patienthealthsystemstayid FROM patient WHERE patient.uniquepid = '021-111547') AND patient.unitdischargetime IS NULL) AND NOT vitalperiodic.respiration IS NULL ORDER BY vitalperiodic.observationtime DESC LIMIT 1