instruction: what was the first value of the pao2 lab test of patient 004-32407 on their first hospital visit.
response: SELECT lab.labresult FROM lab WHERE lab.patientunitstayid IN (SELECT patient.patientunitstayid FROM patient WHERE patient.patienthealthsystemstayid IN (SELECT patient.patienthealthsystemstayid FROM patient WHERE patient.uniquepid = '004-32407' AND NOT patient.hospitaldischargetime IS NULL ORDER BY patient.hospitaladmittime LIMIT 1)) AND lab.labname = 'pao2' ORDER BY lab.labresulttime LIMIT 1