instruction: is sao2 of patient 006-2586 last measured on the current intensive care unit visit greater than first measured on the current intensive care unit visit?
response: SELECT (SELECT vitalperiodic.sao2 FROM vitalperiodic WHERE vitalperiodic.patientunitstayid IN (SELECT patient.patientunitstayid FROM patient WHERE patient.patienthealthsystemstayid IN (SELECT patient.patienthealthsystemstayid FROM patient WHERE patient.uniquepid = '006-2586') AND patient.unitdischargetime IS NULL) AND NOT vitalperiodic.sao2 IS NULL ORDER BY vitalperiodic.observationtime DESC LIMIT 1) > (SELECT vitalperiodic.sao2 FROM vitalperiodic WHERE vitalperiodic.patientunitstayid IN (SELECT patient.patientunitstayid FROM patient WHERE patient.patienthealthsystemstayid IN (SELECT patient.patienthealthsystemstayid FROM patient WHERE patient.uniquepid = '006-2586') AND patient.unitdischargetime IS NULL) AND NOT vitalperiodic.sao2 IS NULL ORDER BY vitalperiodic.observationtime LIMIT 1)