instruction: how much is patient 027-140654's chloride changing/differing last measured on the current hospital visit compared to the value second to last measured on the current hospital visit.
response: SELECT (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 = '027-140654' AND patient.hospitaldischargetime IS NULL)) AND lab.labname = 'chloride' ORDER BY lab.labresulttime DESC LIMIT 1) - (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 = '027-140654' AND patient.hospitaldischargetime IS NULL)) AND lab.labname = 'chloride' ORDER BY lab.labresulttime DESC LIMIT 1 OFFSET 1)