instruction: give the number of patients whose admission location is transfer from hosp/extram and procedure long title is continuous intra-arterial blood gas monitoring.
response: SELECT COUNT(DISTINCT demographic.subject_id) FROM demographic INNER JOIN procedures ON demographic.hadm_id = procedures.hadm_id WHERE demographic.admission_location = "TRANSFER FROM HOSP/EXTRAM" AND procedures.long_title = "Continuous intra-arterial blood gas monitoring"