what is the change in the creatinine of patient 13622 measured at 2104-08-23 11:40:00 compared to the value measured at 2104-08-23 09:40:00.
select ( select labevents.valuenum from labevents where labevents.hadm_id in ( select admissions.hadm_id from admissions where admissions.subject_id = 13622 ) and labevents.itemid in ( select d_labitems.itemid from d_labitems where d_labitems.label = 'creatinine' ) and labevents.charttime = '2104-08-23 11:40:00' ) - ( select labevents.valuenum from labevents where labevents.hadm_id in ( select admissions.hadm_id from admissions where admissions.subject_id = 13622 ) and labevents.itemid in ( select d_labitems.itemid from d_labitems where d_labitems.label = 'creatinine' ) and labevents.charttime = '2104-08-23 09:40:00' )