Dexmedetomidine Medication Records and Delirium After Coronary Artery Bypass Grafting

This retrospective observational study uses de-identified electronic health records from the TriNetX Global Collaborative Network. The procedure eligibility period is 1 January 2010 through 1 July 2025. The primary analysis concerns adults with a recorded qualifying coronary artery bypass grafting (CABG) procedure. Valve-coded procedures are examined in a separately constructed and separately matched exploratory population. The populations may overlap and do not constitute independent replication cohorts. Patients are classified by the presence or absence of a dexmedetomidine medication record on the calendar day before or the day of the index procedure. This definition does not confirm administration, dose or intraday timing. The primary outcome is a qualifying delirium or disorientation code during days 1-30. Nine secondary endpoints concern mortality and selected recorded complications during days 0-30; eight are inferential and the prolonged-ventilation code endpoint is descriptive. An inpatient or observation encounter during days 1-30 is described separately and is not interpreted as readmission. Same-day records cannot establish whether an outcome preceded or followed exposure. No treatment is assigned by the investigators. Analyses use permitted aggregate outputs, without identifiable or row-level participant data. The clinical definitions were revised with knowledge of earlier analyses. CABG primary and F05-only outcomes were first rerun on 5 September 2026 and were seen before a technical amendment permitting automatic propensity-score rematching for each outcome batch and unavoidable comparative calculations accompanying descriptive patient counts. The approved eligibility, exposure and outcome windows, codes, covariates, category boundaries and eight-test multiplicity family were not changed by that technical amendment. Subsequent technical refreshes and their source versions are recorded separately. Neither the original registration nor this amendment