This observational study uses de-identified electronic health record data from the TriNetX Global Collaborative Network (2010-01-01 to 2025-07-01) to examine whether perioperative dexmedetomidine (DEX) is associated with 30-day outcomes after adult cardiac surgery. Adults aged 18-100 years undergoing first-time coronary artery bypass grafting or heart valve surgery are included. Exposure is any DEX administration from 24 hours before to 48 hours after the index operation; comparators receive no DEX in this window. The primary outcome is delirium within 30 days. Secondary outcomes are 30-day all-cause mortality, acute kidney injury, pneumonia, sepsis, red blood cell transfusion/major bleeding, myocardial infarction, ischemic stroke/transient ischemic attack, atrial fibrillation, mechanical ventilation >96 hours (days 4-30), and 30-day readmission (days 1-30). No treatments are assigned by investigators and no identifiable information is used. Findings aim to inform perioperative sedation strategies in routine cardiac surgery care.

This is a retrospective cohort study using de-identified data from the TriNetX Global Collaborative Network (2010-01-01 to 2025-07-01). Adults aged 18-100 years undergoing first-time coronary artery bypass grafting or heart valve surgery will be identified. Perioperative exposure is defined as any dexmedetomidine administration from 24 hours before to 48 hours after the index surgery; the comparison cohort consists of patients without dexmedetomidine in this window. Clinical outcomes within 30 days after surgery include delirium as the primary outcome and a range of major postoperative complications and mortality. Propensity scores based on demographics, comorbidities, baseline medications and laboratory tests will be used to match or adjust between exposure groups, with balance assessed using standardized mean differences. Time-to-event analyses will use Cox proportional hazards models and Kaplan-Meier curves, with multiplicity controlled using the Benjamini-Hochberg false discovery rate. All analyses use only de-identified data within the TriNetX platform, with no direct contact with patients or access to identifiers.

Inclusion Criteria:

• Age 18-100 years.
• First-time CABG or heart valve surgery within TriNetX during 2010-01-01 to 2025-07-01.
• ≥90 days pre-operative observable data and a 30-day post-operative window (death ≤30 days counts as complete).
• Index surgery, exposure window (-24 to +48 h), and outcomes identifiable from standardized platform codes/fields.

Exclusion Criteria:

• End-stage renal disease or dialysis within 90 days before index surgery (ICD-10-CM N18.6, Z49, Z99.2).
• Not first-time CABG/valve in the same admission.
• Missing required fields or conflicting records preventing unique case definition.
• Unable to confirm exposure window or outcomes within the platform.

Adults aged 18-100 years undergoing first-time CABG or valve surgery in the TriNetX Global Collaborative Network (2010-01-01 to 2025-07-01); de-identified EHR data; exposure defined as perioperative dexmedetomidine -24 to +48 h; comparator without dexmedetomidine in that window.

This retrospective observational study uses de-identified data from the TriNetX Global Collaborative Network. Investigators do not receive identifiable information or re-identification keys. The Data Use Agreement with TriNetX and participating health care organizations prohibits sharing or redistributing line-level individual participant data outside the platform. Only aggregate results and model estimates will be shared (e.g., tables, figures); study documents and analysis code may be provided on reasonable request.