title: Risk Factors for Dexmedetomidine-Associated Hemodynamic Instability in Noncardiac Intensive Care Unit Patients.
abstract: BACKGROUND
  The reported incidence of hypotension and bradycardia in patients receiving dexmedetomidine for sedation commonly exceeds 50%. In this study, we describe the incidence of, patient- and treatment-specific risk factors for, and clinical significance of dexmedetomidine-associated hemodynamic instability.
  
  
  METHODS
  This retrospective cohort study was conducted in critically ill adults receiving dexmedetomidine for sedation at Mayo Clinic Hospital in Rochester, MN, during a 1-year period. The primary end point was hemodynamic instability: a composite of hypotension and/or bradycardia, defined as systolic blood pressure <80 mm Hg, diastolic blood pressure <50 mm Hg, or heart rate <50 beats per minute during dexmedetomidine therapy. Cox proportional hazards models were constructed to determine hazard ratios (HRs) and 95% confidence intervals (CIs) for the risk factors of hemodynamic instability.
  
  
  RESULTS
  Hemodynamic instability occurred in 197 of the analyzed 300 patients receiving dexmedetomidine, resulting in a cumulative incidence of 71% at 24 hours via Kaplan-Meier estimation. In addition to dexmedetomidine, univariate analysis identified age, vasopressor use, low baseline arterial blood pressure, and concomitant sedatives as associated with increased risk of hemodynamic instability. Multivariable analysis demonstrated associations between age (HR, 1.23 per 10 years, 95% CI, 1.10-1.38) and low baseline blood pressure (HR, 2.42 at dexmedetomidine initiation, 95% CI, 1.68-3.49) and risk of hemodynamic instability. Variables such as concomitantly administered cardiac medications or sedative therapies and dexmedetomidine infusion rates >0.7 μg/kg/h were not found to be predictors of hemodynamic instability among the analyzed sample.
  
  
  CONCLUSIONS
  Hemodynamic instability commonly occurs in critically ill adults receiving dexmedetomidine, with more than two thirds of this cohort experiencing hypotension and/or bradycardia within 24 hours of initiation. Increasing age and low baseline arterial blood pressure were associated with the development of hemodynamic instability. These findings suggest that clinicians should be aware of the potential risk of hemodynamic instability when using dexmedetomidine in patients with advanced age or low baseline arterial blood pressure.
authors.affiliation: From the *Department of Pharmacy, Spectrum Health, Grand Rapids, Michigan; †Department of Pharmacy Services, ‡Division of Biomedical Statistics and Informatics, §Division of Pulmonary and Critical Care Medicine, and ‖Department of Physiology and Biomedical Engineering, Mayo Clinic Hospital, Rochester, Minnesota.
authors.forename: Calvin J
authors.initials: CJ
authors.lastname: Ice
authors.forename: Heather A
authors.initials: HA
authors.lastname: Personett
authors.forename: Erin N
authors.initials: EN
authors.lastname: Frazee
authors.forename: Ross A
authors.initials: RA
authors.lastname: Dierkhising
authors.forename: Rahul
authors.initials: R
authors.lastname: Kashyap
authors.forename: Richard A
authors.initials: RA
authors.lastname: Oeckler
mesh_terms: D000367:Age Factors; D000368:Aged; D001919:Bradycardia / Q000139:chemically induced / Q000453:epidemiology; D015331:Cohort Studies; D003422:Critical Care / Q000706:statistics & numerical data*; D016638:Critical Illness; D020927:Dexmedetomidine / Q000009:adverse effects*; D023381:Endpoint Determination; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006439:Hemodynamics / Q000187:drug effects*; D006801:Humans; D006993:Hypnotics and Sedatives / Q000009:adverse effects*; D007022:Hypotension / Q000139:chemically induced / Q000453:epidemiology; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D010361:Patients; D012189:Retrospective Studies; D012307:Risk Factors
chemical_list: D006993:Hypnotics and Sedatives; D020927:Dexmedetomidine