Impact of Dexmedetomidine on Analgesic Requirements in Patients After Cardiac Surgery in a Fast-Track Recovery Room Setting

Study Objective. To compare postoperative opioid requirements in patients who received dexmedetomidine versus propofol after cardiac surgery. Design. Retrospective cohort study. Setting. Large, community teaching hospital that uses a fast-track cardiovascular recovery unit (CVRU) model. Patients. One hundred adults who underwent coronary artery bypass graft surgery and/or valvular surgery, and who received either dexmedetomidine (50 patients) or propofol (50 patients) for perioperative sedation. Measurements and Main Results. Patients were matched according to surgery type and left ventricular ejection fraction. Opioid requirements were assessed over two time intervals: from arrival in the CVRU to discontinuation of the sedative infusion, and from CVRU arrival to CVRU discharge, up to a maximum of 72 hours if admission to the intensive care unit was necessary. All postoperative opioid doses were converted to morphine equivalents. Length of mechanical ventilation, quality of sedation, adverse drug events, and sedation-related costs were determined. Opioid requirements were significantly lower during the sedative infusion period for dexmedetomidine-treated patients than for propofol-treated patients (median [range] 0 [0-10 mg] vs 4 mg [0-33 mg], p<0.001), but not through the entire CVRU admission (median [range] 26 mg [0-119 mg] vs 30 mg (0-100 mg], p=0.284). The proportion of patients who did not require opioids during the infusion was significantly higher in the dexmedetomidine group compared with the propofol group (32 [64%] vs 13 [26%], p<0.001). No significant differences were noted between the groups for length of mechanical ventilation, quality of sedation, or adverse events. Sedation-related costs were significantly higher (similar to$50/patient higher) with dexmedetomidine (p<0.001). Conclusion. Dexmedetomidine resulted in lower opioid requirements in patients after cardiac surgery versus those receiving propofol, but this did not result in shorter durations of mechanical ventilation, using a fast-track CVRU model.