Impact of a Protocol Advocating Dexmedetomidine Over Propofol Sedation After Robotic-Assisted Direct Coronary Artery Bypass Surgery on Duration of Mechanical Ventilation and Patient Safety

Abstract

Controversy remains whether propofol or dexmedetomidine is the preferred sedative following cardiac surgery. Dexmedetomidine may offer advantages over propofol among patients undergoing robotic-assisted, minimally invasive, direct coronary artery bypass (MIDCAB) surgery given the rapidity with which this population is usually extubated after surgery. To measure the impact of a surgery protocol advocating use of dexmedetomidine rather than propofol after MIDCAB surgery on discontinuation of mechanical ventilation and patient safety. The records on consecutive adults undergoing MIDCAB surgery who received postoperative sedation with propofol or dexmedetomidine at a 508-bed academic medical center were analyzed before and after implementation of a post-MIDCAB surgery protocol advocating dexmedetomidine use. Seventy-three propofol patients were compared with 53 dexmedetomidine patients. The groups were similar, except propofol patients were older (p = 0.002) and more likely to have underlying heart failure that was either moderate or severe (New York Heart Association class III or IV) (p = 0.0001). Time (median [interquartile range]) to extubation (hours) was shorter in the dexmedetomidine group (5.0 [3.6-7.0] vs 9.8 [5.0-16.3]; p = 0.0001). A Cox proportional hazards model revealed that patient age (p = 0.001) and duration of surgery (p = 0.003) influenced time to extubation between the dexmedetomidine and propofol groups but the presence of moderate or severe heart failure (p = 0.438), the number of coronary vessels operated on (p = 0.130), use of an opioid (p = 0.791), or the total dose of morphine administered (p = 0.215) did not. During sedation administration, more propofol-treated patients experienced 1 or more episodes of hypotension (systolic blood pressure ≤80 mm Hg, 11.6% vs 0%; p = 0.02), tachycardia (heart rate ≥120 beats/min, 8.6% vs 0%; p = 0.04), and unarousability (Sedation Agitation Scale score ≤2, 30.0% vs 9.4%; p = 0.03). Use of a protocol promoting dexmedetomidine, rather than propofol sedation, after MIDCAB surgery facilitates faster discontinuation of mechanical ventilation and is associated with greater hemodynamic stability and arousability.