Purpose: To compare the analgesic effects of remifentanil and alfentanil during breast biopsy under monitored anesthesia care (MAC).
Methods: Sixty patients received sedation with propofol (50 microg.kg(-1).min(-1)). After receiving a loading dose of opioid (either remifentanil 0.5 microg.kg(-1), or alfentanil 2.5 microg.kg(-1)), an infusion was initiated (remifentanil 0.05 microg.kg(-1).min(-1) or alfentanil 0.25 microg.kg(-1).min(-1)), and this was supplemented with local anesthetic infiltration. The pain was evaluated with a ten-point visual analogue scale (VAS) during local anesthetic infiltration and deep tissue dissection. Inadequate analgesia, defined as VAS scores > or = 5, was treated first with boluses of opioid (remifentanil group 10 microg or alfentanil group 50 microg) and if inadequate after two treatments with additional local anesthetic. Postoperative times were recorded including the times until discharge criteria were achieved and patient's actual discharge.
Results: The pain scores were similar between the two groups during the initial injections of local anesthetic in the breast, however, patients in the remifentanil group had lower mean pain scores during deep tissue dissection (2.3 vs 4.3, P < 0.01). Patients in the remifentanil group required fewer rescue doses of opioid (1.9 vs 3.6, P < 0.03) and local anesthetic (5 vs 15, P < 0.006). The two study groups had comparable speed of recovery.
Conclusion: Remifentanil was a better opioid choice than alfentanil for breast biopsy under MAC at the doses studied, but it did not increase the rapidity in which patients recovered postoperatively.