Pain management in augmentation mammaplasty: a randomized, comparative study of the use of a continuous infusion versus self-administration intermittent bolus of a local anesthetic

Abstract

Background Indwelling catheters for pain control after augmentation mammaplasty appear to be safe and effective. However, little is known regarding the comparison of continuous flow to intermittent bolus anesthetics. Objective A prospective, randomized study was developed to compare these 2 systems. Methods Forty-one patients were divided into 2 groups. All patients used the On-Q (I-Flow Corp, Lake Forest, CA) continuous infusion pump system (2 mL per hour) in 1 breast. Group 1 consisted of 20 patients who, in the opposite breast, were permitted to bolus themselves with 20 mL of 0.25% bupivacaine HCl with 1:400,000 epinephrine (Sensorcaine; Astra Zeneca, Wilmington, DE) as needed, every 6 hours for a maximum of 2 doses. Group 2 consisted of 21 patients who were requested to instill 10 mL of 0.25% bupivacaine with 1:400,000 epinephrine every 4 hours (total 4 instillations) regardless of need (except during sleep). Results with regard to effectiveness and patient preference in both groups were assessed. All patients were asked to avoid any additional analgesics or narcotics for 30 to 60 minutes after self-administration in order to record an unbiased self-assessment response to the instillation of local anesthesia. All patients were seen the day after surgery and given an additional 20 mL of bupivacaine on the self-administration side before implant mobility exercises. Results In group 1, 10 patients preferred the continuous On-Q infusion, 9 patients preferred the self-administration bolus, and 1 patient who had no pain on either side was undecided. Among patients in this group, 24-hour pain scores were similar. In group 2, 13 patients preferred the continuous On-Q infusion, 5 patients preferred self-administration, and 3 patients were undecided. Pain scores in group 2 were lower for On-Q. An unexpected finding was that after unilateral self-administration, 20 of 41 patients (42%) noted bilateral reduction of pain. By day 3, 33 of 41 patients (80%) used no narcotics. There were no complications associated with either device. Conclusions After augmentation mammaplasty, both indwelling catheters using continuous flow and intermittent bolus anesthesia as needed are effective in controlling postoperative pain. Continuous flow maintains a steady state of pain control without patient intervention. Self-administration allows patients to have a more active role if they have pain and is an effective low-cost alternative to a commercial pain pump. These conclusions are supported by a review of the literature and by our own experience with more than 380 consecutive patients.