Midfoot Field Block Anesthesia with Monitored Intravenous Sedation in Forefoot Surgery

Fifty consecutive patients, studied prospectively, underwent an elective first metatarsophalangeal joint arthrodesis or proximal metatarsal osteotomy and modified McBride bunionectomy, with or without concomitant lesser toe procedures. A field block was administered only at and distal to the level of the tarsometatarsal joints using 30 cc equal parts 0.25% bupivacaine and 1% lidocaine without epinephrine. Before injection, the monitoring anesthesiologist gave the patient intravenous (IV) sedation, usually an amnestic agent. Narcotic analgesia was not given to any patient before or during surgery to evaluate the efficacy of the block. Detailed records were kept of all intraoperative medication and its dosage, including supplemental local anesthetic. Efficacy and outcome were measured via direct patient monitoring during surgery and by direct interview after surgery, first in the recovery area (visual pain analogue applied) and again at 24 to 48 hr after surgery (recollection of events, duration of block, use of narcotics after surgery, subjective patient satisfaction). Supplemental local anesthetic was required for 15 patients (primarily for those who underwent lesser toe procedures), IV narcotic was required for 3 patients, and conversion to general anesthesia was required for 4 patients for agitation, not pain. The average duration of the local block was 8 hr (range, 5–14 hr); none of the patients had recall of negative events, and overall patient satisfaction was 98%. Midfoot blocks are easy to administer and provide reliable anesthesia for reconstructive forefoot surgery. Monitored IV sedation enhances patient acceptance, facilitates block administration, and provides a valuable measure of patient safety and comfort.