Randomized double-blind study of the clinical duration and efficacy of Nesacaine-MPF 2% and 3% in peribulbar...

To compare 2 commercially available concentrations of Nesacaine-MPF (2-chloroprocaine) to determine the time to onset of adequate motor blockade, the quality of surgical anesthesia, and the duration of motor blockade in the extraocular muscles after peribulbar anesthesia for cataract surgery.

Tampa Eye and Specialty Surgery Center, Tampa, Florida, USA.

This double-blind, randomized, single-center study comprised 40 patients scheduled to receive peribulbar anesthesia before cataract surgery. Patients were given 5 mL of Nesacaine-MPF 2% or 3% before surgery. Beginning at the end of the injection, assessments of ocular and eyelid movement were made every 2 minutes until adequate motor blockade was achieved or 25 minutes elapsed. Ocular assessments were made immediately after completion of surgery, 60 minutes after the end of the initial injection, and at 15 minute intervals thereafter until full recovery. Assessments of the quality of anesthesia achieved by the patient during surgery were made by the surgeon.

The 3% solution provided significantly faster onset of surgical anesthesia than the 2% solution (mean 3.9 minutes +/- 2.2 [SD] versus 6.0 +/- 3.6 minutes) (P = .02) but also required more time for recovery from anesthesia (98.9 +/- 18.7 minutes versus 84.8 +/- 20.6 minutes) (P = .02). All patients had adequate surgical anesthesia. Duration of ocular motor function was brief enough so that all patients could be sent home without an eye patch. Both concentrations were safe for use in this procedure.

Both Nesacaine-MPF 2% and 3% produced safe and effective peribulbar anesthesia in all patients; however, the 3% solution provided better duration of clinical anesthesia.