Cederholm-I. Anskar-S. Bengtsson-M. Sensory, motor, and sympathetic
block during epidural analgesia with 0.5% and 0.75% ropivacaine with and
without epinephrine. Reg-Anesth. 1994 Jan-Feb. 19(1). P 18-33.
BACKGROUND AND OBJECTIVES. Ropivacaine is a new long- acting local
anesthetic, with vasoconstrictive properties. The purpose of this randomized,
double-blind study was to evaluate sensory, motor, and sympathetic block
following epidural anesthesia, and the influence of the addition of epinephrine.
METHODS. Forty-eight male patients, scheduled for transurethral surgery,
received 20 mL of 0.5% or 0.75% ropivacaine with or without addition of
epinephrine (5 micrograms/mL) epidurally. Sensory block was assessed by pinprick,
motor block by a modified Bromage scale, and sympathetic block by skin resistance
level, skin resistance response, skin temperature, and skin blood flow (laser
Doppler flowmetry). RESULTS. Onset time for analgesia was short (Th10 blocked
after median 5.3-6.7 minutes), and maximum segmental level was median Th
2-3 (range, Th5-C4). A tendency toward a dose-response relationship (duration
of sensory block) was noted for the 0.75% solutions (median, 258-264 minutes
at Th10) compared to the 0.5% solutions (median, 228-234 minutes at Th10).
Only about half of the patients exhibited a complete motor block of the lower
extremities with a longer duration with the 0.75% solutions. The majority
of patients had a marked or complete sympathetic block in the lower limbs.
Short-lasting, mild hypotension, responding well to ephedrine intravenously,
was noted in 40%- 70% of the patients. No serious adverse reactions were
observed.
CONCLUSIONS. Ropivacaine given epidurally provided adequate sensory
anesthesia and motor block for transurethral surgery. Addition of epinephrine
did not provide any significant prolongation of the sensory or motor block,
nor any influence upon the sympathetic block.