Background: Preliminary work has shown that ropivacaine provides spinal anesthesia of shorter duration with greater sensory motor dissociation than bupivacaine, and may be of particular use in the day care surgery. Hypothetically, hyperbaric solution of ropivacaine could improve and shorten both sensory and motor block.
Material and methods: This prospective, randomized, double blind study was conducted on 80 patients undergoing lower abdominal surgeries. Patients either received 20.25 mg of plain ropivacaine (group A) or 20.25 mg of hyperbaric ropivacaine in 5% dextrose (group B). The extent and duration of sensory and motor block, haemodynamics, time to home readiness, and the time to first rescue analgesia were recorded.
Results: All patients in group B achieved sensory block at or above T10 dermatome in comparison to only 87.5% patients of group A. Analgesia at T10 was reached in 4 min (4-6 min) in group B vs. 10 min (6-16 min) in group A (p < 0.001). Patients in group B had a longer duration of analgesia at T10; 126 min (97-146 min) vs. 110 min (90-128 min) (p = 0.047). Median duration of sensory block from injection of the anesthetic to complete recovery (regression to S2 dermatome) was shorter in Group B than Group A, 273.5 min (258 - 289 min) vs. 300 min (290 - 312 min) (p < 0.001), as was the time to 2 segment regression 80 min (63-90 min) vs. 102 min (82-124 min) (p < 0.001). Duration of complete motor block (mean ± SD) was significantly less in group B, 93.06 ± 17.38 min compared to 139.89 ± 25.17 min (p < 0.001) in group A, as was the total duration of motor block (181.83 ± 30.21 min in group B vs. 254.91 ± 25.34 min in Group A; p < 0.001). Patients in Group B attained discharge criteria earlier as indicated by a shorter time to home readiness. Cardiovascular changes were unremarkable throughout, and similar in the two groups. There were no major sequelae.
Conclusion: Addition of dextrose 5% to ropivacaine increases the speed of onset, block reliability, duration of useful block for surgery and speed of recovery. Plain solutions are less reliable for surgery above a dermatomal level of T10.