A Comparison of the Dynamics and Pharmacokinetics of Ropivacaine 7.5??mg/mL with and without Epinephrine Used for Epidural Anaesthesia in Urological Surgery

Topical anesthetic analgesic therapy using the combination of ropivacaine and dexmedetomidine: hyaluronic acid modified long-acting nanostructured lipid carriers containing a skin penetration enhancer

Purpose

Hyaluronic acid-poly(ethylene glycol)-distearoyl phosphoethanolamine (HA-PEG-DSPE) modified and tocopheryl polyethylene glycol 1000 succinate (TPGS) contained nanostructured lipid carriers (NLCs) were prepared loading ropivacaine and dexmedetomidine to improve the topical anesthetic analgesic anesthesia efficiency.

Methods

NLCs were prepared by the solvent diffusion method. The average particle size, zeta potential, release behavior, and cytotoxicity of the NLCs were tested. Ex vivo skin permeation was studied using a Franz diffusion cell mounted with depilated rat skin. Local anesthesia antinociceptive efficiency was evaluated by rat tail flick latency study in vivo.

Results

NLCs have sizes of about 100 nm, with negative zeta potentials. All the NLCs formulations were found to be significantly less cytotoxic than free drugs at equivalent concentrations. The cumulative amount of drugs penetrated through rat skin from NLCs was 2.0–4.7 folds higher than that of the drugs solution. The in vivo anesthesia antinociception study displayed that NLCs showed stronger and longer anesthesia antinociceptive effect when compared with single drugs loaded NLCs and drugs solution even at a lower dosage of drugs.

Conclusion

The results demonstrated that the HA modified, TPGS contained, dual drugs loaded NLCs could perform a synergistic effect and may reduce the amount of drugs, which can lower the toxicity of the system and at the meanwhile, increase the anesthesia antinociceptive efficiency.

Epinephrine adjuvant reduced epidural blood vessel penetration incidence in a randomized, double-blinded trial

BACKGROUND

Accidental intravascular injection is a significant and potentially devastating risk of epidural block, particularly in parturients whose epidural veins are engorged and hence more easily pierced. This prospective randomized, double-blinded study determined whether the addition of epinephrine to epidural ropivacaine administered by gravity before catheter insertion was associated with fewer epidural catheter blood vessel penetrations.

METHOD

Four hundred and two parturient patients receiving epidural block for elective C/S were randomly allocated to two groups; group I (n = 201) received only ropivacaine 0.75% with fentanyl 5 μg/mL, whereas group II (n = 200) also received epinephrine 5 μg/mL. Both groups received a total of 21 mL anesthetic solution in four increment doses of 3,5,5,5 mL by gravity into the needle through a 22 inch extension tubing before insertion of the closed-end tip catheter. An additional 3 mL of the anesthetic solution was then administered through the catheter.

RESULTS

Epidural epinephrine adjuvant was associated with fewer epidural vessel penetrations (4% vs. 16.5%, P < 0.0001). The addition of epinephrine also significantly reduced catheter insertion problems (12% vs. 23.5%, P-value 0.0024) including the need for catheter readjustment (4.5% vs. 16%, P-value 0.0002) or reinsertion (2.5% vs. 9%, P-value 0.0054). The addition of epinephrine significantly reduced incidence and severity of sedation and had faster onset of surgical block. Sensory level and overall satisfaction did not differ significantly among the groups.

CONCLUSION

The addition of epinephrine to ropivacaine improves the safety and quality of epidural anesthesia when administered by gravity flow via the Hustead needle for cesarean sections.