Comparison of Effectiveness of Ropivacaine Infusion Regimens for Continuous Femoral Nerve Block for Recovery After Total Knee Arthroplasty: A Randomized Double-Blind Trial

A randomized trial: The safety, pharmacokinetics and preliminary pharmacodynamics of ropivacaine oil delivery depot in healthy subjects

INTRODUCTION

Ropivacaine oil delivery depot (RODD) can slowly release ropivacaine and block nerves for a long timejavascript:;. The aim of the present work was to investigate the safety, pharmacokinetics, and preliminary pharmacodynamics of RODD in subcutaneous injection among healthy subjects.

METHODS

The abdomens of 3 subjects were subcutaneously administered with a single-needle RODD containing 12~30 mg of ropivacaine. The irritation, nerve blocking range and optimum dose were investigated. Forty-one subjects were divided into RODD groups containing 150, 230, 300, 350 and 400 mg of ropivacaine and a ropivacaine hydrochloride injection (RHI) 150 mg group. Multineedle subcutaneous injection of RODD or RHI was performed in the abdomens of the subjects. The primary endpoint was a safe dose or a maximum dose of ropivacaine (400 mg). Subjects' vital signs were observed; their blood was analyzed; their cardiovascular system and nervous systems were monitored, and their dermatological reactions were observed and scored. Second, the ropivacaine concentrations in plasma were determined, pharmacokinetic parameters were calculated, and the anesthetic effects of RODD were studied, including RODD onset time, duration and intensity of nerve block.

RESULTS

Single-needle injection of RODD 24 mg was optimal for 3 subjects, and the range of nerve block was 42.5±20.8 mm. Multineedle subcutaneous injection of RODD in the abdomens of subjects was safe, and all adverse events were no more severe than grade II. The incidence rate of grade II adverse events, such as pain, and abnormal ST and ST-T segment changes on electrocardiography, was approximately 1%. The incidence rate of grade I adverse events, including erythema, papules, hypertriglyceridemia, and hypotension was greater than 10%. Erythema and papules were relieved after 24 h and disappeared after 72 h. Other adverse reactions disappeared after 7 days. The curve of ropivacaine concentration-time in plasma presented a bimodal profile. The results showed that ropivacaine was slowly released from the RODD. Compared with the 150 mg RHI group, Tmax was longer in the RODD groups. In particular, Tmax in the 400 mg RODD group was longer than that in the RHI group (11.8±4.6 h vs. 0.77±0.06 h). The Cmax in the 150 mg RODD group was lower than that in the 150 mg RHI group (0.35±0.09 vs. 0.58±0.13 μg·mL-1). In particular, the Cmax increased by 48% when the dose was increased by 2.6 times in the 400 mg group. Cmax, the AUC value and the intensity of the nerve block increased with increasing doses of RODD. Among them, the 400 mg RODD group presented the strongest nerve block (the percentage of level 2 and 3, 42.9%). The corresponding median onset time was 0.42 h, and the duration median was 35.7⁓47.7 h.

CONCLUSIONS

RODD has a sustained release effect. Compared with the RHI group, Tmax was delayed in the RODD groups, and the duration of nerve block was long. No abnormal reaction was found in the RODD group containing 400 mg of ropivacaine after subcutaneous injection among healthy subjects, suggesting that RODD was adequately safe.

TRIAL REGISTRATION

Chictr.org: CTR2200058122; Chinadrugtrials.org: CTR20192280.

Simultaneous Determination of Ropivacaine and 3-Hydroxy Ropivacaine in Cerebrospinal Fluid by UPLC-MS/MS

In this paper, a UPLC-MS/MS method was developed for the determination of ropivacaine and its metabolite 3-hydroxy ropivacaine in cerebrospinal fluid. The cerebrospinal fluid was processed by ethyl acetate liquid-liquid extraction. The multiple reaction monitoring (MRM) mode was used for quantitative analysis by monitoring the transitions of m/z 275.3 → 126.2 for ropivacaine, m/z 291.0 → 126.0 for 3-hydroxy ropivacaine, and m/z 290.2 → 198.2 for the internal standard. Standard curves for ropivacaine and 3-hydroxy ropivacaine in cerebrospinal fluid were conducted over the concentration range of 0.2–2000 ng/mL, demonstrating excellent linearity, and the lower limit of quantification was 0.2 ng/mL. The intraday precision of ropivacaine and 3-hydroxy ropivacaine was less than 11%, while the interday precision was less than 7%. The accuracy ranged between 87% and 107%, the average extraction efficiency was higher than 79%, and the matrix effect was between 89% and 98%. The developed method was then applied to a case of suspected poisoning of ropivacaine.

Comparison of ropivacaine plus sufentanil and ropivacaine plus dexmedetomidine for labor epidural analgesia: A randomized controlled trial protocol

OBJECTIVE

Effective analgesia during delivery can not only decrease pain, but also have a significant function in ensuring the safety of baby and mother. Sufentanil is generally used opioid with ropivacaine in epidural anesthesia in labor pain management; however it can cause some adverse reaction. Dexmedetomidine is an a2-adrenoceptor agonist with high selectivity. It possesses opioid-sparing and analgesic effects and it is suitable for the long-term and short-term intraoperative sedation. The purpose of this present study is to compare the analgesic effect of ropivacaine with dexmedetomidine against ropivacaine with sufentanyl in epidural labor.

METHODS

This is a single center, placebo-controlled randomized trial which will be performed from May 2020 to May 2021. It was authorized via the Institutional Review Committee in the first medical center of Chinese PLA General Hospital (S2018-211-0). One hundred sixty full-term protozoa are included in this work. They are randomly divided into four groups (n = 40 per group): the RD1 group (with the epidural administration of 0.125% ropivacaine + dexmedetomidine of 0.5 μg/mL), and the RD2 group (with the epidural administration of 0.08% ropivacaine + dexmedetomidine 0.5 μg/mL), the RS1 group (with the epidural administration of 0.125% ropivacaine + sufentanil of 0.5 μg/mL), as well as RS2 group (with the epidural administration of 0.08% ropivacaine + sufentanil of 0.5 μg/mL). Clinical outcomes are pain score, a modified Bromage scale, the Ramsay Sedation Scale, and adverse reactions during analgesia. All the needed analyses are implemented through utilizing SPSS for Windows Version 20.0.

RESULTS

The first table shows the clinical outcomes between these four groups.

CONCLUSION

This current work can provide a primary evidence regarding the clinical outcomes of dexmedetomidine versus sufentanil for labor epidural analgesia.

TRIAL REGISTRATION

This study protocol was registered in Research Registry (researchregistry5877).