A Systematic Review and Meta-analysis of the Analgesic Effects of Lidocaine Administered Intravenously or Intraperitoneally Post-Abdominal Surgery.

BACKGROUND: Reducing postoperative pain is still a tremendous challenge for perioperative clinicians. Lidocaine is a local anesthetic that belongs to the amide class and has anti-inflammatory, anti-hyperalgesic, and analgesic effects. Extensive research has been conducted to determine the optimal route for its administration. OBJECTIVE: To compare the efficacy of perioperative intravenous lidocaine with that of intraperitoneal lidocaine on postoperative analgesia in patients undergoing abdominal surgery. STUDY DESIGN: EMBASE, PubMed, and The Cochrane Library were searched for randomized controlled trials published through December 2022 that compared patients receiving perioperative intravenous lidocaine with those receiving intraperitoneal lidocaine. The primary outcome measures included the pain score, as evaluated by the Visual Analog Scale, and opioid analgesia requirements. The secondary outcome measures were hospitalization length, gastrointestinal function recovery, etc. The data were acquired and recorded in electronic spreadsheets that had been designed for this purpose. METHODS: This systematic review's design was based on the Cochrane Handbook for Systematic Reviews of Interventions and was reported in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) statement. The Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) method was used to examine the certainty of the evidence. Furthermore, we examined the dependability of the calculated (favorable) treatment effects through considerations of information size and modified significance thresholds (trial sequential analysis). RESULTS: Seven trials including 478 patients were included. Our meta-analysis demonstrates that compared with intravenous lidocaine, patients who received intraperitoneal lidocaine had lower pain scores at 4 hours (mean difference [MD] 1.40; 95% CI, 0.22 to 2.59); 12 hours (MD 0.18; 95% CI, 0.06 to 0.30); and 24 hours (MD -0.12; 95% CI -0.40 to 0.17) postsurgery. However, no obvious difference in opioid consumption (P > 0.05) was found. In addition, the intraperitoneal lidocaine group had a longer postsurgery hospital stay than the intravenous lidocaine group (95%CI, -0.17 to -0.00; I2 = 0%). Intravenous lidocaine was more beneficial for achieving gastrointestinal return than intraperitoneal lidocaine (95% CI, -0.26 to -0.10; I2 = 2%). LIMITATIONS: The sample size of enrolled RCTs was small, which could potentially result in an overestimation or underestimation of the treatment effect in the collected data. There was high heterogeneity among the studies. CONCLUSION: This meta-analysis suggests that post-abdominal surgery intraperitoneal lidocaine administration has a better analgesic effect than intravenous lidocaine, with a lower pain score. However, intravenous lidocaine is more beneficial for gastrointestinal recovery after abdominal surgery.

RAC1 is involved in uterine myometrium contraction in the inflammation-associated preterm birth.

In brief: Various etiologies can cause uterine myometrium contraction, which leads to preterm birth. This study demonstrates a new functional relationship between the Ras-related C3 botulinum toxin substrate 1 (RAC1) and uterine myometrium contraction in preterm birth. Abstract: Preterm birth (PTB) is a public health issue. The World Health Organization has recommended the use of tocolytic treatment to inhibit preterm labour and improve pregnancy outcomes. Intrauterine inflammation is associated with preterm birth. RAC1 can modulate inflammation in different experimental settings. In the current study, we explored whether RAC1 can modulate spontaneous uterine myometrium contraction in a mouse model of lipopolysaccharide (LPS)-induced intrauterine inflammation. Subsequently, we recorded uterine myometrium contraction and examined uterine Rac1 expression in a mouse model of preterm birth and a case in pregnant women by Western blotting analysis. We also measured progesterone levels in the blood serum of mice. Murine myometrium was obtained 12 h post LPS treatment. Human myometrium was obtained at the time of caesarean section. We found that in the LPS-treated group of mice, uterine myometrium contraction was enhanced, protein levels and activation of RAC1 were increased and serum progesterone levels were decreased. The protein levels of RAC1 were also increased in preterm birth and in pregnant women. NSC23766, a RAC1 inhibitor, attenuated uterine myometrium contraction and diminished RAC1 activation and COX-2 expression. Furthermore, silencing of RAC1 suppressed cell contraction and COX-2 expression in vitro. In conclusion, our results suggested that RAC1 may play an important role in modulating uterine myometrium contraction. Consequently, intervening with RAC1 represents a novel strategy for the treatment of preterm birth.