[Lidocaine in oncological surgery: the role of blocking in voltage-gated sodium channels. A narrative review]

Lidocaine Inhibits Rat Prostate Cancer Cell Invasiveness and Voltage-Gated Sodium Channel Expression in Plasma Membrane

There is increasing evidence, mostly from breast cancer, that use of local anaesthetics during surgery can inhibit disease recurrence by suppressing the motility of the cancer cells dependent on inherent voltage-gated sodium channels (VGSCs). Here, the possibility that lidocaine could affect cellular behaviours associated with metastasis was tested using the Dunning cell model of rat prostate cancer. Mostly, the strongly metastatic (VGSC-expressing) Mat-LyLu cells were used under both normoxic and hypoxic conditions. The weakly metastatic AT-2 cells served for comparison in some experiments. Lidocaine (1-500 μM) had no effect on cell viability or growth but suppressed Matrigel invasion dose dependently in both normoxia and hypoxia. Used as a control, tetrodotoxin produced similar effects. Exposure to hypoxia increased Nav1.7 mRNA expression but VGSCα protein level in plasma membrane was reduced. Lidocaine under both normoxia and hypoxia had no effect on Nav1.7 mRNA expression. VGSCα protein expression was suppressed by lidocaine under normoxia but no effect was seen in hypoxia. It is concluded that lidocaine can suppress prostate cancer invasiveness without effecting cellular growth or viability. Extended to the clinic, the results would suggest that use of lidocaine, and possibly other local anaesthetics, during surgery can suppress any tendency for post-operative progression of prostate cancer.

The Effect of Intravenous Lidocaine, Ketamine, and Lidocaine-Ketamine Combination in Colorectal Cancer Surgery: A Randomized Controlled Trial

BACKGROUND

Colorectal resections are associated with a pronounced inflammatory response, severe postoperative pain, and postoperative ileus. The aim of this study was to evaluate the main effects of lidocaine and ketamine, and their interaction in colorectal cancer (CRC) patients after open surgery. The interaction could be additive if the effect of 2 drugs given in combination equals the sum of their individual effects, or multiplicative if their combined effect exceeds the sum of their individual effects. We hypothesized that the combination of lidocaine and ketamine might reduce the inflammatory response additively or synergistically.

METHODS

Eighty-two patients undergoing elective open colorectal resection were randomized to receive either lidocaine or placebo and either ketamine or placebo in a 2 × 2 factorial design. After induction of general anesthesia, all subjects received an intravenous bolus (lidocaine 1.5 mg/kg and/or ketamine 0.5 mg/kg and/or a matched saline volume) followed by a continuous infusion (lidocaine 2 mg·kg-1·h-1 and/or ketamine 0.2 mg·kg-1·h-1 and/or a matched saline volume) until the end of surgery. Primary outcomes were serum levels of white blood cell (WBC) count, interleukins (IL-6, IL-8), and C-reactive protein (CRP) measured at 2 time points: 12 and 36 hours after surgery. Secondary outcomes included intraoperative opioid consumption; visual analog scale (VAS) pain scores at 2, 4, 12, 24, 36, and 48 hours postoperatively; cumulative analgesic consumption within 48 hours after surgery; and time to first bowel movement. We assessed the main effects of each of lidocaine and ketamine and their interaction on the primary outcomes using linear regression analyses. A Bonferroni-adjusted significance level was set at .05/8 = .00625 for primary analyses.

RESULTS

No statistically significant differences were observed with either lidocaine or ketamine intervention in any of the measured inflammatory markers. No multiplicative interaction between the 2 treatments was confirmed at 12 or 36 hours after surgery: WBC count, P = .870 and P = .393, respectively; IL-6, P = .892 and P = .343, respectively; IL-8, P = .999 and P = .996, respectively; and CRP, P = .014 and P = .445, respectively. With regard to inflammatory parameters, no evidence of additive interactions was found. Lidocaine and ketamine, either together or alone, significantly reduced intraoperative opioid consumption versus placebo, and, except for lidocaine alone, improved pain scores. Neither intervention significantly influenced gut motility.

CONCLUSIONS

Our study results do not support the use of an intraoperative combination of lidocaine and ketamine in patients undergoing open surgery for CRC.