Comparison of the Effects of Dexmedetomidine and Lidocaine on Stress Response and Postoperative Delirium of Older Patients Undergoing Thoracoscopic Surgery: A Randomized Controlled Trial

Trial watch: dexmedetomidine in cancer therapy

Dexmedetomidine (DEX) is a highly selective α2-adrenoceptor agonist that is widely used in intensive and anesthetic care for its sedative and anxiolytic properties. DEX has the capacity to alleviate inflammatory pain while limiting immunosuppressive glucocorticoid stress during major surgery, thus harboring therapeutic benefits for oncological procedures. Recently, the molecular mechanisms of DEX-mediated anticancer effects have been partially deciphered. Together with additional preclinical data, these mechanistic insights support the hypothesis that DEX-induced therapeutic benefits are mediated via the stimulation of adaptive anti-tumor immune responses. Similarly, published clinical trials including ancillary studies described an immunostimulatory role of DEX during the perioperative period of cancer surgery. The impact of DEX on long-term patient survival remains elusive. Nevertheless, DEX-mediated immunostimulation offers an interesting therapeutic option for onco-anesthesia. Our present review comprehensively summarizes data from preclinical and clinical studies as well as from ongoing trials with a distinct focus on the role of DEX in overcoming (tumor microenvironment (TME)-imposed) cancer therapy resistance. The objective of this update is to guide clinicians in their choice toward immunostimulatory onco-anesthetic agents that have the capacity to improve disease outcome.

Effect of Intraoperative Intravenous Lidocaine on Postoperative Delirium in Elderly Patients with Hip Fracture: A Prospective Randomized Controlled Trial

Purpose

This study was performed to evaluate the effects of intraoperative intravenous lidocaine on postoperative delirium in elderly patients with hip fracture.

Patients and methods

In total, 100 elderly patients undergoing hip fracture surgery were randomized to the lidocaine group (Group L) or saline (control) group (Group C). Before anesthetic induction, Group L received lidocaine at 1 mg/kg for more than 10 minutes followed by continuous infusion at 1.5 mg/kg/h until the end of surgery. Group C received normal saline, and the injection methods were consistent with those in Group L. General anesthesia was induced with propofol, sufentanil, and cis-atracurium. Anesthesia was maintained by propofol and remifentanil. The primary outcome was the incidence of postoperative delirium in the first 7 postoperative days. The secondary outcomes included the severity of delirium, onset and duration of delirium, emergence agitation, adverse events, total propofol dose, intraoperative opioid dosage, length of post-anesthesia care unit stay, extubation time, and patient satisfaction with postoperative pain management.

Results

All 100 patients completed the study. The incidence of postoperative delirium was lower in Group L than in Group C (14% vs 36%, P = 0.011). The delirium severity scores were lower in Group L (3 [3-4]) than in Group C (4 [4-5]) (P = 0.017). In addition, the incidences of hypertension, tachycardia, and emergence agitation were significantly lower in Group L than in Group C. No cases of local anesthetic toxicity occurred in either group.

Conclusion

Patients received lidocaine at 1 mg/kg for more than 10 minutes followed by continuous infusion at 1.5 mg/kg/h until the end of surgery, which can reduce the incidence of postoperative delirium in elderly patients undergoing hip fracture. In addition, the used regimen of lidocaine would not increase the risk of local anesthetic toxicity.

Efficacy of combined use of Suvorexant and Ramelteon in preventing postoperative delirium: a retrospective comparative study

BACKGROUND

Suvorexant and ramelteon have been presented as useful for preventing postoperative delirium. Previous studies reported on the comparison with benzodiazepine hypnotics which have been known for the risk for inducing delirium, but the comparison with patients not taking any hypnotics has not been reported yet. Therefore, we assessed the incidence rates for postoperative delirium comparing cancer patients who received preoperative combined administration with suvorexant and ramelteon and those not taking any hypnotics.

METHODS

Among 110 cancer patients who underwent surgeries at the Division of Hepato-Biliary-Pancreatic Surgery at the Shizuoka Cancer Center between April 1, 2017 and June 30, 2020, 50 patients who received combined administration with suvorexant and ramelteon from 7 days prior to their surgeries and 60 patients who did not take any hypnotics including suvorexant and ramelteon were classified. They were retrospectively observed during the 7 days from their surgeries onward to compare the cumulative incidence rates for postoperative delirium.

RESULTS

The cumulative incidence rate for postoperative delirium during the 7 days in the combined-administration group was 14.0% (7/50), while that for the no-hypnotic group was 36.7% (22/60), which proved that the incidence rate for the former was significantly low (OR: 0.28, 95%CI: 0.11-0.73, P = 0.009).

CONCLUSIONS

The present study suggests that the preventive combined administration with suvorexant and ramelteon starting from the preoperative period for cancer patients can be effective in lowering the incidence rate for postoperative delirium.

TRIAL REGISTRATION

Retrospectively registered.