Dexmedetomidine in colon cancer surgery: Evaluating its impact and efficacy

Abstract

We present an editorial on an article that highlights the benefits of dexmedetomidine (Dex) in colon cancer surgeries, which have been thoroughly investigated in the referenced publication involving 117 subjects. Of these patients, 59 (group A) received Dex before anesthesia induction, while 58 (group B) received normal saline. Group A patients demonstrated several advantages over Group B, including lower propofol and remifentanil requirements, improved cerebral oxygenation as measured by regional cerebral oxygen saturation, better hemodynamic stability, and reduced incidence of postoperative cognitive dysfunction. In addition to its sedative and analgesic effects, Dex decreases the need for other anesthetic agents and enhances cerebral oxygenation in elderly patients undergoing colorectal surgery. The literature also supports the anti-inflammatory properties of Dex, which can reduce surgical stress and improve postoperative recovery in cancer patients. This editorial focuses on the various benefits of Dex, particularly its role in maintaining hemodynamic stability and facilitating early recovery in cancer patients.

Key Words: Colon cancer; Dexmedetomidine; Impact; Human studies; Animal models; In vitro studies

Core Tip: Dexmedetomidine reduces the need for other anesthetic drugs and improves cerebral oxygenation during colon cancer surgery in elderly patients, potentially minimizing intraoperative brain injury, as indicated by lower postoperative serum levels of S100β and neuron-specific enolase. It shows promise in mitigating postoperative cognitive dysfunction and enhancing overall recovery outcomes by reducing neuroinflammation and stabilizing hemodynamics. However, the study's small sample size, single-center design, and short follow-up period limit the generalizability of these findings, highlighting the need for further research with larger, multicenter trials.

INTRODUCTION

Bu et al[1] studied the effect of dexmedetomidine (Dex) during radical surgery for colon cancers in an elderly population. The study involved 117 patients with colon cancer who underwent elective surgery under general anesthesia. The patients were randomly divided into two groups: Group A (59 patients) received Dex before anesthesia induction, while group B (58 patients) received normal saline. This study found that patients in group A required significantly lower doses of propofol and remifentanil compared to group B, indicating that Dex can reduce the need for other anesthetic drugs. Additionally, the regional cerebral oxygen saturation (rSO2) values were significantly higher in group A at various intraoperative time points, suggesting improved cerebral oxygenation. Dex also appeared to stabilize hemodynamics by inhibiting norepinephrine release, which reduces sympathetic nervous system excitability.

MECHANISM OF DEX TO SUPPRESS SURGICAL STRESS

The stress response to surgical trauma is triggered by direct activation of the sympathetic nervous system, leading to increased secretion of pituitary hormones. An excessive inflammatory response can negatively affect wound healing and contribute to complications such as cognitive dysfunction, symptomatic tachyarrhythmias, postoperative pain, and fatigue. Cytokines produced by macrophages and monocytes are inhibited by α2-adrenergic receptors. Dex, known for its sedative and analgesic properties, exerts its effects by activating α2-adrenergic receptors in the central nervous system, which reduces sympathetic nervous system activity, inhibits apoptosis, and decreases oxidative stress. Dex has been shown to suppress inflammation and surgical stress, thereby preserving the immune function of patients undergoing surgery. Additionally, by reducing perioperative cerebral ischemia, Dex may lower the incidence of perioperative neurocognitive disorders.

IMPACT OF DEX ON COLON CANCER SURGERY

The study measured several parameters, including bi-spectral index (BIS), rSO2, glucose extraction rate, lactate production rate, serum S100β, and neuron-specific enolase (NSE). The results indicated that the use of Dex could improve intraoperative cerebral oxygen supply and enhance brain metabolic states. Notably, serum S100β and NSE levels were significantly lower in group A, 24 hours postoperatively, suggesting reduced brain injury. The cognitive dysfunction rates were also lower in group A on postoperative days 1 and 5, highlighting Dex’s potential in mitigating postoperative cognitive dysfunction (POCD). The findings of this study underscore the potential benefits of Dex in elderly patients undergoing radical colon cancer surgery. By reducing the need for other anesthetic drugs and improving cerebral oxygenation, Dex helps maintain brain function and reduces the risk of POCD. The study also highlights the importance of parameters like BIS and rSO2 in assessing anesthesia depth and preserving brain function. Recent evidence suggests that Dex can play a role in reducing perioperative stress and inflammation, which are critical factors in cancer outcomes. A study by Bekker et al[2] demonstrated that Dex has anti-inflammatory properties that may help in minimizing surgical stress and improving postoperative recovery in cancer patients. Another investigation by Hu et al[3] found that the use of Dex was associated with a reduced incidence of postoperative complications and shorter hospital stays in patients undergoing colorectal surgery. A systematic review and meta-analysis conducted by Boyan et al[4] revealed that patients who received Dex as a supplement had reduced concentrations of epinephrine, norepinephrine, and cortisol, thereby demonstrating the sympatholytic effects of Dex. Another systematic review and meta-analysis by Verret et al[5] showed that Dex reduces overall opioid consumption, subsequently decreasing opioid-related adverse effects. Although improvements in sleep quality and a lower incidence of delirium were also observed, the certainty of this evidence was low. Mortality rates and length of hospital stay were found to be reduced as well. Currently, limited literature addresses the protective effects of Dex in frail patients. However, it may be speculated that Dex’s neuroprotective properties could lower the incidence of neurocognitive disorders in patients with frailty.

LIMITATIONS

The study by Bu et al[1] had several limitations. The study's sample size is relatively small, and it is based on a single-center design. This limits the generalizability of the findings. It would be beneficial to include a discussion on the potential impact of these limitations and suggest future multicenter studies with larger sample sizes to validate the results. The follow-up period in the study was short. Longer follow-up periods would provide more insight into the sustained effects of Dex on cognitive function and other outcomes.

CONCLUSION

The study by Bu et al[1] provides valuable insights into the benefits of Dex in elderly patients undergoing radical colon cancer surgery, particularly in terms of reduced anesthetic requirements, improved cerebral oxygenation, and enhanced hemodynamic stability. However, the findings should be interpreted with caution due to certain limitations. The relatively small sample size and single-center design limit the generalizability of the results. Additionally, the short follow-up period raises questions about the long-term effects of Dex, particularly on cognitive function and overall recovery. To strengthen the evidence base, future research should focus on conducting multicenter studies with larger sample sizes to validate these findings across diverse patient populations. Extended follow-up periods would also be essential to assess the sustained impact of Dex on cognitive outcomes and other postoperative parameters.