Ketamine Use in the Surgical Patient: a Literature Review

Perioperative Ketamine and Cancer Recurrence: A Comprehensive Review

Cancer is a significant global health threat and a leading cause of death worldwide. Effective early-stage interventions, particularly surgery, can potentially cure many solid tumors. However, the risk of postoperative cancer recurrence remains high. Recent research highlights the influence of perioperative anesthetic and analgesic choices on the fate of residual cancer cells, potentially affecting recurrence risks. Among these agents, ketamine-a well-known anesthetic and analgesic-has garnered interest due to its antitumor properties, mainly through inhibiting the N-methyl-D-aspartate (NMDA) receptor found in various cancer tissues. Additionally, ketamine's potential immunomodulatory effects, given the expression of NMDA receptors on immune cells, suggest that it plays a significant role during the perioperative period. This review synthesizes current evidence on ketamine's impact on cancer cell biology, inflammation, immune modulation, and the role of the gut microbiota, proposing ketamine as a promising agent for enhancing oncological outcomes.

Ketamine subcutaneous continuous infusion for non-cancer neuropathic pain at home: a case report

OBJECTIVE

Ketamine is a drug that can effectively treat neuropathic pain by blocking the N-methyl-D-aspartate receptor. It has been studied as a supplement to opioids for cancer pain, but its effectiveness for non-cancer pain is still limited. However, despite its usefulness in managing refractory pain, ketamine is not commonly used for home-based palliative care.

METHODS

A case report of a patient with severe central neuropathic pain who was treated with a subcutaneous continuous infusion of morphine and ketamine at home.

RESULTS

The introduction of ketamine in the patient's treatment plan effectively controlled pain. Only one possible ketamine side effect was observed and easily treated with pharmacological and non-pharmacological measures.

CONCLUSIONS

We have found success in using subcutaneous continuous infusion of morphine and ketamine to alleviate severe neuropathic pain in a home setting. We also observed a positive impact on the patient's family members' personal, emotional and relational well-being after ketamine was introduced.

Opioid-Free Anesthesia: The Pros and Cons

Appropriate perioperative pain control is essential to aid in patients' recovery after surgery; however, acute postsurgical pain remains poorly treated and there continues to be an overreliance on opiates. Perioperative pain control starts in the operating room, and opiate-free anesthesia (OFA), where no opiates are used intraoperatively, has been proposed as a feasible strategy to further minimize opiates in the perioperative period. In this article, we address the potential benefits and shortcomings of OFA, while exploring tools available to accomplish multimodal anesthesia and ideally OFA, and the evidence behind the techniques proposed.

Ketamine Does Not Change Natural Killer Cell Cytotoxicity in Patients Undergoing Cancer Surgery: Basic Experiment and Clinical Trial

Background. The natural killer cell cytotoxicity (NKCC) suppressed by nociceptive stimuli, systemic inflammation, and drugs used during cancer surgery may be associated with poor outcomes. We investigated the potential modulation of ketamine on NKCC in vitro and in a clinical setting during cancer surgery. Subjects and Methods. The NK cell line KHYG1 was cultured for the in vitro experiments. The NK cells were treated with 3 and 10 μM ketamine (the ketamine groups) or without ketamine (the control) for 4, 24, and 48 h. The posttreatment NKCC was measured with a lactate dehydrogenase assay and compared among the treatment groups. For the clinical study, lung cancer patients ( $n=38$ ) and prostate cancer patients ( $n=60$ ) who underwent radical cancer surgeries at a teaching hospital were recruited. The patients received propofol and remifentanil superposed with or without ketamine (ketamine group, $n=47$ ; control group, $n=51$ ). The primary outcome was the difference in NKCC between these groups. Results. In the in vitro experiment, the cytotoxicity of NK cells was similar with or without ketamine at all of the incubation periods. The patients’ NKCC was also not significantly different between the patients who received ketamine and those who did not, at the baseline ( $36.6\pm 16.7$ % vs. $38.5\pm 15.4$ %, $p=0.56$ ) and at 24 h ( $25.6\pm 12.9$ % vs. $27.7\pm 13.5$ %, respectively, $p=0.49$ ). Conclusion. Ketamine does not change NKCC in vitro or in the clinical setting of patients who undergo cancer surgery. This trial is registered with UMIN000021231.

Nonopioid Analgesics for the Perioperative Geriatric Patient: A Narrative Review

Management of acute perioperative pain in the geriatric patient can be challenging as the physiologic and pharmacokinetic changes associated with aging may predispose older patients to opioid-related side effects. Furthermore, elderly adults are more susceptible to postoperative delirium and postoperative cognitive dysfunction, which may be exacerbated by both poorly controlled postoperative pain and commonly used pain medications. This narrative review summarizes the literature published in the past 10 years for several nonopioid analgesics commonly prescribed to the geriatric patient in the perioperative period. Nonopioid analgesics are broken down as follows: medications prescribed throughout the perioperative period (acetaminophen and nonsteroidal anti-inflammatory drugs), medications limited to the acute perioperative setting (N-methyl-D-aspartate receptor antagonists, dexmedetomidine, dexamethasone, and local anesthetics), and medications to be used with caution in the geriatric patient population (gabapentinoids and muscle relaxants). Our search identified 1757 citations, but only 33 specifically focused on geriatric analgesia. Of these, only 21 were randomized clinical trials' and 1 was a systematic review. While guidance in tailoring pain regimens that focus on the use of nonopioid medications in the geriatric patient is lacking, we summarize the current literature and highlight that some nonopioid medications may extend benefits to the geriatric patient beyond analgesia.