Impact of inhalational versus intravenous anaesthesia on early delirium and long-term survival in elderly patients after cancer surgery: study protocol of a multicentre, open-label, and randomised controlled trial

Long-term survival in older patients given propofol or sevoflurane anaesthesia for major cancer surgery: follow-up of a multicentre randomised trial

BACKGROUND

Experimental evidence indicates that i.v. anaesthesia might reduce cancer recurrence compared with volatile anaesthesia, but clinical information is observational only. We therefore tested the primary hypothesis that propofol-based anaesthesia improves survival over 3 or more years after potentially curative major cancer surgery.

METHODS

This was a long-term follow-up of a multicentre randomised trial in 14 tertiary hospitals in China. We enrolled 1228 patients aged 65-90 yr who were scheduled for major cancer surgery. They were randomised to either propofol-based i.v. anaesthesia or to sevoflurane-based inhalational anaesthesia. The primary endpoint was overall survival after surgery. Secondary endpoints included recurrence-free and event-free survival.

RESULTS

Amongst subjects randomised, 1195 (mean age 72 yr; 773 [65%] male) were included in the modified intention-to-treat analysis. At the end of follow-up (median 43 months), there were 188 deaths amongst 598 patients (31%) assigned to propofol-based anaesthesia compared with 175 deaths amongst 597 patients (29%) assigned to sevoflurane-based anaesthesia; adjusted hazard ratio 1.02; 95% confidence interval (CI): 0.83-1.26; P=0.834. Recurrence-free survival was 223/598 (37%) in patients given propofol anaesthesia vs 206/597 (35%) given sevoflurane anaesthesia; adjusted hazard ratio 1.07; 95% CI: 0.89-1.30; P=0.465. Event-free survival was 294/598 (49%) in patients given propofol anaesthesia vs 274/597 (46%) given sevoflurane anaesthesia; adjusted hazard ratio 1.09; 95% CI 0.93 to 1.29; P=0.298.

CONCLUSIONS

Long-term survival after major cancer surgery was similar with i.v. and volatile anaesthesia. Propofol-based iv. anaesthesia should not be used for cancer surgery with the expectation that it will improve overall or cancer-specific survival.

CLINICAL TRIAL REGISTRATIONS

ChiCTR-IPR-15006209; NCT02660411.

Delirium in older patients given propofol or sevoflurane anaesthesia for major cancer surgery: a multicentre randomised trial

BACKGROUND

Delirium is a common and disturbing postoperative complication that might be ameliorated by propofol-based anaesthesia. We therefore tested the primary hypothesis that there is less delirium after propofol-based than after sevoflurane-based anaesthesia within 7 days of major cancer surgery.

METHODS

This multicentre randomised trial was conducted in 14 tertiary care hospitals in China. Patients aged 65-90 yr undergoing major cancer surgery were randomised to either propofol-based anaesthesia or to sevoflurane-based anaesthesia. The primary endpoint was the incidence of delirium within 7 postoperative days.

RESULTS

A total of 1228 subjects were enrolled and randomised, with 1195 subjects included in the modified intention-to-treat analysis (mean age 71 yr; 422 [35%] women); one subject died before delirium assessment. Delirium occurred in 8.4% (50/597) of subjects given propofol-based anaesthesia vs 12.4% (74/597) of subjects given sevoflurane-based anaesthesia (relative risk 0.68 [95% confidence interval {CI}: 0.48-0.95]; P=0.023; adjusted relative risk 0.59 [95% CI: 0.39-0.90]; P=0.014). Delirium reduction mainly occurred on the first day after surgery, with a prevalence of 5.4% (32/597) with propofol anaesthesia vs 10.7% (64/597) with sevoflurane anaesthesia (relative risk 0.50 [95% CI: 0.33-0.75]; P=0.001). Secondary endpoints, including ICU admission, postoperative duration of hospitalisation, major complications within 30 days, cognitive function at 30 days and 3 yr, and safety outcomes, did not differ significantly between groups.

CONCLUSIONS

Delirium was a third less common after propofol than sevoflurane anaesthesia in older patients having major cancer surgery. Clinicians might therefore reasonably select propofol-based anaesthesia in patients at high risk of postoperative delirium.

CLINICAL TRIAL REGISTRATION

Chinese Clinical Trial Registry (ChiCTR-IPR-15006209) and ClinicalTrials.gov (NCT02662257).

Anaesthesia by intravenous propofol reduces the incidence of intra-operative gastric electrical slow-wave dysrhythmias compared to isoflurane

Gastric motility is coordinated by bioelectrical slow-wave activity, and abnormal electrical dysrhythmias have been associated with nausea and vomiting. Studies have often been conducted under general anaesthesia, while the impact of general anaesthesia on slow-wave activity has not been studied. Clinical studies have shown that propofol anaesthesia reduces postoperative nausea and vomiting (PONV) compared with isoflurane, while the underlying mechanisms remain unclear. In this study, we investigated the effects of two anaesthetic drugs, intravenous (IV) propofol and volatile isoflurane, on slow-wave activity. In vivo experiments were performed in female weaner pigs (n = 24). Zolazepam and tiletamine were used to induce general anaesthesia, which was maintained using either IV propofol (n = 12) or isoflurane (n = 12). High-resolution electrical mapping of slow-wave activity was performed. Slow-wave dysrhythmias occurred less often in the propofol group, both in the duration of the recorded period that was dysrhythmic (propofol 14 ± 26%, isoflurane 43 ± 39%, P = 0.043 (Mann-Whitney U test)), and in a case-by-case basis (propofol 3/12, isoflurane 8/12, P = 0.015 (Chi-squared test)). Slow-wave amplitude was similar, while velocity and frequency were higher in the propofol group than the isoflurane group (P < 0.001 (Student's t-test)). This study presents a potential physiological biomarker linked to recent observations of reduced PONV with IV propofol. The results suggest that propofol is a more suitable anaesthetic for studying slow-wave patterns in vivo.

Age-Related Perioperative Neurocognitive Disorders: Experimental Models and Druggable Targets

With the worldwide increase in life span, surgical patients are becoming older and have a greater propensity for postoperative cognitive impairment, either new onset or through deterioration of an existing condition; in both conditions, knowledge of the patient's preoperative cognitive function and postoperative cognitive trajectory is imperative. We describe the clinical utility of a tablet-based technique for rapid assessment of the memory and attentiveness domains required for executive function. The pathogenic mechanisms for perioperative neurocognitive disorders have been investigated in animal models in which excessive and/or prolonged postoperative neuroinflammation has emerged as a likely contender. The cellular and molecular species involved in postoperative neuroinflammation are the putative targets for future therapeutic interventions that are efficacious and do not interfere with the surgical patient's healing process.

Anesthetics or anesthetic techniques and cancer surgical outcomes: a possible link

As of 2018 cancer is responsible for almost 9.6 million deaths annually and, with an aging population, the incidence of cancer is expected to continue to rise. Surgery is an important treatment modality for patients with solid organ cancers. It has been postulated that, due to potentially overlapping processes underlying the development of malignancy and the therapeutic pathways of various anesthetic agents, the choice of anesthetic type and method of administration may affect post-operative outcomes in patients with cancer. This is a literature review of the most recent evidence extracted from various databases including PubMed, EMBASE, and the Cochrane, as well as journals and book reference lists. The review highlights the pathophysiological processes underpinning cancer development and the molecular actions of anesthetic agents, pre-clinical and retrospective studies investigating cancer and anesthetics, as well as ongoing clinical trials. Overall, there are conflicting results regarding the impact of regional vs. general anesthesia on cancer recurrence, whilst the majority of data suggest a benefit of the use of intravenous propofol over inhalational volatile anesthetics. The biological changes associated with the surgical inflammatory response offer a unique opportunity to intervene to counteract any potentially cancer-promoting effects.

Effects of general versus regional anaesthesia on circadian melatonin rhythm and its association with postoperative delirium in elderly patients undergoing hip fracture surgery: study protocol for a prospective cohort clinical trial

INTRODUCTION

Postoperative delirium (POD) is a common neurological complication after hip fracture surgery and is associated with high morbidity and mortality in elderly patients. Although the specific mechanism of POD remains unclear, circadian rhythm disruptions have recently drawn increased attention. To date, only limited postoperative time points of plasma melatonin level measurements were recorded in previous studies, and such data cannot represent a comprehensive melatonin rhythm. The process of anaesthesia (either general anaesthesia (GA) or regional anaesthesia (RA)) is known to influence the melatonin rhythm. However, how these two anaesthesia methods differently affect the postoperative melatonin rhythm is still unknown. Therefore, we hypothesise that RA may attenuate the disruption of the melatonin rhythm, which might decrease the incidence of POD in elderly patients undergoing hip surgery.

METHODS AND ANALYSIS

In this prospective cohort clinical trial, 138 patients scheduled for hip fracture surgery will be divided into two groups to receive either GA or RA. The primary aim is to compare the circadian rhythm of melatonin secretion between the two groups and explore its association with the incidence of POD.

ETHICS AND DISSEMINATION

The study has been approved by the Medical Science Research Ethics Committees of Beijing Jishuitan Hospital (JLKS201901-04). The results of the study will be published in peer-reviewed international journals.

TRIAL REGISTRATION NUMBER

ChiCTR1900027393.

Perioperative probiotic treatment decreased the incidence of postoperative cognitive impairment in elderly patients following non-cardiac surgery: A randomised double-blind and placebo-controlled trial

BACKGROUND

Given that population aging is a global health challenge, the high prevalence of postoperative neurocognitive impairment in elderly patients necessitates the development of novel simple and effective prevention methods.

OBJECTIVE

To evaluate the effects of perioperative application of oral probiotic as a prophylaxis for cognitive impairment in elderly patients following non-cardiac surgery.

METHODS

This randomised double-blind and placebo-controlled trial included 120 elderly patients (in a modified intention-to-treat analysis) scheduled for elective orthopaedic or colorectal surgery. Patients were assigned to receive either probiotics or a placebo from hospital admission until discharge. The primary endpoint was the incidence of postoperative cognitive impairment, defined as a decrease of ≥3 points in the Mini-Mental State Examination (MMSE) scores from admission baseline to the 7th day post-surgery. Secondary endpoints included changes in plasma interleukin-6 (IL-6) and cortisol, postoperative pain intensity, postoperative sleep quality, gastrointestinal function recovery, and faecal microbiota composition.

RESULTS

The incidence of postoperative cognitive impairment in the probiotic group was significantly lower than in the control group (3 of 59 patients [5.1%] vs. 10 of 61 patients [16.4%], P = 0.046). In addition, compared to pre-surgery, the levels of plasma IL-6 and cortisol in the probiotic group decreased more than in the control group 5-7 days after surgery (IL-6: -117.90 ± 49.15 vs. -14.93 ± 15.21, P = 0.044; cortisol: -158.70 ± 53.52 vs. 40.98 ± 72.48, P = 0.010). Relative abundance at the genus level in the faeces of the probiotic group also changed more than in that of the control group during the perioperative period. In contrast, postoperative pain intensity, sleep quality, and gastrointestinal function recovery did not differ significantly between the two groups.

CONCLUSION

Perioperative application of oral probiotic prevents postoperative cognitive impairment in elderly patients following non-cardiac surgery, possibly via the limitation of peripheral inflammation and the stress response.

Risk of tuberculosis reactivation during interleukin-17 inhibitor therapy for psoriasis: a systematic review

Immunosuppressive therapies, effective in treating inflammatory disorders such as psoriasis, increase the risk of serious infections, such as tuberculosis (TB). For example, tumour necrosis factor (TNF)-alpha inhibitors significantly increase the risk of TB reactivation in patients with latent TB infection (LTBI), which has led clinicians to routinely test for TB prior to initiation of these medications. This protocol has since extended to other, newer immunomodulatory therapies for psoriasis, such as interleukin (IL)-17 inhibitors, including secukinumab, ixekizumab and brodalumab. We conducted a systematic review to examine whether there is any evidence that IL-17 inhibitor therapy for psoriasis increases the risk of TB reactivation. Using PubMed and EMBASE, our literature search resulted in 139 total articles. After manually reviewing each article for the discussion of IL-17 inhibitors for psoriasis, with data originating from clinical trials, and assessment for incidence of TB reactivation, 23 articles met the full inclusion criteria for our review. Overall, we found no cases of TB reactivation in patients treated with IL-17 inhibitors for psoriasis. This suggests that IL-17 inhibitors may be safely used in psoriasis patients with LTBI who receive appropriate LTBI treatment. However, long-term real-world studies are warranted to further evaluate this risk.

Inhalational versus Propofol-Based Total Intravenous Anaesthesia: Practice Patterns and Perspectives among Australasian Anaesthetists

Increasing evidence suggests that total intravenous anaesthesia (TIVA) may be the preferred anaesthetic for cancer resection surgery. To assist the preparation of a randomised controlled trial (RCT) examining Volatile (versus TIVA) Anaesthesia and Perioperative Outcomes Related to Cancer (VAPOR-C) we developed an 18-question electronic survey to investigate practice patterns and perspectives (emphasising indications, barriers, and impact on cancer outcomes) of TIVA versus inhalational general anaesthesia in Australasia. The survey was emailed to 1,000 (of 5,300 active Fellows) randomly selected Australian and New Zealand College of Anaesthetists (ANZCA) Fellows. The response rate was 27.5% (n=275). Of the respondents, 18% use TIVA for the majority of cases. In contrast, 46% use TIVA 20% of the time or less. Respondents described indications for TIVA as high risk of nausea, neurosurgery, and susceptibility to malignant hyperthermia. Lack of equipment, lack of education and cost were not considered barriers to TIVA use, and a significant proportion (41%) of respondents would use TIVA more often if setup were easier. Of the respondents, 43% thought that TIVA was associated with less cancer recurrence than inhalational anaesthesia, while 46% thought that there was no difference. Yet, only 29% of respondents reported that they use TIVA often or very often for cancer surgery. In Australasia, there is generally a low frequency of TIVA use despite a perception of benefit when compared with inhalational anaesthesia. Anaesthetists are willing to use TIVA for indications where sufficient evidence supports a meaningful level of improvement in clinical outcome. The survey explores attitudes towards use of TIVA for cancer surgery and demonstrates equipoise in anaesthetists’ opinions regarding this indication. The inconsistent use of TIVA in Australasia, minimal barriers to its use, and the equipoise in anaesthetists’ opinions regarding the effect of TIVA versus inhalational anaesthesia on cancer outcomes support the need for a large prospective RCT.

Preoperative vitamin D deficiency increases the risk of postoperative cognitive dysfunction: a predefined exploratory sub-analysis

BACKGROUND

Vitamin D is important for maintaining physiological functions including cognition and its deficiency is associated with the occurrence of cognitive impairment. This study was to explore the association between preoperative vitamin D status and the occurrence of postoperative cognitive dysfunction (POCD) in elderly patients undergoing major surgery.

METHODS

This was a predefined exploratory sub-analysis of one-centre data from a randomized controlled trial. In all, 123 elderly (≥ 65 years) patients who were scheduled to undergo major cancer surgery were recruited. Serum 25-hydroxyvitamin D concentration was measured before surgery. In total, 59 nonsurgical control subjects with comparable age and education level were also enrolled. A battery of neuropsychological tests was administered the day before and the 7th day after surgery in patients or at the same time interval in control subjects. POCD was diagnosed according to the ISPOCD1 definition.

RESULTS

71.5% (88/123) of elderly patients had vitamin D deficiency (serum 25-hydroxyvitamin D concentration < 12 ng/ml) before surgery; 24.4% (30/123) of them developed cognitive dysfunction at 1 week after surgery. After adjusting for confounding factors, high preoperative serum 25-hydroxyvitamine D concentration was related to a decreased risk of POCD (odds ratio [OR]: 0.829, 95% confidence interval [CI]: 0.708-0.971; P = 0.020), whereas preoperative vitamin D deficiency was associated with an increased risk of POCD (OR: 8.427, 95% CI: 1.595-44.511; P = 0.012).

CONCLUSIONS

Vitamin D deficiency is prevalent in elderly patients undergoing major cancer surgery and increases the risk of early POCD development. Whether prophylactic vitamin D supplementation can reduce POCD in the elderly deserves further study.