Cognitive changes after surgery in the elderly: does minimally invasive surgery influence the incidence of postoperative cognitive changes compared to open colon surgery?

Index of consciousness monitoring during general anesthesia may effectively enhance rehabilitation in elderly patients undergoing laparoscopic urological surgery: a randomized controlled clinical trial

BACKGROUND

Based on electroencephalogram (EEG) analysis, index of consciousness (IoC) monitoring is a new technique for monitoring anesthesia depth. IoC is divided into IoC1 (depth of sedation) and IoC2 (depth of analgesia). The potential for concurrent monitoring of IoC1 and IoC2 to expedite postoperative convalescence remains to be elucidated. We investigated whether combined monitoring of IoC1 and IoC2 can effectively enhances postoperative recovery compared with bispectral index (BIS) in elderly patients undergoing laparoscopic urological surgery under general anesthesia.

METHODS

In this prospective, controlled, double-blinded trail, 120 patients aged 65 years or older were arbitrarily assigned to either the IoC group or the control group (BIS monitoring). All patients underwent blood gas analysis at T1 (before anesthesia induction) and T2 (the end of operation). The Mini-Mental State Examination (MMSE) and Montreal Cognitive Assessment (MoCA) were administered to all patients at T0 (1 day before surgery) and T4 (7 days after surgery). Serum concentrations of C-reactive protein (CRP) and glial fibrillary acid protein (GFAP) were assessed at T1, T2, and T3 (24 h after surgery). Postoperative complications and the duration of hospitalization were subjected to comparative evaluation.

RESULTS

The incidence of postoperative cognitive dysfunction (POCD) was notably lower in the IoC group (10%) than in the control group (31.7%) (P = 0.003). Postoperative serum CRP and GFAP concentrations exhibited significant differences at time points T2 (CRP: P = 0.000; GFAP: P = 0.000) and T3 (CRP: P = 0.003; GFAP: P = 0.008). Postoperative blood glucose levels (P = 0.000) and the overall rate of complications (P = 0.037) were significantly lower in Group IoC than in Group control.

CONCLUSION

The employment of IoC monitoring for the management of elderly surgical patients can accelerate postoperative convalescence by mitigating intraoperative stress and reducing peripheral and central inflammatory injury.

TRIAL REGISTRATION

Chinese Clinical Trial Registry Identifier: ChiCTR1900025241 (17/08/2019).

Efficiency of probiotics in elderly patients undergoing orthopedic surgery for postoperative cognitive dysfunction: a study protocol for a multicenter, randomized controlled trial

BACKGROUND

Postoperative cognitive dysfunction (POCD) refers to a neurological dysfunction after a major surgery and anesthesia. It is common in elderly patients and is characterized by impairment in consciousness, orientation, thinking, memory, and executive function after surgical anesthesia. However, at present, there is no definite preventive or treatable strategy for it. Previous animal experiments showed that giving probiotics to mice before operation can prevent POCD, but there is a lack of clinical evidence. This study aims to intervene with the intestinal flora imbalance using probiotics during the perioperative period to reduce the incidence of POCD in elderly patients after orthopedic surgery and to provide new ideas and methods for the clinical prevention and treatment of POCD.

METHODS

A multicenter, double-blind, placebo-controlled clinical trial will be performed to evaluate the efficacy of probiotics in elderly patients undergoing orthopedic surgery. Participants (n = 220) will receive probiotics (Peifeikang, Live Combined Bifidobacterium, 210 mg per capsule, twice a day, four capsules each time, which contains Bifidobacterium longum, Lactobacillus acidophilus and Streptococcus faecalis no less than 1.0 × 10⁷ CFU viable bacteria respectively) or placebo from 1 day before surgery to 6 days after surgery. Neuropsychological tests will be performed 1 day before surgery and 1 week and 1 month after surgery. The main outcome of this study is the incidence of POCD 7 days after surgery. Our secondary objective is to assess the incidence of POCD 1 month after surgery; the cognitive status will be determined based on a telephone interview and will be evaluated via TICS-m; postoperative delirium will be assessed 7 days after surgery using the Confusion Assessment Method (CAM).

DISCUSSION

Discovering the correlation between the intestinal microbiota and POCD is an important breakthrough. Based on the key role of the intestinal microbiota in other cognitive disorders, we hope that probiotics can reduce its incidence in elderly orthopedic patients.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04017403. Registered on August 15, 2019.

Preoperative Risk Factors Associated with Increased Incidence of Postoperative Delirium: Systematic Review of Qualified Clinical Studies

Postoperative delirium (POD) is an acute alteration of mental state, characterized by reduced awareness and attention, occurring up to five postoperative days after recovery from anesthesia. Several original studies and reviews have identified possible perioperative POD risk factors; however, there is no comprehensive review of the preoperative risk factors in patients diagnosed with POD using only validated diagnostic scales. The aim of this systematic review was to report the preoperative risk factors associated with an increased incidence of POD in patients undergoing non-cardiac and non-brain surgery. The reviewed studies included original research papers that used at least one validated diagnostic scale to identify POD occurrence for more than 24 h. A total of 6475 references were retrieved from the database search, with only 260 of them being suitable for further review. Out of the 260 reviewed studies, only 165 that used a validated POD scale reported one or more preoperative risk factors. Forty-one risk factors were identified, with various levels of statistical significance. The extracted risk factors could serve as a preoperative POD risk assessment workup. Future studies dedicated to the further evaluation of the specific preoperative risk factors' contributions to POD could help with the development of a weighted screening tool.

Preventing postoperative cognitive dysfunction using anesthetic drugs in elderly patients undergoing noncardiac surgery: a systematic review and meta-analysis

Postoperative cognitive dysfunction (POCD) is a common neurological system disorder in surgical patients. The choice of anesthetic can potentially reduce POCD. The authors performed this network meta-analysis to compare different anesthetic drugs in reducing the incidence of POCD for elderly people undergoing noncardiac surgery. We searched MEDLINE, EMBASE, the Cochrane Library, and the Web of Science for randomized controlled trials comparing the different anesthetic drugs for noncardiac surgery in elderly from inception until July, 2022. The protocol was registered on the PROSPERO database (CRD#42020183014). A total of 34 trials involving 4314 patients undergoing noncardiac surgery in elderly were included. The incidence of POCD for each anesthetic drug was placebo (27.7%), dexmedetomidine (12.9%), ketamine (15.2%), propofol (16.8%), fentanyl (23.9%), midazolam (11.3%), sufentanil (6.3%), sevoflurane (24.0%), and desflurane (28.3%). Pairwise and network meta-analysis showed dexmedetomidine was significantly reducing the incidence of POCD when compared with placebo. Network meta-analysis also suggested dexmedetomidine was significantly reducing the incidence of POCD when compared with sevoflurane. Sufentanil and dexmedetomidine ranked the first and second in reducing the incidence of POCD with the surface under the cumulative ranking curve value of 87.4 and 81.5%. Sufentanil and dexmedetomidine had the greatest possibility to reduce the incidence of POCD for elderly people undergoing noncardiac surgery.

Laparoscopic versus open hepatectomy for malignant liver tumours in the elderly: systematic review and meta-analysis

To evaluate comparative outcomes of laparoscopic versus open hepatectomy for malignant liver tumours in elderly patients. A systematic online search was conducted using the following databases: PubMed, Scopus, Cochrane database, The Virtual Health Library, Clinical trials.gov, and Science Direct. Comparative studies comparing laparoscopic (LH) versus open hepatectomy (OH) for both primary and metastatic malignant liver tumours in the elderly were included. Total operative time (minutes), need to perform Pringle's manoeuvre, blood loss (ml), the requirement for blood transfusion intra-operatively/post-operatively, post-operative complications, r0 resection rate, specimen resection margin (mm), re-operation rate, length of hospital stay (LOS), and 90-day mortality were the evaluated outcome parameters. Twelve studies reporting a total number of 1762 patients who underwent laparoscopic (n = 831) or open (n = 931) hepatectomy were included. OH group was associated with a significantly higher overall number of post-operative complications compared to LH (P = 0.00001). Complications such as post-operative liver failure (P = 0.02), ascites formation (P = 0.002), surgical site infection (P = 0.02), blood loss (P = 0.03), blood transfusion rate (P = 0.05), and LOS (P = 0.00001) were significantly higher in the OH group when compared to LH. There was no significant difference between the two groups in terms of total operative time (P = 0.53), bile leak (P = 0.12), r0 resection rate (P = 0.36), re-operation (P = 0.70), and 90-day mortality (P = 0.11). Laparoscopic liver resections are safe with at least equal or superior peri-operative outcomes in the elderly population, although available data regards mainly the results of minor resections. Laparoscopic major resections in the elderly population should be carefully evaluated and preferably performed in expert centres.

[Effects of dexmedetomidine doses on postoperative cognitive dysfunction and serum β- amyloid and cytokine levels in elderly patients after spine surgery: a randomized controlled trial]

OBJECTIVE

To explore the immunomodulatory mechanism and optimal dose of dexmedetomidine (DEX) for preventing postoperative cognitive dysfunction (POCD) in elderly patients undergoing spinal surgery.

OBJECTIVE

A total of 120 elderly patients undergoing elective spinal surgery with general anesthesia were randomized into 4 groups to receive a loading dose of 0.3 μg/kg DEX for 10 min before anesthesia induction followed by maintenance doses of 0.2, 0.5, and 0.8 μg · kg^-1·h^-1 (low-, medium-, and high-dose DEX groups, respectively) or an equal volume of normal saline (control group). DEX and saline was discontinued 40 min before the end of the surgery. Before induction (D₀) and on day 1 (D₁), day 3 (D₂) and day 7 (D₃) after the operation, the cognitive function of the patients was assessed using the MMSE scale and their serum levels of β-amyloid (Aβ), TNF-α, IL-1β and IL-6 were measured. The occurrence of adverse effects including bradycardia and hypotension and the recovery time of the patients were recorded.

OBJECTIVE

Compared with those on D₀, serum levels of Aβ, IL-1β, IL-6, and TNF-α on D₁ were markedly increased in all the groups (P < 0.05); the levels of Aβ decreased to the baseline level on D₃ in medium- and high-dose DEX groups (P > 0.05) but remained high in the other two groups. On D₂, TNF-α, L-1β and IL-6 recovered their baseline levels in medium- and high-dose DEX groups (P > 0.05) but remained elevated in the other two groups. The incidences of POCD in medium- and high-dose DEX groups were comparable but significantly lower than that in the control group (P < 0.05). The incidences of hypotension and bradycardia were the highest in high-dose DEX group (P < 0.01), which also had longer recovery time than the other 3 groups (P < 0.05).

OBJECTIVE

With a loading dose of 0.3 μg/kg followed by a maintenance doses of 0.5 μg · kg^-1·h^-1, DEX can effectively reduce the incidence of POCD in elderly patients undergoing spinal surgery by inhibiting the production of Aβ and pro-inflammatory cytokines.

Evaluation of the Effect of Dexmedetomidine on Postoperative Cognitive Dysfunction through Aβ and Cytokines Analysis

Postoperative cognitive dysfunction is a common postoperative neurological complication in elderly patients, and has some relationship with neuroinflammation. some studies have shown ability of dexmedetomidine to improve cognitive performance in elderly individuals who underwent thoracic surgery. Therefore, our study hypothesized that dexmedetomidine treatment may reduce the incidence of POCD in elderly patients.In addition,this study detected the antineuroinflammatory effects of dexmedetomidine by β-amyloid aggregation inhibitors and release of cytokines in elderly patients . The results show that dexmedetomidine used during operation can inhibit the postoperative release of Aβ and cytokines in elderly patients, and dexmedetomidine used during operation can reduce the incidence of postoperative cognitive dysfunction, with dose-dependence. These results provide a clinical application direction for clinical anesthesiologists and ICU physicians.

Risk assessment of dementia after hysterectomy: Analysis of 14-year data from the National Health Insurance Research Database in Taiwan

BACKGROUND

Anesthesia and surgery may increase the risk of dementia in the elderly, but the higher prevalence of dementia in women and other evidence suggest that dementia risk increases in younger women undergoing hysterectomy. In this study, we assessed the risk of dementia after hysterectomy.

METHODS

Hysterectomies registered in the National Health Insurance Research Database from 2000 to 2013 were evaluated using a retrospective generational research method. Multivariate Cox regression analysis was used to assess the effect of age at surgery, anesthesia method, and surgery type on the hazard ratio (HR) for the development of dementia.

RESULTS

Among 280 308 patients who underwent hysterectomy, 4753 (1.7%) developed dementia. Age at surgery and anesthesia method were associated with the occurrence of dementia, independent of surgery type. Among patients 30-49 years of age, general anesthesia (GA) was associated with a higher risk of dementia than spinal anesthesia (SA). The HR for GA was 2.678 (95% confidence interval [CI] = 1.269-5.650) and the risk of dementia increased by 7.4% for every 1-year increase in age (HR = 1.074; 95% CI = 1.048-1.101). In patients >50 years of age, the HR for GA was 1.206 (95% CI = 1.057-1.376), and the risk of dementia increased by 13.0% for every 1-year increase in age (HR = 1.130; 95% CI = 1.126-1.134).

CONCLUSION

The risk of dementia in women who underwent hysterectomy was significantly affected by older age at surgery, and the risk might not increase linearly with age, but show instead an S-curve with exponential increase at about 50 years of age. Although less significant, GA was associated with higher risk than SA, and the effect of the anesthesia method was greater in patients <50 years of age. In contrast, the surgical procedure used was not associated to the risk of dementia.

Laparoscopic vs. open pancreaticoduodenectomy: a comparative study in elderly people

The purpose of the study is to evaluate whether laparoscopic pancreatoduodenectomy (LPD) is safe and feasible for elderly patients. From December 2015 to January 2019, 142 LPD surgeries and 93 OPD surgeries were performed by the same surgeon in the third affiliated hospital of Soochow University. After applying the inclusion and exclusion criteria, we retrospectively collected the date of three defined groups: LPD aged < 70 years (group I, 84 patients), LPD aged ≥ 70 years (group II, 56 patients) and OPD aged ≥ 70 years (group III, 28 patients). Baseline characteristics and short-term surgical outcomes of group I and group II, group II and group III were compared. Totally, 168 patients were included in this study; 100 cases were men; 68 cases were women; mean age was 67.9 ± 9.5 years. LPD does not perform as well in elderly as it does in non-elderly patients in terms of intraoperative blood loss (300.0 (200.0-500.0) ml vs. 200.0 (100.0-300.0) ml, p = 0.003), proportion of intraoperative transfusion (17.9% vs. 6.0%, p = 0.026) and time to oral intake (5.0 (4.0-7.0) day vs. 5.0 (3.0-6.0) day, p = 0.036). Operative time, conversion rate, postoperative stay, and proportion of reoperation, Clavien-Dindo classification, 30-day readmission and 90-day mortality were similar in two groups. In elderly patients, when compared with OPD, LPD had the advantage of shorter time to start oral intake (5.0 (4.0-7.0) day vs. 7.0 (5.0-11.3) day, p = 0.005) but the disadvantage of longer operative time (380.0 (306.3-447.5) min vs. 292.5 (255.0-342.5) min, p < 0.001) and higher hospitalization cost (12447.3 (10,189.7-15,340.0) euros vs. 7251.9 (8994.0-11,717.4) euros, p < 0.001). There was no difference between the two groups in terms of postoperative stay, and proportion of reoperation, Clavien-Dindo classification, 30-day readmission and 90-day mortality. LPD is safe and feasible for elderly people, but we need to consider its high cost and long operative time over OPD.

Intestinal dysbacteriosis mediates the reference memory deficit induced by anaesthesia/surgery in aged mice

BACKGROUND

Postoperative cognitive dysfunction (POCD) is associated with increased morbidity and mortality and has become a major concern for patients and caregivers. POCD is most common in older patients. Previous studies demonstrated that the gut microbiome affects cognitive function and behaviour, and perioperative factors, including the operation itself, antibiotics, opioids or acid-inducing drugs, affect the gut microbiome. Thus, we hypothesised that intestinal dysbacteriosis caused by anaesthesia/surgery induces POCD.

METHODS

Tibial fracture internal fixation was performed in 18-month-old C57BL/6 mice under isoflurane anaesthesia to establish the POCD model. The Morris water maze was used to measure reference memory after anaesthesia/surgery. High-throughput sequencing of 16S rRNA from faecal samples was used to investigate changes in the abundance of intestinal bacteria after anaesthesia/surgery. To confirm the role of the gut microbiome in POCD, we pretreated mice with compound antibiotics or mixed probiotics (VSL#3). Anaesthesia/surgery impaired reference memory and induced intestinal dysbacteriosis in aged mice.

RESULTS

The 16S rRNA sequencing data revealed 37 genera (18 families) of bacteria that changed in abundance after anaesthesia/surgery. Pretreating mice with compound antibiotics or mixed probiotics (VSL#3) prevented the learning and memory deficits induced by anaesthesia/surgery. We further conducted quantitative real-time polymerase chain reaction (qRT-PCR) of 22 common types of bacteria among the 37 total types to verify the results of bacterial flora changes after anaesthesia/surgery. Numbers of 8 types of bacteria changed after anaesthesia/surgery but returned to normal after treatment with a mix of probiotics.

CONCLUSIONS

Our data suggest that deficits in reference memory induced by anaesthesia/surgery are mediated by intestinal dysbacteriosis.

Effect of flurbiprofen axetil on postoperative delirium for elderly patients

OBJECTIVES

Proinflammatory cytokines triggered by surgery and postoperative pain are major causes of postoperative delirium (POD). This study investigated the effects of flurbiprofen axetil on POD when used for postoperative analgesia after major noncardiac surgery in elderly patients.

METHODS

Patients over 65 years old were randomly divided into two groups: the sufentanil group (S group), in which 150 μg of sufentanil was used in the patient-controlled analgesia (PCA) pump for 3 days; the sufentanil combined with flurbiprofen axetil group (SF group), in which 150 μg of sufentanil was combined with 300 mg of flurbiprofen axetil in the PCA pump for 3 days. The Confusion Assessment Method scale was used for POD evaluation. The pain intensity, side effects, and risk factors (age, gender, surgical position, and category of surgery) for POD were evaluated.

RESULTS

Ultimately, 140 patients were included. The overall incidence of POD was not significantly different between the S and SF groups. The incidence of POD was significantly lower in the SF group than in the S group among patients over 70 years (5.1% vs. 20.7%, p = 0.045, odds ratio = 0.146, 95% confidence interval = 0.020-1.041). The incidence of POD was no difference in patients classified by the category of surgery, surgical position, or gender between groups. Sufentanil and flurbiprofen axetil in the PCA pump was completely used within 72 hr. The pain intensity, consumed sufentanil dosage of the PCA, and the side effects was not different between groups.

CONCLUSIONS

Flurbiprofen axetil might reduce POD in patients over 70 years undergoing major noncardiac surgery.

Laparoscopic liver resection in elderly patients: systematic review and meta-analysis

Laparoscopic liver resection (LLR) is becoming standard practice, replacing the open approach in terms of safety and feasibility. However, few data are available for the elderly. The objective of this study is to assess the feasibility of LLR in elderly patients, by making a comparison with open liver resection (OLR) and with non-elderly patients. Relevant studies found in the Cochrane Library, Embase, PubMed, and Web of Science were used in order to perform a systematic review and meta-analysis. Nine fully extracted comparative studies were included and two groups were identified: Group 1 with a comparison between OLR and LLR in the elderly and Group 2 with a focus on differences after LLR between elderly and non-elderly patients. A total number of 497 elderly patients who underwent LLR were analyzed. A random effect model was used for the meta-analysis. In Group 1, 1025 elderly patients were included: 640 underwent OLR and 385 underwent LLR. LLR was associated with minor blood loss (MD - 240 mL, 95% CI - 416.61, - 63.55; p 0.008; I² = 96%), less transfusion (8% vs. 13.1%; RR 0.61, 95% CI 0.41, 0.91; p = 0.02; I² = 0%), fewer postoperative Clavien-Dindo III/IV complications (RR 0.48 in favor of LLR; 95% CI 0.29, 0.77; p = 0.003; I² = 0%). On the other hand, no significant difference was observed in terms of bile leakage, ascites, mortality, liver failure, or R0 resection. Group 2 included 112 elderly and 276 non-elderly patients who underwent LLR. The meta-analysis showed no significant difference in terms of blood loss, transfusions, liver failure, Clavien-Dindo III/IV complications, postoperative mortality, ascites, bile leak, hospital stay, R0 resection, and operative time. Laparoscopic liver resection is a safe and feasible procedure for elderly patients. However, further randomized studies are required to confirm this.

Diabetes, but Not Hypertension and Obesity, Is Associated with Postoperative Cognitive Dysfunction

BACKGROUND/AIMS

Older people undergoing surgery are at risk of developing postoperative cognitive dysfunction (POCD), but little is known of risk factors predisposing patients to POCD. Our objective was to estimate the risk of POCD associated with exposure to preoperative diabetes, hypertension, and obesity.

METHODS

Original data from 3 randomised controlled trials (OCTOPUS, DECS, SuDoCo) were obtained for secondary analysis on diabetes, hypertension, baseline blood pressure, obesity (BMI ≥30 kg/m2), and BMI as risk factors for POCD in multiple logistic regression models. Risk estimates were pooled across the 3 studies.

RESULTS

Analyses totalled 1,034 patients. POCD occurred in 5.2% of patients in DECS, in 9.4% in SuDoCo, and in 32.1% of patients in OCTOPUS. After adjustment for age, sex, surgery type, randomisation, obesity, and hypertension, diabetes was associated with a 1.84-fold increased risk of POCD (OR 1.84; 95% CI 1.14, 2.97; p = 0.01). Obesity, BMI, hypertension, and baseline blood pressure were each not associated with POCD in fully adjusted models (all p > 0.05).

CONCLUSION

Diabetes, but not obesity or hypertension, is associated with increased POCD risk. Consideration of diabetes status may be helpful for risk assessment of surgical patients.

Impact of surgical approach on postoperative delirium in elderly patients undergoing gastrectomy: laparoscopic versus open approaches

BACKGROUND

Postoperative delirium is a frequent complication in elderly patients undergoing major abdominal surgery and is associated with a poor outcome. We compared postoperative delirium in elderly patients following laparoscopic gastrectomy (LG) versus open gastrectomy (OG).

METHODS

In total, 130 patients aged ≥ 65 years with gastric cancer undergoing LG and OG were enrolled prospectively. Postoperative delirium and cognitive status were assessed daily using the Confusion Assessment Method (CAM) and Mini-Mental Status Examination (MMSE), respectively, for 3 days postoperatively. For CAM-positive patients, delirium severity was then assessed using the Delirium Index (DI).

RESULTS

In total, 123 subjects (LG, n = 60; OG, n = 63) were included in the analysis. In both groups, the overall incidences of postoperative delirium were similar: 31.6% (19/60) in the LG group and 41.2% (26/63) in the OG group. When considering only those with delirium, the severity, expressed as the highest DI score, was similar between the groups. A decline in cognitive function (reduction in MMSE ≥ 2 points from baseline) during 3 days postoperatively was observed in 23 patients in the LG group (38.3%) and 27 patients in the OG group (42.9%) (P = 0.744). In both groups, postoperative cognitive decline was significantly associated with postoperative delirium (P < 0.001).

CONCLUSIONS

We found that, compared with traditional open gastrectomy, laparoscopic gastrectomy did not reduce either postoperative delirium or cognitive decline in elderly patients with gastric cancer.