Assessment of different anesthesia depth under total intravenous anesthesia on postoperative cognitive function in laparoscopic patients

Effects of anesthetic depth on postoperative pain and delirium: a meta-analysis of randomized controlled trials with trial sequential analysis

BACKGROUND

Whether anesthetic depth affects postoperative outcomes remains controversial. This meta-analysis aimed to evaluate the effects of deep vs. light anesthesia on postoperative pain, cognitive function, recovery from anesthesia, complications, and mortality.

METHODS

PubMed, EMBASE, and Cochrane CENTRAL databases were searched until January 2022 for randomized controlled trials comparing deep and light anesthesia in adult surgical patients. The co-primary outcomes were postoperative pain and delirium (assessed using the confusion assessment method). We conducted a meta-analysis using a random-effects model. We assessed publication bias using the Begg's rank correlation test and Egger's linear regression. We evaluated the evidence using the trial sequential analysis and Grading of Recommendations Assessment, Development and Evaluation (GRADE) methodology. We conducted subgroup analyses for pain scores at different postoperative time points and delirium according to cardiac or non-cardiac surgery.

RESULTS

A total of 26 trials with 10,743 patients were included. Deep anesthesia compared with light anesthesia (a mean difference in bispectral index of -12 to -11) was associated with lower pain scores at rest at 0 to 1 h postoperatively (weighted mean difference = -0.72, 95% confidence interval [CI] = -1.25 to -0.18, P  = 0.009; moderate-quality evidence) and an increased incidence of postoperative delirium (24.95% vs. 15.92%; risk ratio = 1.57, 95% CI = 1.28-1.91, P  < 0.0001; high-quality evidence). No publication bias was detected. For the exploratory secondary outcomes, deep anesthesia was associated with prolonged postoperative recovery, without affecting neurocognitive outcomes, major complications, or mortality. In the subgroup analyses, the deep anesthesia group had lower pain scores at rest and on movement during 24 h postoperatively, without statistically significant subgroup differences, and deep anesthesia was associated with an increased incidence of delirium after non-cardiac and cardiac surgeries, without statistically significant subgroup differences.

CONCLUSIONS

Deep anesthesia reduced early postoperative pain but increased postoperative delirium. The current evidence does not support the use of deep anesthesia in clinical practice.

The effects of remifentanil-propofol combined with dexmedetomidine on cognitive dysfunction in elderly patients after ureteroscopic holmium laser lithotripsy: a double-blind randomized controlled trial

Background

A clinical study indicated that infusion of dexmedetomidine without a loading dose administered intraoperatively provided a smooth and hemodynamically stable emergence and improved the quality of recovery with fewer postoperative side effects and reduced analgesic requirements. The objective was to determine whether administering remifentanil-propofol combined with dexmedetomidine during general anesthesia would decrease the incidence and severity of postoperative emergence agitation, anxiety, and depression without affecting cognitive dysfunction in elderly patients.

Methods

A total of 120 elderly patients scheduled for ureteroscopic holmium laser lithotripsy were randomly allocated to the PR group and administered normal saline, and the PRD group was administered dexmedetomidine 0.4 μg kg⁻¹ h⁻¹ intravenously after the induction of anesthesia and stopped 30 min before the end of surgery. The primary outcome was the Mini-Mental State Examination score. The secondary outcomes were the Richmond Agitation Sedation, the State-Trait Anxiety Inventory, and the Zung Self-Rating Depression Scale scores; the memory span for Arabic numerals; the duration of surgery; and the time to spontaneous respiration, recovery, and extubation.

Results

The MMSE scores were lower at T_1–2 in the two groups (P < 0.001). The dosage of propofol and remifentanil decreased more significantly in the PRD group than in the PR group (P < 0.001). Both the RASS scores and the incidence of emergence agitation (EA) in the PRD group were significantly lower than those in the PR group at t_1–3 (P < 0.001). Compared to the PR group, the ZSDS scores and STAI scores at T_1–2 were lower in the PRD group (P < 0.005). The number of the Arabic numbers that were accurately recalled from memory was lower at T₂ in the PR group than in the PRD group (P < 0.001).

Conclusion

Dexmedetomidine administration has no influence on postoperative cognitive dysfunction but could reduce both the dosage of remifentanil and propofol needed during ureteroscopic holmium laser lithotripsy and the incidence and severity of postoperative emergence agitation, anxiety, and depression in elderly patients.

Trial registration

Chinese Clinical Trial Registry ChiCTR1900021254. Registered on 3 February 2019

Inhalation of low-dose desflurane prevents the hemodynamic instability caused by target-controlled infusion of remifentanil and propofol during laparoscopic gynecological surgery: A randomized controlled trial

The objective of the present study was to determine whether the addition of inhaled desflurane is superior to remifentanil-propofol total intravenous anesthesia (TIVA) alone in patients undergoing laparoscopic gynecological surgery. A total of 60 patients who were scheduled to undergo laparoscopic gynecological surgery were prospectively enrolled and randomly allocated to receive either propofol-remifentanil (PR group; n=30) or combined propofol-remifentanil and low-dose desflurane (PRD group; n=30) for the maintenance of anesthesia. Hemodynamics [mean arterial pressure (MAP); heart rate (HR)], recovery parameters and complications were recorded. The results of the present study indicated that the addition of desflurane significantly reduced the amount of propofol and remifentanil that was administered in the PRD group, compared with that in the PR group. MAP and HR were significantly higher at T3 (5 min post-pneumoperitoneum), but significantly lower at T4 (removal of pneumoperitoneum needle) and T5 (post-operation immediately) in the PR group, compared with the PRD group. Moreover, MAP and HR were significantly altered at multiple time points within the PR group; however, they were relatively stable in the PRD group. There were no significant differences in the recovery parameters and complications between the two groups. In conclusion, combining low-dose desflurane with PR may represent an efficient anesthesia regimen to prevent the hemodynamic instability of TIVA in patients undergoing laparoscopic gynecological surgery.

Is the bispectral index monitoring protective against postoperative cognitive decline? A systematic review with meta-analysis

BACKGROUND

Several studies have suggested that monitoring the depth of anaesthesia might prevent the development of postoperative cognitive decline. We aimed to conduct a meta-analysis to investigate the effects of bispectral index (BIS) monitoring in anaesthesia.

METHODS

We searched in six major electronic databases. Trials were included if they discussed anaesthesia with and without BIS monitoring or low (<50) and high (≥50) BIS levels and which measured the risk of postoperative delirium (POD) and/or postoperative cognitive dysfunction (POCD).

RESULTS

We included fourteen studies in the systematic review, eight of which were eligible for meta-analysis. BIS proved to be protective against POD at 1 day postoperatively in a cohort of 2138 patients (16.1% vs. 22.8% for BIS vs. no BIS groups, respectively; relative risk [RR] 0.71; 95% confidence interval [CI] 0.59 to 0.85, without significant between-study heterogeneity I2 = 0.0%, P = 0.590). The use of BIS was neutral for POCD at 1 week but protective for POCD at 12 weeks (15.8% vs. 18.8% for BIS vs. no BIS groups, respectively; RR = 0.84, CI: 0.66 to 1.08), without significant between-study heterogeneity (I2 = 25.8%, P = 0.260). The neutral association at 1 week proved to be underpowered with trial sequential analysis. In the comparison of low BIS versus high BIS, the incidence of POD at 1 day was similar in the groups.

CONCLUSION

Our findings suggest a protective effect of BIS compared to not using BIS regarding the incidence of POD at 1 day and POCD at 12 weeks. However, limitations of the evidence warrant further investigation to identify those groups of patients by age, comorbid conditions and other individual variables who would benefit the most from the use of BIS monitoring.

Processed Electroencephalogram Monitoring and Postoperative Delirium: A Systematic Review and Meta-analysis

WHAT WE ALREADY KNOW ABOUT THIS TOPIC

WHAT THIS ARTICLE TELLS US THAT IS NEW: BACKGROUND:: Postoperative delirium complicates approximately 15 to 20% of major operations in patients at least 65 yr old and is associated with adverse outcomes and increased resource utilization. Furthermore, patients with postoperative delirium might also be at risk of developing long-term postoperative cognitive dysfunction. One potentially modifiable variable is use of intraoperative processed electroencephalogram to guide anesthesia. This systematic review and meta-analysis examines the relationship between processed electroencephalogram monitoring and postoperative delirium and cognitive dysfunction.

METHODS

A systematic search for randomized controlled trials was conducted using Ovid MEDLINE, PubMed, EMBASE, Cochrane Library, and Google search using the keywords processed electroencephalogram, Bispectral Index, postoperative delirium, postoperative cognitive dysfunction. Screening and data extraction were conducted by two independent reviewers, and risk of bias was assessed. Postoperative delirium combined-effect estimates calculated with a fixed-effects model were expressed as odds ratios with 95% CIs.

RESULTS

Thirteen of 369 search results met inclusion criteria. Postoperative cognitive dysfunction data were excluded in meta-analysis because of heterogeneity of outcome measurements; results were discussed descriptively. Five studies were included in the quantitative postoperative delirium analysis, with data pooled from 2,654 patients. The risk of bias was low in three studies and unclear for the other two. The use of processed electroencephalogram-guided anesthesia was associated with a 38% reduction in odds for developing postoperative delirium (odds ratio = 0.62; P < 0.001; 95% CI, 0.51 to 0.76).

CONCLUSIONS

Processed electroencephalogram-guided anesthesia was associated with a decrease in postoperative delirium. The mechanism explaining this association, however, is yet to be determined. The data are insufficient to assess the relationship between processed electroencephalogram monitoring and postoperative cognitive dysfunction.

An investigation into the effect of depth of anesthesia on postoperative pain in laparoscopic cholecystectomy surgery: a double-blind clinical trial

Backgrounds and objective

Some studies have shown that deeper anesthesia is more effective on postoperative analgesia and reduces the need for sedative drugs. This study sought to investigate the effect of depth of anesthesia on postoperative pain in laparoscopic cholecystectomy.

Materials and methods

In this double-blind clinical trial, 60 patients undergoing laparoscopic cholecystectomy were randomly divided into two groups: low bispectral index (L-BIS=35–44) and high bispectral index (H-BIS=45–55). Anesthesia protocol was the same for both groups (propofol and remifentanil). The pain intensity (at rest and during cough) was evaluated based on the visual analog scale scores in recovery and at 8, 16 and 24 hours after surgery.

Results

The mean pain score was significantly lower in patients in the L-BIS group at all examined times at rest and during cough than that in the H-BIS group. The number of patients in need of additional sedative drug in the H-BIS group in recovery was significantly more than that in the L-BIS group (27 vs 18 patients, P=0.007). The incidence of nausea in the recovery room 8 hours after the surgery was significantly less in the L-BIS group than that in the H-BIS group, while at 16 and 24 hours, no case of nausea was reported in the two groups.

Conclusion

Given the results of this study, it seems that general anesthesia with propofol and remifentanil with L-BIS causes less need for additional analgesic drug and less nausea and vomiting compared to anesthesia with H-BIS.